Introduction: Body height loss (BHL) greater than 5 mm is reported to be associated with increased mortality. Although new vertebral fractures (VFs) contribute to BHL in patients with osteoporosis, BHL can also occur in the absence of new VFs. This study aims to identifyfactors, other than VFs, that are associated with BHL in individuals with osteoporosis.
Methods: This study included 413 of 458 patients who visited our osteoporosis outpatient clinic and were re-assessed one year later, excluding 45 patients with VFs within the year timeframe. Body height was measured at baseline (first visit) and one year later, with a difference greater than 5 mm defined as the BHL (+) group. Data on age, sex, body mass index, lumbar spine of bone mineral density (BMD), Controlling Nutritional Status (CONUT) score, TRACP5b level, sagittal vertical axis (SVA), number of prior VFs, grip strength, and lean muscle mass at baseline were compared between the BHL (+) and BHL (−) groups. The CONUT score evaluated the nutritional status of individuals, and SVA measured the spinal sagittal alignment. Multiple logistic regression analysis was performed to identify independent risk factors for BHL. A correlation analysis was conducted between the changes in height and other measurements. Comparisons between the BHL(+) and BHL (−) groups were also performed.
Results: A total of 104 patients (25.2%) had BHL greater than 5 mm. The BHL (+) group had a significantly higher age and SVA compared to the BHL (−) group (p < 0.05). Multiple logistic regression analysis identified higher SVA at baseline as an independent predictor of BHL. A weak correlation was observed between the changes in BHL and muscle mass. Additionally, the BHL (+) group showed significantly smaller changes of lumbar spine of BMD, lean muscle mass, and body weight compared to the BHL (−) group (p<0.05).
Discussion: More than 25% of patients with osteoporosis experienced a BHL greater than 5 mm. Older age and higher SVA were associated with BHL after one year, even in the absence of new VFs. Furthermore, higher SVA was identified as an independent risk factor for BHL. In contrast, BHL was associated with a limited increase in BMD, despite the administration of appropriate medications for osteoporosis, and with significant reductions in muscle mass and body weight. BHL has been reported to be linked to an increased risk of fragility fractures, gastrointestinal symptoms, cardiovascular disease, and mortality. These findings highlight the importance of addressing not only VFs prevention but also spinal sagittal malalignment and muscle mass reduction to mitigate BHL and its associated complications.