Sex-specific association between metabolic score for insulin resistance and mortality in incident peritoneal dialysis patients

BACKGROUND: The relationship between metabolic score for insulin resistance index (METS-IR) and all-cause and cardiovascular disease (CVD) mortality in peritoneal dialysis (PD) patients remains unexplored. Hence, we aimed to assess the association of METS-IR with mortality, specifically examining sex differences. METHODS: In this multicenter cohort study, a total of 3,471 patients were enrolled between 01 January 2006 and 31 December 2017. Associations between METS-IR and all-cause and CVD mortality were examined using multivariate Cox regression analysis, with sex-based differences also assessed. RESULTS: Participants had a mean age of 51.34 ± 14.61 years, 44.04% female. The mean MESTS-IR in Quartile 1, Quartile 2, Quartile 3, and Quartile 4 was 26.22 ± 2.18, 31.40 ± 1.21, 35.94 ± 1.42 and 44.07 ± 5.29 respectively. A comparison of Quartile 4 to Quartile 1 using the multivariate Cox regression analysis revealed significant increases in the hazard ratio (HR) for all-cause mortality (HR: 1.42, 95% confidence interval (CI): 1.02 to 1.97) and CVD mortality (HR: 1.78, 95% CI: 1.16 to 2.54) in the entire population. In female PD patients, the Quartile 4 was associated with an approximately 126% greater risk of all-cause mortality and 165% greater risk of CVD mortality compared with Quartile 1 in the multivariate analysis. However, the result showed no significance in men. CONCLUSIONS: The METS-IR could serve as an effective prognostic indicator of mortality in women undergoing PD, indicating that early detection and intervention toward insulin resistance, represented by the METS-IR index, may offer clinical benefits for this identified group.