The association between Helicobacter pylori infection, type 1 diabetes mellitus, and autoimmune thyroiditis

Type 1 diabetes mellitus (T1DM) can be associated with an increased prevalence of Helicobacter pylori infection, which could contribute to the pathogenesis of autoimmune thyroiditis observed in this disease.

The aim of this study was to assess the relationship between H. pylori infection and T1DM and to identify of the interconnection between H. pylori infection and autoimmune thyroiditis in patients with T1DM.

A case-control design was used. The study group included 60 children and adolescents with T1DM who were selected from the pediatric outpatient clinic of Suez Canal University Hospital by a systematic random sampling method. The control group included 60 healthy children and adolescents matched for age and sex and selected from among relatives (brothers or cousins) of the patients with T1DM. The study participants were subjected to several investigations including estimation of levels of HbA1c, thyroid stimulating hormone (TSH), T3, T4, anti-thyroglobulin (anti-Tg), and anti-thyroid peroxidase (anti-TPO).

The mean age of the patients with T1DM was 12.53±2.35 years, whereas that of the control group was 12.30±1.98 years, with no statistically significant difference between the two groups. The patients with diabetes had significantly higher levels of H. pylori IgG, TSH, anti-TPO, and anti-Tg (20.43±14.84  μ/ml, 4.03±1.53 mIu/l, 14.98 ±5.04 Iu/ml, and 5.66±3.37 Iu/ml, respectively) and significantly lower levels of T3 and T4 (120±15.86 μg/dl and 4.93±0.93 μg/dl, respectively) compared with the control group. In addition, the seroprevalence rate of H. pylori, anti-Tg, and anti-TPO was significantly higher in diabetic patients, and the duration of diabetes was significantly longer in H. pylori-positive patients with higher levels of HbA1c, insulin requirement, TSH, anti-TPO, and anti-Tg.

The association between H. pylori infection and autoimmune thyroiditis in patients with T1DM was revealed in this study. Hence, screening and treatment of H. pylori infection in T1DM patients is recommended.