Optimal body mass index for protecting middle-aged and elderly patients with fatty liver from future fractures.

Objective: Previous studies have suggested that body mass index (BMI) should be considered when assessing the relationship between fatty liver (FL) and osteoporosis. The aim of this study was to investigate future fracture events in people with FL, focusing on the effect of BMI in both sexes.

Methods: This retrospective cohort study from 2011 to 2019 enrolled 941 people, including 441 women and 500 men, aged 50 years or older who underwent liver imaging (ultrasound, computed tomography, or magnetic resonance image) and dual-energy X-ray absorptiometry (DXA, for bone mineral density measurements). The study examined predictors of osteoporosis in both sexes, and the effect of different ranges of BMI (18.5-24, 24-27, and ≥27 kg/m2 in women; 18.5-24, 24-27, 27-30 and ≥30 kg/m2 in men) on the risk of future fractures in FL patients.

Results: The average follow-up period was 5.3 years for women and 4.2 years for men. Multivariate analysis identified age and BMI as independent risk factors for osteoporosis in both sexes. Each unit increase in BMI decreased the risk of osteoporosis by ≥10%. In both women and men with FL, a BMI of 24-27 kg/m2 offered protection against future fractures, compared to those without FL and with a BMI of 18.5-24 kg/m2.

Conclusion: The protective effect of a higher BMI against future fractures in middle-aged and elderly women and men with FL is not uniform and decreases beyond certain BMI ranges.