Exploring the bidirectional associations between handgrip strength and depression in middle and older Americans.

Objective: Current evidence on the relationship between decreased handgrip strength and depression risk is controversial, and there is limited study focus on the potential bidirectional associations between them. We aim to explore their bidirectional relationships.

Methods: This study used panel data from the Health and Retirement Study involving 17,713 aging Americans (≥50 years old) who participated in at least 2 waves. Smedley spring-type hand-held dynamometer was used to assess the handgrip strength. Depression was evaluated by the 8-item Center for Epidemiologic Studies-Depression (CESD) scale. Time-lagged general estimating equations (GEE) were used to assess the bidirectional association between handgrip strength and the depression risk.

Results: In the fully adjusted model, every 5 kg decreased handgrip strength was associated with a 6% (95%CI: 3%-9%) increased risk of depression. Compared with non-weakness participants, those with weakness had a higher depression risk (OR = 1.22, 95%CI: 1.09-1.36). Conversely, depression might associate with a 0.33 kg (95% CI: 0.09-0.56) decrease in handgrip strength and increased the risk of weakness by 18% (95% CI: 6%-33%). In addition, the results remained stable in the stratified analyses by gender and sex. Interestingly, the above-mentioned associations were also observed in overweight and obese participants.

Conclusions: The present study found bidirectional associations between handgrip strength and depression risk. Our results indicated early interventions for depression and handgrip strength might achieve reciprocal benefits over time.