Prevalence of Hypertension and Its Associated Risk Factors Among Adults Attending Medical Outpatient Clinics at Ibn Sina General Hospital Authority in Mukalla City, Yemen

Background: Hypertension (HTN) is the most generally acknowledged modifiable risk factor for cardiovascular disease, cerebrovascular disease, and end-stage renal disease. Accordingly, the World Health Organization has listed HTN as the third greatest cause of death globally. Objectives: The objective of this study was to assess the prevalence of HTN and its associated risk factors among adults attending medical clinics at Ibn Sina Hospital Authority in Mukalla City, Yemen. Methods: A cross-sectional descriptive survey was conducted using a self-administered questionnaire applied to 384 male and female adults aged ≥18 years attending Ibn Sina General Hospital Authority outpatient clinics in Mukalla City, Yemen, between December 2022 and May 2023. The participant’s body weight, height, and waist circumference were measured. The data were analyzed using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25.0, Armonk, NY). P values of <0.05 were considered statistically significant. Results: Among the 384 participants, 20.5% had HTN, and the remaining (79.5%) did not have HTN, with a substantial proportion (47.2%) reporting a positive family history of HTN. Diabetes mellitus was present in 16.1% of the participants, whereas dyslipidemia and other chronic diseases were reported by 9.3% and 15.8% of the participants, respectively. A total of 75.6% of the participants had never smoked, and 11.7% were past smokers. More than half of the participants (57.29%) had never chewed khat, 20.57% were former khat chewers, and 22.14% were currently chewing khat. Nutritional status, as indicated by body mass index, showed that 29.8% were overweight. Conclusions: HTN was found to be prevalent among the study participants. However, the respondents’ awareness of the problem and the overall control rates were very low. Certain factors, such as family history of HTN, diabetes mellitus, and high body mass index, were found to be associated with HTN. Therefore, intervention measures are warranted emphasizing modifiable risk factors to prevent HTN.


Introduction
Hypertension (HTN), which is a significant public health issue on a global scale, is the most generally acknowledged modifiable risk factor for cardiovascular disease (CVD), cerebrovascular disease, and endstage renal disease [1,2].Accordingly, the World Health Organization (WHO) has listed HTN as the third highest cause of death globally, accounting for one in eight of all fatalities [3].Along with HTN, abdominal obesity, dyslipidemia, and insulin resistance are also common risk factors for CVD [4].
The impact of the HTN epidemic has been felt by all nations, regardless of economic status.Nearly one billion individuals worldwide have HTN, with two-thirds of them living in low-income countries [5].Approximately 10 million individuals die each year from HTN, which affects an estimated 1.3 billion people globally [6].As a result of multiple factors, including economic growth and population aging, the prevalence of HTN has increased over the past few decades worldwide, even in developing countries [7].The prevalence of HTN in adults can be influenced by variations in study protocols, genetic background, and environmental factors such as food intake and physical activity [8].
A new set of guidelines for the prevention and management of HTN was recently outlined in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7).The JNC-7 report defines normal blood pressure as having a systolic blood pressure (SBP) of <120 mmHg and a diastolic blood pressure (DBP) of <80 mmHg; whereas pre-HTN is defined as having an SBP of 120-139 mmHg or a DBP of 80-90 mmHg [9].HTN is considered present when blood pressure is taken on two different days with systolic and/or diastolic readings both greater than 140 mmHg [10,11].
HTN prevalence varies widely around the world, ranging from 3.4% to 78%, with South Africa having the greatest frequency and rural India having the lowest, according to an analysis of data from six countries [12]; HTN prevalence was reported to be 49.39% in Malaysia.Age, household income, body mass index (BMI), and diabetes are all strongly associated with HTN [13].In Turkey, pre-HTN showed a prevalence of 14.5%, whereas that of HTN was 44.0%.The age range of 60-69 years exhibited the highest prevalence of HTN, which increased with aging.Interestingly, HTN is inversely correlated with the amount of education, current cigarette usage, and physical activity; and positively correlated with marital status, parity, and quitting smoking [14].In Nepal, the prevalence of HTN was 22.4% overall (males: 32.7% and females: 15.3%).HTN prevalence significantly increases with age, as indicated by age-specific frequencies of 8-35% [15].In Ethiopia, the prevalence of HTN was 21.2% among the general population; where age, occupation, wealth status, consuming vegetables and animal fat, BMI family history of HTN, and diabetes were associated with the presence of HTN at 95% confidence intervals (CIs) [16].In a 2013 study in Saudi Arabia, 917,188 (7.1%) Saudis reported a diagnosis of HTN; age, sex, and previous diabetes and high cholesterol diagnoses were linked to HTN [17].
As there has been no recent study conducted and published on adults regarding HTN in Yemen, and because of the different highly associated risk factors that are practiced in the study region, it is very important to use descriptive studies when no previous studies are available.Therefore, in this study, we aim to measure the prevalence of HTN and its associated risk factors among adults attending Ibn Sina General Hospital Authority outpatient clinics in Mukalla City, Yemen.

Study design
This study adopted a cross-sectional descriptive survey design.The study was performed by a group of medical students at Hadhramout University, Mukalla, Yemen.

Study setting and duration
The study was conducted at Ibn Sina General Hospital Authority in Mukalla City, Yemen.Ibn Sina General Hospital Authority is a hospital with a usable area of 37,500 m 2 and a clinical capacity of 300 beds, providing services to the governorates of Hadhramout, Shabwa, and Al-Mahrah, as well as the island of Socotra and some villages of Hadhramout.In general, it is estimated that the hospital provides services to 33% of the total area of the eastern region of Yemen.The study was conducted between December 2022 and May 2023.

Study population
The study population comprised all adults attending Ibn Sina General Hospital Authority outpatient clinics in Mukalla City at the time of data collection.The participants were considered hypertensive when they were documented to have an increase in blood pressure.

Inclusion criteria
The following inclusion criteria were used for the selection of participants: adults attending outpatient clinics in Ibn Sina General Hospital Authority in Mukalla City at the time of the study who were either diagnosed with HTN or not.According to the National Institutes of Health (NIH), an adult is a person ≥18 years of age unless national law delimits an earlier age [18].

Exclusion criteria
Participants were excluded from the study if they met any of the following criteria: attendants who are not considered adults according to the aforementioned NIH definition, those who have intellectual disability, and all patients with severe illnesses, acute life-threatening conditions, or severe injury, including patients with head injuries.

Sample size estimation
The sample size was calculated using the WHO formula for estimating the sample size.The level of certainty was 1.96, the proportion of the characteristics in the population was 50%, and the precision or allowable error was 5%.

Sampling method
Selection of the participants was done by convenience sampling among adults who visited all Ibn Sina General Hospital Authority outpatient clinics (excluding the psychiatry clinic due to insufficient data) during the study period.We chose the number of participants from each clinic by measuring the flow rate per clinic in August, September, and October of the year 2022 to ensure that every outpatient clinic visitor had an equal chance to participate in the study (Table 1).The sample size was distributed proportionally among the 12 available outpatient clinics in Ibn Sina General Hospital Authority according to the number of adults visiting each clinic (i.e., the flow rate in the last three months) (Table 2).The total number of adults attending the outpatient clinics from August to October of 2022 was 7883.

Data collection and tools
A structured questionnaire with close-ended questions was designed by using the WHO STEPwise approach to non-communicable disease risk factor surveillance [19].The questionnaire was developed in English and then translated into Arabic by experts.The questionnaire was designed to have two main parts: part one included questions about socio-demographic information, and part two included questions about risk factors associated with HTN.In addition, a weight scale, a stadiometer, and a measuring tape were used to measure weight, height, and waist circumference, respectively [20].

Data analysis
Data entry and statistical analysis were done using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25.0, Armonk, NY).Data are presented using descriptive statistics in the form of frequencies and percentages.Binary regression was used to find associations between variables.Statistical significance was considered at p<0.05.

Ethical considerations
Everyone who took part in the study provided oral informed consent.The revised Declaration of Helsinki served as the foundation for the present study.In addition, approval for this study was obtained from Hadhramaut University, College of Medicine, Department of Community Medicine (approval number: CM/REC/4/2023), and from the participants.The participants were assured that they would remain anonymous and that their data would remain confidential.

Results
Finally, our cross-sectional study included 384 participants.As shown in   Regarding behavioral risk factors, 75.6% of participants had never smoked, and 57.29% had never chewed khat.Dietary habits showed that 59.6% consumed fruits one to three days per week, and 57.3% consumed vegetables one to three days per week.Most participants (63.8%) perceived their salt intake as adequate (Table 5).

TABLE 5: Behavioral measures of study participants (n=384)
Nutritional status, as indicated by BMI, showed that 10.1% of the participants were underweight, 36.2% had a normal BMI, 29.8% were overweight, 19.2% were classified as having class I obesity, and 4.7% had a BMI exceeding 35.Waist circumference measurements demonstrated that 28.8% of male participants had a waist circumference of <90 cm, whereas 36.2% had a waist circumference of ≥90 cm.Among the female participants, 12.7% had a waist circumference of <80 cm, and 22.3% had a waist circumference of ≥80 cm (Table 6).Based on our results, we found a significant statistical association between the presence of HTN and some variables, whereas others showed no association.For example, increased age, diabetes mellitus, dyslipidemia, history of smoking, and BMIs of 30.0-34.9 showed a statistically significant association with HTN, as their p-values were <0.05.On the other hand, sex, marital status, educational status, employment status, monthly income, family history of HTN, khat chewing status, fruit and vegetable consumption, salt consumption, physical activity, BMIs except 30.0-34.9, and waist circumference did not show a statistically significant association with HTN, as their p-values were >0.05.Therefore, we can say that the association between HTN and some variables was supported by the logistic regression analysis, whereas that of other variables was not supported (Tables 7-10).

Discussion
HTN, as the most common cardiovascular disorder, is now regarded as a major public health problem.Many people may not be aware that they have HTN until they develop complications such as heart attack, stroke, or kidney failure.Therefore, early detection, diagnosis, and management of HTN are critical in preventing or delaying the onset of these complications [21].
As no recent study has identified the prevalence of HTN in Yemen, this study was conducted to identify the magnitude of the problem of HTN among individuals attending medical outpatient clinics, who are likely to have underlying health conditions.By identifying the risk factors associated with HTN, both the public and healthcare providers can develop policies and targeted interventions to prevent or manage HTN effectively [22].In our community-based cross-sectional study, which included 384 individuals aged ≥18 years, HTN had a prevalence of 20.5%, which is lower than prior studies in Nepal (22.4%) [15] and Kurdistan, Iraq (25.3%) [23], and higher than that recently reported in one study of four Sudanese states (Khartoum, Gezira, Blue Nile, and Kassala; 15.9%) [24] and in another hospital-based study conducted in Ethiopia (10.55%) [25].
This study revealed a widespread prevalence of various risk factors among participants.HTN prevalence was significantly higher in males than in females.Similarly, numerous studies have found that more men have HTN than women [26][27][28].One proposed explanation for the gender gap in HTN prevalence is a combination of biological sex differences and behavioral risk factors such as smoking, alcohol use, and physical activity.We hypothesize that abstaining from chewing khat and smoking are two preventive factors against HTN in women.In addition, as women have been found to be more interested in using healthcare services and are more likely to report ill health, they are more likely to have better health [29,30].HTN was more prevalent in subjects aged ≥50 years.Other studies revealed similar findings, in which increased age was positively correlated with HTN [30,14].More than half (56.45%) of the participants with HTN also had diabetes mellitus.Forty-eight of the participants with HTN had a positive family history of HTN, which indicated a strong correlation between the two.Approximately 73.43% of participants with HTN had a BMI of ≥25.
Other studies have also reported a direct relationship between high BMI and an increasing rate of HTN [30,31].Our results did not show a significant association between smoking, khat chewing, and HTN.Our study also revealed that more than half of the participants with HTN did not consume enough fruits and vegetables.
We believe that the findings of our study will contribute to the efforts made to uncover the burden of HTN in our community.One of the strengths of this study is that its topic is not very similar to those of other studies in Mukalla, Yemen, making it of scientific value; furthermore, the participants from each clinic were chosen without any type of bias, the data were collected using a questionnaire, and the sample size was calculated using a specific formula.However, there are certain limitations of this study worth mentioning.First, as this was a cross-sectional study with a relatively small sample size, it is difficult to generalize the findings for the country as a whole.Besides, assessments of behavioral risk factors such as smoking and khat chewing were based on only the history of use of these substances without assessment of the amount and duration of use.As a result, a cause-and-effect relationship could not be established.

Table 3 ,
63.7% of the participants were male, and 36.3% were female.The age distribution was diverse, with 33.6% aged 18-29, 24.4% aged 30-39, 17.1% aged 40-49, and 24.9% aged ≥50.The majority of participants were married (65%).Although the educational level varied, it was clear that the majority (31.3%) of participants were at the primary school level.Employment status was diverse, with 28.8% of participants being government employees and 21.5% being self-employed.The monthly income distribution showed that 39.6% of participants earned <50,000 Yemeni Riyal, and 20.8% earned >100,000 Yemeni Riyal.

TABLE 3 : Socio-demographic characteristics of the study participants (n= 384)
Among the participants, 20.5% had HTN, and 47.2% reported a positive family history of HTN.Diabetes mellitus was present in 16.1% of participants, whereas dyslipidemia and other chronic diseases were present in 9.3% and 15.8% of participants, respectively (Table4).

TABLE 10 : Multivariate analysis of the nutritional data in association with hypertension
*Considered statistically significant; n: number; Ref: reference; OR: odd ratio; CI: confidence interval