Untangle the relationship of muscle mass and bone mineral content on handgrip strength: Results of ELSA-Brasil

The study aims to investigate the independent association of muscle mass (MM) and bone mineral content (BMC) in the performance of the handgrip strength (HGS) test and whether there is effect modification by sex and age. In 12,491 participants from the ELSA-Brasil we estimated the associations between MM, BMC and HGS using linear regression models. All the analyses were performed for total population, also stratified for sex and age. For total population an interaction term was included between each explanatory variable of interest with sex and age to verify the presence of effect modification. We observed that the higher quintiles of MM and BMC were associated to an increasing in the mean of HGS compared to the first quintile, with greater magnitudes in men compared to women, also adults compared to elderly. When we estimated the independent effect of each exposure of interest, MM showed stronger effect in HGS in women, men and adults then BMC. In conclusion, we observed that higher amounts of MM and BMC are associated with higher HGS, regardless of sociodemographic characteristics, health conditions and lifestyle, with this effect being greater in men and adults.