Linking metabolic syndrome with low bone mass through insights from BMI and health behaviors.

The objective of this study is to investigate the relationship between metabolic syndrome (MetS), and bone density in a 30- to 50-year-old Taiwanese population, and to explore the combined effects of BMI and health behaviors on this association. A total of 52,912 individuals aged 30-50 years from the Taiwan Biobank were included in this cross-sectional study. Bone density status was assessed using quantitative ultrasound (QUS). The joint effect was assessed by including an interaction term in the multi-logistic regression models to test the association between MetS, BMI, and bone density while controlling for potential confounders. MetS was associated with reduced bone density, with the risk of severe low bone density (SLBD) higher among BMI < 24 kg/m individuals with MetS (adjusted odds ratio [aOR] 1.5, 95% confidence interval [CI] 1.09-2.16), while the risk was not significant among BMI ≥ 24 kg/m individuals with MetS. Smoking, alcohol consumption, and lack of regular exercise among individuals with a BMI < 24 kg/m and MetS were associated with higher risk of severe low bone density (SLBD), the aORs (95%CI) were 2.9 (1.59-5.20), 2.1 (1.06-4.22), and 1.8 (1.24-2.54) respectively. Our study suggests that metabolic syndrome could increase the risk of severe low bone density, but this risk can be minimized through higher BMI, non-smoking, no alcohol consumption, and regular exercise. Conversely, smoking, alcohol consumption or lack of regular exercise may exacerbate the risk of severe low bone density. These findings highlight the importance of a multifactorial approach in managing bone healthcare.