[Association between height loss and calcaneus bone mineral density in Chinese adults]

Objective: To examine the association between height loss and calcaneus bone mineral density (BMD) through data gathered from the China Kadoorie Biobank (CKB). Methods: The present study included 24 231 participants who attended the CKB resurvey during 2013-2014, in which calcaneus BMD was measured by quantitative ultrasound method for the first time. Height loss was calculated according to the differences appeared in height measurement between baseline and resurvey. We used linear regression models to estimate the association between height loss and BMD measures. Results: The mean interval between baseline and resurvey was (8.0±0.8 ) years. 33.0% of the participants showed a height loss of ≥1.0 cm, and another 3.7% were with height loss of ≥3.0 cm. After adjustment for potential confounders, there was a linear correlation seen between height loss and BMD (P for all linear trend were <0.001). The βs (95%CIs) for each 1.0 cm of height loss were -0.79 (-0.95--0.63) for broadband ultrasound attenuation (BUA), -2.74 (-3.35--2.13) for speed of sound (SOS), and -1.29 (-1.54--1.04) for stiffness index (SI). Compared with participants with stable height, the multivariate-adjusted βs (95%CIs) for those with height loss of ≥3.0 cm were -3.29 (-4.08--2.50) for BUA, -10.70 (-13.66--7.73) for SOS, and -5.16 (-6.36--3.96) for SI, respectively. According to the subgroup analyses, the association of height loss with BMD measures seemed to be more apparent among females, in those aged ≥55 years, and those being less physically active. Conclusions: BMD became lower with the increase of height loss. Regular height measurement may contribute to the early diagnosis and prevention of osteoporosis.