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

Abstract 

Background and study aims

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.

Patients and methods

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.

Results

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).

Conclusion

Serum leptin was elevated in cirrhotic patients and may have a role in the pathogenesis of osteoporosis in liver cirrhosis.

Keywords: Liver cirrhosis, Leptin, Bone density, Osteocalcin