Estimation of serum insulin, Homeostasis model assessment-insulin resistance and C-peptide can help identify possible cardiovascular disease risk in thyroid disorder patients

AIM: We aimed at evaluating the cardiovascular disease (CVD) risk of thyroid disorder patients at diagnosis, using the traditional lipid profile, apo-B and apo-A1 in correlation with serum insulin and insulin resistance (IR) and C-peptide. BACKGROUND: With an ever increasing incidence of CVD in most urban populations, there has been a demand for newer techniques that could help in the early detection of the risk of this disease complex. MATERIALS AND METHODS: The present study was conducted on 100 healthy controls and 150 hypothyroid and 70 hyperthyroid patients, coming for the first time to our OPDs. The patients were selected on the basis of symptomatology and serum T3, T4, thyroid stimulating hormone (TSH) evaluations. They were then analyzed for body mass index (BMI), blood pressure (BP), serum insulin, homeostasis model assessment-insulin resistance (HOMA-IR), C-peptide, lipid profile and apo-B and -A1. Statistical analysis was done using Student's “t” test and Spearman's coefficient of correlation. RESULTS: The hypothyroid patients presented with high BMI, diastolic hypertension, dyslipidemia, hyperinsulinemia, IR and raised serum C-peptide. There was highly significant correlation of serum insulin, HOMA-IR and C-peptide with lipid fractions and CVD risk ratios, T. chol/HDLc and apo-B/apo-A1, in hypothyroid patients. The hyperthyroid patients presented with systolic hypertension and a significant correlation of T. chol/HDLc with HOMA-IR. Hyperthyroid patients also had hyperinsulinemia, but reduced serum C-peptide levels. CONCLUSION: We conclude that the estimation of traditional lipid profile along with serum insulin, IR, C-peptide, apo-A1 and apo-B would not only help assess the thyroid status, but can also help in the early evaluation of a possible risk of CVD.