Association between handgrip strength to Cystatin C ratio and hearing loss: insights from the CHARLS study

Hearing loss (HL) is among the most prevalent sensory impairments affecting the elderly population. This study aimed to investigate the predictive value of handgrip strength to Cystatin C (HGS/CysC) ratio in assessing the risk of HL among the Chinese population.

Data collected from the Chinese Health and Retirement Longitudinal Study (CHARLS) in 2015 were used for analysis. We enrolled 12,745 individuals in the CHARLS database and divided them equally into four groups according to quartile of HGS/CysC ratio. Multivariable logistic regression and restricted cubic splines (RCS) analysis were conducted to evaluate the association between HGS/CysC ratio and risk of HL. Subgroup analyses and interaction tests were also performed.

The prevalence of HL among participants in quartiles (Q) 1-4 of HGS/CysC ratio were 19.11%, 13.94%, 9.76%, and 7.47%, respectively. In comparison to the lowest quartile, the adjusted odds ratios (with 95% confidence intervals) for HL for Q2-Q4 were 0.92 (0.79-1.06), 0.75 (0.63-0.89), and 0.66 (0.54-0.82), respectively. RCS analysis revealed a significant negatively linear association between HGS/CysC ratio and risk of HL after fully adjustment (nonlinear P > 0.05). Subgroup analyses indicated that the relationship between the HGS/CysC ratio and HL was consistent across all subgroups, including age, sex, hypertension, diabetes, smoking status, drinking status, rural residence, marital status, and education. Furthermore, the predictive ability of HGS/CysC ratio for HL was 0.622, which surpassed that of both HGS and CysC (P < 0.001), while the composite variable exhibited the highest predictive accuracy (P < 0.001).

A higher HGS/CysC ratio was independently associated with the risk of HL. Further studies on HGS/CysC ratio could be beneficial for preventing and treating HL.