JMIR Publications

ABSTRACT

Background:

Cardiovascular disease (CVD) is the main cause of death in middle-aged and elderly people in China.The interplay between sarcopenia and insulin resistance (IR) in driving CVD risk has not been fully understood, particularly regarding sarcopenia severity and IR heterogeneity.

Objective:

The aim of this study was to investigate the relationship between IR and sarcopenia and the risk of new-onset CVD.

Methods:

Using data from the China Health and Retirement Longitudinal Study (CHARLS). Cox proportional hazards models were utilized to assess associations of sarcopenia status (non-sarcopenia, possible sarcopenia, sarcopenia and severe sarcopenia) and six IR indices (TyG, TyG-BMI, TyG-WC, TyG-WHtR, TG/HDL-C, METS-IR) with incident CVD. Subgroup analyses by age and sex were performed.

Results:

In the present study, during a median 9 years of follow-up, we included 5,514 middle-aged and elderly (aged ≥45 years) residents, of whom 550 presented with CVD incidence. Participants with possible sarcopenia and high IR exhibited 1.24–1.85-fold higher CVD risk versus non-sarcopenia/low IR counterparts (P < 0.05) after adjustment for potential confounders. TyG-BMI (adjusted HR=1.004 per SD, P=0.023) and TyG-WC (HR=1.001, P=0.021) demonstrated robust associations, whereas TG/HDL-C and METS-IR lost significance after adjustment. In subgroups of different ages and sexes, the combination of lR and sarcopenia is associated with the highest risk of CVD.

Conclusions:

We found that lR and sarcopenia (especially early-stage sarcopenia) synergistically increase the incidence of CVD in older adults. These findings advocate for dual-targeted CVD interventions (muscle preservation and IR mitigation) in aging societies, particularly during the transitional phase of possible sarcopenia.