Abstract 11443: Gradients in High-Density Lipoprotein Levels in Urban Africans Presenting with Communicable Versus Non-Communicable Forms of Heart Disease: The Heart of Soweto Study
Background: We have recently shown that the urban enclave of Soweto, South Africa is at the crossroads between communicable (CD) and non-communicable (NCD) forms of heart disease. We hypothesised that patients with CD would display low levels of athero-protective high-density lipoprotein (HDL).
Methods: A clinical registry captured detailed clinical data on all de novo cases of heart disease presenting to the Cardiology Unit of the Baragwanath Hospital in Soweto during 2006-2008. Overall, 1199 patients of African descent (59% female; mean ± SD age 58±14 years) had fasting blood lipid levels (HDL, total cholesterol [TC] and low density lipoprotein [LDL]) documented. Lipid profiles were then compared according to pre-specified coding of cases according to the presence of NCD (e.g. hypertensive heart disease) versus CD (active or latent infection, e.g. chronic rheumatic heart disease or HIV-related cardiomyopathy).
Results: There was a significant age gradient (p<0.001) according to the presence of NCD (n=681, 57%, 60.1±13.1 years), latent CD (n=440, 37%, 57.5±14.6 years) versus active CD (n=78, 7%, 46.5±13.4 years). Similarly, there were parallel gradients in HDL (1.2±0.5 vs. 1.0±0.5 vs. 0.8±0.5 mmol/L); TC (4.3±1.3 vs. 3.7±1.3 vs. 3.4±1.2 mmol/L); and LDL (2.5± 1.0 vs. 2.2±0.9 vs. 2.1±0.9 mmol/L) in those with NCD, latent CD and active CD, respectively; p<0.001 for all comparisons. Using NCEP ATPIII cut-offs for low HDL (<1.29 mmol/L HDL in women; <1.03mmol/L in men), overall, 57%, 72% and 86% of patients with NCD, latent CD and active CD, respectively, had low HDL levels (p<0.001). Adjusting for the age and sex of patients (and in a separate model body mass index), those with latent CD (OR 1.83, 95%CI 1.41 to 2.39) and active forms of CD (OR 3.34, 95%CI 1.70 to 6.57) were significantly more likely to record a low HDL relative to those presenting with a NCD.
Conclusions: Despite largely favorable lipid profiles among urban African patients presenting with de novo heart disease in Soweto, there are clear gradients according to aetiology of underlying disease. Those with active forms of CD have particularly low levels of HDL relative to those with NCD. This phenomenon may leave relatively young Africans at increased risk of atherosclerotic heart disease in the future.
- © 2011 by American Heart Association, Inc.