The Relationship Between Subclinical Hypothyroidism and Gestational Diabetes Mellitus

Abstract

The most common metabolic disorder during pregnancy is gestational diabetes mellitus (GDM). GDM can occur in anywhere between 1.7 and 11.6 percent of people. In hypothyroidism, the rates of glucose oxidation and glycogen synthesis are reduced, and the peripheral tissues' consumption of glucose is also delayed. Patients with subclinical and overt hypothyroidism develop insulin resistance because insulin is unable to adequately maintain the muscles' use of glucose. According to the literature, hypothyroidism is linked to 6–15 percent of GDM pregnancies. Additionally, the chance of having GDM is 4.3 times higher in pregnant women who have hypothyroidism. This study aimed to reveal the relationship between first-trimester thyroid function tests and GDM. This retrospective cohort study was conducted between May 2021 and May 2022. 100 pregnant patients diagnosed with GDM and 500 healthy controls were included in the study. Using a 75 g glucose challenge test, GDM was identified. The trimester-specific recognized normal limits were used to evaluate the TSH and fT4 readings. There was a statistically significant difference in terms of SCH between patients with and without GDM (p=0.04). TSH's performance in predicting GDM was evaluated using AUC and ROC (AUC=0.586 and p=0.006). To forecast GDM, the TSH level cut-off value was discovered to be 1.58. The AUC was found to be 0.586 (0.521-0.652). Furthermore, the selectivity is 58% and the sensitivity is 41%. There are many studies in the literature investigating thyroid functions and the development of gestational diabetes mellitus. Our study also found a correlation between the diagnosis of subclinical hypothyroidism in the first trimester and GDM. The study adds to the literature the importance of being cautious and vigilant in terms of the development of gestational diabetes mellitus based on the results of the thyroid function test in the first trimester.