Correlation of T3, T4 and TSH with lipid indices in obesity

Background: Aim was to study the influence of Thyroid hormones on lipid indices in obese individuals. Thyroid dysfunction is a common occurence in South India. Increased accumulation of fats is a common feature of obesity and hypothyroidism.Methods: The study was undertaken at GGH, Guntur and 150 Obese individuals with BMI of >30 were recruited. They are classified into 3 groups based on thyroid profile - Euthyroid (N=77), hypothyroid (N=45)and hyperthyroid (N=28). Their fasting venous blood samples were analysed for thyroid profile, lipid profile, FBS and creatinine. Anthropometric data like height, weight and abdominal circumference was recorded. Lipid indices, atherogenic index of plasma (AIP), Castelli’s Risk Index (CRI) 1 and 2, small dense LDL (sdLDL), Atherogenic coefficient (AC) and BMI were calculated.Results: All the 3 groups showed female preponderance. In hypothyroid cases TSH, T3 and T4 showed significant correlation with lipid parameters (p value<0.0001) and with lipid ratios TSH and T4 significantly elevated (p value <0.00001). There was significant correlation of TSH with TC, TG and LDL between hypothyroid, hyperthyroid and euthyroid cases(p<0.0001). Spearman’s Rho correlation analysis showed negative correlation of Lipid ratios with T3, T4 and TSH in all 3 groups.(r≤1.0). Whereas multiple regression analysis of lipid ratios in all 3 groups with TSH as dependent variable demonstrated positive relation with sdLDL (p<0.01).Conclusions: Assessment of thyroid function is mandatory in all obese individuals to predict complications especially cardiovascular disease