Association between the metabolic score for insulin resistance trajectory and new-onset metabolic syndrome: a retrospective cohort study based on health check-up data in China.

Background: The Metabolic Score for Insulin Resistance (METS-IR) is a novel biomarker for evaluation of insulin resistance (IR). Emerging evidence suggests this metric may be able to predict the onset of metabolic syndrome (MetS). The aim of this study was to determine whether there is a correlation between sustained METS-IR values and the future risk of MetS.

Methods: Data for 3,750 individuals who attended a tertiary hospital in Zhengzhou for a health check-up between 2017 and 2022 were analyzed. The METS-IR was used to evaluate IR. A latent class trajectory model was created by dividing the subjects into high-stability and low-stability categories based on three consecutive years of data. The incidence of MetS between 2020 and 2022 was calculated using the Kaplan-Meier method and Cox regression modeling.

Results: Over a median follow-up of 2.13 years, we identified 430 cases of MetS (11.47%). The incidence rate was 35.48% in the high-stability group and 8.32% in the low-stability group (P < 0.001). Multivariate Cox regression, controlling for sex, age, hypertension status, diabetes status, and serum uric acid, low-density lipoprotein cholesterol, and gamma-glutamyl transferase levels, revealed that the risk of MetS was significantly higher in the high-stability group (hazard ratio [HR] = 4.77, 95% confidence interval [CI]: 3.714-6.126, P < 0.001). Stratified analysis by age showed that the risk of MetS was also significantly higher in individuals aged < 45 years (HR = 6.202, 95% CI: 4.312-8.921) and in those aged ≥ 45 years (HR = 3.89, 95% CI: 2.720-5.566) in the high-stability group. Receiver operating characteristic (ROC) curve analysis showed that the trajectory of METS-IR could predict MetS. The respective areas under the ROC curve for the 1-year, 2-year, and 3-year risk of MetS were 0.575, 0.641, and 0.628. Sensitivity analyses showed that an elevated METS-IR value was associated with an increased risk of new-onset MetS.

Conclusions: In this study, there was a significant correlation between the METS-IR value and the future risk of MetS. METS-IR measurement over time may allow early detection of individuals at high risk of MetS, which would lessen the impact of chronic disease.