Awareness, Treatment, and Control of Hypertension Among 10663 Adults in Kherameh: A Population-Based Study

Background: Hypertension (HTN) is known to be a modiable risk factor for Cardiovascular Disease (CVDs), stroke, and kidney disease. The present study aimed to determine awareness, treatment, and control of HTN and the related factors in Kherameh, Iran. Methods: This cross-sectional study was performed on 10663 individuals over 40 years of age using Kherameh cohort data. HTN was dened as either Systolic/Diastolic Blood Pressure (SBP/DBP) ≥ 140/90 mmHg or taking medications. Logistic regression was used to examine the relationship between awareness, treatment, and control and their related factors. Results: Awareness, treatment, and control rates were 80.3%, 78%, and 53.6%, respectively among the individuals with HTN. Age, gender, body mass index, and CVD were associated with all dependent variables in the regression model. In addition, occupation, diabetes, chronic diseases, history of CVD in the rst- and second-degree relatives, and history of chronic diseases in the second-degree relatives were related to all dependent variables, except for treatment. Conclusion: The results indicated that despite the high level of awareness, the proportion of patients under treatment and control gradually decreased, such a way that about half of the patients had abnormal blood pressure. Hence, educational intervention is recommended to increase the patients’ awareness to ensure the continuous use of antihypertensive drugs in order to help control the disease more eciently.


Background
Hypertension (HTN) is an important public health challenge worldwide because of its high prevalence and concomitant risks of cardiovascular and kidney diseases (1). It has been identi ed as the third cause of disability-adjusted life years (2) and has been reported to be directly responsible for 49% of ischemic heart diseases and 62% of cerebrovascular diseases, as the most common cause of death in developing countries (3). The number of persons living with HTN is increasing and has been projected to grow to about 1.5 billion by 2025 (4). Many studies have shown that urbanization and adaptation to the Western lifestyle, due to the economic growth and changes observed with age, have led to an epidemic of noncommunicable chronic diseases, such as HTN (5,6). The prevalence of HTN varies across the world considerably. Its prevalence has been reported to be 43.5% in Malaysia (7), 23.7% in Sri Lanka (8), 30% in sub-saharan Africa (9), and 26.21% in Iran (5).
The most important barrier to diagnosis of HTN is the lack of awareness of the disease and its complications (11). Epidemiological studies have revealed the need for increasing the awareness of HTN, especially in low-and middle-income countries where the public awareness of the disease is relatively unpleasant (10). Moreover, while HTN is a preventable disease, antihypertensive drugs are not used often (11). In a population-based survey in China, 42.6% of the patients were aware of their HTN status and 34.1% received antihypertensive treatments (12). In Vietnam, 48.4% were aware of their elevated Blood Pressure (BP), 29.6% were under treatment, and 10.7% achieved the targeted BP control (13). In Iran, 49.6% of the patients were aware, 55.7% were treated, and 69.2% were controlled (14).
A comprehensive strategy to reduce the complications of HTN should include prevention approaches, such as increasing awareness, early diagnosis, adequate treatment, and careful BP control (15). This study aims to investigate awareness, treatment, and control of HTN and their related factors based on the baseline data of Kherameh cohort study.

Methods
This cross-sectional study was performed on 10663 individuals aged 40-70 years in Kherameh cohort study during 2015-2016. Kherameh cohort study is a part of the Prospective Epidemiological Research Studies in Iran (PERSIAN), and logic, goals, and design of the PERSIAN cohort study have already been published (16).
The main purpose of Kherameh cohort study was to determine the prevalence and risk factors of noncommunicable diseases at the beginning and follow-up. Firstly, the participants lled out the informed consent forms and then, trained staff conducted the interviews and collected the data. After admission, the participants underwent laboratory and physical examinations, including measurement of height, weight, waist circumference, and BP. BP was measured after a 10-minute rest in the sitting position using a standard calibrated sphygmomanometer (Reister Model, Germany). The individuals were required not to be active, consume food or uids, and smoke at least half an hour before the measurement. Weight was measured with minimal coverage and without shoes using a SECA scale made in Germany with an accuracy of 100 grams. Height was also measured using a measuring tape to the nearest 0.1 cm with light clothing and without shoes. Then, Body Mass Index (BMI) was calculated by dividing weight by height squared. Furthermore, blood glucose, triglyceride, and cholesterol tests were performed by the Mindray device (made in Japan) using Pars Azmoon kits. The individuals were required to fast for 12 hours before sampling and not to smoke or drink alcohol.
Physical activity was assessed using a questionnaire, which included sports, occupation, and the amount of time spent sleeping and eating during a day. After that, the Metabolic Equivalent Task (MET) index was computed for each activity. Finally, physical activity was divided into four groups; i.e., mild, moderate, high, and severe, based on the quartiles. Socioeconomic Status (SES) included homeownership, home size, number of bathrooms within the house, having cars, price of the cars, domestic and international travels, and owning mobile phones, televisions, vacuum cleaners, washing machines, refrigerators, microwaves, and computers. Instead of statistically analyzing each component of the SES, exploratory factor analysis was utilized in order to generate fewer hidden factors. Accordingly, each individual was given a quantitative score at the signi cance level of 0.4. Additionally, education level was classi ed into ve categories, namely illiterate, less than ve years, six to eight years, high school, and academic. It should also be noted that the rstdegree relatives included father, mother, brother, sister, son, and daughter.

De nition
According to the guideline for management of HTN in Europe, HTN was de ned as Systolic BP (SBP) equal to or above 140 mmHg, Diastolic BP (DBP) equal to or above 90 mmHg, or being under treatment for HTN (17). Besides, dyslipidemia was de ned as high cholesterol (≥ 200 mg /dL) or high serum triglyceride levels (≥ 150 mg/dL). Diabetes was de ned as the history of known diabetes or fasting blood sugar ≥ 126 mg /dL (18). Moreover, awareness was regarded as the self-report of a previous diagnosis by the health staff. Finally, treatment was considered as taking antihypertensive medications and control was de ned as BP less than 140/90 mmHg.

Statistical analysis
Mean and standard deviation were used to describe quantitative variables and frequency and percentage were used for qualitative ones. Multivariate logistic regression was used to determine the relationship between the factors associated with awareness, treatment, and control of the disease. All tests were twotailed at the signi cance level of 0.05 and were carried out by the SPSS software, version 20.
Among the participants who were aware of their disease, 720 (30.32%) had abnormal BP despite taking medications. On the other hand, 70 individuals (2.94%) did not take medications and had abnormal BP despite being aware of the disease. Furthermore, 1584 participants (66.72%) were taking medications and had normal BP at the time of measurement (Fig. 2).
The results of the multivariate logistic models have been summarized in Table 2. Brie y, female gender had higher odds for higher awareness compared to male gender (OR = 1.3, p = 0.02) and was associated with better treatment (OR = 2.57, p = 0.01) and control (OR = 1.37, p = 0.04). In addition, older individuals had better awareness (OR = 1.05, p < 0.001), treatment (OR = 1.05, p = 0.02), and control (OR = 1.04, p < 0.001). BMI and cerebrovascular disease were also directly related to all three outcomes. The factors that were directly related to better awareness and control included diabetes (OR = 3.29, p < 0.001; OR = 2.66, p

Discussion
In Iran, HTN has been the second leading cause of morbidity and mortality since 1990 (19,20). In this country, the prevalence of HTN has been estimated to range from 27.7% (21) to 42.7% (22). Effective control of people with HTN requires improving awareness among health professionals and the general public.
Unlike other studies, the patients were more aware of their disease in the present investigation (80.3%) (23). In addition, 78% of the hypertensive patients and 97% of those who were aware of their disease were treated. In other studies, these measures were found to be 40.9% (24) and 51.9% (25), respectively.
In the current research, BP was controlled in 53.6% of all patients and in 68.7% of those taking drugs. These values were similar to those of the study by Gandomkar et al. (69.1%) (14), but higher than those obtained by Li (23). Similar results were also obtained in a survey performed on the people aged 65-94 years in Germany. In that study, 80.2% of the patients knew that they had HTN and 74.4% of the patients and 92.8% of the informed individuals took antihypertensive drugs (26). The higher awareness in the present study might result from a better access to health care. Besides, the better treatment and control of the disease in this study compared to other studies might be due to the fact that a larger number of people followed the treatment plan because of the larger population that was aware of their disease. In one study, poor treatment status was mentioned due to lower SES, lower health literacy, and misconceptions about treatment (27). Given that about half of the patients had abnormal or uncontrolled BP, it could be justi ed that poor control of the disease was related to individual factors (asymptomatic disease and misconceptions) as well as health system factors (lack of antihypertensive drugs, long distance to medical centers, high cost of medicine, and shortage of skills and resources) (28).
In the present study, 19.2% of the patients were unaware of their status. Among the hypertensive patients who were aware of their disease and were taking medications, 66.72% had their disease controlled, but 30.32% had abnormal BP. Among those who did not take medications despite being aware of the disease, 2.94% had abnormal BP, which was on the contrary to the results of other investigations. Identifying the information of each of these subgroups might help researchers make better decisions to nd the reason for not taking medications or controlling the disease and to nd a solution for it.
The present study results showed that awareness, treatment, and control of HTN were higher among females and older individuals. These ndings were consistent with those of other studies (22,29), and might be due to the fact that these groups often refer to health centers to receive services (30).
In the present survey, education level was inversely associated with awareness, which was in line with the ndings of the research by Malekzadeh (22). However, another study demonstrated that literacy was associated with better treatment (31). The inverse relationship might be due to the lower utilization of health services by the highly educated groups (32).
In the current study, physical activity was associated with awareness and control, while Rajati reported that it was only associated with treatment (33). In addition, higher BMI was directly related to all three outcomes. The higher level of awareness in obese people might result from receiving more attention from the health system (34).
In agreement with the current study ndings, Zhang indicated that better disease control was inversely related to high cholesterol level (35). In addition, the present study ndings revealed that the individuals who drank alcohol had lower awareness about their status, which was in line with the results obtained by Lv et al. (36).
The results of a previous research indicated that the patients with diabetes had higher awareness (35), which was consistent with the results of the current study. This study also showed that the individuals with a history of cardiovascular disease had higher awareness and better treatment and control, which was in agreement with the results of the study performed by Gandmakar et al. (31). Having other chronic diseases was associated with higher awareness and better control, too. In one study, people with diabetes, obesity, heart disease, and stroke were more likely to see a doctor and have their BP checked (26). In the present study, the patients who had a history of cardiovascular disease in their rst-and second-degree relatives had higher awareness and better control. Nonetheless, the awareness and control levels were 50% lower among the individuals with a family history of chronic diseases in comparison to those without this condition. The ndings of two prior studies showed that the people with a family history of HTN had a higher level of awareness (25,37). This might imply that a family history of HTN might encourage people to check their BP. Physicians might also pay more attention to this group because they are at a higher risk for heart diseases (38).
This study had a few limitations. First, the cross-sectional design of the study made it di cult to rule out the inverse causation of variables. HTN risk factors such as stress and dietary habits have not been analyzed. Despite these limitations, the strong points of the study included its large sample size and precise collection of data regarding the potentially relevant demographic and lifestyle factors. Also, the relationship between family history of various diseases has been investigated while it has been less seen in other studies.

Conclusion
The ndings of this study indicated that despite the high level of awareness, the proportion of patients under treatment and control gradually decreased, such a way that about half of the patients had abnormal BP. Thus, educational intervention was recommended to increase the awareness of the patients who were unaware of their disease to ensure the continuous use of antihypertensive drugs in order to help control the disease more e ciently.