The relationship between fatty liver index and bone mineral density in Koreans: KNHANES 2010-2011.

UNLABELLED

Analyses using a nationally representative cohort have revealed that high fatty liver index (FLI) is associated with low bone mineral density (BMD) regardless of insulin resistance in men, thereby supporting the deteriorated bone metabolism in nonalcoholic fatty liver disease (NAFLD).

INTRODUCTION

NAFLD is linked to deteriorated bone health. We investigated the association of FLI, a scoring model for NAFLD, with BMD.

METHODS

This was a population-based, cross-sectional study from the Korea National Health and Nutrition Examination Surveys including 4264 Koreans (1908 men and 2356 women). FLI was calculated using body mass index, waist circumference, serum triglyceride, and gamma-glutamyltranspeptidase level. Insulin resistance was evaluated using the homeostasis model assessment-estimated insulin resistance (HOMA-IR) index. BMD was measured using dual-energy X-ray absorptiometry at the lumbar spine, total hip, femoral neck, and whole body.

RESULTS

Men had a higher FLI than women, while the HOMA-IR index was similar between men and women. The significant association between FLI and BMD was observed only in men, but not in women. FLI was negatively correlated with total hip, femoral neck, and whole body BMD in men after adjusting for all potential confounders, including HOMA-IR (P < 0.001 to 0.010). Lumbar spine, total hip, femoral neck, and whole body BMD in men showed a decreasing trend as the FLI tertile increased after adjusting for all potential confounders, including HOMA-IR (P for trends < 0.001 to 0.034). In men aged 50 years or older, odds ratios for combined osteopenia and osteoporosis increased across increasing FLI tertiles after adjusting for confounders (P for trends < 0.011 to 0.029).

CONCLUSION

NAFLD is associated with low bone density regardless of insulin resistance in men. These findings suggest an undiscovered direct link between liver and bone that increases the risk of osteoporosis in men with NAFLD.