Association between Thyroid Dysfunction and Gestational Diabetes Mellitus

Lenin C and Manoharan A

Published on: 2024-10-08

Abstract

Thyroid hormone dysregulation is commonly observed in patients with heart failure (HF), and growing evidence suggests that altered levels of thyroid-stimulating hormone (TSH), free thyroxine (free T4), and free triiodothyronine (free T3) may have prognostic significance. This study aims to evaluate the relationship between thyroid hormone levels and the clinical outcomes of patients with heart failure, with a focus on their potential use as prognostic markers.

Objective: This study aimed to determine the prevalence of thyroid dysfunction in pregnant women during the first trimester, including subclinical hypothyroidism, overt hypothyroidism, and hyperthyroidism. Methods: A total of 1,000 pregnant women were enrolled in this prospective study and underwent thyroid function testing, which included measurements of thyroid-stimulating hormone (TSH), free thyroxine (free T4), and thyroid peroxidase antibodies (TPO-Ab). Participants were categorized into four groups based on thyroid function status: euthyroid, subclinical hypothyroidism, overt hypothyroidism, and hyperthyroidism.

Results: Euthyroid: 780 women (78.0%) had normal thyroid function. Subclinical Hypothyroidism: 130 women (13.0%) were diagnosed with elevated TSH levels but normal free T4. Overt Hypothyroidism: 40 women (4.0%) had elevated TSH and low free T4. Hyperthyroidism: 50 women (5.0%) presented with low TSH and high free T4. Age Based Distribution: The prevalence of thyroid dysfunction increased with age, with subclinical hypothyroidism being more common in women aged 30 years and older (17.5%) compared to those under 30 years (10%). Overt hypothyroidism was also more prevalent in older women (6.25%) compared to younger women (2.5%). Thyroid Peroxidase Antibodies (TPO-Ab): Positive TPO-Ab was found in 70 women (7.0%). Of these, 19.2% had subclinical hypothyroidism, 50% had overt hypothyroidism, and 20% had hyperthyroidism. Body Mass Index (BMI) Associations: Higher BMI was associated with an increased prevalence of thyroid dysfunction. In overweight/obese women, subclinical hypothyroidism was present in 15.5%, overt hypothyroidism in 5.5%, and hyperthyroidism in 6.4%, compared to lower rates in women with normal BMI.

Conclusion: The study reveals that thyroid dysfunction is prevalent in a significant proportion of pregnant women during the first trimester, with subclinical hypothyroidism being the most common disorder. The prevalence of thyroid dysfunction increases with age and BMI. Positive TPO-Ab is strongly associated with overt hypothyroidism. These findings underscore the importance of routine thyroid screening in early pregnancy to identify and manage thyroid disorders effectively.