Research

Increase in blood pressure over a 7-year period in a mixed-ancestry South African population

S F G Davids, T E Matsha, N Peer, R T Erasmus, A P Kengne

Abstract


Background. An increase in the prevalence of high blood pressure (BP) has been reported globally and in the South African (SA) population.

Objectives. To investigate temporal changes in absolute BP levels and hypertension prevalence in the mixed-ancestry South Africans.

Methods. Participants were from two independent cross-sectional surveys conducted during 2008/09 (N=928) and 2014/16 (N=1 969) in Bellville South, Cape Town, SA. Participants’ eligibility was based on several criteria, including age >20 years and neither bedridden nor pregnant. Data were obtained by administered questionnaires, clinical measurements (BP and anthropometry) and biochemical assessments (oral glucose tolerance tests and cotinine levels). Known hypertension was based on a self-reported history of doctor-diagnosed hypertension and ongoing treatment. Comparison across years was based on the crude prevalence of hypertension as well as direct age-standardised prevalence, based on the SA 2011 mixed-ancestry population distribution, in 10-year age increments.

Results. In all, 708 participants (76.3%) in 2008/09 and 1 488 (75.6%) in 2014/16 were female. Between 2008/09 and 2014/16, mean systolic BP increased from 124 to 136 mmHg (absolute mean difference 15 mmHg) and mean diastolic BP from 75 to 85 mmHg (absolute mean difference 9 mmHg) in the overall sample. The prevalence of screen-detected hypertension increased from 11.6% to 24.8%, with a similar increase in males and females, while the prevalence of known cases remained stable. These changes remained significant after adjustment for age and gender.

Conclusions. A rightward shift in absolute BP translated into a significant increase in the prevalence of hypertension over time in this population. The predominant increases in screen-detected hypertension suggest that the deteriorating profile was not matched by efforts to detect and manage individuals with higher-than-optimal BP levels.

 


Authors' affiliations

S F G Davids, Department of Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; South African Medical Research Council/Cape Peninsula University of Technology Cardiometabolic Health Research Unit, Department of Biomedical Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town, South Africa

T E Matsha, South African Medical Research Council/Cape Peninsula University of Technology Cardiometabolic Health Research Unit, Department of Biomedical Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town, South Africa

N Peer, Department of Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa

R T Erasmus, Department of Chemical Pathology, National Health Laboratory Service and Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa

A P Kengne, Department of Medicine, Faculty of Health Sciences, University of Cape Town, South Africa; Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa

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Keywords

Blood pressure; Hypertension; Screen-detected hypertension; Age; Mixed ancestry; South Africa

Cite this article

South African Medical Journal 2019;109(7):503-510. DOI:10.7196/SAMJ.2019.v109i7.13663

Article History

Date submitted: 2019-06-28
Date published: 2019-06-28

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