Handgrip strength and health outcomes: Umbrella review of systematic reviews with meta-analyses of observational studies

Purpose: The aim of the present study was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies on handgrip strength and health outcomes. Methods: An umbrella review of systematic reviews with meta-analyses of observational studies was conducted. We assessed meta-analyses of observational studies based on random-effect summary effect sizes and their p values, 95% prediction intervals, heterogeneity, small-study effects, and excess significance. We graded the evidence from convincing (Class I) to weak (Class IV). Results: From 504 articles returned in a search of the literature, 8 systematic reviews were included in our review, with a total of 11 outcomes. Overall, nine of the 11 of the outcomes reported nominally significant summary results (p < 0.05), with 4 associations surviving the application of the more stringent p value (p < 10(-6)). No outcome presented convincing evidence. Three associations showed Class II evidence (i.e., highly suggestive): (1) higher handgrip values at baseline were associated with a minor reduction in mortality risk in the general population (n = 34 studies; sample size = 1,855,817; relative risk = 0.72, 95% confidence interval (95%CI): 0.67-0.78), (2) cardiovascular death risk in mixed populations (n = 15 studies; relative risk = 0.84, 95%CI: 0.78-0.91), and (3) incidence of disability (n = 7 studies; relative risk = 0.76, 95%CI: 0.66-0.87). Conclusion: The present results show that handgrip strength is a useful indicator for general health status and specifically for early all-cause and cardiovascular mortality, as well as disability. To further inform intervention strategies, future research is now required to fully understand mechanisms linking handgrip strength scores to these health outcomes.

Automated summary

The study assessed the credibility and strength of evidence from systematic reviews with meta-analyses of observational studies on handgrip strength and health outcomes. Overall, handgrip strength was found to be a useful indicator for general health status, early all-cause and cardiovascular mortality, as well as disability, requiring further research on mechanisms linking handgrip strength scores to these health outcomes.