Bone health status of the elderly in Taiwan by quantitative ultrasound

Bone density of the elderly in Taiwan was assessed by quantitative ultrasound bone densitometry of the heel in the Elderly Nutrition and Health Survey in Taiwan (1999-2000). Broadband ultrasound attenuation (BUA) was measured, and the corresponding Z-score was calculated. Physical examination data of 1123 males and 1034 females were included in the current analysis, and data of 752 males and 721 females who also had complete questionnaire information were used for analysis of relationships between several risk factors and BUA status. The results show that in elderly Taiwanese males, higher BMI and intake of dietary calcium is positively associated with a higher BUA Z-score. Advancing age and living in the second stratum in the southern areas appeared to be negatively associated with BUA Z-score in elderly females. BMI, height, years of education, and intake of dietary calcium were positive predictors of BUA Z-score. Further analysis was performed by grouping subjects according to the gender-specific medians of intake levels of dietary calcium, protein, and sodium. The results revealed that for both genders, those in the "high calcium/high protein" group had a higher mean BUA Z-score. The results of the current analysis show that in Taiwan, BMI and dietary calcium intake are positive predictors of BUA Z-score in elderly males, whereas BMI, height, years of education, and dietary calcium intake are positively associated with BUA Z-score in elderly females. The effects of dietary calcium intake may be influenced by the intake of other nutrients such as sodium and protein.