Prevalence and distribution of (micro)albuminuria in toddlers

Microalbuminuria is common in the general adult population, with a prevalence of similar to 7%, and is an independent indicator of renal and cardiovascular risks. Whether albuminuria is acquired during life (as a result of hypertension/diabetes) or is congenital and already present at birth is unknown. We studied the prevalence of microalbuminuria in toddlers and compared the distribution of albuminuria with that of the general adult population. In addition, we looked for possible associations between microalbuminuria and antenatal, postnatal and maternal factors. The urinary albumin concentration (U-AC) was measured in 1352 children and the urinary albumin:creatinine ratio (U-ACR) in 1288 children from the Groningen Expert Center for Kids with Obesity (GECKO) Drenthe cohort (age range 20-40 months). Albuminuria distribution was compared with the albuminuria distribution in 40 854 participants of the general adult cohort of the Prevention of Renal and Vascular End stage Disease (PREVEND) study. Associations between albuminuria (expressed as U-AC and U-ACR) and antenatal, postnatal and maternal factors were tested with linear regression analysis. The median U-AC in the GECKO study was 2.3 mg/L (5th-95th percentiles: 2.1-25.5) and in the PREVEND study it was 6.0 mg/L (2.3-28.6) (P distribution comparison 0.053). The prevalence of U-AC a parts per thousand yen 20 mg/L was 6.9% in the GECKO study and 7.8% in the PREVEND study (P = 0.195). The prevalence of U-ACR a parts per thousand yen 30 mg/g in the GECKO study was 23.4%. U-AC and U-ACR were lower in boys. U-AC was not associated with other determinants, but U-ACR was associated with age and gestational diabetes. The distribution of U-AC and the prevalence of U-AC > 20 mg/L in toddlers and in the young general adult population are comparable. These findings suggest that microalbuminuria is a congenital condition that may predispose to a higher cardiovascular risk later in life.