# Middle-aged and older populations with different subtypes and definitions of metabolic syndrome face different future cardiovascular disease risks: results from a comparison of two Chinese definitions

## TL;DR

This study shows that different definitions of metabolic syndrome in middle-aged and older Chinese people predict varying future cardiovascular disease risks.

## Contribution

The study compares two Chinese definitions of metabolic syndrome and their associations with cardiovascular disease risk in a longitudinal cohort.

## Key findings

- The WCGH definition of metabolic syndrome showed a stronger association with cardiovascular disease risk than the CDS definition.
- Seven of the 16 CDS-based subtypes of metabolic syndrome were not linked to cardiovascular disease, while all WCGH subtypes were.
- The WCGH criteria outperformed the CDS in predicting cardiovascular disease risk with higher AUC, IDI, and NRI values.

## Abstract

Differences in the association between metabolic syndrome (MetS) and cardiovascular disease (CVD) across definitions and subtypes are unknown. The aim of this study was to investigate the differences between the associations of MetS defined by the Chinese Diabetes Society (CDS) and the Writing Group of 2024 Chinese Guidelines for the Management of Hypertension (WCGH) with CVD.

This cohort study included participants aged ≥ 40 years without cardiovascular disease from the 2011 survey of the China Health and Retirement Longitudinal Study. Individuals meeting different definitions of MetS based on criteria from the CDS and the WCGH were identified and followed up until 2020. Cox proportional risk models were used to analyze the association between different definitions and subtypes of MetS with CVD, and the predictive performance of the models was compared using the area under the curve (AUC) of the time-dependent receiver operating characteristic curve, integrated discrimination improvement (IDI), and net reclassification improvement (NRI).

Both CDS and WCGH based MetS were significantly associated with increased CVD risk, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.51 (1.38 ~ 1.66) and 1.81 (1.66 ~ 1.99), respectively, both P < 0.001. 7 of the 16 subtypes of MetS based on CDS were not associated with CVD; all 5 subtypes of MetS based on WCGH were significantly associated with an increased risk of CVD. When participants were grouped based on meeting two definitions, compared with the CDS-WCGH- group, CVD risk increased most significantly in the CDS-WCGH + group (HR and 95%CI: 2.57 [1.94 ~ 3.39], P < 0.001), showed a significant increase in the CDS + WCGH + group (HR and 95%CI: 1.66 [1.51 ~ 1.83], P < 0.001), and showed no significant increase in the CDS + WCGH- group (HR and 95%CI: 0.93 [0.7 ~ 1.23], P = 0.606). The AUC of WCGH was higher than that of CDS at all time points. IDI and NRI analyses showed that the WCGH standard demonstrated significant improvements in risk reclassification and identification compared to CDS.

The association between MetS and CVD depends on the definition criteria and specific component combinations employed. The WCGH definition, which integrates diagnostic criteria for dyslipidemia, has been demonstrated to be more robust than the CDS.

The online version contains supplementary material available at 10.1186/s12986-026-01095-3.