Risk for osteoporosis in elderly nuns: need for better recognition and treatment

The risk for osteoporosis in Catholic sisters (nuns) may be even higher than that of the general female population given their longer life expectancy (82.0 to 89.0 years vs 79.6 years for the average white woman) and the use of a traditional habit as a young adult, resulting in limited sun exposure (ie, exposure to vitamin D).

The aim of this study was to determine, in a group of elderly nuns attending an annual health screening day (Health Forum), how many met National Osteoporosis Foundation (NOF) treatment criteria using peripheral bone mineral density (BMD) measurements and risk factors; what proportion received adequate vitamin D; whether BMD was related to length of time that nuns wore a habit; and whether BMD measurement led to medical interventions. In addition, we compared the usefulness of calcaneal BMD with that of BMD at central sites for identification of those at risk for osteoporosis.

This cross-sectional study assessed BMD by calcaneal dual energy X-ray absorptiometry (DXA) and, for some participants, central DXA. A baseline questionnaire and follow-up mail survey also were included.

Of the 230 nuns attending the Health Forum, 146 (63%) (mean age, 70 years; range, 48-90 years) participated in the study. Of these, 14% had calcaneal osteoporosis (T-score <-2.5) and 32% met NOF treatment criteria, indicating risk comparable to that of other postmenopausal American women. Sixty-four percent were receiving less than the recommended amount of vitamin D (≥400 IU/d for those aged <71 years and ≥600 IU/d for those aged ≥71 years). Calcaneal BMD was inversely related to the length of time nuns had worn a habit. Fifty-six women subsequently underwent central DXA. Using a calcaneal T-score of -1.2 to identify those with central osteoporosis, sensitivity and specificity of 78% and 76%, respectively, were obtained. According to the mail survey, 11 of 42 respondents who had met NOF treatment criteria started new medications for osteoporosis.

Elderly nuns are at substantial risk for osteoporosis. Most receive inadequate vitamin D. For nuns and others who may have limited access to central DXA measurement, peripheral measurements may help identify those in need of further intervention. Further efforts, in addition to BMD measurements, are necessary to ensure appropriate therapy for those who meet treatment criteria.