RISK-FACTORS FOR THE DEVELOPMENT OF VERTEBRAL AND TOTAL SKELETON OSTEOPOROSIS IN PATIENTS WITH PRIMARY BILIARY-CIRRHOSIS

The objectives of this work was to (1) study the bone mineral density (BMD) of the lumbar spine, total skeleton, and body composition in pat ients with primary biliary cirrhosis (PBC) and (2) evaluate the risk f actors (premature menopause, stages of the disease, hyperbilirubinemia ) and bone and liver biochemical parameters for the development of ost eoporosis. We studied 23 women with a compatible diagnosis of PBC. The BMD and body composition were evaluated by X-ray absorptiometry (Luna r DPX-L). The average age of the population was 56.7 +/- 10.2 years. T he BMD of the lumbar spine and of the total skeleton was 1.3 SDs below the normal population matched for sex and age. In the total skeleton, the legs were the most severely affected area (Z score -1.5). The bod y composition showed no significant difference compared with the norma l population. The BMD of 56% of the patients was less than -2.5 SDs fr om the average normal young values. Patients with a history of vertebr al fractures had diminished mineral density of the lumbar spine, as di d those who had had no fractures. Of the risk factors studied, patient s with premature menopause had a lower bone mass compared with patient s with normal menopausal age (Z score of the total skeleton was -2.1 /- 1.8 versus -1.1 +/- 1.0) but the difference did not reach statistic al significance. The bone mass was not affected in patients with regul ar menstrual cycles. There were no statistically significant differenc es in high levels of bilirubin, advanced stages of the disease, or the biochemical variables studied. It is concluded that patients with pri mary biliary cirrhosis present diminished cortical and trabecular bone mass, whereas body composition was unaffected. Premature hormone defi cit, possibly triggered by the chronic hepatic pathology, is a contrib uting factor to the osteoporosis in this population.