Association between quantitative bone ultrasound and self-reported physical activity in nursing homes residents.

Abstract

Low bone mineral density has been reported in institutionalized old people, but limited data are available on the association between bone density and physical activity (PA) and calcium intake in that population. We explored the predictors of bone density in old people living in nursing homes, focusing on PA and calcium intake. In a cross-sectional study, we measured bone density with quantitative ultrasound (QUS) in 292 nursing homes residents (233 women and 59 men), mean age 82.4 ± 6.5years. Information on lifestyle habits and calcium intake was obtained with questionnaires. All QUS bone parameters were significantly higher in men than in women (p < 0.001). A T score for quantitative ultrasound index (QUI) of - 2.2 or lower was found in 8.5% of men and 51.9% of women. Participants of both genders with low PA had a significantly lower QUI, QUI-T score compared to those with good/very good PA. When controlling for age, gender, body mass index and calcium intake, participants with good PA had better QUI than those with low PA (β = 7.12 with 95% CI [2.51, 11.74]) The odds of QUI-T score < - 2.2 were lower (OR 0.49 with 95% CI [0.27, 0.90]) in participants with good PA compared to those with low PA. The prevalence of osteoporosis measured by QUS was high in women but not in men. In our study sample, PA played a more important role than calcium intake in preserving bone density in old people.