Effect of age, weight and lifestyle factors on calcaneal quantitative ultrasound in premenopausal women: the ESOPO study.

The objective of this study was to identify the determinants of bone mass as measured by quantitative ultrasound (QUS) in premenopausal women. The study population is part of the "Epidemiological Study On the Prevalence of Osteoporosis" (ESOPO) on risk of the general population of Italy. We report the data on 2727 premenopausal women aged 40-50 years who are still regularly menstruating. Bone stiffness (called simplicity stiffness), which is derived from the values of broadband ultrasound attenuation (BUA) and speed of sound (SoS), was measured by a heel QUS device (Achilles Apparatus, Lunar, Co. USA). The most commonly recognized determinants of bone mass were modelled with stiffness by multiple regression analysis or analysis of variance (ANOVA). Bone stiffness was negatively related to age and number of cigarettes and positively to body weight, body weight at 25 years, height and estimated daily calcium intake. By multiple regression analysis, independent, positive, predictors of bone stiffness were age, weight at 25 years and daily calcium intake. Bone stiffness adjusted for age and body weight at 25 years was positively associated with outdoor activity score and negatively with number of pregnancies, chronic use of any drug, smoking and subjective health status. Bone stiffness was also somewhat (p < 0.015) negatively related to history of prolonged bedrest and thyroxin use. In conclusion, our results indicate that risk factors usually associated in other studies with DXA-BMD in elderly women are also associated with calcaneal bone stiffness, as measured by QUS in premenopausal women. These findings should help to identify premenopausal women at risk and to design an early strategy for osteoporosis prevention based on eliminating modifiable risks.