Is handgrip strength normalized to body weight a useful tool to identify dynapenia and functional incapacity in post-menopausal women?

Objective: To investigate whether handgrip strength normalized to body weight could be a useful clinical tool to identify dynapenia and assess functional capacity in post-menopausal women. Method: A total of 136 postmenopausal women were recruited. Body composition (Dual Energy X-ray Absorptiometry [DEXA], Bio-electrical Impedence Analysis [BIA]), grip strength (dynamometer) and functional capacity (senior fitness tests) were evaluated. Dynapenia was established according to a handgrip strength index (handgrip strength divided by body weight (BW) in Kg/KgBW) obtained from a reference population of young women: Type I dynapenic (< 0.44 kg/KgBW) and type II dynapenic (< 0.35 kg/KgBW). Results: The results show a positive correlation between handgrip strength index (in kg/KgBW) and alternate-step test (r=0.30, p< 0.001), chair-stand test (r=0.25, p< 0.005) and one-leg stance test (r=0.335, p< 0.001). The results also showed a significant difference in non-dynapenic compared to type I dynapenic and type II dynapenic for the chair-stand test (Non-dynapenic: 12.0 +/- 3.0; Type I: 11.7 +/- 2.5; Type II: 10.33.0) (p=0.037 and p=0.005, respectively) and the one-leg stance test (Non-dynapenic: 54.2 +/- 14.2; Type I: 43.8 +/- 21.4; Type II: 35.0 +/- 21.8) (p=0.030 and p=0.004, respectively). Finally, a significant difference was observed between type II dynapenic and non-dynapenic for the chair-stand test (p=0.032), but not with type I dynapenic. Conclusion: The results showed that handgrip strength was positively correlated with functional capacity. In addition, non-dynapenic women displayed a better functional status when compared to type I and type II dynapenic women. Thus, the determination of the handgrip strength thresholds could be an accessible and affordable clinical tool to identify people at risk of autonomy loss.