The effect of anti-TNF therapy on thyroid function in patients with inflammatory bowel disease.

The aim of this study was to investigate for first time the thyroid function in patients with inflammatory bowel disease (IBD) and the potential effect of anti-TNF (tumor necrosis factor) therapy. We evaluated 41 patients with IBD (25M/16F, 36.5 ± 11.3 y, 27 with Crohn's disease and 14 with ulcerative colitis), without any known thyroid disorder. Eighteen patients (9M/9F, 33.6 ± 8.8 y) were on anti-TNF therapy, while 23 patients (16M/7F, 38.7 ± 12.5 y) were treated with Azathioprine and Mesalazine (Aza/Mes) for more than 1 year. Twelve patients from the second group were then treated with anti-TNF and studied 6 months later. We assessed thyroid function by measuring thyroid stimulating hormone (TSH), free thyroxine (FT4), triiodothyronine (T3), thyroid peroxidase autoantibodies (TPOAb) and thyroglobulin autoantibodies (TgAb) levels. One patient presented with overt and one with subclinical hyperthyroidism. Thyroid auto-antibodies were positive in 12.2%. Patients from the anti-TNF group had lower levels of FT4 (1.09 ± 0.15 vs. 1.38 ± 0.9 ng/dL, p = 0.042), while TSH and T3 were comparable. The percentage of patients with positive thyroid auto-antibodies was lower in the anti-TNF group (5.6% vs. 17.4%). In the subgroup of patients who changed to anti-TNF, we found statistically significant reduction in FT4 after 6 months (1.26 ± 0.24 vs. 1.08 ± 0.15 ng/dL, p = 0.044), without changes in TSH and T3 levels. There was no change regarding thyroid auto-antibodies. In conclusion, patients with IBD showed a quite high percentage of thyroid autoimmunity. After treatment with anti-TNF, FT4 levels were found to be reduced, while no changes in TSH, T3 levels and thyroid auto-antibodies were noted.

Favorable Effect of Anti-TNF Therapy on Insulin Sensitivity in Nonobese, Nondiabetic Patients with Inflammatory Bowel Disease.

BACKGROUND: The aim of this study was to investigate the effect of anti-TNF therapy on glucose and lipid metabolism in nondiabetic, nonobese patients with inflammatory bowel disease (IBD). PATIENTS AND METHODS: We studied 44 patients with IBD, without a known history of diabetes. Three of the patients were diagnosed with overt diabetes and were excluded. Eighteen of the remaining patients (9 M/9 F, 33.6 ± 8.8 years) were on anti-TNF therapy for longer than 1 year, while 23 patients (16 M/7 F, 38.7 ± 12.5 years) were treated with aminosalicylates (AMSs). Twelve of the patients from the second group were then treated with anti-TNF and reassessed 6 months later. Fasting glucose, insulin, c-peptide, HbA1c, lipid, CRP, and fibrinogen levels were determined, and HOMA-IR index was calculated in all patients. RESULTS: Patients from the two therapy groups were matched for age and BMI and were not obese. We did not find any differences between patients from the two therapy groups regarding fasting glucose, c-peptide, HbA1c, total cholesterol, HDL, LDL, triglycerides, CRP, and HOMA-IR index. In patients who were treated for 6 months with anti-TNF, a statistically significant decrease in insulin (before 15.5 ± 5.9 versus after 9.9 ± 2.9 µIU/ml, p = 0.042) and c-peptide (before 2.4 ± 1 versus after 1.3 ± 0.4 ng/ml, p = 0.030) levels as well as the HOMA-IR index (before 4.2 ± 1.9 versus after 2.2 ± 0.9, p = 0.045) was observed, without any changes in weight, BMI, glucose, HbA1c, lipid, CRP, and fibrinogen levels. CONCLUSION: Anti-TNF therapy exerts a favorable effect on insulin sensitivity, while it has no effect on lipid levels in nondiabetic, nonobese patients with inflammatory bowel disease.