Association of nonalcoholic fatty liver disease with low bone mass in postmenopausal women

Osteoporosis is a disease associated with insulin resistant states such as central obesity, diabetes, and metabolic syndrome. Non-alcoholic fatty liver disease (NAFLD) is also increased in such conditions. However, little is known about whether osteoporosis and nonalcoholic fatty liver disease are etiologically related to each other or not. We examined whether bone mineral density (BMD) is associated with NAFLD in pre- and postmenopausal women. Four hundred eighty-one female subjects (216 premenopausal and 265 postmenopausal) were enrolled. Lumbar BMD was measured using dual-energy X-ray absorptiometry. Liver ultrasonography was done to check the severity of fatty liver. We excluded subjects with a secondary cause of liver disease. Blood pressure, lipid profile, fasting plasma glucose, alanine aminotransferase (ALT), aspartate aminotransferase, and body mass index were measured in every subject. Mean lumbar BMD was lower in subjects with NAFLD than those without NAFLD in postmenopausal women (0.98 +/- A 0.01 vs. 1.01 +/- A 0.02 g/cm(2), P = 0.046). Multiple correlation analysis revealed a significant association between mean lumbar BMD and NAFLD in postmenopausal subjects after adjusting for age, body mass index, ALT, smoking status, and alcohol consumption (beta coefficient -0.066, 95% CI -0.105 to -0.027, P = 0.001). Even after adjusting the presence of metabolic syndrome, the significance was maintained (beta coefficient -0.043, 95% CI -0.082 to -0.004, P = 0.031). Lumbar BMD is related with NAFLD in postmenopausal females. We suggest that postmenopausal women with NAFLD may have a higher risk of osteoporosis than those without.