Iron status and cardiovascular disease risk in black South African women: the PURE study

ABSTRACT

Objective: To examine the associations between measures of iron status and cardiovascular disease (CVD) risk factors in South African women.Method: In a cross-sectional study; demographic information and health history were obtained during individual interviews using validated questionnaires in the North West Province; South Africa. Anthropometric indices; iron indices; blood pressure; blood glucose and lipid profiles were measured using standard procedures in 1 262 apparently healthy black South African women aged 35 years or older. Iron status was assessed using serum concentrations of ferritin; transferrin receptor (TfR) and TfRferritin ratio.Results: Associations between iron status parameters and CVD risk factors were generally weak (r 0.3; p 0.01) and were not retained when adjustment was made for age; body mass index; smoking; alcohol consumption and C-reactive protein in the analysis. Waist circumference (WC) and waisthip ratio (WHR) were higher in the fourth quartile of serum ferritin than in the third quartile; and also in the third quartile compared to the second quartile (P 0.05). Based on WC and WHR respectively; 31 and 52of the women had excess abdominal obesity. The mean (95 confidence interval) serum TfR concentration was high; at 9.09 ?g/ml (8.77; 9.44); indicating risk of iron deficiency. The mean (95 confidence interval) concentrations of lipids [total cholesterol 4.78 mmol/l (4.64; 4.93); high-density lipoprotein cholesterol 1.45 mmol/l (1.39; 1.52); low-density lipoprotein cholesterol 1.65 mmol/l (1.53; 1.78); triglyceride 1.12 mmol/l (1.07; 1.18)] were within reference ranges.Conclusion: No significant association was found between iron status parameters and established CVD risk factors. However; excessive abdominal adiposity indicated by high WC and WHR contributes significantly to increased serum ferritin concentration in this population