Osteoporosis in primary biliary cirrhosis revisited

Background - Primary biliary cirrhosis (PBC) is increasingly being diagnose d in the earlier non-cholestatic stages of disease. Accepted wisdom has bee n that PBC is frequently complicated by osteoporosis. Whether this associat ion holds true for the broader spectrum of PBC patients now recognised has not as yet been studied. Aims - To examine the extent to which osteoporosis occurs more commonly in PBC patients than in normal individuals of the same age and sex. Design - Retrospective review of a large cohort of well characterised PBC p atients. Patients - A total of 272 PBC patients with definite or probable PBC follow ed up for a mean of 10.1 years (total follow up 2726 patient years) who had at least one bone mineral density measurement (BMD). Results - In this unselected group of PBC patients, mean Z scores (number o f SDs from age and sex matched normal mean values) at the neck of femur (NO F) and lumbar spine (LS) at first BMD measurement (7 (6) years after PBC di agnosis) were -0.1 (1.4) and 0.1 (1.4), respectively. At first BMD measurem ent, 18 PBC patients had Z scores less than -2.0 and 85 had T scores less t han -2.5. No factors predictive of osteoporosis were found in affected pati ents. A total of 957 BMD measurements were performed (0.35 per patient year of follow up); 220 patients had two or more measurements. No patient went on to develop de novo osteoporosis during follow up. In the 51 patients (wh o were clinically representative of the whole group) who received no PBC or bone related treatment during follow up, %BMD changes per year at the NOF and LS were -1.6 (3.2) and 0.1 (2.2), respectively. No variance in this "na tural" rate of BMD measurement was seen in patients receiving PBC modulatin g agents (including prednisolone and UDCA) or osteoporosis prophylaxis/ther apy. Significant improvement at the LS was seen in patients undergoing live r transplantation. Conclusions-Osteoporosis is not a specific complication of PBC.