Association Between Body Composition and Glomerular Hyperfiltration Among Chinese Adults

High body mass index (BMI) is the most common parameter to assess excess adiposity, and has been linked to glomerular hyperfiltration (GH). However, BMI may be misleading in the estimation of body fat content due to its inability to discriminate between body fat and lean mass. In recent years, the convenient biological impedance analysis has made prediction of certain diseases somewhat feasible and accessible using body composition (BC). Accordingly, we conducted a cross-sectional study to explore the association between BC and GH among Chinese adult population. A total of 6902 adults (aged 38.6 +/- 8.3 years, 70.1% males) who consecutively visited the Health Checkup Clinic were enrolled. BC including fat mass and lean body mass (LBM) was evaluated by biological impedance analysis. The upper quartile of eGFR which exceeded 117.3 mL/min/1.73 m(2) was defined as GH, in comparison with the lower three quartiles (control group). As a categorical outcome, GH subjects had higher fat/LBM than the control group, which was 34.7 +/- 10.9 (%) vs. 34.0 +/- 10.5 (%), P = 0.01; however, the BMI in GH group was lower than in the control group, which was 24.5 +/- 3.7 (%) vs. 24.9 +/- 3.6 (%), P < 0.001. Fat/height and Fat/BSA were not significantly different between the two groups. Moreover, after adjusting for potential confounders, fat/LBM significantly correlated with GH (OR = 2.09, 95% CI, 1.11 to 3.93). The study revealed that fat/LBM significantly correlated with GH among Chinese adult population, which highlights that adiposity might be an important and potentially modifiable determinant of GH.