Blood glutathione and subclinical atherosclerosis in African men: the SABPA study

Abstract

Background: Sub-Saharan Africans face an increasing burden of hypertension and related cardiac and cerebrovascular morbidity and mortality, making the identification of factors leading to early vascular abnormalities imperative. Methods: We investigated the possible influence of the antioxidant glutathione (GSH) on early subclinical atherosclerosis in 63 hypertensive (aged 45.2 years) and 34 normotensive (aged 38.9 years; P < 0.001) nondiabetic African men. We measured ambulatory daytime systolic and diastolic blood pressure (SBP, DBP) as well as daytime mean arterial pressure (MAP), carotid intima-media thickness (CIMT), and calculated the cross-sectional wall area.We determined the reduced form of GSH in whole blood and blood glucose in serum. Results: Blood glucose (110 vs. 92 mg/dl; P < 0.001) and CIMT (0.75 vs. 0.61 mm; P < 0.001) were higher in hypertensives compared to normotensives. No significant difference existed for GSH. Associations in normotensives suggested the hypotensive effect of GSH after single (SBP: r = ―0.35,P ≤ 0.05; DBP: r=-0.37, P ≤ 0.05; MAP: r=-0.38, P ≤ 0.05) and multiple (SBP: B = ―0.015, P < 0.05; DBP: B = ―0.011, P < 0.05; MAP: B = ―0.012, P < 0.05) regression analyses. In hypertensives, CIMT (B = ―0.00027, P < 0.01) and cross-sectional wall area (CSWA) (B = ―0.0066, P < 0.05) correlated negatively with GSH.These findings were consistent after excluding 10 human immunodeficiency virus (HIV)-positive hypertensive subjects. Conclusions: In hypertensive African men, CIMT is negatively associated with GSH, suggesting a possible contributory role of attenuated GSH levels in the development of subclinical atherosclerosis.