CHG index, a novel metabolic biomarker calculated from total cholesterol, high-density lipoprotein cholesterol, and fasting blood glucose, is associated with type 2 diabetes and cardiovascular diseases. However, its association with the risk of new-onset sarcopenia in middle-aged and older adults remains unclear.

We included participants aged ≥50 years from the CHARLS 2011–2012, with follow-up in 2015−2016. Cumulative CHG was derived from measurements in 2011 and 2015. New-onset sarcopenia was diagnosed according to the 2025 AWGS consensus. Multivariable Cox regression and logistic regression were used to examine the associations of baseline and cumulative CHG with new-onset sarcopenia. ROC curves were employed to compare the predictive capability of CHG and TyG.

A total of 5580 participants were included in the baseline analysis. During the 4-year follow-up, 590 (10.6%) participants developed sarcopenia. Compared with the lowest quartile (Q1) of baseline CHG, the highest quartile (Q4) was significantly associated with an increased risk of sarcopenia (HR = 1.287, 95% CI: 1.022−1.619) in the fully adjusted model. K-means clustering categorized 3287 participants into two distinct groups based on cumulative CHG trajectories. Compared with the low-stable group (Cluster 1, n = 1783), the high-declining group (Cluster 2, n = 1504) had a significantly higher risk of new-onset sarcopenia (OR = 1.25, 95% CI: 1.02–1.45). RCS analysis revealed a linear association between baseline CHG and sarcopenia risk. The predictive performance of the baseline and cumulative CHG index was modestly higher than that of the baseline and cumulative TyG index.

Elevated baseline and cumulative CHG indices are independent risk factors for new-onset sarcopenia in middle-aged and older Chinese adults.