Analyses of Brain Natriuretic Peptide Levels in Patients with Newly Diagnosed Hyperthyroidism without Cardiac Diseases

Objectives: This study examined blood brain natriuretic peptide (BNP) concentrations in newly diagnosed primary hyperthyroidism (PHT) patients, compared them to healthy controls, and examined their correlation with age, gender, and biochemical variables triiodothyronine (T3), tetraiodothyronine (T4), and thyroid stimulating hormone (TSH). The study also sought out a BNP limit for primary hyperthyroidism. Design and methods: The present study included 45 PHT patients without thyroid medication, heart failure, acute coronary syndrome, hypertension, renal failure, pregnancy, Cushing’s syndrome, liver disease, and obesity. In addition, 90 subjects served as the control group in the study. Patients’ and controls’ blood sera were used to measure the concentrations of T3, T4, and TSH by ELFA and BNP by ELISA. Results: The group with PHT had significantly higher BNP levels than the control group. BNP exhibited a significant positive correlation with T3 levels and with age in the PHT group, and its level was higher in females. BNP demonstrated a perfect area under the curve (AU C) where the optimal cutoff value was >32.17, with high sensitivity and specificity. Conclusions: PHT influences BNP levels, potentially reflecting disease presence and severity or thyroid-related complications. BNP levels increase with age, with female patients having higher mean levels. A cutoff value can aid clinicians in diagnosing and managing PHT, guiding evaluation and treatment decisions. Further research is needed to substantiate findings and investigate the underlying mechanisms of BNP’s role in thyroid dysfunction.