Microalbuminuria in nondiabetic adults - Relation of blood pressure, body mass index, plasma cholesterol levels, and smoking: The Gubbio Population Study

Background: Evidence exists that cardiovascular risk factors influence progression toward end-stage renal failure. We tested the hypothesis that in nondiabetic middle-aged adults without macroalbuminuria, cardiovascular risk factors are related to urinary albumin excretion and prevalence of microalbuminuria, a sign of early nephropathy. Methods: Cross-sectional analysis of data for 1567 participants in The Gubbio Population Study (677 men and 890 women), aged 45 to 64 years, without macroalbuminuria, without diabetes mellitus, and with fasting plasma glucose levels of less than 7.8 mmol/L (140 mg/ dL). Data collection included albumin and creatinine excretion in timed overnight urine collection; levels of fasting plasma cholesterol, glucose, triglycerides, creatinine, and uric acid; creatinine clearance; red blood cell sodium-lithium countertransport; blood pressure; weight; height; medical history; smoking status; and alcohol intake. Urinary albumin excretion and prevalence of microalbuminuria were the dependent variables. Results: Blood pressure, plasma cholesterol levels, smoking, and body mass index significantly related to urinary albumin excretion and prevalence of microalbuminuria. In analyses with control for multiple variables, relative risk for microalbuminuria (urinary albumin excretion, 20-199 mu g/min) in men and women was 2.51 and 1.62, respectively, with 18 mm Hg higher (1 SD) systolic blood pressure; 2.25 and 2.10, respectively, with 1.0-mmol/L (40 mg/dl) higher plasma cholesterol level; 1.99 and 1.91, respectively, for smokers vs nonsmokers; and 1.83 and 1.33, respectively, with 4 kg/m(2) higher body mass index. Findings were similar for microalbuminuria defined as urinary albumin excretion of at least 25 mu g/dL glomerular filtration rate. Conclusion: Major cardiovascular risk factors are independent correlates of microalbuminuria in nondiabetic middle-aged adults.