Neuropeptide Y-Agouti related peptide ratio (NAR) in patients with idiopathic primary hypothyroidism: Nudge and Risk

To illustrate the role of neuropeptide Y (NPY), agouti-related-peptide (AgRp) and their ratio in patients with primary hypothyroidism (PHT) regarding the effect of levothyroxine (LT4) replacement therapy.

The case-control study was conducted at the Department of Pharmacology, College of Medicine, Mustansiriya University, Baghdad, Iraq, from March to June, 2020 and involved 40 patients with primary hypothyroidism (PHT), including 20 newly diagnosed patients and 20 patients on levothyroxine (LT4) replacement therapy compared to 20 healthy controls. Anthropometric, lipid and pressure profiles were evaluated. Also T3, T4, TSH, NPY and AgRp serum level were estimated in different treated groups. SPSS version 20.00 was used for data analysis.

Body mass index (BMI) was higher in the newly diagnosed patients without thyroxine therapy as compared to patients on thyroxine therapy (P=0.03). Blood pressure profile was higher in patients with PHT compared to the controls (P=0.0001). NPY serum level was lower in patients with PHT without thyroxine therapy (27.32±10.30ng/dL) as compared to patients with PHT on thyroxine therapy (61.10±22.78ng/dL), (P=0.04). AgRP serum level was lower in patients with PHT (9.81±4.86ng/dL) as compared to the patients on the thyroxine therapy (28.99±2.16ng/dL), (P=0.03). Besides, NPY-AgRP ratio (NAR) was higher in patients with PHT (2.78±0.14) as compared to patients with PHT on thyroxine therapy (2.10±0.19), (P=0.0001).

Both of NPY and AgRP serum levels are reduced in the newly diagnosed patients with PHT and ameliorated following LT4 replacement therapy. Also NPY/AgRP ratio is linked with early PHT and regarded as a prognostic value for the outcomes of patients with PHT.