The burden of hypertension in sub-Saharan Africa: a four-country cross sectional study

Abstract

BackgroundHypertension, the leading single cause of morbidity and mortality worldwide, is a growing public health problem in sub-Saharan Africa (SSA). Few studies have estimated and compared the burden of hypertension across different SSA populations. We conducted a cross-sectional analysis of blood pressure data collected through a cohort study in four SSA countries, to estimate the prevalence of pre-hypertension, the prevalence of hypertension, and to identify the factors associated with hypertension.MethodsParticipants were from five different population groups defined by occupation and degree of urbanization, including rural and peri-urban residents in Uganda, school teachers in South Africa and Tanzania, and nurses in Nigeria. We used a standardized questionnaire to collect data on demographic and behavioral characteristics, injuries, and history of diagnoses of chronic diseases and mental health. We also made physical measurements (weight, height and blood pressure), as well as biochemical measurements; which followed standardized protocols across the country sites. Modified Poison regression modelling was used to estimate prevalence ratios (PR) as measures of association between potential risk factors and hypertension.ResultsThe overall age-standardized prevalence of hypertension among the 1216 participants was 25.9 %. Prevalence was highest among nurses with an age-standardized prevalence (ASP) of 25.8 %, followed by school teachers (ASP = 23.2 %), peri-urban residents (ASP = 20.5 %) and lowest among rural residents (ASP = 8.7 %). Only 50.0 % of participants with hypertension were aware of their raised blood pressure. The overall age-standardized prevalence of pre-hypertension was 21.0 %. Factors found to be associated with hypertension were: population group, older age, higher body mass index, higher fasting plasma glucose level, lower level of education, and tobacco use.ConclusionsThe prevalence of hypertension and pre-hypertension are high, and differ by population group defined by occupation and degree of urbanization. Only half of the populations with hypertension are aware of their hypertension, indicating a high burden of undiagnosed and un-controlled high blood pressure in these populations.

Physical Activity and Associated Socioeconomic Determinants in Rural and Urban Tanzania: Results from the 2012 WHO-STEPS Survey

“…The observed differences in PA status in rural and urban settings have also been reported previously and reflect the rural-urban differences in NCDs prevalence [27][28][29]. Different studies conducted in Africa have consistently reported higher prevalence of diabetes, hypertension, and cardiovascular risk factors in urban compared to rural settings [27][28][29]. In addition, we observed a negative linear relationship between PA levels and a number of cardio metabolic risk factors including high blood pressure.…”

“…This could render GPAQ less appropriate for in between groups' evaluation, meaning that some of the comparisons between groups have been interpreted with caution. Despite these limitations, studies employing different PA questionnaires and/or objective PA assessment have reported similar trends of PA [27][28][29]. This means that while the observations presented in the current study require further verification, the overall PA status reported reflects the real situation.…”

Determinants of high blood pressure and barriers to diagnosis and treatment in Dar es Salaam, Tanzania

“…The proportion of participants in DUCS-HTN that sought care, took treatment, and had their hypertension controlled, although low, is higher than what previous studies had found in Dar es Salaam [7,9,10] and other sub-Saharan African cities [11]. This may be because awareness has increased over time in Africa: from 17% in 1990 to 34% in 2010 [28].…”

“…Two repeated cross-sectional population surveys conducted in Dar es Salaam in 1987 and 1998 showed an increase in hypertension prevalence from 33% to 63% in men and from 48% to 62% in women [6]. Other cross-sectional surveys in the same city have found varying prevalences, from 29–30% in 1996 to 19–43% around 2010 [7–10]. …”

Biochemical parameters as indicators of antihypertensive efficacy of leaf aqueous extract of Tridax procumbens (Lin) in L-NAME induced hypertensive rats

“…The major risk factors include diabetes, smoking, and dyslipidemia [2]. Several studies acknowledged that hypertension is the most prevalent trigger for CVDs with other risk factors [1,3].…”