Determining the Association Between Helicobacter pylori Infection and Treatment-Refractory Hypothyroidism

Introduction Refractory hypothyroidism, despite weight-based thyroxine dosing, is a common endocrinology consultation in outpatients. Chronic Helicobacter (H.) pylori infection has been reported to be responsible for the poor absorption of thyroxine from the small gut leading to suboptimal response with contradictory evidence. This study was carried out to determine the association of chronic Helicobacter pylori infection with refractory hypothyroidism in outpatients presenting to a tertiary care hospital. Methods One hundred thirty patients with the diagnosis of hypothyroidism, visiting Jinnah Allama Iqbal Institute of Diabetes and Endocrinology (JAIDE) Jinnah Hospital Lahore, Pakistan, from January 2020 to February 2021, were included in the study after informed consent following the non-probability consecutive sampling technique. All of these patients were 15-70 years of age, non-pregnant, and receiving thyroxine treatment for at least six weeks. Patients with a history of gastric surgery, malabsorption syndrome, or poor compliance were excluded from the study. Patients’ age, sex, and body mass index (BMI) were recorded in a structured proforma. Patients were categorized into two groups, i.e. controls (biochemically euthyroid on thyroxine treatment with TSH < 4.5mU/L) and cases (refractory hypothyroidism despite 1.6 mcg/kg thyroxine treatment with TSH > 4.5 mU/L). The presence of chronic H. pylori infection was checked with serum immunoglobulin G (IgG) testing by enzyme-linked immunoassay (ELISA) from the hospital laboratory and data analysis was done by SPSS version 21.0 (IBM Corp., Armonk, NY). Results One hundred thirty patients were included in this study, with an age range from 15 to 70 years. Of these, 65/130 (50%) were euthyroid on treatment and 65/130 (50%) had treatment-refractory hypothyroidism. The mean age of patients in our study was 45.81 ± 11 years, with 118 (90.8%) female patients. The prevalence of positive H. pylori IgG antibody was 47/130 (36.2%) overall, with 23 patients (35.4%) in the control (euthyroid) group and 24 patients (36.9%) in the cases (refractory hypothyroidism) group. The difference between the two groups was not statistically significant with an odds ratio of 1.069 (CI 0.523 - 2.187) and a p-value of 0.855. Moreover, age, gender, and BMI had no effect on chronic H. pylori association with refractory hypothyroidism. Conclusion This study does not suggest any significant association between chronic H. pylori infection and treatment-refractory hypothyroidism. Other factors like poor compliance, drug-drug interactions, and malabsorption disorders should be preferably sought in case of refractory hypothyroidism.