Handgrip strength is an independent predictor of distal radius bone mineral density in postmenopausal women

Several cross-sectional studies have reported a positive correlation betwee n muscle strength and local bone mineral density. However, very few studies have evaluated the possible role of confounding variables, which may be su bstantial as both bone mineral density and muscle strength are multifactori al variables. We studied 140 postmenopausal women who underwent their first osteodensitometry in our hospital. Of these, 102 women affected neither by bone diseases apart from primary osteoporosis nor treated with drugs affec ting bone mass were selected. Distal radius bone mineral density of the non -dominant arm was assessed by dual photon absorptiometry. Handgrip strength was measured by a handheld dynamometer. The following factors influencing bone mass were also considered: age, years since menopause, years of cyclic ovarian activity, body weight, body height, body mass index, and both calc ium and alcohol dietary intake. Statistical evaluation was performed by ste pwise multiple regression analysis. This showed that only two variables wer e independently related to bone mineral density: handgrip strength (which w as the best bone density predictor among the studied independent variables) and years since menopause. R-2 value was 0.43 (F=38.04, p<0.001). All the other variables studied were not significantly related to bone density when the effects of both strength and years since menopause were considered. In conclusion, the data showed that handgrip strength was a strong independen t predictor of distal radius bone mineral density in postmenopausal women. Clinical assessment of osteoporosis risk factors, including muscle strength , is recommended: although it is not an adequate substitute for bone densit ometry, it can help clinicians to identify the risk groups at which to dire ct bone density measurement.