Prevalence and distribution of (micro)albuminuria in toddlers.

BACKGROUND Microalbuminuria is common in the general adult population, with a prevalence of ∼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. METHODS The urinary albumin concentration (UAC) was measured in 1352 children and the urinary albumin:creatinine ratio (UACR) 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 UAC and UACR) and antenatal, postnatal and maternal factors were tested with linear regression analysis. RESULTS The median UAC 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 UAC ≥ 20 mg/L was 6.9% in the GECKO study and 7.8% in the PREVEND study (P = 0.195). The prevalence of UACR ≥ 30 mg/g in the GECKO study was 23.4%. UAC and UACR were lower in boys. UAC was not associated with other determinants, but UACR was associated with age and gestational diabetes. CONCLUSIONS The distribution of UAC and the prevalence of UAC > 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.