Background: Microalbuminuria is considered as a strong predictor of cardiovascular diseases. However, limited information is available for childhood blood pressure (BP) levels and microalbuminuria in adulthood.
Methods: This study examined 2,122 individuals enrolled in the Bogalusa Heart Study as children, aged 5 to 17 years, and as adults, aged 20 to 37 years, with an average follow-up period of 16 years. Microalbuminuria is defined as urinary albumin (in milligrams per liter) to creatinine (mmoles per liter) ratio at or above the 90th percentile specific for age, ethnicity, and sex or urinary albumin levels >/=30 mg/L.
Results: As children, African American boys had higher BP than white boys. As adults, African Americans had higher BP and urinary albumin/creatinine ratio than whites. After adjusting for age, sex, and body mass index (BMI), African Americans with microalbuminuria in adulthood by either measure had higher systolic (P =.03) and diastolic (P =.02) BP as adults, and higher diastolic (P <.01) as children than those without this condition. On the other hand, whites showed no such significant association. In a multivariate regression analysis, adjusting for sex, childhood BMI, and age, and current smoking status, childhood BP and rate of change in BP from childhood to adulthood were significant predictors of increased urine albumin excretion in African Americans, but not in whites.
Conclusions: Elevated BP beginning in childhood is associated with microalbuminuria in adulthood in African Americans, but not in whites, suggesting that African Americans may be more susceptible than whites to BP-related renal damage.