Fig. 1

Smooth curve fitting of eGFR and uric acid levels. a eGFR and SUA; b eGFR and UUA; c eGFR and Cur; d eGFR and FLur; e eGFR and FEur; f eGFR and FEur (grouped by gender); g eGFR and EurGF; h eGFR and EurGF (grouped by gender). Solid smooth curves represent the fitting results of eGFR and dotted smooth curves represent the 95% CI of eGFR except Figure F and H which solid smooth curves represent male and dotted smooth curves represent female. The nonlinear relationships between eGFR and uric acid levels were observed after adjusting for age, height, weight, body surface area. And an obvious inflection point exists in smooth curve fitting of eGFR and FEur as well as eGFR and EurGF, and different inflection points appear according to gender grouping