Association Between Body Composition and Glomerular Hyperfiltration Among Chinese Adults.

Area of Science:

• Nephrology
• Endocrinology
• Public Health

Background:

• High body mass index (BMI) is a common indicator of excess adiposity and is associated with glomerular hyperfiltration (GH).
• BMI may inaccurately estimate body fat due to its inability to differentiate between fat mass and lean body mass (LBM).
• Biological impedance analysis (BIA) offers a feasible method for assessing body composition (BC) and predicting health risks.

Purpose of the Study:

• To investigate the association between body composition (BC) and glomerular hyperfiltration (GH) in a Chinese adult population.
• To determine if body fat percentage or fat-to-lean mass ratio is a better predictor of GH than BMI.

Main Methods:

• A cross-sectional study of 6902 Chinese adults who visited a Health Checkup Clinic.
• Body composition (fat mass and LBM) was assessed using biological impedance analysis (BIA).
• Glomerular hyperfiltration (GH) was defined as the upper quartile of estimated glomerular filtration rate (eGFR) (>117.3 mL/min/1.73 m²).

Main Results:

• Subjects with GH had a higher fat/LBM ratio compared to the control group (34.7% vs. 34.0%, P=0.01).
• Conversely, individuals with GH had a lower BMI than the control group (24.5 vs. 24.9, P<0.001).
• After adjusting for confounders, a higher fat/LBM ratio significantly correlated with GH (OR=2.09, 95% CI: 1.11-3.93).

Conclusions:

• Body fat to lean mass ratio, rather than BMI, is significantly associated with glomerular hyperfiltration in Chinese adults.
• Adiposity, specifically the fat/LBM ratio, may be an important and modifiable determinant of GH.
• These findings highlight the limitations of BMI in assessing metabolic and renal health risks.