Association between metabolic syndrome and incident chronic kidney disease among Chinese: A nation-wide cohort study and updated meta-analysis

Aims: We prospectively examined the relationship between metabolic syndrome (MetS) and incident chronic kidney disease (CKD) among middle-aged and elderly Chinese, and conducted a systematic review and meta-analysis of all cohort studies on this topic.

Materials and methods: Our research data were derived from the China Health and Retirement Longitudinal Study. Participants (n=5752, age ≥45 years) without CKD (defined as estimated glomerular filtration rate <60 ml/min/1.73m² ) at baseline were followed up for 4 years. We applied logistic regressions to examine the association of MetS with incident CKD. In addition, we pooled our effect estimates and those from previous cohort studies in the meta-analysis.

Results: In a 4-years follow-up, 61 (4.27%) developed CKD in participants with MetS versus 102 (2.36%) in participants without MetS. After adjustment for potential confounders, odds ratio for incident CKD was 1.82 [95% confidence interval (95% CI): 1.19-2.78] comparing participants with MetS with those without MetS. There was a linear positive association between the number of MetS components and incident CKD (p for trend <0.001). In the updated meta-analysis of 25 studies among 350,655 participants with 29,368 incident cases of CKD, the pooled relative risk of developing CKD in participants with MetS was 1.34 (95% CI: 1.28-1.39), compared with those without MetS.

Conclusions: Individuals with MetS had higher risk of incident CKD in middle-aged and elderly Chinese adults, which was supported by a comprehensive review of cohort studies from multiple populations. It may be advisable to routinely monitor renal functions among individuals with MetS.