HEALTHY ELDERLY FRENCH WOMEN LIVING AT HOME HAVE SECONDARY HYPERPARATHYROIDISM AND HIGH BONE TURNOVER IN WINTER

It was recently demonstrated that calcium and vitamin D supplements we re capable of decreasing the incidence of hip fractures in institution alized elderly subjects through a reduction of senile secondary hyperp arathyroidism. As there are no appropriate data to recommend such a su pplement to the elderly living at home, the aim of this study was to d etermine the incidence of senile secondary hyperparathyroidism in old French women from the general community, its relation to vitamin D sta tus, and its contribution to bone turnover. Four hundred and forty wom en, aged 75-90 yr, were randomly selected from the general community b y mailing from electoral listing in 5 French cities whose latitude var ies from 49 degrees 9N to 43 degrees 6N. At the end of the winter, wom en with previous hip fractures or those who were institutionalized wer e excluded. The results obtained in these women were compared to those obtained in 59 institutionalized old women and 54 younger healthy wom en. In the five cities for the women living at home, we found a mean P TH value greater than that obtained in young women (63 +/- 28 vs. 43 /- 15 pg/mL; P = 0.001), but lower that that found in institutionalize d women (76 +/- 49 pg/mL; P = 0.05). The mean 25-hydroxyvitamin D (250 HD) level was not different in subjects from the 5 cities, but in all of them it was significantly greater than that found in 59 institution alized women (42.5 +/- 25.0 us. 15.5 +/- 6.5 nmol/L; P = 0.0001) but l ower than that in young adults (P < 0.001). The main determinants of P TH were in equal ratio, i.e. age (r = 0.19;P < 0.001), 25OHD, and, to a lesser degree, creatinine clearance (r; 0.10; P = 0.03). For 25OHD, the main determinant was the personal outdoor score and, to a lesser e xtent, the amount of daily sunlight in the city. The mean values of bi ochemical markers of bone turnover, bone alkaline phosphatase, osteoca lcin, and Crosslaps, were significantly increased compared with the re sults obtained in young women, and significant negative correlations w ere found between these markers and hip bone mineral density. These re sults show that vitamin D status of a French aged population in good h ealth and living at home depends mainly on lifestyle. Like institution alized women, old women living at home exhibit clear evidence of senil e hyperparathyroidism in the winter, secondary in part to a reduced 25 OHD level and associated with biological signs of increased bone turno ver. The maintenance of PTH within the normal range for healthy adults by vitamin D and calcium treatment might constitute an approach for t he prevention of bone loss in the entire aged population.