Association of waist-to-height ratio with estimated glomerular filtration rate in middle-aged and elderly Chinese

Objective: This study aimed to assess the relationship between waist-to-height (WHtR) and estimated glomerular filtration rate (eGFR) in men, non-menopausal, and postmenopausal women among middle-aged and elderly Chinese. Methods: This study analyzed the data of 7,807 participants in a cross-sectional survey, ie, the third wave of the China Health and Retirement Longitudinal Study. Restrictive cubic-spline regression with three knots was used to assess the dose-response association of WHtR with eGFR. Piecewise linear regression models were further established to calculate the slope of each segment and their 95% confidence interval (CI). Results: After adjusting for potential confounders, an inverse L-shaped dose-response relationship was found between WHtR and eGFR among men (P-nonlinear = 0.024, threshold = 0.513) and postmenopausal women (P-nonlinear = 0.009, threshold = 0.503). The slopes on the right sides of the threshold were statistically significant among men (beta(2) = -33.77, 95% CI: -53.23 to -14.31) and postmenopausal women (beta(2) = -36.53, 95% CI: -49.71 to -23.35), respectively. A weak negative linear relationship existed between WHtR and eGFR in non-menopausal women. Conclusions: The relationship between WHtR and eGFR tended to be inverse-L-shaped in men and postmenopausal women, but may vary with postmenopausal status in women.