Associations of anaemia with blood pressure in women of reproductive age: a cross-sectional study in Johannesburg, South Africa.

Introduction: South Africa has approximately 8.45 million adults living with human immunodeficiency virus (HIV) with women being higher at risk. Anaemia is proportional to HIV severity and a predictor for cardiovascular disease. In this study, we aimed to determine associations between anaemia, HIV, and blood pressure among women of childbearing age in Roodepoort, a suburb within the city of Johannesburg.

Methods: in this cross-sectional study premenopausal women were recruited from a primary healthcare facility, Johannesburg. Socio-demographics, lifestyle behaviours, and medical history, including HIV status, were collected. Anthropometrical measurements and blood pressure (BP) were obtained, and venous blood was drawn to determine hemoglobin (Hb) concentration. Multiple and logistic regression analyses were performed to determine the association between hemoglobin (Hb), HIV and blood pressure (BP).

Results: of 228 women, 72% were pregnant and 22% HIV positive. Pregnant women had lower BP (SPB: 104 ± 11 vs 115 ± 11 mmHg, p<0.001; diastolic BP (DBP): 68 ± 8 vs 80±10 mmHg, p<0.001) compared to non-pregnant women. Hb levels were lower among HIV positive compared to HIV negative participants (11.4 ± 1.6 vs 12.1 ± 1.4 g/dL, p=0.010). More HIV positive women were classified as anaemic (37% vs 16%, p=0.003). In unadjusted multiple linear models, Hb concentration was associated with systolic blood pressure (SBP) (β 1.20 (95% CI, 0.28, 2.33), p=0.013) and DBP (β 1.94 (95% CI, 1.08,2.80) p<0.001), and in unadjusted logistic regression models, women with anaemia had increased odds for hypertension (OR 1.18 (95% CI, 1.20, 2.80), p=0.006). However, in both cases, significance was lost when adjusting for covariates.

Conclusion: the results suggest anaemia may be a risk factor for hypertension and should be investigated in larger, homogenous samples.