Abstract

Background. Hypertension is the main contributor to the morbidity and mortality of patients with cardiovascular disease. Even though hypertension is very common in comorbid type 2 diabetic patients, it is frequently overlooked. This study aimed to assess blood pressure control and its associated factors among hypertension comorbid type 2 diabetic patients in Bale Zone public hospitals in Southeast Ethiopia. Methods and Materials. A hospital-based cross-sectional study design was conducted among hypertension comorbid type 2 diabetic patients. The data were collected using an interviewer-administered structured questionnaire and a review of the medical charts of patients. A simple random sampling technique was used to select the study participants. The bivariate and multivariate logistic regression analyses were performed to assess the association between blood pressure control and its associated factors. Independent variables that showed a in the bivariate analysis was included in the multivariate analysis. Finally, variables with a were declared statistically significant factors. Results. The total number of participants in the study was 378. The overall magnitude of uncontrolled hypertension among hypertension comorbid diabetic patients was found to be 82.5% (95% CI: 78.7%, 86.4%). Nonadherence to antihypertensive medication (AOR = 2.45, 95% CI: 1.11, 5.39, ), duration of hypertension >10 years (AOR = 5.2, 95% CI: 1.27, 21.38, ), participants who attended secondary education (AOR = 3.2, 95% CI: 1.18, 8.87, ), and being obese (AOR = 4.1, 95% CI: 1.24, 13.49, ) were significantly associated with uncontrolled hypertension. Conclusion. Uncontrolled hypertension was found to be high among hypertension comorbid type 2 diabetic patients. Patients’ adherence to antihypertensive medication, physical activity, and alcohol abstinence should be maximized. Loss of weight is also crucial, as is the early detection and management of comorbidities.

1. Background

Hypertension is a major global health concern and a major preventable risk factor for cardiovascular events that affects over one billion people worldwide [1, 2]. Hypertension, in particular, is responsible for nearly 45% of heart disease deaths and 51% of stroke deaths [3]. On a global scale, nearly 40% of adults aged 25 and older were estimated to have hypertension [3]. The global prevalence of hypertension ranges from 4% to 78% [4]. Hypertension is still an important public health problem; it will increase to 1.56 billion globally by 2025 [5].

According to the 2014-JNC-8 hypertension guideline, uncontrolled hypertension is defined as blood pressure greater than or equal to 140/90 mmHg [1, 6]. Hence, the hypertension level at which the availability of therapy reduces morbidity and mortality associated with hypertension is demonstrated in people aged 18 and older [7].

More than 80% of deaths from hypertension and related cardiovascular diseases occur in low- and middle-income countries, and people with low socioeconomic status are more likely to suffer from the problem [5]. Hypertension can occur together with other cardiometabolic conditions, namely, diabetes, stroke, dyslipidemia, insulin resistance, glucose intolerance, and obesity [4, 6]. Between 20 and 60% of individuals with type 2 DM will have concomitant uncontrolled hypertension [8]. Africa had the highest prevalence of hypertension among the WHO regions, at 46% for all adults combined in 2019 [9]. Unfortunately, if hypertension is not controlled, it can lead to blindness, myocardial infarction, dementia, cardiac failure, and stroke [5, 10, 11]. It is predicted to be responsible for 7.5 million deaths or about 12.8% of all deaths in sub-Saharan Africa each year [1214].

Hypertension has rapidly increased in prevalence, affecting a large number of people in sub-Saharan Africa [11]. In sub-Saharan Africa, the prevalence ranges from 25.4% to 41.1% in men and 27.2% to 38.7% in women [15]. Hyperinsulinemia, extracellular fluid volume expansion, and increased arterial stiffness have also been proposed as contributing factors for the development of hypertension in diabetic patients; diabetes roughly doubles the risk of cardiovascular disease, and concurrent hypertension nearly doubles that risk again [16].

Based on the evidence provided by clinical trials, guidelines recommend that patients who have been diagnosed with cardiovascular disease and its equivalents should reduce their blood pressure to <140/90 mmHg (so do hypertension comorbid type 2 diabetic patients) [17].

Chronic noncommunicable diseases (NCDs) are becoming more prevalent in Ethiopia, creating a double burden on the population. Population-based studies showed a high prevalence of NCDs in both rural and urban settings, including hypertension, other cardiovascular diseases, and diabetes [18, 19]. However, the Ethiopian health system is primarily focused on communicable disease prevention and control, with little emphasis on noncommunicable diseases (NCDs) such as hypertension and diabetes [20].

The reported prevalence of hypertension in various Ethiopian regions varied significantly [4, 21]. Uncontrolled hypertension ranges from 11.4 to 69.9% among hypertensive patients on treatment in Ethiopia [2224]. This may increase if the patient has type 2 diabetes; other studies have revealed that in Ethiopia, the prevalence of uncontrolled hypertension among adults increased alarmingly from 9.3% in 2011 to 23.5% in 2015 [2527]. Only about 28.4% of patients were taking an antihypertensive drug [27]. In Ethiopia, 97% of hypertensive patients do not receive the proper preventive care or treatment; only 2.8% of them receive treatment, and only 1.5% have their hypertension under control [28, 29]. There are currently only a few published articles in Ethiopia that assess uncontrolled blood pressure in hypertension comorbid type 2 diabetic patients. As a result, the study aimed to assess blood pressure control and its associated factors among hypertension comorbid type 2 diabetic patients in Southeast Ethiopia.

2. Methods and Materials

2.1. Study Area, Period, and Setting

A study was conducted in public hospitals in the Bale Zone of Southeast Ethiopia. It is approximately 403 kilometers from Addis Ababa, the country’s capital. During the data collection period, there were three hospitals in the Bale Zone: Goba Referral Hospital and two general hospitals (Dellomena General Hospital and Robe General Hospital). Approximately 3,308 adult HIV/AIDS patients registered for ART follow-up in public hospitals between February 19 and April 30, 2020/2021. A hospital-based cross-sectional study design was conducted among hypertension comorbid type 2 diabetic patients from February 19 to April 30, 2020. Three public hospitals serving a catchment area of about 3 million people each provided care for more than 25,000 inpatients and 90,000 outpatients annually. The study included all adults with co-existing type 2 diabetes and adult hypertension who were 18 years of age or older, received antihypertensive medication for at least 6 months prior to the study period, and were being monitored.

2.2. Sample Size and Sampling Procedures

The sample size was calculated using a single population proportion formula, assuming a 95% confidence interval (CI), a prevalence of 56.5% for uncontrolled hypertension taken from a study conducted at Jimma University Medical Center [30], a 5% margin of error, a 1.5 design effect, and a 10% nonresponse rate. The final sample size was 405, and a simple random sampling technique was used to select the study participants from the chronic disease follow-up clinic registration book, which consists of lists of 700 hypertension comorbid type 2 diabetic patients in both randomly selected hospitals (Robe General Hospital and Goba Referral Hospital).

2.3. Data Collection, Procedure, and Quality Control

Data were collected using a structured questionnaire adapted from the WHO’s step-wise approach to sociodemographic profile, behavioral and physical measurements, risk factors, and chronic disease surveillance [31]. Blood pressure (BP) was measured by using a digital mercury sphygmomanometer on the upper arm in a sitting position with back support after study participants rested for at least 5 minutes. A measurement was made after ensuring that respondents had rested from vigorous work or exercise, avoided smoking, and not consumed caffeine and alcohol for the last 30 minutes; otherwise, the BP measurement was postponed for 30 minutes. The respondent was told to sit relaxed without crossing legs and to stop talking. Two consecutive measurements were made in the left arm with the respondents in the same position, with an interval of at least 10 minutes. The average systolic and diastolic blood pressures were determined after taking the two measurements and recorded. Height and weight were measured with subjects standing with bare feet and wearing light clothes. The weight was measured using a well-calibrated digital weighing scale. The height was measured using a portable stadiometer, which was considered anthropometric with a simple triangular headboard. In taking the height of the respondent, the adult was made to stand straight with his or her shoe off and head erected such that the external auditory meatus and the lower border of the eye were in one horizontal plane (Frankfurt plane). Height was recorded to the nearest 0.5 cm and weight to the nearest 100 gm. Medication adherence of the study participants was assessed using the Morisky Medication Adherence Scale (MMAS-8) which has eight items and from this, individuals who scored six and greater than six were adherent to antihypertensive drug [32]. Physical activity level is classified into moderate and vigorous physical activity. An activity that involves walking briskly, bicycling, swimming for recreation, dancing, or mowing for at least 30 minutes for at least 5 days per week was considered as moderate physical activity, whereas an activity that involves running, fast swimming, fast cycling, or carrying/moving heavy loads greater than 20 kg for at least 10 minutes continuously was considered as vigorous physical activity [33]. WHO recommends a reduction to <2 g/day salt intake to help reduce blood pressure in adults with hypertension (strong recommendation). Hence, we have used teaspoons to categorize the level of salt intake [34].

The questionnaire was prepared in English and then translated into the local language (Afaan Oromo). Data were collected by four trained nurses who speak and write the local language; patients’ medical charts and medical records were reviewed after all data collection tools were pretested before actual data collection time; and corrections were made. The data were checked for completeness and accuracy, cleared, and coded before being exported to SPSS for analysis.

2.4. Data Processing and Analysis

The collected data were entered into EpiData version 3.1 and exported to the Statistical Package for Social Sciences (SPSS) version 21.0 for analysis. Categorical and continuous data were analyzed using descriptive statistics such as frequency, percentages, median, mean, and standard deviation, which were calculated as study variables to describe the result of the study. The bivariable and multivariable binary logistic regression analyses were performed to assess the association between dependent and independent variables using the crude odds ratio (OR) and adjusted odds ratio (AOR). Confounders who were theoretically significant, regardless of their value, and variables with a value of less than 0.25 in a bivariable analysis were included in the multivariable model to control for confounders. Model fitness was checked using the Hosmer–Lemeshow test. Finally, the variables that showed were considered statistically significant.

3. Results

Of the total sample, 378 (93.3%) individuals participated in the study. Of the 378 study participants, 211 (55.8%) were male. The median age of the respondents was 47 years, 171 (45.2%) were >50 years old, and 307 (81.2%) were married. Of the 378 study participants, 165 (43.7%) were Muslim religion followers and 210 (55.6%) were Oromo in ethnicity (Table 1).

3.1. Clinical Characteristics of Participants

The clinical characteristics of patients showed that 202 (53.4%) study participants had a family history of hypertension and 183 (48.4%) had a family history of diabetes. Of the study participants, 197 (52.1%) and 198 (52.4%) patients were living with hypertension and diabetes for less than five years, respectively. The mean and standard deviation (mean ± SD) for the duration of hypertension were 6.65 years ± 4.61 years with a range of 1–23 years (Table 2).

3.2. Behavioral and Dietary Characteristics of Study Participants

Of the 378 study participants, 122 (32.3%) were alcohol drinkers, 61 (16.1%) were cigarette smokers, and 59 (15.6%) were daily current smokers; 51 (13.5%) had eaten high-calorie food (burger, pizza, and kukis), and about 272 (72%) had eaten animal sources of fatty flesh meat, with regard to physical exercise; only 43 (11.4%) study participants reported that they had been involved in vigorous intensive physical activity, and 208 (55%) were using less than one teaspoon of salt per day. Almost all study participants practiced unhealthy diets or high-calorie foods (Table 3).

3.3. Antihypertensive and Hypoglycemic Medications

The overall utilization of antihypertensive drugs showed that 230 (60.85%) patients were on dual antihypertensive treatment. Most of the patients, about 113 (29.89%), were on a combination of enalapril and amlodipine, followed by hydrochlorothiazide and enalapril (73 (19.31%)). About 7.41% of patients were taking triple antihypertensive drugs (Table 4).

3.4. The Magnitude of Uncontrolled Blood Pressure among Hypertensive Diabetic Patients

The mean and standard deviation (mean ± SD) of systolic blood pressure (SBP) were 142.35 ± 17.82, while the mean and standard deviation (mean ± SD) of diastolic blood pressure (DBP) were 87.58 ± 4.38. Of the 378 study participants, about 269 (71.2%) had an uncontrolled SBP, whereas about 39.2% had a controlled DBP. Overall uncontrolled hypertension was observed in 312 (82.5%) (95% CI: 78.7%, 86.4%) study participants (Figure 1).

3.5. Factors Associated with Uncontrolled Hypertension among Hypertensive Diabetic Patients

Factors associated with uncontrolled hypertension were examined using bivariable and multivariable binary logistic regression methods. In bivariable binary logistic regression analysis, age, educational level, occupation, duration with hypertension (HTN), duration with diabetes (DM), body mass index, comorbidities, and medication adherence risk factors showed associations with uncontrolled hypertension. Finally, the multivariable binary logistic regression technique was used for further analysis, and the level of education, body mass index, adherence level to antihypertensive drugs, and duration of hypertension with a duration greater than 10 years were significantly associated with uncontrolled hypertension (Table 5).

4. Discussion

According to our study, 82.5% of hypertensive diabetic patients had uncontrolled hypertension. Body mass index, duration of hypertension, and nonadherence to antihypertensive medication were all linked to uncontrolled hypertension.

In this study, the prevalence of hypertension was found to be 82.5%, which was higher than in previous studies at Jimma University Medical Center (56.49%) [30], Debre Tabor General Hospital (59.5%) [35], Morocco (70.4%) [36], a national diabetes center in Jordan (72.4%), Greece (55.6%) [37], and the USA (49.8%) [38]. This disparity in uncontrolled hypertension may be due to an increase in systolic and diastolic blood pressure with age. The majority of patients in this study were over the age of 50, which could have a negative impact on hypertension control as age increased [35, 39] and as patient being comorbid with type 2 diabets hinders hypertension control [30].

However, studies conducted in Canada at the Maritime Provinces among type 2 diabetic patients indicated the magnitude of uncontrolled hypertension were (78.7%) [40], in rural South Africa (75.5%) [41], Iraq (89.6%) [42], and Afro-Caribbean individuals living in the United Kingdom (82%) [43] had comparable levels of uncontrolled hypertension to those in the current study; this could be due to the presence of related comorbidities [16] as well as how patients adhere to their antihypertensive treatment plan.

According to the current study, patients who did not take their antihypertensive medication as prescribed were twice as likely to have uncontrolled hypertension as their counterparts (AOR 2.45, ). The finding is in line with the results obtained from studies from Jimma University Medical Center [30], South Africa [44], Ayder Comprehensive Specialized Hospital Tigray, Northern Ethiopia [45], the USA [38], and Nigeria [46]. This could have suggested that for hypertension comorbid type 2 diabetic patients, treatment compliance with antihypertensive medications is crucial to achieving target blood pressure levels [30]. Based on the findings of this study, patients were advised and encouraged to stick to their antihypertensive treatment, which is critical for achieving the recommended target blood pressure level (140/90 mmHg), especially in patients requiring intensive hypertension control, like comorbid diabetes.

This study found that patients with a history of hypertension for more than ten years were five times (AOR = 5.2, ) more likely to have uncontrolled hypertension than those without a history of hypertension. This is supported by research from Jimma University Medical Center [30] and Tikur Anbessa General Specialized Hospital [23]; finding that diabetes and hypertension are common risk factors reported in other studies in other countries, the risk of hypertension increased as DM patients got older, which showed the risk of uncontrolled hypertension increased as diabetic patients ages increased [18].

In this study, body mass index (BMI) was also significantly associated with uncontrolled hypertension (AOR = 4.09). Participants in the study with a BMI of 30 kg/m2 were four times more likely to develop uncontrolled hypertension than those with a normal BMI. Similarly, obesity or being overweight increases the risk of developing hypertension. Several studies reveal that obesity is now emerging as a factor even in the poor population of developing countries [18, 45, 47].

4.1. Limitation of the Study

This study aimed to examine the determinants of uncontrolled hypertension in a study area with no prior evidence of the distribution and associated risk factors. Although the study used primary data on the magnitude of uncontrolled hypertension, medication adherence, and dietary assessments with trained data collectors and supervisors, the findings must be interpreted in light of the following limitations: first, due to the cross-sectional nature of the study, a cause-and-effect relationship cannot be established between the risk factors and uncontrolled hypertension; second, participants were assessed using self-reported surveys of adherence to drugs, cigarette smoking, and alcohol drinking, which might be liable to social desirability bias; and third, as it is hospital-based, the finding may not be generalizable to the total population. Due to the silent nature of the cases, future studies could use more objective measurements and qualitative studies to further explore factors related to behavioral aspects of hypertension and diabetes.

5. Conclusion

In this study, the magnitude of uncontrolled hypertension was found to be high among hypertension comorbid type 2 diabetic patients in Bale Zone public hospitals. The findings of this study call for local and national strategies, and more actions should be targeted for this group of patients to achieve target levels of blood pressure among hypertensive diabetic patients.

Abbreviations

AOR:Adjusted odds ratio
ART:Antiretroviral therapy
BMI:Body mass index
COR:Crude odds ratio
DM:Diabetes mellitus
NCDs:Noncommunicable disease
SPSS:Statistical Package for Social Sciences.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon reasonable request.

Ethical Approval

This research was carried out in accordance with the principles of the Helsinki Declaration. An ethical approval letter was obtained from the Institutional Review Board (IRB) of Hawassa University College of Medicine and Health Sciences with ethical approval number IRB/062/12. Patients’ participation in this study was completely voluntary and confidential. Individual information such as name and address was coded and protected.

Each study participant was asked to sign a written informed consent before data collection, and for those unable to read and write, parents or legal guardians had been requested for consent, and accordingly, informed consent was obtained from their parents or legal guardians.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Authors’ Contributions

FD conceptualized the study; curated the data; involved in formal analysis; acquired funding; investigated the data; designed the methodology; administered the project; provided resources; provided software; supervised the study; validated the data; visualized the data; wrote the original draft; and wrote, reviewed, and edited the manuscript. SM conceptualized the study; involved in formal analysis; designed the methodology; validated the data; visualized the data; and wrote, reviewed, and edited the manuscript. FB validated the data; visualized the data; wrote, reviewed, and edited the manuscript; provided resources; provided software; and supervised the study. DW conceptualized the study; involved in formal analysis; designed the methodology; validated the data; visualized the data; and wrote, reviewed, and edited the manuscript. YT validated the data; visualized the data; wrote, reviewed, and edited the manuscript; provided resources; provided software; and supervised the study. DZ validated the data; visualized the data; wrote, reviewed, and edited the manuscript; provided resources; provided software; and supervised the study. BS validated the data; visualized the data; wrote, reviewed, and edited the manuscript; provided resources; provided software; and supervised the study. DH validated the data; visualized the data; wrote, reviewed, and edited the manuscript; provided resources; provided software; and supervised the study.

Acknowledgments

We are thankful to the data collectors and chronic follow-up staff for their valuable contribution to managing the data of this study. We extend our thanks to the study participants for agreeing and participating in this study. This research was funded by Hawassa University.