Evaluation of Thyroid Function Tests Among Obese Adults Attending a Nutrition Clinic in Abia State, South East Nigeria

Thyroid dysfunction may contribute to obesity through its effects on basal metabolic rate, lipid metabolism, and energy expenditure, creating a bidirectional relationship that warrants systematic laboratory investigation in obese populations. This study evaluated thyroid function test profiles among obese adults attending a nutrition and dietetics clinic at Federal Medical Centre Umuahia, Abia State, South East Nigeria. A cross-sectional study enrolled 180 obese adults defined by body mass index of 30 kg/m2 or above and 90 age-matched normal-weight controls. Serum thyroid-stimulating hormone, free thyroxine, and free triiodothyronine were measured by ELISA. Fasting lipid profile, blood glucose, and anthropometric measurements were also determined. Thyroid dysfunction was detected in 26.7% of obese participants. Subclinical hypothyroidism, defined as elevated TSH with normal free T4, was the most common abnormality at 18.9%. Overt hypothyroidism was found in 7.8%. TSH showed significant positive correlation with body mass index and waist circumference. Dyslipidaemia was significantly more prevalent in obese participants with thyroid dysfunction than in euthyroid obese subjects. Duration of obesity above five years was associated with higher rates of thyroid abnormality. The study supports routine thyroid function screening for all obese adults presenting to nutrition services and recommends integration of thyroid evaluation into obesity management protocols at secondary and tertiary health facilities across South East Nigeria. Keywords: thyroid function, obesity, subclinical hypothyroidism, TSH, Abia State