Grip strength and depressive symptoms in a large-scale adult population: The TCLSIH cohort study.

BACKGROUND: Previous studies suggest that muscle-derived cytokines (myokines) are linked with brain function. Although muscle strength measured by handgrip strength is a prognostic indicator of functional decline, epidemiological studies directly examining the association between grip strength and mental health remain scarce. The aim of this study is to clarify the association between grip strength and depressive symptoms in the general adult population.

METHODS: This is a cross-sectional study of 24,109 Chinese adults (41. 5  ± 11.9 years; 46.0% females). Grip strength was measured by dynamometer and the greatest force was normalized to body weight (NGS, kg/kg). Depressive symptoms were assessed using the Self-Rating Depression Scale (SDS). Models of logistic regression were conducted to assess the association between NGS and depressive symptoms, with adjustment for established confounding factors.

RESULTS: Of the 24,109 participants, the prevalence of depressive symptoms (SDS ≥45) was 16.8% (males 15.7%, females 18.0%). After adjusting for multiple confounding factors, the odds ratios and 95% confidence interval for depressive symptoms in the quartiles of NGS were 1.00, 0.96 (0.84-1.10), 0.91 (0.79-1.05), and 0.91 (0.78-1.07) (P = 0.03) in males; 1.00, 0.92 (0.80-1.06), 0.90 (0.77-1.04), and 0.80 (0.69-0.94) (P = 0.0002) in females, respectively.

LIMITATIONS: This cross-sectional study cannot determine causality.

CONCLUSIONS: Grip strength was inversely associated with depressive symptoms, with stronger association observed among females than males.  Further prospective studies or randomized trials are required to clarify these findings.