You're also at greater risk if you're extremely thin (with a body mass index of 19 or less) or have a small body frame because you may have less bone mass to draw from as you age.

如果你相当单薄(体重指数为19或更少)或者身体骨架很小的话，你患上骨质疏松的风险也很高，因为如果这样的话，当上年纪后你的骨量可能会较少而不胜流失。

youdao

OBJECTIVE: To analyze the effects of age, menopausal duration, menopause age, height, body mass and body mass index on bone mineral density (BMD) in postmenopausal women.

目的：分析年龄、绝经年限、绝经年龄、身高、体质量及人体质量指数对绝经后妇女骨密度的影响。

youdao

The researchers accounted for other factors affecting bone strength, including gender, age, body-mass index and lifestyle.

研究人员认为，包括性别、年龄、体质指数和生活方式等在内的其他因素也会影响骨骼强度。

youdao