Differential associations of cardio-metabolic diseases by population group, gender and adiposity in South Africa.

Aims: To describe the distribution and examine the associations of diabetes, hypertension and hypercholesterolaemia across and within population groups, gender and body mass index (BMI) categories.

Methods: This national cross-sectional study was conducted in 2013 among ≥18-year-old black African, coloured, white and Indian adults self-selected for screening. Data collection included self-reported behavioural risk factors and clinical measurements comprising blood pressure, anthropometry and point-of-care random blood glucose and cholesterol assessments.

Results: Among the 7711 participants, 2488 men and 5223 women, the prevalence of diabetes and hypertension increased by BMI category across population groups. Compared with white men and women, black African men (odds ratio: 2.66, 95% confidence interval: 1.70-4.16) and women (2.10, 1.49-2.96), coloured men (2.28, 1.44-3.60) and women (2.15, 1.52-3.05) and Indian men (4.38, 2.65-7.26) and women (3.64, 2.50-5.32) were significantly more likely to have diabetes. The odds for hypertension were significantly higher only in coloured men compared with white men (1.37, 1.02-1.83), while it was significantly higher in black African, coloured and Indian women compared with white women. The odds for hypercholesterolaemia were significantly lower in black African men (0.64, 0.49-0.84) and women (0.52, 0.43-0.62) compared with white men and women, and significantly higher in Indian men (1.47, 1.05-2.08) compared with white men. Black African women compared with their male counterparts were less likely to have diabetes (0.64, 0.46-0.89). Black African (0.66, 0.54-.082), coloured (0.65, 0.50-0.84) and white (0.69, 0.53-0.88) women were significantly less likely to have hypertension compared with their male counterparts. The odds for hypercholesterolaemia were higher in coloured (1.44, 1.16-1.80) and white (1.47, 1.18-1.84) women compared with their counterparts.

Conclusions: The cardio-metabolic diseases of diabetes, hypertension and hypercholesterolaemia were differentially associated with population groups and gender in South Africa. The insights obtained highlight the need for multi-disciplinary targeted management approaches in high-risk populations.