Hypothyroidism in Bangladesh: Is Autoimmunity the Next Big Threat?

In many low and middle-income countries, iodine-deficient hypothyroidism leads to complex public health consequences. However, increasing evidence from population-based studies has linked thyroid autoimmunity with excess iodine intake. The iodine supplementation program in Bangladesh was a success story. This cross-sectional study aims to assess the pattern and predictors of autoimmunity among Bangladeshi hypothyroid patients. In this study, 154 consecutive, newly detected, biochemically-confirmed patients with primary hypothyroidism were recruited from the Endocrinology outpatient department of Bangabandhu Sheikh Mujib Medical University and tested for anti-thyroid peroxidase and anti-thyroglobulin antibody levels from October 2015 and November 2016. Patterns of thyroid autoimmunity were assessed via descriptive statistics. Predictors of autoimmunity were assessed with multivariable mixed-effect logistic regression. The mean age of participants was 36.1±11.0 years, and 70.1% were female. The frequency of thyroid autoimmunity in the study subjects was very high, 89.0% were positive for either anti-TPO or anti-Tg antibodies and 48.7% were positive for both. More participants were positive for anti-TPO antibodies (82.5%) than anti-Tg antibodies (55.2%). The risk of autoimmunity was associated with the thyroid's structural abnormalities but not with functional status. Weight gain and hypertension were associated with autoimmunity, whereas diabetes was protective against autoimmunity.