Association between high-sensitivity C-reactive protein and renal function in Korean adults: A sex-specific analysis of Korea National Health and Nutrition Examination Survey 2015 to 2018 data.

This study aimed to investigate the association between high-sensitivity C-reactive protein (hs-CRP) levels, as a surrogate marker of systemic inflammation, and renal function among Korean adults grouped by age, sex, and body mass index. This study analyzed data obtained from the Korea National Health and Nutrition Examination Survey 2015 to 2018, a cross-sectional and nationally representative survey conducted by the Korean Centers for Disease Control and Prevention. Of the 22,451 subjects included in this study, 19,607 (87.3%) and 2844 (12.7%) had normal kidney function and incident chronic kidney disease, respectively. Reduced renal function was more frequently observed in subjects with high hs-CRP levels than in those with low hs-CRP levels (odds ratio [OR], 1.438; 95% confidence interval [CI], 1.234-1.674). In the group aged ≥ 65 years, the odds of reduced renal function were higher among subjects with a high hs-CRP level compared to those with a low hs-CRP level (OR, 1.528; 95% CI, 1.191-1.960). The association between hs-CRP level and renal function was observed only in women (OR, 2.485; 95% CI, 1.779-3.470) and further stratified by age and sex, the odds of reduced renal function were likely higher in women aged ≥ 65 years with a high hs-CRP level (OR, 2.338; 95% CI, 1.622-3.369). Moreover, reduced renal function was more observed in subjects aged ≥ 65 years and those with a body mass index < 25 kg/m2 (OR, 1.502; 95% CI, 1.087-2.075). This study showed that a high hs-CRP level likely contributes to the increased prevalence of reduced renal function. This association may aid the identification of individuals at high risk for reduced renal function, especially elderly women, in clinical or public health practice.