Increased risk of low bone mineral density in patients with non-alcoholic fatty liver disease: a cohort study

Background Non-alcoholic fatty liver disease (NAFLD) has been suggested to be a risk factor associated with low BMD (bone mineral density) in several cross-sectional studies. The present longitudinal cohort study aims to explore the effect of NAFLD and its severity on low BMD. Methods Between January 2013 and August 2018, individuals who participated in annual comprehensive health examinations were included. BMD was presented using dual-energy X-ray absorptiometry (DXA). These subjects were diagnosed with fatty liver by ultrasound detection. Results A total of 1720 subjects were included (1064 subjects with normal BMD and 656 subjects with low BMD) at baseline. Among the 1064 participants with normal BMD at baseline, 399 participants developed low BMD. The multivariable-adjusted hazard ratio for incident low BMD comparing the NAFLD group vs the non-NAFLD group was 2.24 (1.18, 2.81). Increased non-invasive fibrosis markers of NAFLD were positively associated with an increased incidence of low BMD in a graded manner. In addition, obese subjects and women with NAFLD at baseline are more likely to develop low BMD. Conclusion NAFLD and its severity were independently associated with an increased incidence of low BMD. Obesity and female gender are risk factors associated with low BMD. Our findings indicated NAFLD can be a significant contributor to low BMD pathogenesis, requiring further studies to elucidate the potential mechanisms.