Leptin, osteocalcin, and bone mineral density in post-hepatitic liver cirrhosis

ABSTRACT

The pathophysiology of osteoporosis complicating chronic liver disease is unknown. Some studies have found leptin to be a potent inhibitor of bone formation. The aim of this study is to investigate the relationship between leptin, osteocalcin and bone mineral density [BMD] in liver cirrhosis. Sixty patients with post-hepatitic liver cirrhosis were classified into three groups group I, 20 pre-menopausal females; group II, 20 post-menopausal females; and group III, 20 males. In addition, 21 age- and sex-matched healthy subjects [seven for each group] were included as control subjects. Patients were classified according to Child-Pugh classification into grade A [n = 0], grade B [n = 38] and grade C [n = 22]. Serum osteocalcin, leptin and parathyroid hormone [PTH], in addition to liver functions test, hepatitis B surface antigen [HBsAg], anti-hepatitis C virus [HCV], serum phosphorus and calcium were measured. Bone mineral density [BMD] was measured by calcaneal ultrasound. Leptin was elevated in all groups [I, II and III] when compared with their control groups [p < 0.01, p < 0.001 and p < 0.01, respectively]. Further, it was high in female groups [I and II] compared to males [group III], [p < 0.01 each]. BMD and serum osteocalcin decreased in each group compared with the respective control [p < 0.001; p < 0.01 in group I, p < 0.05; p < 0.001 in group II and p < 0.001; p < 0.001 in group III, respectively]. In the Child-Pugh grade C group, BMD and osteocalcin were low [p < 0.001, p < 0.05, respectively], while serum leptin was elevated [p < 0.05], when compared with grade B group. Leptin correlated negatively with serum osteocalcin [r = -0.553; p < 0.001], BMD [r = -0.229; p < 0.05], albumin [r = -0.449; p < 0.001] and albumin/globulin [A/G] ratio [r = -0.661; p < 0.001], while positively correlated with both aspartate transaminase [AST] [r = 0.462; p < 0.001], and alanine transaminase [ALT] [r = 0.483; p < 0.001]. Osteocalcin negatively correlated with intact iPTH [r = -0.370, p < 0.001], while positively correlated with BMD [r = 0.418; p < 0.001], albumin [r = 0.659; p < 0.001] and A/G ratio [r = 0.444; p < 0.001]. Serum leptin was elevated in cirrhotic patients and may have a role in the pathogenesis of osteoporosis in liver cirrhosis