Association between liver enzymes and bone mineral density in Koreans: a cross-sectional study

Osteoporosis is a major health concern for both men and women, and associated fractures incur substantial economic burden. While there are a multitude of studies on bone mineral density (BMD) and liver diseases, not many studies have assessed the association between liver enzyme levels and BMD in homogeneous populations. The current study investigated the association between serum liver enzyme levels and BMD at various sites in Koreans. Out of 21,517 surveyees of the 5th Korean National Health and Nutrition Examination Survey (2010-2012), 7160 participants' data on BMD, serum liver enzymes, and full covariate data were included for cross-sectional analysis. BMD at the femoral neck, lumbar spine, entire femur, and whole body was assessed using dual energy X-ray absorptiometry (DEXA), and liver enzymes included aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma(gamma)-glutamyl transferase (GGT) levels. Differences in participant characteristics by BMD and liver enzyme levels were analyzed, and complex sample design regression analysis adjusted for multiple covariates was performed to assess the relationship between liver enzymes and BMD. Negative associations were seen with GGT and BMD at all sites (P 0.02), ALT with lumbar spine (P = 0.0013), and AST with lumbar BMD (P = 0.0009). In particular, GGT presented strong negative associations with BMD in postmenopausal women and elder men. This study demonstrates a negative relationship between liver enzyme levels and BMD, and suggests that a significant association exists between osteoporosis/decreased BMD and liver disorders.