Trends of Hypertension Stages among Iranian Adults from 2005 to 2025 using WHO STEPS studies: A Comparison among 2017 ACC/AHA, JNC7, and 2020 ISH Guidelines

doi:10.21203/rs.3.rs-3966386/v1

Download PDF

Article

Trends of Hypertension Stages among Iranian Adults from 2005 to 2025 using WHO STEPS studies: A Comparison among 2017 ACC/AHA, JNC7, and 2020 ISH Guidelines

https://doi.org/10.21203/rs.3.rs-3966386/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Reducing the prevalence of hypertension, a major risk factor with significant health and economic implications is a target outlined by The World Health Assembly. This study investigated the prevalence of hypertension stages in Iran from 2005 to a projection for 2025 by three different guidelines. Eight nationally and sub-nationally representative cross-sectional WHO STEPwise approach to NCD risk factor surveillance (STEPS) studies were conducted from 2005 to 2021 in Iran. Staging followed the Joint National Committee's seventh report (JNC7), the American College of Cardiology/American Heart Association's 2017 guidelines (ACC/AHA), and the International Society of Hypertension's 2020 guidelines (ISH). Using data from a total of 210,546 participants, ACC/AHA projected higher prevalence in stage 1 and stage 2 hypertension, particularly 35–44 and 45–54 age groups of males, each reaching approximately 35% in 2025. Stage 1 hypertension demonstrated a stable trend (about 17%) for ISH and JNC7, whereas ACC/AHA exhibited a significant decrease from 37.07–30.32% between 2005 and 2025. Conversely, all guidelines indicated a significant decreasing trend for stage 2 hypertension from 2005 to 2025 (ACC/AHA: 26.60–23.27%, JNC7 and ISH: about 9–6.6%). The study indicated that the prevalence of hypertension stages has not remarkably changed based on all guidelines in recent years and is projected to remain stable by 2025. The choice of guidelines should consider cost-effectiveness analyses and the available resources.

Health sciences/Diseases/Cardiovascular diseases

Health sciences/Risk factors

Health sciences/Medical research/Epidemiology

Health sciences/Health care/Health policy

Health sciences/Health care/Public health

hypertension

Iran

trend

guidelines

2017 ACC/AHA

2020 ISH

JNC7

Hypertension is a prominent modifiable risk factor, imposing a significant global health and economic burden. The global age-standardized prevalence of hypertension in adults has been stable from 1990 to 2019¹, and by 2025, it is estimated that nearly 29.2% of adults globally will have hypertension², with a higher prevalence in low- and middle-income countries (LMICs)³. Approximately 10% of global healthcare expenditures are attributed to hypertension⁴. In 2019, hypertension was the foremost risk factor for morbidity and mortality in Iran, a low-middle-income country, with a Disability-Adjusted Life Year (DALY) rate of 2523.51 per 100,000⁵. Only the direct cost of hypertension treatment in Iran was estimated to be $87.54 million in 2020⁶. The high burden and costly comorbidities associated with hypertension underscore the importance of monitoring its prevalence over time. Recognizing this urgency, the World Health Assembly set a target in 2013 to reduce hypertension prevalence by 25% by 2025 in comparison with 2010, aligning with global non-communicable disease (NCD) targets⁷.

Several guidelines have been provided for the detection, treatment, and management of hypertension. While the seventh report of the Joint National Committee (JNC7) published in 2003⁸, with a hypertension threshold of 140/90 mmHg (systolic blood pressure (SBP)/diastolic blood pressure (DBP)), has been widely adopted, the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline introduced lower thresholds of 130/80 mmHg⁹. Recent randomized clinical trials have demonstrated that maintaining SBP below 130 has led to a reduction in mortality and various morbidities associated with hypertension¹⁰. Additionally, adults with a SBP of 130 had nearly half the risk of developing cardiovascular diseases compared to those with a blood pressure of 140¹¹. Furthermore, the 2020 International Society of Hypertension (ISH) guideline, by considering economic differences among countries, introduced essential and optimal strategies for the management of hypertension, defining it with a blood pressure threshold of 140/90¹². Transitioning to lower thresholds may reduce all-cause and cardiovascular-specific mortality and morbidity¹³, yet this approach in LMICs should be approached cautiously due to its potential economic impact on already resource-constrained health systems^14–16. This debate underscores the need for country-specific investigations to estimate hypertension burdens based on different guidelines

In Iran, similar to many countries, JNC7 remains the predominant guideline for defining and treating hypertension. Despite guidelines like IraPen, which is developed based on the World Health Organization (WHO) Package of essential noncommunicable disease (PEN) interventions for primary health care in low-resource settings (WHO PEN)^17,18, and the national family physician HTN guideline¹⁹ aligning with JNC7 thresholds, the recent slow adoption of the ACC/AHA guideline in Iran suggests a changing trend²⁰. Hence, exploring the potential impact of different guidelines on hypertension stage prevalence in Iran is crucial. This study aimed to assess trends in the prevalence of different hypertension stages among the Iranian population, both nationally and sub-nationally, projecting their prevalence until 2025. The findings sought to provide policymakers with a comprehensive understanding of the hypertension landscape in Iran and guide the consequences of selecting different guidelines on the hypertension situation in Iran.

Baseline characteristics

A total of 210,546 participants were included in this study and their baseline characteristics are detailed in Table 1. The age distribution across studies exhibited a consistent pattern until 2011, with similar proportions observed. However, remarkable age group shifts were noted in subsequent years: a rise in the shares of age groups 25–34 (31.09%) and 55–64 (29.00%) in 2011, an increase in the share of age group 25–34 (30.69%) and a decrease in the share of age group 55–64 (18.42%) in 2016, and, in 2021 an increase in the share of age group 35–44 (28.94%) and a decrease in the share of age group 55–64 (21.16%) compared to prior years. Examining the gender distribution, a consistent balance in proportions was observed across all studies, except for 2011 and 2021, where a notable elevation in the share of females was evident. The proportion of participants from urban areas revealed a progressive increase, peaking at nearly 70% since 2011 and maintaining relatively stable.

Table 1

Baseline characteristics of the STEPS surveys participants included in this study.
	2005	2006	2007	2008	2009	2011	2016	2021
Age
25–34(%)	15,590(24.54%)	5,922(24.83%)	5,933(24.97%)	5,952(25.11%)	5,961(25.02%)	2,293(31.09%)	7,138(30.69%)	5,216(24.54%)
35–44(%)	15,905(25.04%)	5,948(24.94%)	6,022(25.35%)	5,972(25.20%)	5,966(25.04%)	1,494(20.26%)	6,365(27.36%)	6,151(28.94%)
45–54(%)	16,206(25.51%)	6,063(25.42%)	6,006(25.28%)	5,968(25.18%)	5,960(25.01%)	1,449(19.65%)	5,473(23.53%)	5,382(25.32%)
55–64(%)	15,822(24.91%)	5,918(24.81%)	5,797(24.40%)	5,807(24.50%)	5,939(24.93%)	2,139(29.00%)	4,286(18.42%)	4,503(21.19%)
Missing (%)	0(0%)	0(0%)	0(0%)	0(0%)	0(0%)	0(0%)	0(0%)	0(0%)
Gender
Male (%)	32,126(50.57%)	11,877(49.80%)	11,816(49.73%)	11,860(50.04%)	11,878(49.85%)	2,990(40.54%)	11,062(47.55%)	9,240(43.48%)
Female (%)	31,368(49.38%)	11,974(50.20%)	11,936(50.25%)	11,839(49.96%)	11,928(50.06%)	4,385(59.46%)	12,200(52.45%)	12,012(56.52%)
Missing (%)	29(0.05%)	0(0%)	6(0.02%)	0(0%)	20(0.08%)	0(0%)	0(0%)	0(0%)
Urbanization
Rural (%)	22,050(34.71%)	9,094(38.13%)	9,735(40.98%)	9,034(38.12%)	10,939(45.91%)	2,171(29.44%)	6,687(28.75%)	5,772(27.16%)
Urban (%)	41,473(65.29%)	14,757(61.87%)	14,020(59.02%)	14,664(61.88%)	12,886(54.09%)	5,204(70.56%)	16,575(71.25%)	15,480(72.84%)
Missing (%)	0(0%)	0(0%)	3(0.01%)	1(0%)	1(0%)	0(0%)	0(0%)	0(0%)
Total	63,523	23,851	23,758	23,699	23,826	7,375	23,262	21,252

The national age-sex standardized trend of hypertension

The national age-sex standardized trend of hypertension, depicted in Fig. 1, revealed both similarities and disparities in the prevalence patterns of various hypertension stages from 2005 to 2025 among the different guidelines. Considering the prevalence of normal blood pressure, all three guidelines exhibited comparable patterns over the years. However, both JNC7 and ACC/AHA guidelines demonstrated a significant increase, rising from approximately 27–34% between 2005 and 2025. In contrast, the ISH guideline indicated no significant change during this period, maintaining a consistently higher prevalence of around 60%. For the elevated stage, ACC/AHA and ISH guidelines exhibited a significant increase from 9.25% (95% UI: 8.99–9.48) and 12.71% (12.44–12.99) to 12.30% (11.05–13.69) and 15.14% (13.78–16.51), respectively, from 2005 to 2025. In comparison, JNC7 reported a significant decrease from 46.30% (45.88–46.71) to 42.70% (40.83–44.56), although it remained notably higher than the other two guidelines. Concerning stage 1 hypertension, ISH and JNC7 guidelines demonstrated a stable trend, with no significant change, hovering around 17%. Conversely, the ACC/AHA guideline displayed a significant decrease from 37.07% (36.67–37.46) to 30.32% (28.68–31.84) between 2005 and 2025. In contrast, all guidelines indicated a decreasing trend for stage 2 hypertension from 2005 to 2025. The ACC/AHA guideline reported a significant decrease from 26.60% (26.29–26.95) to 23.27% (21.90-24.55), while the JNC7 and ISH guidelines declined significantly from about 9–6.60%.

Hypertension trend based on sex and age groups

The trends in hypertension stages across different age groups and sexes are delineated in Figs. 2 to 4. For elevated hypertension, the ACC/AHA guideline showed a similar prevalence pattern across age groups which was stable over the years for both sexes. Notably, in males, younger age groups exhibited higher prevalence in specific years. Overall, the projected prevalence for all age groups was anticipated to be within the range of 10–15% in 2025 for both sexes. In contrast, the ISH guideline revealed a steady prevalence pattern across age groups, particularly in females, where older age groups demonstrated higher prevalences. Projections for 2025 indicated an anticipated highest prevalence of around 19% for females in the 45–54 and 55–64 age groups, while males exhibited the highest prevalence of approximately 20% in the 35–44 and 55–64 age groups. Under the JNC7 guideline, a notable increase in prevalence was observed in females aged 55–64, reaching about 44% by 2025, making it the age group with the highest prevalence of elevated hypertension. In males, the highest prevalence belonged to the 25–34 age group in 2007, almost 55%, and the 2025 projection anticipated the highest prevalence in the 35–44 age group, nearly 50%, with the 55–64 age group having the lowest at about 40% (Fig. 2).

Considering stage 1 hypertension, both ISH and JNC7 guidelines exhibited similar and stable prevalence patterns across age groups over the years for both sexes, showing an age-associated increase in prevalence (approximately 7%, 12%, 21%, and 26% in females, and 11%, 16%, 25%, and 31% in males for the age groups 25–34, 35–44, 45–54, and 55–64, respectively, in 2025). Under the ACC/AHA guideline, females in the 45–54 and 55–64 age groups had the highest prevalence in 2025, reaching approximately 30%. While males showed higher prevalence in younger age groups, peaking at about 44% in the 25–34 age group in 2007, the 2025 projection indicated that age groups 35–44 and 45–54 would have the highest prevalence, reaching about 35% (Fig. 3).

Regarding Stage 2 hypertension, all guidelines indicated that older age groups had a higher prevalence in both sexes. Interestingly, the differences among age groups were more pronounced in males, whereas in females, the prevalences in the 45–54 and 55–64 age groups were more similar. ACC/AHA guideline projected significantly higher prevalences for all age groups in 2025, with males expected to have prevalences of 13.55% (95% UI: 12.39–14.65), 23.69% (22.33–24.88), 33.35% (31.59–35.18), and 44.89% (43.15–47.23), and females with prevalences of 7.73% (6.93–8.34), 16.59% (15.61–17.68), 34.35% (32.41–36.04), and 41.08% (38.94–42.5) for the 25–34, 35–44, 45–54, and 55–64 age groups, respectively (Fig. 4).

The subnational situation of hypertension

The projected 2025 prevalence of various hypertension stages at the sub-national level revealed significant variability among provinces. Additionally, variations were observed between the sexes, with males mainly exhibiting a higher prevalence across different stages of hypertension (Fig. 5). According to the ISH guideline, the majority of provinces demonstrated low prevalences of different hypertension stages, although some provinces, particularly among males, exhibited higher prevalence. Conversely, the ACC/AHA guideline indicated higher prevalences of stage 1 and stage 2, while the JNC7 guideline was associated with a notably higher prevalence of the elevated blood pressure stage. Noteworthy is the observation that in certain provinces, such as Sistan and Baluchestan (64.63%), Qazvin (60.76%), Ilam (63.33%), and West Azerbaijan (64.27%), the prevalence was projected to exceed 60% in males.

The comparison of age-sex-standardized prevalences of different hypertension stages between 2005 and 2025 indicated that, in most provinces, the situation has either remained similar or worsened (Fig. 6). According to the ACC/AHA guideline, elevated blood pressure in none of the provinces had statistically decreased. However, the situation for stage 1 and stage 2 had improved in some provinces. In contrast, based on the ISH guideline, almost all provinces experienced either a similar or worse situation during these two decades. According to the JNC7 guideline, the situation for elevated blood pressure remained mainly stable or improved in limited provinces, notably in Gilan, where it decreased from about 50–25%. The situations for stage 1 and stage 2 were almost similar across provinces. Notably, South Khorasan experienced a remarkably worsened situation in prevalence for all stages based on different guidelines.

In this study, we investigated the trends of hypertension stages based on the 2017 ACC/AHA, 2020 ISH, and JNC7 guidelines, utilizing data from eight STEPS studies conducted in Iran. The findings of this study revealed both similarities and disparities in the prevalence of different stages based on various guidelines across different sexes, age groups, and national and subnational levels.

Overall, the ACC/AHA guidelines identified more individuals as hypertensive, while ISH guidelines allocated more to the normotensive category. However, ISH's allocation to stages 1 and 2 aligned closely with JNC7; JNC7 categorized most of the population as having elevated blood pressure. When considering hypertensive individuals, all guidelines indicated a decreasing trend in age-sex standardized prevalence for stage 2 hypertension, with approximately 13% reduction for JNC7 and ISH, and 27% for ACC/AHA. Both ISH and JNC7 guidelines demonstrated a stable trend for stage 1 hypertension, while the ACC/AHA guideline showed a significant decrease of about 19%. Analyzing age groups and sexes, the age groups 35–44 and 45–54 exhibited higher prevalence in elevated stages and stage 1 among males. In females, an increase in age was associated with higher prevalence across all stages. Furthermore, the comparison of age-sex-standardized prevalences of different hypertension stages between 2005 and 2025 indicated that, in most provinces, the situation either remained similar or worsened.

Our study revealed that adopting the ACC/AHA guideline would allocate approximately 30%, 25%, and 12% of the adult population to stages 1, 2, and elevated stages, respectively, with only 33% considered normotensive in 2025. In contrast, the widely used JNC7 guideline would allocate only about 15% and 6% to stages 1 and 2, and interestingly, 40% of the population would be classified as having an elevated stage. While ISH is similar to JNC7 in the definition of stages 1 and 2, its application would indicate that about 60% of the population is normotensive. In other words, adopting the ACC/AHA guideline would increase the prevalence of the hypertensive population by about 2.6 compared to the other two guidelines.

Similar studies in both Iran and other countries showed comparable changes when shifting to lower threshold recommendations for hypertension. STEPS 2016 data indicated a rise in hypertension prevalence from 29.9–53.7% under the 2017 ACC/AHA guideline²¹. Another study across 16 Iranian provinces projected an increase in age-sex standardized prevalence from 22.3–36.5%²⁰. In Tehran²², Yazd²³, and Khuzestan²⁴, hypertension prevalence was estimated to change from 20.4–47.1%, 28.9–61.0%, and dramatically from 15.81–42.85% with ACC/AHA adoption instead of JNC7. Internationally, adopting the ACC/AHA guideline in China doubled hypertension prevalence²⁵, and also showed a steeper trend, while Brazil experienced a 2.6-fold increase, from 21.1–54.7%²⁶. In Bangladesh, JNC7 and 2017 ACC/AHA classified 25.7% and 48.0% of the population as having hypertension, respectively²⁷. The US labeled 63% of the 45–75 population with ACC/AHA, while in China, it was 55%, representing a 26.8% increase in the US and 45.1% in China compared to the JNC7 guideline¹⁴. South Korea's hypertension prevalence was 49.2% versus 30.4%, based on ACC/AHA and JNC7, respectively²⁸.

The conclusion that lowering the hypertension thresholds would impose a higher burden on the health system has been established. However, for a more comprehensive understanding of how the implementation of each guideline would impact this burden, it is imperative to evaluate the approach of each guideline in the management of patients. According to the ACC/AHA guideline⁹, pharmacological intervention is not required until reaching stage 2 (≥ 140/90 mmHg). Exceptions are made for patients in stage 1 (130–139/80–89 mmHg) with a higher risk of cardiovascular disease (CVD). Those in stage 1 and the elevated stage may require medications and lifestyle changes, with a recommended reassessment every 3–6 months. Similarly, in JNC7⁸, patients do not need medications until reaching ≥ 140/90 mmHg or 130–139/80–89 mmHg with diabetes or chronic kidney diseases. Lifestyle modifications are recommended before reaching these thresholds. Therefore, the transition from JNC7 to ACC/AHA is expected to have a limited impact on medication prescriptions, as previous studies in Iran demonstrated only marginal increases of about 21.18%²⁴ and 30%²¹ after the shift, resulting in only slightly higher costs for the health system. However, in other countries such as the US and China, this change was associated with significantly higher costs¹⁴. This disparity could be attributed to differences in the age structure of studies conducted in these countries, which included elderly populations, as well as a higher proportion of elderly individuals in the reference population. In contrast, the ISH guideline does not recommend initiating medication before reaching 140/90 mmHg¹². In constrained settings, only high-risk patients would receive medications, and patients with lower risk are recommended to undergo lifestyle interventions for 3–6 months. If blood pressure does not improve after this period, medication can then be initiated.

A cost-effectiveness study on the application of the 2020 ISH guideline in Ethiopia indicated its cost-effectiveness²⁹. However, previous studies have shown that the population attributable fraction (PAF) attributed to SBP greater than 120 mmHg for ischemic heart diseases (IHD), cerebrovascular accidents (CVA), and CVD mortalities in Iran was 0.72, 0.43, and 0.32, respectively³⁰. Additionally, there was an increasing adjusted hazard ratio by 1.18 for all-cause mortality with each 20 mm Hg increase in SBP³¹. This indicates a substantial proportion of mortality could be averted if BP were controlled. To reach a more evidence-based conclusion on which guideline would be appropriate in the Iranian context, scenario-based cost-effectiveness studies should be implemented in the future.

Our study revealed that the ACC/AHA guideline would reclassify a higher proportion of individuals across all age groups to higher stages of hypertension. However, the effectiveness of this approach, aimed at encouraging lifestyle changes and non-pharmacological interventions⁹, is a subject of debate. Previous studies have indicated that the adoption of the 2017 ACC/AHA guideline led to a decrease in awareness, treatment, and control among hypertensive patients^20,21,23. Interestingly, awareness of hypertension in both Iran and other countries has not consistently equal adherence to healthier lifestyle choices^32–34. While reductions in salt consumption, smoking, and alcohol intake were associated with hypertension awareness^35,36, other lifestyle changes such as increased fruit and vegetable consumption, physical activity, and a healthy diet showed no significant correlation. This lack of association might stem from the extensive education focused on the effects of salt and smoking on hypertension, overshadowing other lifestyle factors. Only a marginal improvement, approximately 5%, was observed in patients adopting non-smoking behaviors and engaging in physical activity two years after a hypertension diagnosis³⁷, and only 1.7% of people with hypertension had a fully healthy lifestyle in the US³⁴. Policymakers should consider implementing evidence-based strategies, such as individual and group educational interventions³⁸, to address this issue.

Moreover, healthcare providers, particularly physicians, need to familiarize themselves with guidelines and incorporate their recommendations into patient care. Previous findings indicate that 24% of hypertensive patients did not receive any lifestyle change recommendations, and receiving recommendations was not associated with blood pressure control³⁹. Physician knowledge and adherence to guidelines pose additional challenges. A Study in Iran reported that only 31.8% of physicians were familiar with clinical guidelines⁴⁰, and family physicians adhered to only one-third of the recommendations in the national hypertension guideline¹⁹. Among cardiologists at a teaching hospital in Iran, only 60% exhibited high adherence to the ACC/AHA guidelines in managing cardiovascular disease risk factors⁴¹. Thus, transitioning to the ACC/AHA guideline requires addressing fundamental requirements, including considerations of cost, and necessitates changes in both patient and physician behaviors.

The prevalence patterns of different hypertension stages across age groups remained consistent for both sexes throughout the study years. Notably, in females, higher age groups were associated with elevated prevalence across all stages. In contrast, among males, the JNC7 guideline indicated elevated stage prevalence in age groups 35–44 and 45–54, while the ACC/AHA guideline identified higher prevalence in stage 1 for the same age groups. This highlighted a significant proportion of Iranian males aged 35–54 with blood pressure levels of 130–139/80–89, aligning with findings from other studies where newly diagnosed hypertensive patients, based on ACC/AHA criteria, were predominantly young, literate males with low-risk factors^20,22. This observation could be related to the cohort effect⁴², as recent cohorts of females in Iran displayed lower hypertension prevalence, while some recent male cohorts showed higher prevalence, suggesting that lifestyle factors in the early years of life may significantly influence blood pressure in adulthood⁴³ or reflect potentially unhealthier lifestyle choices in these age groups.

Moreover, previous research has consistently shown that awareness, treatment, and control of hypertension are greater in females, resulting in lower systolic and diastolic blood pressure in this population^20,21,44. However, it is noteworthy that hypertension control was higher in younger adults, despite the lowest awareness and treatment²¹. Targeting this specific age group and ensuring the reproductive population's health could yield long-term positive consequences for hypertension management in the country.

Our study revealed that the hypertension situation in Iran had not improved over the years, both at the national and sub-national levels. Nationally, the prevalence of different hypertension stages, irrespective of the guideline used, remained stable from 2010 to 2025 without remarkable changes, failing to meet the World Health Assembly's goal of a 25% reduction in hypertension by 2025 in comparison with 2010⁷. Other studies on the Iranian population consistently showed either independence from the year or even an increase in hypertension prevalence^45–48. Examining provinces, some regions witnessed improvements, particularly in stage 1 hypertension when considering the ACC/AHA guideline. However, for other stages and guidelines, the situation remained stable or worsened over the 20 years. Immediate evidence-based strategies are crucial to address the high prevalence observed in the 35–54 age group with elevated or stage 1 hypertension, which may exacerbate the situation in the future.

While empowering the primary health system has proven effective in controlling hypertension in Iran⁴⁹, and guidelines like IraPen for cardiovascular diseases have demonstrated cost-effectiveness⁵⁰, it would be wise to consider the available resources situation when choosing strategies. Evidence-based approaches, such as those suggested by WHO's "Best Buys"⁵¹, HEARTS program⁵², follow-ups using text messages^53,54, and the application of machine learning algorithms^54,55, should be implemented after thorough cost-effectiveness analyses. Setting rational and achievable goals based on the results of such analyses, similar to India's initiative to cover 75 million people with hypertension or diabetes on standard care by 2025⁵⁶, is crucial. Moreover, the decision on which guideline to use should align with this approach. For instance, in situations where drug availability and healthcare resources are limited, the ISH essential approach might be more rational. However, the challenge of choosing the best strategies is not unique to Iran. While numerous studies on hypertension treatment and risk factors have been conducted, transferable guidance is scarce on achieving better hypertension outcomes for entire populations¹. Future research should focus on addressing this issue comprehensively.

This study has several limitations that should be acknowledged. Firstly, although the overall designs of STEPS studies in Iran have been similar, there were disparities in sampling, such as changes in provinces until the last version in 2010. Except for the STEPS surveys conducted in 2016 and 2021, in other iterations, only post-stratification and non-response weights were utilized in estimations⁵⁷. Secondly, the cross-sectional study design employed provides only a one-time assessment of BP. Assessing BP on a single occasion is likely to result in an overestimation of true values and does not account for within-individual variability detected by repeated visits^44,58. Thirdly, this study lacks data for the elderly group, which constitutes one of the main age groups with a high health burden. Despite these limitations, our study leveraged the most comparable studies with national and subnational representative samples, featuring large sample sizes to estimate the trends of different stages of hypertension using various guidelines.

Overall, our study revealed that the prevalence of different stages of hypertension has not undergone remarkable changes based on all guidelines in recent years. If the current trends persist, the situation is projected to remain largely unchanged by 2025. The application of the 2017 ACC/AHA guideline resulted in a higher percentage of the population being categorized into elevated stages of hypertension, particularly among younger age groups in males. However, the decision regarding the preferable guideline should be based on comprehensive cost-effectiveness analyses, taking into account the available resources at both provincial and national levels.

Data source and study design

In this retrospective study, we used eight nationally and sub-nationally representative cross-sectional WHO STEPwise approach to NCD risk factor surveillance (STEPS) studies conducted in Iran in 2005, 2006, 2007, 2008, 2009, 2011, 2016, and 2021. As mentioned by the WHO⁵⁹, STEPS is a simple and consistent method for collecting, analyzing, and sharing data about important risk factors for NCDs in different countries, which each country can customize the variables according to its needs. This allows countries to track trends within their borders and compare their data with other countries. To obtain a nationally representative sample of the Iran population, a multi-stage cluster random sampling method in non-hospitalized and non-institutionalized Iranian adults, with a probability proportional to the size was used in all STEPS studies, and selection of the sampling units was done using Iranian national zip code databank.

In each STEPS study, a strong collaboration was established between the central team appointed by the Iranian Ministry of Health and Medical Education and the associated medical universities. The medical university officers were responsible for selecting interview team members and district supervisors based on specific qualifications, including strong communication skills and knowledge of the local geography and cultures. Prior to each study, extensive training workshops were conducted at both national and regional levels. These workshops aimed to provide training to medical university officers, supervisors, interviewers, data collectors, and other study collaborators.

In the first to eighth STEPS studies, we had the participation of 89,404, 29,976, 29,991, 29,773, 29,888, 12,000, 30,541, and 27,874 individuals, respectively. While WHO recommends that surveillance studies should involve people aged 25 to 64 years, each country has the flexibility to include other age groups. In the 2005, 2006, 2007, 2008, 2009, and 2011 STEPS studies, an additional age group of 15 to 24 years was included. In contrast, the 2016 and 2021 studies incorporated age groups of 18 to 24 years and those over 65 years. In this study, we included all participants without any missing values regarding their SBP and DBP from the common age group shared by all studies, which is 25 to 64 years old, to maintain consistency across them.

Data collection and variable measurement

STEPS studies consist of three main phases: questionnaire-based data collection (phase 1), physical measurements (phase 2), and biochemical measurements (phase 3). In five of the studies, namely the 2005, 2007, 2011, 2016, and 2021 studies, all three phases were conducted. However, in the remaining three studies, only phases 1 and 2 were completed. Despite these variations across studies, their fundamental characteristics remain similar, ensuring overall consistency. For this study, we utilized the recorded information from phases 1 and 2 across all the studies.

In the first phase, participants' socio-demographic characteristics, behavioral risk factors, medical histories, and history of known risk factors for NCDs were asked using questionnaires primarily drawn from the templates supplied by the WHO for STEPS studies. This questionnaire underwent a translation process into Farsi and then back into English, carried out by independent translators. Subsequently, rigorous assessments were conducted to evaluate its validity and reliability. Additionally, certain questions were added or modified to better capture local characteristics and research interests.

Regarding phase 2 of the studies, all measurements adhered to the protocols established by WHO. All instruments and tools were prepared by central committees from the same brands and were standardized and calibrated before the examination. Central committees prepared the identical brands of instruments and tools, and rigorously standardized and calibrated them before the examination process. Blood pressure was measured in a sitting position preferably from the right arm at least after 5 min of rest, by an appropriately-sized standard cuff sphygmomanometer for each individual. This assessment was performed twice in 2005 and 2006, and three times in other studies, with each reading taken at approximately 5-minute intervals. Supervisors in each province conducted periodic assessments as part of the measurement quality control process.

Variable definitions

To conduct this study, we retrieved the variables from previous STEPS studies datasets, encompassing the study year, age, sex, residential location, province of residence, systolic blood pressure, and diastolic blood pressure. We categorized participants into four age groups (25–34, 35–44, 45–54, 55–64). Over recent decades, changes in Iran's administrative divisions have resulted in shifts in the number and boundaries of provinces. To rectify this, we adopted the most recent administrative division, which comprises 31 provinces since 2010, as our reference point. We reorganized the STEPS dataset for earlier years by aligning provinces with district-level data. Unfortunately, in 2016, one province (Qom) declined to participate in the survey. The average values of the second and third measurements of systolic and diastolic blood pressures for each participant were considered as their SBP and DBP, respectively. However, for the first two STEPS, where measurements were taken only twice, the average of those two readings was considered. We employed 2017 ACC/AHA ⁹, 2020 ISH ¹², and JNC7 ⁸guidelines to define hypertension stages, including elevated, stage 1, and stage 2, as presented in Table 2. It is noteworthy that although JNC8 was published in 2014 with its main focus solely on discussing the thresholds for treatments⁶⁰, this version did not address hypertension stages, nor did it redefine high blood pressure (BP). The JNC8 panel believed that the 140/90 mmHg definition from JNC7 remains reasonable.

Table 2

Definitions of hypertension stages in different guidelines.
guideline	2017 ACC/AHA		2020 ISH		JNC7
BP classification	SBP (mmHg)	DBP (mmHg)	SBP (mmHg)	DBP (mmHg)	SBP (mmHg)	DBP (mmHg)
Normal	< 120	and < 80	< 130	and < 85	< 120	and < 80
Elevated (Prehypertension)	120–129	and < 80	130–139	and/or 85–89	120–139	or 80–89
Stage 1 hypertension	130–139	or 80–89	140–159	and/or 90–99	140–159	or 90–99
Stage 2 hypertension	≥ 140	or ≥ 90	≥ 160	and/or ≥ 100	≥ 160	or ≥ 100
BP: Blood pressure, SBP: Systolic blood pressure, DBP: Diastolic blood pressure

Statistical Analyses

The statistical analyses aimed to assess trends in prevalences using data from eight STEPS studies. To achieve nationally representative prevalence estimates, including 95% confidence intervals (95% CI), each study was weighted based on its design, population size, and the distribution of age groups/categories. A smoothing spline was employed to model outcome trends at the national level from 2005 to 2025. This model, implemented through simulations with 1000 iterations, produced robust estimates, including the median and 0.025 and 0.975 quantiles of all 1000 simulations. These estimates were utilized to determine point estimates and 95% uncertainty intervals (95% UI) for each year. For years lacking STEPS studies from 2005 to 2021, the model interpolated values, while extrapolation was applied for years beyond 2021 until 2025. Subsequently, proportions of age groups, sexes, and provinces were incorporated into the modeled values to derive subgroup-specific prevalence estimates. To make comparisons across different years and provinces possible, direct age standardization was performed using data from the National Population and Housing Census conducted by the Statistical Center of Iran in 2011⁶¹. Statistical significance was evaluated by considering the overlap of 95% UI. All visualizations and statistical analyses were conducted using R statistical software v3.4.3 (http://www.r-project.org (http://www.r-project.org/)).

Ethical considerations

This study constituted a secondary analysis of data derived from eight successive STEPS studies. Ethical approval was obtained for each of these STEPS studies, ensuring that participants received comprehensive information regarding the study's aims and procedures. Verbal and written informed consent were acquired from all participants. Researchers were exclusively granted access to de-identified datasets for analysis purposes. This study was conducted according to the guidelines of the Declaration of Helsinki⁶² and the ethical approval was granted by the ethical committee of the Tehran University of Medical Sciences (ID: IR.TUMS.EMRI.REC.1401.124), ensuring all applied methods followed the relevant guidelines and regulations.

Conflict of interest statement

The authors had no conflicts of interest.

Funding

This study received no grants or funding support.

Author Contribution

G.S. conceptualized and designed the study. A.G. wrote the main manuscript and visualized the results. A.S. analyzed the data. S.K., A.O., R.H., and G.S. were involved in the literature review, interpreting the data, and revising the draft and materials for accuracy. All authors revised the manuscript carefully and approved the final draft.

Acknowledgments

The authors would like to thank all who contributed to this study.

Zhou, B. et al. Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants. The Lancet 398, 957–980 (2021).
Kearney, P. M. et al. Global burden of hypertension: analysis of worldwide data. The lancet 365, 217–223 (2005).
Mills, K. T., Stefanescu, A. & He, J. The global epidemiology of hypertension. Nature Reviews Nephrology 16, 223–237 (2020).
Gaziano, T. A., Bitton, A., Anand, S. & Weinstein, M. C. The global cost of nonoptimal blood pressure. Journal of hypertension 27, 1472–1477 (2009).
Vos, T. et al. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet 396, 1204–1222 (2020).
Zamandi, M., Daroudi, R. & Sari, A. A. Direct Costs of Hypertension Treatment in Iran. Iranian Journal of Public Health 52, 1973 (2023).
Organization, W. H. NCD global monitoring framework. Geneva: World Health Organization (2013).
Chobanian, A. V. et al. Seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. hypertension 42, 1206–1252 (2003).
Whelton, P. K. et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Journal of the American College of Cardiology 71, e127-e248 (2018).
Group, S. R. A randomized trial of intensive versus standard blood-pressure control. New England Journal of Medicine 373, 2103–2116 (2015).
Bundy, J. D. et al. Systolic blood pressure reduction and risk of cardiovascular disease and mortality: a systematic review and network meta-analysis. JAMA cardiology 2, 775–781 (2017).
Unger, T. et al. 2020 International Society of Hypertension global hypertension practice guidelines. Hypertension 75, 1334–1357 (2020).
Muntner, P. et al. Potential US population impact of the 2017 ACC/AHA high blood pressure guideline. Circulation 137, 109–118 (2018).
Khera, R. et al. Impact of 2017 ACC/AHA guidelines on prevalence of hypertension and eligibility for antihypertensive treatment in United States and China: nationally representative cross sectional study. bmj 362 (2018).
Watkins, D. A. Implications of the 2017 ACC/AHA hypertension guideline for public health in Nepal. JAMA Network Open 1, e180778-e180778 (2018).
Abariga, S. A., Khachan, H. & Al Kibria, G. M. Prevalence and determinants of hypertension in India based on the 2017 ACC/AHA guideline: evidence from the India national family health survey. American Journal of hypertension 33, 252–260 (2020).
Peykari, N. et al. National action plan for non-communicable diseases prevention and control in Iran; a response to emerging epidemic. Journal of Diabetes & Metabolic Disorders 16, 1–7 (2017).
Azmin, M. et al. (2023).
Nezafat, A. V., Tavakolifard, N. & Vaezi, A. Adherence of general practitioners to the national hypertension guideline, Isfahan, Iran. International Journal of Preventive Medicine 11 (2020).
Sepanlou, S. et al. Prevalence, awareness, treatment, and control of hypertension based on ACC/AHA versus JNC7 guidelines in the PERSIAN cohort study. Scientific reports 12, 4057 (2022).
Mahdavi, M. et al. Insight into blood pressure targets for universal coverage of hypertension services in Iran: the 2017 ACC/AHA versus JNC 8 hypertension guidelines. BMC Public Health 20, 1–9 (2020).
Asgari, S., Khaloo, P., Khalili, D., Azizi, F. & Hadaegh, F. Status of hypertension in Tehran: potential impact of the ACC/AHA 2017 and JNC7 guidelines, 2012–2015. Scientific reports 9, 6382 (2019).
Mirzaei, M., Mirzaei, M., Mirzaei, M. & Bagheri, B. Changes in the prevalence of measures associated with hypertension among Iranian adults according to classification by ACC/AHA guideline 2017. BMC cardiovascular disorders 20, 1–9 (2020).
Sadeghi, F. et al. Impact of 2017 ACC/AHA guideline on prevalence, awareness, treatment, control, and determinants of hypertension: a population-based cross-sectional study in southwest of Iran. Population Health Metrics 19, 1–11 (2021).
Zheng, L. et al. Secular trends of hypertension prevalence based on 2017 ACC/AHA and 2018 Chinese hypertension guidelines: Results from CHNS data (1991-2015). The Journal of Clinical Hypertension 23, 28–34 (2021).
Cesena, F. H., Nary, F. C., Santos, R. D. & Bittencourt, M. S. The contribution of the systolic and diastolic components for the diagnosis of arterial hypertension under the 2017 ACC/AHA Guideline and metabolic heterogeneity among individuals with Stage 1 hypertension. The Journal of Clinical Hypertension 22, 1192–1199 (2020).
Kibria, G. M. A. et al. The new 2017 ACC/AHA guideline for classification of hypertension: changes in prevalence of hypertension among adults in Bangladesh. Journal of human hypertension 32, 608–616 (2018).
Lee, J. H. et al. Blood pressure control and cardiovascular outcomes: real-world implications of the 2017 ACC/AHA hypertension guideline. Scientific reports 8, 13155 (2018).
Davari, M., Sorato, M. M., Kebriaeezadeh, A. & Sarrafzadegan, N. Cost-effectiveness of hypertension therapy based on 2020 International Society of Hypertension guidelines in Ethiopia from a societal perspective. Plos one 17, e0273439 (2022).
Sepanlou, S. G. et al. Cardiovascular disease deaths and years of life lost attributable to non-optimal systolic blood pressure and hypertension in Northeastern Iran. Archives of Iranian medicine 18, 144 (2015).
Sepanlou, S. et al. Hypertension and mortality in the Golestan Cohort Study: A prospective study of 50 000 adults in Iran. Journal of human hypertension 30, 260–267 (2016).
Akbarpour, S. et al. Healthy lifestyle behaviors and control of hypertension among adult hypertensive patients. Scientific reports 8, 8508 (2018).
Kim, Y. & Kong, K. A. Do hypertensive individuals who are aware of their disease follow lifestyle recommendations better than those who are not aware? PloS one 10, e0136858 (2015).
Fang, J., Moore, L., Loustalot, F., Yang, Q. & Ayala, C. Reporting of adherence to healthy lifestyle behaviors among hypertensive adults in the 50 states and the District of Columbia, 2013. Journal of the American Society of Hypertension 10, 252–262. e253 (2016).
Scheltens, T. et al. Awareness of hypertension: will it bring about a healthy lifestyle? Journal of human hypertension 24, 561–567 (2010).
Banegas, J. R. et al. Achievement of cardiometabolic goals in aware hypertensive patients in Spain: a nationwide population-based study. Hypertension 60, 898–905 (2012).
Neutel, C. I. & Campbell, N. R. Changes in lifestyle after hypertension diagnosis in Canada. Canadian Journal of Cardiology 24, 199–204 (2008).
Tam, H. L., Wong, E. M. L. & Cheung, K. Effectiveness of educational interventions on adherence to lifestyle modifications among hypertensive patients: an integrative review. International journal of environmental research and public health 17, 2513 (2020).
Ahmadi, S. et al. Lifestyle modification strategies for controlling hypertension: How are these strategies recommended by physicians in Iran? Medical Journal of the Islamic Republic of Iran 33, 43 (2019).
Mounesan, L., Nedjat, S., Majdzadeh, R., Rashidian, A. & Gholami, J. Only one third of Tehran's physicians are familiar with ‘Evidence-Based Clinical Guidelines’. International Journal of Preventive Medicine 4, 349 (2013).
Hosseinzadeh-Shanjani, Z., Hoveidamanesh, S., Ramezani, M., Davoudi, F. & Nojomi, M. Adherence of cardiologist physicians to the American Heart Association guideline in approach to risk factors of cardiovascular diseases: An experience from a teaching hospital. ARYA atherosclerosis 15, 38 (2019).
Hosseini, M. et al. Twenty-year dynamics of hypertension in Iranian adults: age, period, and cohort analysis. Journal of the American Society of Hypertension 9, 925–934 (2015).
Li, Y. et al. Exposure to the Chinese famine in early life and the risk of hypertension in adulthood. Journal of hypertension 29, 1085–1092 (2011).
Esteghamati, A. et al. Awareness, treatment and control of pre-hypertension and hypertension among adults in Iran. Archives of Iranian Medicine 19, 0–0 (2016).
Sepanlou, S. G. et al. Levels and trends of hypertension at national and subnational scale in Iran from 1990 to 2016: a systematic review and pooled analysis. Archives of Iranian Medicine 24, 306–316 (2021).
Farzadfar, F. et al. Health system performance in Iran: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet 399, 1625–1645 (2022).
Oori, M. J. et al. Prevalence of HTN in Iran: meta-analysis of published studies in 2004–2018. Current hypertension reviews 15, 113–122 (2019).
Mohammadi, S. et al. Prevalence of hypertension in Iran: An updated systematic review and meta-analysis of community-based studies. Caspian Journal of Internal Medicine 14, 607 (2023).
Farzadfar, F. et al. Effectiveness of diabetes and hypertension management by rural primary health-care workers (Behvarz workers) in Iran: a nationally representative observational study. The Lancet 379, 47–54 (2012).
Mokhtari, M., Khalil, D., Farzadfar, F., Daroudi, R. & Asadi-Lari, M. The Burden of Cardiovascular Disease Attributable to Modifiable Risk Factors and Cost-effectiveness Analysis of IraPEN Program in the General Population of Iran. Medical Journal of the Islamic Republic of Iran 36 (2022).
Organization, W. H. NCD best buys and other effective intervention. (World Health Organization. Regional Office for the Eastern Mediterranean, 2018).
Campbell, N. R. et al. WHO HEARTS: a global program to reduce cardiovascular disease burden: experience implementing in the Americas and opportunities in Canada. Canadian Journal of Cardiology 37, 744–755 (2021).
Zhou, B., Perel, P., Mensah, G. A. & Ezzati, M. Global epidemiology, health burden and effective interventions for elevated blood pressure and hypertension. Nature Reviews Cardiology 18, 785–802 (2021).
Tengnah, M. A. J., Sooklall, R. & Nagowah, S. D. in Telemedicine technologies 139–152 (Elsevier, 2019).
Montagna, S. et al. Machine learning in hypertension detection: a study on World Hypertension Day data. Journal of Medical Systems 47, 1 (2022).
WHO. India: 75 million people with hypertension or diabetes on standard care by 2025, <https://www.who.int/southeastasia/news/detail/18-05-2023-india-75-million-people-with-hypertension-or-diabetes-on-standard-care-by-2025> (2023).
Efazati, N. et al. General and abdominal obesity trends in the Iranian adult population from 2004 to 2021. Journal of Diabetes & Metabolic Disorders 22, 1745–1761 (2023).
Ostchega, Y., Dillon, C. F., Hughes, J. P., Carroll, M. & Yoon, S. Trends in hypertension prevalence, awareness, treatment, and control in older US adults: data from the National Health and Nutrition Examination Survey 1988 to 2004. Journal of the American Geriatrics Society 55, 1056–1065 (2007).
Organization, W. H. WHO STEPS surveillance manual: the WHO STEPwise approach to chronic disease risk factor surveillance. Report No. 9241593830, (World Health Organization, 2005).
James, P. A. et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). Jama 311, 507–520 (2014).
Iran, S. C. o. National Population and Housing Census 2011, <https://www.amar.org.ir/> (
Association, W. M. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. Jama 310, 2191–2194 (2013).

No competing interests reported.

Download PDF

Version 1

posted

You are reading this latest preprint version

Trends of Hypertension Stages among Iranian Adults from 2005 to 2025 using WHO STEPS studies: A Comparison among 2017 ACC/AHA, JNC7, and 2020 ISH Guidelines

Status:

Version 1

Abstract

Figures

Introduction

Results

Baseline characteristics

The national age-sex standardized trend of hypertension

Hypertension trend based on sex and age groups

The subnational situation of hypertension

Discussion

Conclusion

Material and Methods

Data source and study design

Data collection and variable measurement

Variable definitions

Statistical Analyses

Ethical considerations

Declarations

Conflict of interest statement

Funding

Author Contribution

Acknowledgments

References

Additional Declarations

Status:

Version 1