Metabolic bone disease in primary biliary cirrhosis

Diagnosis and Management of Cirrhosis-Related Osteoporosis

Management of cirrhosis complications has greatly improved, increasing survival and quality of life of the patients. Despite that, some of these complications are still overlooked and scarcely treated, particularly those that are not related to the liver. This is the case of osteoporosis, the only cirrhosis complication that is not solved after liver transplantation, because bone loss often increases after immunosuppressant therapy. In this review, the definitions of bone conditions in cirrhotic patients are analyzed, focusing on the more common ones and on those that have the largest impact on this population. Risk factors, physiopathology, diagnosis, screening strategies, and treatment of osteoporosis in cirrhotic patients are discussed, presenting the more striking data on this issue. Therapies used for particular conditions, such as primary biliary cirrhosis and liver transplantation, are also presented.

Alendronate is more effective than etidronate for increasing bone mass in osteopenic patients with primary biliary cirrhosis

OBJECTIVES

Osteopenia increases the morbidity of primary biliary cirrhosis (PBC). In this study, we have compared two bisphosphonates, alendronate and cyclical etidronate, that inhibit osteoclast-mediated bone resorption and have examined their effects on bone mass in patients with this disease.

METHODS

A total of 32 women with PBC were randomly assigned to receive alendronate (10 mg/day) or etidronate (400 mg/day) for 14 days every 3 months. Bone mineral density of the lumbar spine and proximal femur were measured initially and every 6 months. Bone fractures and markers of bone mineral metabolism were also evaluated.

RESULTS

Sixteen patients were allocated to each group, which were comparable with respect to the severity of PBC and osteopenia. Thirteen patients in each group completed the 2-yr trial. Both treatments increased bone mineral density after 2 yr, although the increase at the lumbar spine and at the proximal femur was significantly higher in patients receiving alendronate than in patients on etidronate. This higher effect of alendronate paralleled with changes in the biochemical markers of bone turnover. No patient developed new vertebral fractures, but new peripheral fractures were detected in two patients on alendronate and in one on etidronate. There were no serious adverse effects. Neither treatment impaired liver function or cholestasis.

CONCLUSIONS

Alendronate effectively increases bone mass and has greater antiresorptive power than etidronate in patients with primary biliary cirrhosis, and is associated with minor or no side effects.

Evidence of continuing bone recovery at a mean of 7 years after liver transplantation

Patients with end-stage liver disease have low bone-turnover osteoporosis, and there is often further bone loss of 20% to 30% after orthotopic liver transplantation (OLT). Bone recovery after OLT has been reported, but data are limited. We undertook studies to determine whether bone recovery continues in the long term. Twenty-eight adult patients alive at least 5 years after OLT were studied (14 men, 14 women). Bone mineral density (BMD), serum parathyroid hormone (PTH), osteocalcin, and vitamin D levels were measured pretransplantation, at 3 months, 12 months, a mean of 46 months, and a mean of 85 months (range, 63 to 117 months) after transplantation. When BMD is expressed as a z score, the results were as follows: x0.82 +/- 0.22 pre-OLT; -2.04 +/- 0.27 at 3 months; -1.68 +/- 0.24 at 12 months; -1.23 +/- 0.24 at a mean of 46 months; and -1.0 +/- 0.26 at a mean of 85 months after OLT. The results at 46 and 85 months were significantly greater than the measurement at 3 months after OLT (P <.05). Furthermore, mean BMD (expressed as a z score) returns to the pre-OLT level at a mean of 85 months. At final follow-up, 9 of 28 patients had elevated PTH levels, and 14 of 27 patients had elevated osteocalcin levels. Five patients had spontaneous fractures in the first 12 months after transplantation, and 5 more patients had fractures by final follow-up. Even at 7 years after OLT, there was a significant increase in BMD (expressed as a z score) compared with 3 months after transplantation. Elevation of serum PTH and osteocalcin levels in some patients suggests continuing bone remodeling.