Increased Risk of Low Bone Mineral Density in Patients with Non-Alcoholic Fatty Liver Disease: A Cohort Study

Abstract

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 study aims to explore the effect of NAFLD and its severity on low BMD in a longitudinal cohort study. 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 defined as fatty liver by ultrasound detection. Findings: A total of 1,720 subjects were included (1,064 subjects with normal BMD and 656 subjects with low BMD) at baseline. Among 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(1.178, 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, obesity and women with NAFLD at baseline, are more likely to develop low BMD. Interpretation: 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. Funding Statement: Supported by National Natural Science Foundation of China (No.81770586). Declaration of Interests: Zhe Shen, Li Cen, Xufeng Chen, Jiaqi Pan, Youming Li, Weixing Chen and Chaohui Yu declare that they have no confict of interest. Ethics Approval Statement: The present study was approved by the Research Ethics Committee of the First Affiliated Hospital, College of Medicine, Zhejiang University (IRB No.2018-980).