Effects of combined interferon alpha and ribavirin therapy on thyroid functions in patients with chronic hepatitis C.

OBJECTIVE To determine the frequency of thyroid dysfunction in patients of chronic hepatitis C during treatment with interferon alpha-2b and ribavirin therapy. STUDY DESIGN A cohort study. PLACE AND DURATION OF STUDY Army Medical College and Military Hospital, Rawalpindi, from February 2006 to January 2007. METHODOLOGY One hundred and sixty seven non-cirrhotic chronic hepatitis C patients were grouped into treatment group (n=107) and control group (n=60) awaiting treatment. Baseline serum(s.) Alanine Transferase (ALT) and S. Aspartate Transferase (AST) were measured by IFCC method. Serum Thyroid Stimulating Hormone (S. TSH), serum free thyroxine (S. Free T4) and serum total triiodothyronine (S.T3) level were determined by chemiluminescence. Study group patients underwent 24 weeks IFN and ribavirin therapy and were followed-up for thyroid dysfunction at weeks 0, 12 and 24. Control group patients underwent the same tests at weeks 0, 12 and 24. Statistical analysis was done on SPSS 15. RESULTS Out of 107 patients of treatment group, 20 patients (18.69%) developed thyroid dysfunction. Females were at higher risk with Relative Risk (RR) of 11.25 and Attributable Risk (AR) of 91%. Hypothyroidism was more common than hyperthyroidism. CONCLUSION Interferon-alpha and ribavirin therapy induces thyroid dysfunction in chronic hepatitis C patients. Hypothyroidism was more common. Females are at a higher risk of developing thyroid dysfunction.