The association between underweight and the development of albuminuria is different between sexes in relatively healthy Korean subjects.

BACKGROUND There are limited data on the association between underweight and albuminuria. The aim of this study is to verify the effect of underweight on the development of albuminuria. METHODS Participants who underwent two health check-ups with a 2-year interval at a tertiary hospital in Korea between 2002 and 2009 were studied. After exclusion of participants with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) or dipstick albuminuria ≥1+ at the first check-up, 53 876 participants were enrolled. We measured the incidence of albuminuria at the second check-up and calculated the odds ratio (OR) for the development of albuminuria according to body mass index (BMI). RESULTS After 2 years, 746 cases of incident albuminuria were observed among 53 876 participants. The effect of BMI on the development of albuminuria was modified by sex in a multivariate logistic model with adjustment for age, diabetes, hypertension, dyslipidaemia, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, uric acid, eGFR, current smoking status and alcohol intake (P-value for interaction <0.001). Compared with participants in the normal weight range (BMI, 18.5-22.9), the ORs for incident albuminuria were 1.93 [95% confidence interval (CI), 1.35-2.76; P ≤ 0.001], 1.19 (0.84-1.67; P = 0.329) and 0.71 (0.43-1.17; P = 0.177) in underweight (BMI, <18.5), overweight (BMI, 23.0-24.9) and obese (BMI, ≥25) women. However, the ORs were 0.9 (95% CI, 0.39-2.05; P = 0.794), 1.08 (0.84-1.38; P = 0.567) and 1.38 (1.09-1.75; P = 0.007) for each corresponding group of men. CONCLUSIONS Underweight was significantly associated with the development of albuminuria after 2 years in relatively healthy Korean females, but this relationship was not significant in males. This study suggests the need for more studies on the role of underweight in renal injury in men and women.