Continuous intraperitoneal insulin infusion does not increase the risk of organ-specific autoimmune disease in type 1 diabetic patients: results of a multicentric, comparative study.

Aim: The purpose of this national multicenter prospective study by the French EVADIAC group was to investigate the possibility that continuous intraperitoneal insulin infusion using an implanted pump (CIpii) increases the risk of autoimmune disease in type 1 diabetic patients as it increased anti-insulin immunogenicity.

Methods: Prevalence of clinical (Hashimoto's disease, hyperthyroidism, gastric atrophic disease and vitiligo) and subclinical (presence of anti-thyroperoxidase antibodies, anti-intrinsic factor antibodies, abnormal TSH levels) autoimmune diseases was estimated by comparing two groups of patients already treated by either CIpii (n=154) or external pump (CSII) (n=121) for an average of 6 years. Incidence of autoimmune disease was determined by comparing the same measurements one year after inclusion.

Results: No significant difference was observed for the total prevalence of clinical and subclinical auto-immune thyroid and gastric di-seases (35.6% and 3.2% respectively in the CIpii group versus 40.4% and 2.6% in the CSII group). No significant difference for the incidence of clinical and subclinical auto-immune diseases was observed: 7.2% and 0% in CIpii and 7.3% and 1.7% in CSII.

Conclusion: As previously shown AIA (anti-insulin antibodies) levels were higher in CIpii than in CSII (32.9% vs 20.2%, P<0.0001) but no correlation was observed with either clinical or subclinical autoimmune disease. This large-scale study eliminates the possibility that CIpii increases the risk of autoimmune disease.