Abstract
BACKGROUND: This study aimed to assess the longitudinal association between dynapenic abdominal obesity and new-onset arthritis among the middle-aged and older Chinese population. METHODS: We included 6863 participants from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). Dynapenia was defined as handgrip strength < 28 kg for males, and < 18 kg for females. Abdominal obesity was defined as a waist circumference ≥ 90 cm for males and ≥ 85 cm for females. Based on the definitions, all participants were divided into four groups: no dynapenia and no abdominal obesity (ND/NAO), abdominal obesity alone (ND/AO), dynapenia alone (D/NAO), and dynapenia and abdominal obesity (D/AO). The association between dynapenic abdominal obesity and new-onset arthritis was assessed by sex using the Poisson regression models. RESULTS: After a four-year follow-up, 1272 (18.53%) participants reported new-onset arthritis. Those in the D/AO group had a significantly increased risk of new-onset arthritis compared to those in the ND/NAO group (adjusted relative risk (RR): 1.34, 95% confidence interval (CI): 1.01-1.77). In females, the ND/AO (RR: 1.21, 95% CI: 1.03-1.43) and D/AO (RR: 1.39, 95% CI: 1.01-1.93) groups were associated with a higher risk of arthritis. This significant association was not observed in males. CONCLUSIONS: Our results indicated that the combined effect of dynapenia and abdominal obesity significantly increased the risk of new-onset arthritis in females, but this association was not observed in males.