Regional and Sex Differences in the Prevalence and Awareness of Hypertension: An H3Africa AWI-Gen Study Across 6 Sites in Sub-Saharan Africa

Abstract

Background There is a high prevalence of hypertension and related cardiovascular diseases in sub-Saharan Africa yet few large studies exploring hypertension in Africa are available. The actual burden of disease is poorly understood and awareness and treatment to control it is often suboptimal. Objectives To report the prevalence of measured hypertension and to assess awareness and control of blood pressure among older adults in rural and urban settings in six sites located in west, east and southern Africa. In addition, we examined regional, sex, and age differences related to hypertension. Methods A population-based cross-sectional study was performed at six sites in four African countries - Burkina Faso (Nanoro), Ghana (Navrongo), Kenya (Nairobi) and South Africa (Agincourt, Dikgale, Soweto). Blood pressure measurements were taken using standardized procedures on 10,696 adults aged 40 to 60 years. Hypertension was defined as SBP ≥ 140mm Hg and/or DBP ≥ 90 mm Hg or taking anti-hypertensive medication. Results The mean prevalence of hypertension ranged from 15.1% in Nanoro to 54.1% in Soweto. All three of the South African sites had a mean prevalence of hypertension of over 40.0%, significantly higher than Nairobi (25.6%) and Navrongo (24.5%). Prevalence increased with age in both sexes and at all sites. A significantly higher prevalence of hypertension was observed in women in Agincourt, Dikgale and Nairobi, while in Nanoro this trend was reversed. Within the hypertensive group the average proportion of participants who were aware of their blood pressure status was only 39.4% for men and 53.8% for women, and varied widely across sites. Conclusions Our study demonstrates that the prevalence of hypertension and the level of disease awareness differ not only between but also within sub-Saharan African countries. Each nation must tailor their regional hypertension awareness and screening programs to match the characteristics of their local populations.

Determinants of body mass index by gender in the Dikgale Health and Demographic Surveillance System site, South Africa

“…Data on socio-demographic-, behavioural- and biological factors were collected via the translated (Se-Pedi) and pilot-tested paper questionnaire by trained field workers, and captured into REDCap, a secure web-based application [24]. Approximately 10% of all data entries were checked for accuracy as described in detail elsewhere [26]. …”

Prevalence and health effects of communicable and non‐communicable disease comorbidity in rural KwaZulu‐Natal, South Africa

“…This number is thought to be an underestimate . A recent study across six sites in sub‐Saharan Africa found that despite South Africa having the highest blood pressure, 60% of men and 46% of women with hypertension in South Africa were unaware of it . Despite evidence of the increasing prevalence of multimorbidity in sub‐Saharan Africa, evidence of its impact on quality of life and hospitalisation is scarce .…”

Genomic and environmental risk factors for cardiometabolic diseases in Africa: methods used for Phase 1 of the AWI-Gen population cross-sectional study

“…The importance of the baseline data generated from this study has been demonstrated in several recent publications, including the identification of regional and sex differences in the prevalence of hypertension across SSA [60], and the six papers on BMI distribution in this special edition of Global Health Action [67–72]. Manuscripts discussing the prevalence of diabetes, body composition and obesity, dyslipidemia, kidney disease, and smoking and alcohol consumption are currently in preparation.…”

“…As such, hypertension was defined as the presentation of one or more of the following conditions: previous diagnosis by a healthcare provider (which excluded cases of hypertension during pregnancy), taking medication for the condition, systolic blood pressure greater than 140 mm Hg and/or diastolic blood pressure greater than 90 mm Hg at the time of the study visit [60]. …”