Risk variables of insulin resistance syndrome in African-American and Caucasian young adults with microalbuminuria: The Bogalusa Heart Study

Microalbuminuria is a strong predictor of cardiovascular disease. Previous studies are inconsistent regarding the relationship between microalbuminuri a and insulin resistance syndrome. Therefore, we examined this relationship in 1031 young adults (61% Caucasian, 39% African-American) aged 19 to 32 y ears. Individuals with either urinary albumin to creatinine ratio at or abo ve the 90th percentile (age, race, and gender specific) or urinary albumin level at or above 30 mg/L were considered as having slightly elevated album in excretion (microalbuminuria). The multiple risk variables of insulin res istant syndrome measured include body mass index, waist circumference, bloo d pressure (BP), triglycerides, high-density lipoprotein (HDL) cholesterol, glucose, insulin, insulin resistance index (calculated from a homeostasis model assessment equation), and uric acid. After controlling for age and ge nder, African-Americans with microalbuminuria by either measure had higher mean systolic P <.001) and diastolic (P < .05) BP, prevalence of hypertensi on (P <.05), and, contrary to expectations, HDL cholesterol (P <.05) than t hose without this condition. On the other hand, Caucasians showed no such a ssociations. In African-Americans, the above differences in BP levels persi sted when hypertensive subjects were excluded. None of the other risk varia bles displayed any relation to microalbuminuria in both races. These result s suggest that microalbuminuria is not necessarily an intrinsic component o f the insulin resistance syndrome, at least in the young adult age. Further more, the observed association between hypertension and microalbuminuria am ong young African-Americans may reflect early evidence of renal dysfunction due to the burden of elevated BP in this group. Am J Hypertens 2000; 13:12 74-1279 (C) 2000 American Journal of Hypertension, Ltd.