['Hepatic osteodystrophy has been reported in patients with various chronic liver diseases, including liver cirrhosis. However, it has not been well investigated in patients with hepatitis B virus infection. The aim of this study was to investigate the association between hepatitis B surface antigen (HBsAg) seropositivity and bone mineral density (BMD) in a population representative of normal Koreans.', 'Subjects with both HBsAg and BMD levels examined during the 2008-2010 Korea National Health and Nutrition Examination Surveys were included. HBsAg-seropositive (+) subjects were compared with those who were HBsAg-seronegative (-). BMD was measured at the lumbar spine and femur by dual-energy X-ray absorptiometry. Multivariable logistic regression was performed for BMD .', 'In total, 11,306 participants were included in this study, among which 423 (3.7\xa0%) were HBsAg(+): 153 premenopausal female (3.4\xa0%), 83 postmenopausal female (3.5\xa0%), and 187 male (4.2\xa0%). Multivariable logistic regression analysis adjusted for age and body mass index showed that HBsAg(+) male had significantly lower BMD of the femoral neck than HBsAg(-) male (0.810\xa0±\xa00.009 vs. 0.827\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.035). Further adjustment for waist circumference, smoking, drinking, exercise, income, occupation, and vitamin D levels showed that HBsAg(+) male had significantly lower BMD of the femur neck (0.810\xa0±\xa00.010 vs. 0.831\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.032) and lumbar spine (0.953\xa0±\xa00.011 vs. 0.974\xa0±\xa00.003\xa0g/cm(2), p\xa0=\xa00.049) than HBsAg(-) male.'] Are males seropositive for hepatitis B surface antigen at risk of lower bone mineral density : the 2008-2010 Korea National Health and Nutrition Examination Surveys?