Bone density, vitamin D status, and disordered bone remodeling in end-stage chronic liver disease

Hepatic osteodystrophy occurs in up to 50% of patients with chronic liver d isease (CLD). The aim of this study was to determine the relative contribut ion of increased resorption and decreased formation to hepatic osteodystrop hy by measuring biochemical markers. Twenty-seven patients with advanced CL D (14 female, 13 male) were enrolled. Bone mineral density (BMD), measured at the lumbar spine, and femoral neck, were measured by dual energy X-ray a bsorptiometry (DXA); bone turnover was assessed using biochemical markers o f bone formation and resorption. Based on WHO criteria, osteoporosis and os teopenia were present in 41% and 18% of patients, respectively. All three m arkers of bone resorption (free deoxypyridinoline, pyridinoline, and hydrox yproline) were increased significantly in patients with CLD. There was a le ss marked change in the markers of bone formation (osteocalcin, procollagen type 1 peptide, and bone alkaline phosphatase), resulting in a negative un coupling index in 23/27 (85%) of the patients. Only two (7%) patients had b iochemical changes consistent with osteomalacia. The results suggest that i ncreased bone resorption is the predominant cause of hepatic osteodystrophy and therapeutic strategies should be designed to suppress bone resorption, especially in preparation for liver transplantation. Bone biomarkers may b e useful alternatives to bone biopsy in evaluating hepatic osteodystrophy.