1. ¹School for Physiology, Nutrition and Consumer Sciences, North-West University, Potchefstroom, South Africa
2. ²Department of Internal Medicine III, Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
3. ³School of Biokinetics, Recreation and Sport Science, North-West University, Potchefstroom, South Africa
4. ⁴Centre for Genome Research (CGR), North-West University (Potchefstroom Campus), Pretoria, South Africa
5. ⁵DNAbiotec (Pty) Ltd., Pretoria, South Africa

Correspondence: Professor AE Schutte, School for Physiology, Nutrition and Consumer Sciences, North-West University (Potchefstroom Campus), Hoffman Street, Private Bag X6001, Potchefstroom 2520, South Africa. E-mail: alta.schutte@nwu.ac.za

Received 22 February 2008; Revised 14 March 2008; Accepted 16 March 2008; Published online 24 April 2008.

Abstract

Hypertension is highly prevalent in South Africa, resulting in high stroke mortality rates. Since obesity is very common among South African women, it is likely that obesity contributes to the hypertension prevalence. The aims were to determine whether black African women have higher blood pressures (BPs) than Caucasian women, and whether obesity is related to their cardiovascular risk. African (N=102) and Caucasian (N=115) women, matched for age and body mass index, were included. Correlations between obesity (total body fat, abdominal obesity and peripheral fat) and cardiovascular risk markers (haemodynamic parameters, lipids, inflammatory markers, prothrombotic factors, adipokines, HOMA-IR (homoeostasis model assessment insulin resistance)) were compared between the ethnic groups (adjusted for age, smoking, alcohol and physical activity). Comparisons between low- and high-BP groups were also made for each ethnic group. Results showed that African women had higher BP (P<0.01) with increased peripheral vascular resistance. Surprisingly, African women showed significantly weaker correlations between obesity measures and cardiovascular risk markers when compared to Caucasian women (specifically systolic BP, arterial resistance, cardiac output, fibrinogen, plasminogen activator inhibitor-1, leptin and resistin). Interestingly, the latter risk markers were also not significantly different between low- and high-BP African groups. African women, however, presented significant correlations of obesity with triglycerides, C-reactive protein and HOMA that were comparable to the Caucasian women. Although urban African women have higher BP than Caucasians, their obesity levels are weakly related to traditional cardiovascular risk factors compared to Caucasian women. The results, however, suggest a link with the development of insulin resistance.