High prevalence of low femoral bone mineral density in elderly women living in nursing homes or community-dwelling: A plausible role of increased parathyroid hormone secretion

The present study was designed to visit elderly women living in nursing hom es and to compare their femoral neck bone mineral density (BMD) and circula ting levels of parathyroid hormone (PTH) and 25-OH vitamin D (25-OHD) with those of subjects living at home, in the immediate vicinity of the nursing homes. Of 1483 women, aged 70 years and older, who were selected, 993 agree d to participate in this trial. Their femoral neck BMD (n = 993) was measur ed by dualenergy X-ray absorptiometry, with a specific device installed in a mobile truck. The circulating levels of 25-OHD and PTH were assessed afte r an overnight fast (n = 748). After stratification for age, there were no significant differences in mean femoral neck BMD values, prevalence of femo ral neck osteoporosis, mean serum 25-OHD and prevalence of absolute or rela tive 25-OHD deficiency between the two groups. Serum levels of PTH were sig nificantly higher in women over 80 years old living in nursing homes, compa red with the community-dwelling women. After adjustment for age, a signific ant relation was found between femoral neck BMD and PTH levels in the whole population (p = 0.004) and in community-dwelling subjects (p = 0.039). Whe n stratifying our population by quartiles of serum PTH values, the odds rat ios for femoral neck osteoporosis were significantly increased for the top two quartiles compared with the lowest one both before (p = 0.00146) and af ter (p = 0.0013) adjustment for age and type of housing, From this study we conclude that femoral osteoporosis is largely underestimated in European w omen, Living in a nursing home is not, per se, a risk factor for decreased femoral BMD, and circulating PTH levels are a key determinant of low femora l bone density and osteoporosis.