MANAGEMENT OF DYSLIPIDAEMIA AND HYPERTENSION BY GLYCAEMIC STATUS IN URBAN SOUTH AFRICANS

Abstract

Objective: To describe the prevalence and management of hypertension and dyslipidaemia in adults in Cape Town with 1) known diabetes, and those identified as high-risk for diabetes and subsequently diagnosed with 2) normoglycaemia, or 3) newly diagnosed diabetes, through oral glucose tolerance tests. Design and method: Cross-sectional data collection comprised administered interviews, clinical measurements, and biochemical analyses. Group differences between detection, treatment and control indices were calculated using univariate analyses (median and 25th 75th percentiles, or prevalence and percentage). Multiple logistic regressions described the association with sociodemographic, and cardiovascular risk factors (odds ratios and 95% confidence intervals). Results: This study included 618 participants (82% women) between 49–63 years of age. Known diabetes participants (n = 339) were significantly older and less obese (Body mass index < 30 kg/m2) compared to normoglycaemia (n = 212) or newly diagnosed diabetes (n = 70). Hypertension prevalence was lower in normoglycaemia (66%) and newly diagnosed diabetes (64%) compared to known diabetes (89%) (p < 0.001). Among normoglycaemia, newly diagnosed and known diabetes participants with hypertension, detection was 80%, 89% and 97%, with 60%, 68% and 88% taking medication, while hypertension control was 46%, 44% and 74%, respectively (p < 0.001 for all). Dyslipidaemia prevalence (low-density lipoprotein cholesterol > 3mmol/l or on treatment) was lower in normoglycaemia (43%) compared with newly diagnosed diabetes (74%) and known diabetes (83%) (p < 0.001). Among normoglycaemia, newly diagnosed and known diabetes participants with dyslipidaemia, 36%, 37% and 85% were detected, 22%, 23% and 73% were on lipid lowering treatment, and 14%, 10% and 49% were controlled, respectively (p < 0.001 for all). Regression analysis showed that having a pre-existing diabetes diagnosis was associated with higher odds for being detected, treated, and controlled for dyslipidaemia. However, the odds of attaining hypertension control in those taking medication were higher only in known diabetes who were uncontrolled (HbA1C > 7%). Conclusions: Hypertension and dyslipidaemia prevalence and management were higher in participants with known diabetes compared with their counterparts. Improved screening and management are required for high-risk individuals who were probably not in regular contact with healthcare services.