Biological Sex and the Association Between Grip Strength and Cardiovascular Disease: a Scoping Review.

Background: This scoping review examines how biological sex has been considered in studies investigating the association between grip strength and cardiovascular outcomes and risk factors. Methods: We used the Askey and O'Malley framework, reported as per the PRISMA extension for scoping reviews. A search was conducted in four electronic bibliographic databases to identify relevant peer-reviewed studies published after 2001. Results: Of the 39 included studies, 82.0% (n = 32) used biological sex as a confounder variable in the association of interest. Two studies used interaction terms between biological sex and grip strength and found no statistically significant interactions. Five studies used sex-stratified analyses alone. Three of these studies found that the cardiovascular risk due to low grip strength is higher in males than in females. Two other studies used both interaction terms between biological sex and grip strength and sex-stratification analyses and found no statistically significant differences. Sociocultural gender was not considered in any of the identified studies. Conclusion: We found that biological sex was often considered as a confounder variable in the association between grip strength and cardiovascular outcomes, as well as cardiovascular risk factors. On the other hand, two studies reported the presence of effect modification by sex rather than confounding, that these associations were stronger in males versus females. Five other studies did not identify evidence of interaction nor effect modification. Future research is needed to clarify the nature of these associations and understand any potential biological mechanisms.