Evaluating the correlation between leptin levels and thyroid hormones in patients with morbid obesity

Author(s): Suhad Shaheed Ali
Date: 09/10/2026
doi: https://doi.org/10.5281/zenodo.8425890

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Abstract

There are important endocrine and metabolic abnormalities associated with morbid obesity. Leptin 
is a hormone secreted by fat cells and acts to control energy balance, appetite, and neuroendocrine 
function; thyroid hormones are involved in metabolic rate and thermogenesis.  The purpose of this 
study was to evaluate the relationship between blood leptin levels and thyroid hormones in morbidly 
obese patients. The study was a cross-sectional study of 80 subjects comprising 50 morbidly obese 
(MO) and 30 healthy controls (HC). Leptin, thyroid-stimulating hormone (TSH), free 
triiodothyronine (FT3), free thyroxine (FT4) were measured by ELISA and immunoassay methods 
and body mass index (BMI) calculated. A significant increase in leptin and TSH was seen in obese 
patients compared to control (p < 0.05). Leptin showed a positive correlation with BMI and TSH, 
and a weak negative correlation with FT4. The results indicate that hyperleptinemia associated with 
obesity could play a role in metabolic dysfunction and thyroid dysfunction in morbid obesity. 

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