Frequency and Pattern of Thyroid Dysfunction among Patients with Diabetes Mellitus: A Cross-Sectional Study

Abstract

Background: Diabetes mellitus and thyroid dysfunction are two common endocrine disorders that frequently coexist. Altered thyroid hormone levels may affect glucose metabolism, insulin sensitivity, lipid profile, cardiovascular risk, and overall glycemic control. Early detection of thyroid dysfunction in diabetic patients may help improve clinical outcomes.

Objective: To determine the frequency and pattern of thyroid dysfunction among diabetic patients.

Methods: This cross-sectional study was conducted on 170 diagnosed diabetic patients attending the medical outpatient department and diabetic clinic. Patients aged 18 years and above with type 1 or type 2 diabetes mellitus were included. Patients with known thyroid disease on treatment, pregnancy, acute severe illness, chronic renal failure, liver failure, or drugs affecting thyroid function were excluded. Demographic data, duration and type of diabetes, body mass index, HbA1c, and thyroid function tests including serum thyroid-stimulating hormone, free triiodothyronine, and free thyroxine were recorded. Thyroid dysfunction was classified as overt hypothyroidism, subclinical hypothyroidism, overt hyperthyroidism, and subclinical hyperthyroidism. Data were analyzed using SPSS version 26.

Results: Among 170 diabetic patients, 83 were males and 87 were females. The mean age was 51.8 ± 10.6 years. Type 2 diabetes mellitus was present in 152 patients, while 18 patients had type 1 diabetes mellitus. Thyroid dysfunction was observed in 48 patients, giving an overall frequency of 28.2%. The most common abnormality was subclinical hypothyroidism, found in 23 patients, followed by overt hypothyroidism in 13 patients, subclinical hyperthyroidism in 7 patients, and overt hyperthyroidism in 5 patients. Thyroid dysfunction was more frequent in females than males, 36.8% versus 19.3%, respectively. Patients with diabetes duration greater than five years had a higher frequency of thyroid dysfunction than those with shorter duration, 37.1% versus 13.8%.

Conclusion: Thyroid dysfunction was found in more than one-fourth of diabetic patients, with subclinical hypothyroidism being the most frequent pattern. Female sex and longer duration of diabetes were associated with higher frequency of thyroid dysfunction. Routine thyroid screening, especially in high-risk diabetic patients, may be beneficial for early detection and management.