Osteoporosis in patients with primary biliary cirrhosis

Abstract

Metabolic bone disease has been recognized as an important complication of chronic liver disease particularly in cholestatic disorders [primary biliary cirrhosis (PBC) and primary sclerosing cholangitis] and after liver transplantation. It includes osteoporosis and more rarely osteomalacia, which is more frequent in severe malabsorption and advanced liver disease. The pathogenesis of this disorder is complex and is likely to be multifactorial. Regardless of the etiology of osteoporosis in PBC patients, they have an increased risk of spontaneous or low-trauma fracturing leading to significant patient morbidity, deterioration of quality of life, and even patient mortality. The development of bone densitometry has allowed assessment of bone mass and then contributed in estimating the fracture risk. The gold standard of bone mineral density measurement is currently the dual- energy X-ray absorptiometry. Recommendations formulated by the World Health Organization have reported the diagnostic ranges of osteoporosis based on the t-score: patient with osteoporosis has a t-score less than -2.5 SD, osteopenia has a t-score between -1.0 and -2.5 SD and a normal individual has a t-score more than -1.0 SD. The risk of fracture shows a correlation with bone mineral density but no fracture threshold was determined and the best site of characterizing the hip fracture risk is the measure of the bone mineral density of the proximal femur. The treatment of osteoporosis in patients with PBC is largely based on trials of patients with postmenopausal osteoporosis as there are a few and smaller studies of osteoporotic patients with PBC. Bisphosphonates seem to be effective in biliary disease and are more tolerated.