Estimated Change in Prevalence of Hypertension in Bangladesh According to Following JNC 7 and ACC/AHA 2017: Secondary Analysis From Nationally Representative Data


 Most studies followed either Joint National Committee 7 (JNC 7) or World Health Organization-International Society of Hypertension (WHO-ISH) guidelines to ascertain the prevalence of hypertension among Bangladeshi adults. The American College of Cardiology/American Heart Association (ACC/AHA) revised the definition of hypertension in 2017, which has significant public health importance. Identifying the change in the new guideline has resulted in the prevalence and associated factors of hypertension compared to that of the JNC7 guideline in Bangladesh. This study used data from the most recent round (2017-18) of the Bangladesh Demographic and Health Survey (BDHS). According to the 2017 ACC/AHA guideline, the participants were categorized as hypertensive if they had BP measurements greater than or equal to 130/80 mm Hg, which was greater than or equal to 140/90 mm Hg according to the JNC 7 guideline. A total of 11 959 weighted participants were included in the analysis. The median (IQR) age of the respondents was 34.0 (18.0-95.0) years. The prevalence of hypertension was 24.0% according to the JNC 7 guideline, which was 50.5% according to the 2017 ACC/AHA guideline. Participants who were overweight and obese, aged, member of affluent households, urban residents, and Rangpur division inhabitants had significantly higher odds of being hypertensive according to both guidelines. The new guideline suggests that half of the adult population in Bangladesh is hypertensive when measured according to the new guideline, urging the policymakers and public health practitioners to take immediate action to address the already established modifiable risk factors.

Association (ACC/AHA) Guideline for Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults reduced BP threshold for hypertension. According to 2017 ACC/AHA guideline, hypertensive individuals have systolic blood pressure (SBP) greater than or equal to 130 mmHg and/or diastolic blood pressure (DBP) greater than or equal to 80 mmHg 10 . c.
Due to these changes in the 'cut-off' values, a signi cant number of people are reclassi ed as hypertensive, who were previously considered as pre-hypertensive 6,[11][12][13] . For example, the prevalence of hypertension among adult Nepalese population was almost doubled using the ACC/AHA guidelines compared to the JNC 7 guidelines 11 .
Muntner et al. reported a 14.7% increase in hypertension prevalence in the United States (USA) among the adult population aged more than 19 years 14 . Another study also found a 45.1% and 26.8% increase in the prevalence of hypertension among adults aged between 45 and 75 years in the USA and China, respectively, with new guideline 15 . Several studies recognized the importance of this revised classi cation for public health resource planning and prevention strategies [14][15][16] . Despite the increased burden of CVDs in developing countries, there remain inadequate available information on hypertension prevalence using ACC/AHA guidelines [17][18][19] .
Previous studies in Bangladesh also reported a signi cant increase in hypertension prevalence in  20 . In another paper, Kibria et al. also reported that the association's factors and level changed when using the JNC 7 guidelines and ACC/AHA guidelines 12 . These changes in the prevalence and risk factors of hypertension have direct and indirect implications and hold signi cant merit in revising the public health policies and plans in addressing the issue 21 . However, all of these studies reported the ndings from the 2011 BDHS survey data. Therefore, the present research was carried out to identify the change the new guideline has resulted in the prevalence and associated factors of hypertension in comparison to that of the JNC 7 guideline using the most recent Bangladesh Demographic and Health Survey (BDHS) 2017-18 data. This new dataset encompasses comparatively larger measurement of BP with greater participants than the previous round. Therefore, the ndings using this latest dataset can have broad policy implications regarding hypertension management in Bangladesh.
Key Points: Question. What is the change the new guideline has resulted in the prevalence and associated factors of hypertension in comparison to that of the JNC 7 guideline among the adult population in Bangladesh?

Methods
Data sources. The current study analyzed the most recent (2017-18 (BDHS) data. The survey was carried out from October 2017 to March 2018 under the authority of the National Institute of Population Research and Training (NIPORT), Medical Education and Family Welfare Division, Ministry of Health and Family Welfare. The survey's principal objective was to assess the health indicators and provide a detailed overview of population, maternal, and child health issues along with the status of several noncommunicable diseases such as hypertension and diabetes among adults.
Study population and survey design. The sampling frame used for the 2017-18 BDHS is the complete list of enumeration areas (EAs) covering the entire population residing in Bangladesh. The survey used a list of enumeration areas (EAs) provided by the Bangladesh Bureau of Statistics (BBS) of the 2011 Population and Housing Census of the People's Republic of Bangladesh. The survey's primary sampling unit (PSU) is an EA covering on average 120 households, in 2017-18. The BDHS 2017-18 was a multistage strati ed cluster sample of households' survey, carried out in two and three stages in rural and urban settings. In the rst stage of sampling, in rural areas, wards were selected, followed by Primary Sampling Units (PSUs), then households were selected from the PSUs. In urban areas, wards were selected through the PSUs technique, and one enumeration area (EA) was taken from each PSUs, then the households were taken from the selected EAs sample. A detailed description of the survey design, methodologies, sample size, questionnaires, and ndings can be found in the nal report summary of BDHS 2017-18 22 . Anthropometric measurements and blood pressure (BP) were measured only from the study participants' systematically selected subsample.
Measurements. The participants' Bodu Mass Index (BMI), height, and weight were measured using the World Health Organization (WHO) standard procedures and classi ed accordingly 23 . The BMI was calculated by dividing body weight in kilograms by the square of height (m 2 ) in meters. As underweight (<18.5 kg/m 2 ), normal weight (18.5-25.5 kg/m 2 ), overweight (25.5-29.9 kg/m 2 ), and obese (≥30.0 kg/m 2 ) 23 . In the time of the individual interview, three times the BP was measured using UA-767F/FAC (A&D Medical) blood pressure monitors at about 5 minutes interval 24 . The average of the second and third measurement was used to categorize the respondents with respect to hypertension as recommended by (WHO 1999;NIH 1997) 24 . The LIFE SOURCE® UA-767 Plus BP monitor was used to measure blood pressure. This automatic device includes separate cuffs (small, medium, and large). Three blood pressure measurements were taken at intervals of approximately 10 minutes. The average of the second and third measurements was used to report respondents' blood pressure values 22 .
De nition of hypertension. The dependent variable for this study was hypertension. A person with systolic blood pressure (SBP) greater than or equal to (≥140 mmHg) or a diastolic blood pressure (DBP) greater than or equal to (≥90 mmHg) was considered hypertensive as suggested by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) 25 . While according to the American College of Cardiology/American Heart Association 2017 (ACC/AHA 2017) guideline, individuals who have an SBP greater than or equal to (≥130 mm Hg) or a DBP greater than or equal to (≥80 mm Hg) or take any prescribed anti-hypertensive drugs to control blood pressure were categorized as hypertensive 26 . The category of pre-hypertension was transformed into elevated blood pressure in the 2017 ACC/AHA guideline 26 . Independent variables . The independent variables included in the study were selected based on previous literature reporting the risk of developing hypertension in population in low-and middle-income countries 6,11,12,[27][28][29][30] . The household factors included administrative division, place of residence and wealth quintile whereas the socioeconomic and individual factors included: participants' current age; education level; and occupation; behavioural characteristics included cigarette smoking; and the BMI was categorized as underweight (BMI<18.5 kg/m 2 ), normal (BMI: 18.5-24.5 kg/m 2 ), overweight (BMI: 25.5-29.9 kg/m 2 ) and obese (BMI ≥30.0 kg/m 2 ).
Statistical analysis. Before estimating the prevalence of hypertension in both settings, the normality of the continuous variables was investigated through skewed distribution and reported with medians and interquartile ranges (IQRs). We estimated the prevalence of hypertension and reported the differences between the two guidelines. Besides, we reported the prevalence by background characteristics of the study participants through complex sample design. Along with this, the study utilized a logistic regression model to identify the most potential confounders associated with developing hypertension and described those factors found statistically signi cant at p-value less than (<0.005). Before doing the analysis, the datasets were weighted to adjust due to the clustered sampling design followed by appropriate techniques of Demographic Health Survey (DHS). The Statistical Package for Social Science (SPSS. 26) version was used to analyze this study's data.
Ethical consideration. The study used secondary data from the Demographic and Health Surveys Program publicly available; therefore, we did not require any further ethical approval. The details of ethical procedures followed by the Demographic and Health Surveys Program can be found in the BDHS report 22 .

Results
A total of 11 959 weighted participants were included in this analysis. The median (IQR) age of the respondents was 34.0 years (18.0-95.0). Of the total survey participants, 6835 (57.2%) were female ( Table 1). The median (IQR) SBP and DBP were 118 (109-131) and 80 (73-87), respectively. The majority of the participants (75.8%) reported having their blood pressure measured at least once previously. The median BMI was 21.91 (19.4-24.9). In addition, 25.4% had no education, and 73.4% were residing in rural areas.   Table 3 describes the factors associated with developing more risk of having hypertension under the two guidelines after adjusting all confounders. As per the two guidelines, these factors more aged, higher BMI and living in Rangpur division were identi ed as signi cant risk factors. According to ACC/AHA guideline but not JNC 7 guideline, people living in urban areas were identi ed as signi cant. Alternatively, smoking reduced the risk of hypertension found in both guidelines.  6,11 . These studies found an absolute change in hypertension prevalence after applying the new 2017 ACC/AHA guidance. The bene t of earlier detecting individuals with hypertension would reduce complications associated with hypertension and cardiovascular morbidity. Interesting, our ndings reported a similar prevalence of hypertension among male and female participants. If we compare the nding based on the previous study, the prevalence rate increased among female participants more than male counterparts 12,27 . The plausible explanation could be biological and behavioural characteristics among the females might have increased over the period. This fact is supported by the previous evidence that females have a higher risk of obesity and diabetes compared with men 34,35 . This needs females to require more awareness and public health information to control hypertension and minimize adverse complications 27 . Our study ndings reported that people with higher socioeconomic status had higher odds of having hypertension. The higher wealth status participants can generally purchase more consumable resources with a large amount of calorie intake, making them overweight or obese, putting them at a greater risk of being hypertensive than those lower wealth status 36,37 . This suggests the need for prevention and control program for hypertension in urban areas of Bangladesh.
The prevalence of hypertension was higher among those living in urban areas, which is in line with previous studies where urban people were reported more hypertensive 6,27,38,39 . The possible reason could be prevailing unhealthy lifestyle factors such as less physical activity, consumption of unhealthy diets among the urban populations might have contributed to the disease burden [40][41][42] . However, this nding warrants further detailed investigation of causes for the increased prevalence or odds of hypertension in several Bangladesh divisions 27 . This nding suggests the need to understand the social inequalities among the rural and urban community, which may have played a role in such variation. Understanding the inequalities mentioned earlier may help design the comprehensive hypertension prevention and control program for Bangladesh peoples.
There is another explanation that would help understand why the prevalence of hypertension is high in urban areas. The study found that higher educated and higher wealth status of people are likely lives in urban areas, resulting from having a sedentary lifestyle such as low physical activity. A lack of open spaces for playing games or physical activity might result in the high-risk prevalence of hypertension 27 .
Since most urban participants are educated, and these had a higher prevalence of hypertension. Thus our study recommends that educated individuals in urban areas need to receive more public health awareness information to control raised blood pressure levels 27 .
This study identi ed the potential risk factors of hypertension using both JNC 7 and 2017 ACC/AHA guideline alongside to the estimation of the prevalence. People of older age 25 to more, female, overweight, and obese had relatively higher odds, which is in line with previous studies elsewhere 6,11,[43][44][45] . Notably, in the current study, administrative divisions, and place of residence were also found signi cantly associated with hypertension inline with suggest 2017 ACC/AHA guidelines. People from Rangpur division found higher odds in the two guidelines. Much is unknown why the people from Rangpur division owned higher risk of being hypertensive; however, the reason may be because of socioeconomic inequalities such as limited resources, income inequality, low level of education and social safety net programs, poor connectivity with the urban centres, insu ciency or absence of public infrastructure 46,47 .
The new 2017 ACC/AHA guideline recommends treating stage 1 hypertension with changing lifestyle measures and taking antihypertensive medicines to prevent future cardiovascular disease risks 11 . Our study ndings are signi cant because it shows that above fty per cent of adults with hypertension or elevated blood pressure according to the new 2017 ACC/AHA classi cation require active lifestyles and healthy dietary habits. Public health programs should adequately address this emerging problem; in Bangladesh, emphasis should be paid to prevention and self-management of a condition not only for those with hypertension but also for all adults 11 . Therefore, it is essential to estimate the prevalence based on both thresholds to control this hypertension burden, which might exacerbate cardiovascular disease. These ndings might help future researchers and appropriate authority design any programs and policies regarding control and prevent hypertension burden and overcome this massive public health challenge.
The strengths and weaknesses of this study are accredited. The strength that lies in this study is the generalizability of the ndings for Bangladesh since this survey covered nationally representative data covering all divisions. Along with appropriate statistical methods to estimate the weighted prevalence of hypertension from the sample. This study is the rst epidemiological study that analyzed the most recent round data sets based on JNC 7 and 2017 ACC/AHA, which present the exact prevalence that might aid the authorities in taking up initiatives to prevent hypertension.
The limitations of the study are appropriately acknowledged. Due to a cross-sectional setup, no causality can not be established, and the individuals' blood pressure was measured three times in a single day.
However, both guidelines recommend longitudinal measurement of blood pressure levels to diagnose hypertension 11 . This survey also used an automated device, though both guidelines recommend recording blood pressure with a sphygmomanometer 31,48,49 .

Conclusions
The present study highlighted that the prevalence of hypertension was almost doubled according to the 2017 ACC/AHA guideline compared to the JNC7 guideline. The policymakers and public health practitioners should consider the new guideline and make new strategies to increase awareness among the adult population in Bangladesh. The study nding also points towards addressing the already established modi able risk factors of hypertension such as overweight/obesity, high-income status and urban residence, which are also identi ed as the risk factors according to both guidelines.  Figure 1