Microalbuminuria in pediatric obesity: prevalence and relation to other cardiovascular risk factors

BACKGROUND: Microalbuminuria (MA) has emerged as a strong predictor of cardiovascular (CV) events, even in nondiabetic adults. While the mechanisms behind this association remain to be established, most studies suggest that MA is the result of increased vascular leakage denoting endothelial dysfunction associated with early vasculopathy. OBJECTIVE: To examine if a urine albumin creatinine ratio (UACR) in the microalbuminuric range is related to metabolic markers of CV risk in obese and pre-diabetic youth recruited from an obesity clinic. METHODS: MA was defined as a UACR between 2.0 and 20 mg/mmol. Subjects with gross proteinuria (UACR>20 mg/mmol) were excluded from the study. Analyses were performed to assess the relationship of MA and markers of CV risk, including body mass index (BMI), % body fat, blood pressure (BP), lipid profile, inflammatory markers, insulin sensitivity indexes and degrees of oral glucose tolerance. MA was also correlated with risk factor constellations unique to the metabolic syndrome, a distinct CV risk entity. RESULTS: Postchallenge alterations in glucose metabolism and overall loss in insulin sensitivity were strongly and positively correlated with the presence of MA (P = 0.002 and 0.01, respectively). Neither the metabolic syndrome nor any of the individual CV risk factors examined were associated with MA. CONCLUSIONS: These data suggest that early glucose toxicity, as reflected by postchallenge elevations in plasma glucose even below the diagnostic cutoff for diabetes mellitus may contribute to the presence of MA. Whether MA is equally as predictive of CV disease in youth, as in adulthood, remains to be investigated.