RECTAL STEROIDS SUPPRESS BONE-FORMATION IN PATIENTS WITH COLITIS

Background: The aetiology of bone loss in inflammatory bowel disease i s multifactorial, but oral corticosteroids are an important contributo ry factor. Rectally administered steroids are widely used in patients with distal disease, but very little is known about their effect on bo ne metabolism. The aim of this study was to investigate the effect of a standard course of rectal prednisolone on biochemical markers of bon e turnover. Methods: In a longitudinal study of 10 patients, biochemic al markers of bone turnover were measured before, during and after tre atment with prednisolone metasulphobenzoate (Predfoam, Pharmax Ltd) 20 mg twice daily for 2 weeks. Bone formation markers measured were seru m osteocalcin (BGP), bone-specific alkaline phosphatase (BALP) and pro collagen carboxyterminal propeptide (PICP), Urinary deoxypyridinoline (dPyr) was measured to assess bone resorption. Results: Disease activi ty scores improved during treatment (difference in mean Powell-Tuck sc ore = 2.3 (+/-3.1), 95% CI: 0.11-4.48, P = 0.04). There was a signific ant fall in BALP (P = 0.02) during treatment, and a rapid but non-sign ificant fall in BGP (P = 0.19). PICP (0.42), and urinary dPyr (0.30) d id not change significantly during treatment. Conclusions: Following a standard 2-week course of rectal prednisolone metasulphobenzoate, we observed a significant fall in bone-specific alkaline phosphatase acti vity. These results suggest that bone formation is suppressed in patie nts with distal colitis treated with pharmacological doses of rectal s teroids.