CAN WE STOP BONE LOSS AND PREVENT HIP-FRACTURES IN THE ELDERLY

The two main determinants of hip fractures are falls and bone loss lea ding to an intrinsic femoral fragility. Substantial femoral bone loss continues throughout old age, with a continuous and exponential increa se in the risk of hip fracture; thus any reduction or arrest of this l oss will induce an important reduction in the incidence of hip fractur e. Preventive measures may be achieved during childhood by increasing peak bone mass with calcium and exercise, by using long-term estrogen replacement therapy after menopause, but also by using vitamin D and c alcium supplements for late prevention in the elderly. Vitamin D insuf ficiency and a deficit in calcium intake are very common in the elderl y living either in institutions or at home and the cumulative response to these deficits is a negative calcium balance which stimulates para thyroid hormone secretion. This senile secondary hyperparathyroidism i s one of the determinants of femoral bone loss and can be reversed by calcium and vitamin D supplements. We have shown in a 3-year controlle d prospective study that the daily use of supplements (1.2 g calcium a nd 800 IU vitamin D3) given in a large population of 3270 elderly ambu latory women living in nursing homes reduced the number of hip fractur es by 23% (intention-to-treat analysis). In parallel, serum parathyroi d hormone concentrations were reduced by 28% and low baseline serum 25 -hydroxyvitamin D concentration returned to normal values. After 18 mo nths of treatment the bone density of the total proximal femoral regio n had-increased by 2.7% in the vitamin D3-calcium group and decreased by 4.6% in the placebo group (p < 0.001). This prevention is safe and can be recommended for people living in institutions. It could also be useful in other elderly subjects at particular risk due to a low calc ium intake, an absence of solar exposure, a low femoral bone density, a high serum parathyroid hormone concentration, a low serum 25-hydroxy vitamin D concentration and a previous history of falls. Prospective s tudies are needed for further evaluation of these risk factors.