Association of Thyroid Hormones with Insulin Resistance in Female Hypertensives with or Without Type II Diabetes

Abstract Purpose Thyroid function alteration is linked to insulin resistance (IR). Limited and conflicting data exist on the thyroid-IR link in African women with hypertension, in the presence or absence of type 2 diabetes (T2DM). This investigation looks into the connection between free thyronine (FT3), free thyroxine (FT4), T3/T4 ratio, and IR in female hypertensive patients with or without T2DM. Methods A cross-sectional study on 122 female participants (≥ 18 years), categorized into three groups: 42 healthy controls, 40 hypertensive (HT), and 40 diabetic hypertensive (HT + DM) patients were recruited. Assessments and comparisons between the groups were made using baseline clinical and biochemical indicators. Results Mean waist circumference, systolic, and diastolic blood pressures were significantly higher in HT (p < 0.001) and HT + DM groups (p < 0.0001) compared to controls. Plasma FT3 levels were higher in HT (p = 0.042) and HT + DM (p = 0.012) compared to controls. HT group exhibited a higher T3/T4 ratio than HT + DM (p = 0.016). Mean HOMA-IR values were significantly elevated in HT (p = 0.044) and HT + DM (p = 0.047) compared to controls, with HT + DM having a higher HOMA-IR than HT. Conclusion These findings demonstrate that FT3 may be a better predictor of insulin resistance compared to FT4 or T3/T4 ratio in hypertensive females with or without type 2 DM.