Joint association of metabolic syndrome and low handgrip strength with incident stroke in middle-aged and older adults: findings from the CHARLS cohort.

BACKGROUND

Metabolic syndrome (MetS) and low handgrip strength (HGS) are each associated with cardiovascular disease, but their joint association with incident stroke remains unclear. We examined the combined and independent associations of MetS and low HGS with incident stroke.

METHODS

We analyzed 6200 participants aged ≥50 years from the China Health and Retirement Longitudinal Study. Low HGS was defined by AWGS 2025 criteria; MetS was defined by NCEP ATP III criteria with updated Chinese-specific waist circumference thresholds. Participants were classified into four groups. Incident stroke was identified by self-reported physician diagnosis during follow-up. Stabilized inverse probability weighting was used to balance covariates. Cox models estimated hazard ratios (HRs) with additive and multiplicative interaction tests.

RESULTS

After weighting, low HGS alone was not significantly associated with stroke (HR 1.262, 95% CI 0.910-1.751). MetS alone (HR 1.928, 1.606-2.315) and the joint exposure (HR 2.048, 1.503-2.791) were associated with elevated risk. The excess risk in the joint group was primarily driven by MetS. No significant additive or multiplicative interaction was detected.

CONCLUSIONS

In middle-aged and older Chinese adults, MetS rather than low HGS drove the excess stroke risk when the two conditions coexisted. Metabolic risk management should be prioritized for stroke prevention in this population.