Obesity, albuminuria, and urinalysis findings in US young adults from the Add Health Wave III study.

BACKGROUND AND OBJECTIVES Obesity has been associated with kidney disease in adults. This study was designed to evaluate the association of obesity with an early marker of kidney disease, albuminuria, among young adults. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Urinalysis (n = 9371), albumin-to-creatinine ratio (n = 4463), and body mass index (kg/m2) were measured in the Add Health Wave III cohort (2001 to 2002), a multiethnic sample of young adults followed for approximately 6 yr. Multivariate logistic regression modeled the association of sex-specific albuminuria with body mass index, adjusted for sample weights, sex, race, ethnicity, and glycosuria. RESULTS Urinalysis revealed that 0.8% had proteinuria, 4.6% had hematuria, 0.2% had combined hematuria and proteinuria, and 1.5% had glycosuria. Albuminuria prevalence was 4.4%. Mean body mass index was higher among those with albuminuria compared with those without. There were no associations between body mass index categories of 25 to < 30 or 30 to < 35 kg/m2 with albuminuria compared with the lowest body mass index (< 25 kg/m2); however, the highest category (> or = 35 kg/m2) was associated with albuminuria, compared with the lowest category (OR = 1.76, 95% CI: 1.02 to 3.04). Glycosuria (OR = 4.0; 95% CI: 1.5 to 11.1, p < 0.01) as well as increasing body mass index during the 6-yr follow-up (OR: 1.07 per unit change in kg/m2; 95% CI: 1.00 to 1.13, p = 0.04) were also associated with albuminuria. CONCLUSIONS Given the increasing prevalence of obesity, the association of albuminuria associated with obesity in young adults is particularly concerning. Obesity may be a target for primary prevention of kidney and cardiovascular disease.