Microalbuminuria and the metabolic syndrome in non-diabetic black Africans

It is recognised that the metabolic syndrome promotes the development of cardiovascular disease. Although several studies have shown a relationship between the metabolic syndrome and kidney disease, few of these have used non-diabetic subjects, especially in the African population. This was a cross-sectional study of subjects of African origin, using the metabolic syndrome (MS) criteria of the National Cholesterol Education Program (NCEP) third Adult Treatment Panel (ATP III). Subjects with impaired fasting glucose, with two-hour glucose >or= 11.1 mmol/L after a glucose tolerance test, were excluded. Spot urine for albumin-to-creatinine ratio (ACR) was measured and the glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease (MDRD) equation. Microalbuminuria was defined as ACR between 3-30 mg/mmol. There was a significant decline in GFR and a significant increase in ACR with increasing number of MS traits. ACR increased four-fold between subjects with no MS traits and those with four or more traits. In subjects with the metabolic syndrome, there was a significant correlation between ACR and systolic blood pressure (SBP), diastolic blood pressure (DBP) and fasting glucose. Estimated GFR correlated significantly and inversely with body mass index (BMI) and serum leptin. These observations raise major clinical and public health concerns for developing countries, where both the metabolic syndrome and kidney disease are being reported more and more frequently. The potential economic impact is huge.