Relationships among asprosin, leptin, and other biomarkers in diabetic patients with hypothyroidism or hyperthyroidism

Thyroid disorders and diabetes mellitus frequently occur and disrupt metabolic balance. Vitamin D, leptin, and asprosin contribute to metabolic regulation, and alterations in lipid profiles can further complicate this condition. To investigate relationships among asprosin, leptin, and other biomarkers in diabetic patients with hypothyroidism or hyperthyroidism, a cross-sectional study was conducted with 130 participants divided into three groups: diabetes with hypothyroidism (n = 50), diabetes with hyperthyroidism (n = 50), and diabetes with normal thyroid function (n = 30). Participants were recruited from Al-Yarmouk Hospital in Baghdad, Iraq, between July 2024 and May 2025. Thyroid hormone levels (TSH, free T3, free T4) and vitamin D were measured using an enzyme-linked fluorescence assay. Lipid profile and HbA1c levels were assessed using a spectrophotometer. Levels of asprosin and leptin were determined by enzyme-linked immunosorbent assay. Patients with hypothyroidism showed significantly higher leptin and asprosin levels and lower vitamin D comparedwith the other groups. Hypothyroid diabetics also had less favorable lipid profiles, including increased LDL and total cholesterol. Free T3 showed negative correlations with total cholesterol and positive correlations with HbA1c and vitamin D. Triglycerides and BMI showed positive correlations with TSH. Thyroid dysfunction significantly affects metabolic markers in diabetes. Hypothyroidism is associated with increased asprosin and leptin. Monitoring these markers may improve management.