ECE2013 Poster Presentations Thyroid (non-cancer) (100 abstracts)
1Service of Endocrinology, Diabetes and Metabolism, São João Hospital Centre, Porto, Portugal; 2Department of Immunology, São João Hospital Centre, Porto, Portugal; 3Department of Health information and Decision Sciences, Porto, Portugal; 4Faculty of Medicine, University of Porto, Porto, Portugal.
Objective: To evaluate the interrelationships between Graves disease (GD) and cardiovascular risk factors.
Subjects and methods: We analyzed thyroid function tests, anti-thyroid antibodies, BMI, insulin resistance markers, namely homeostasis model assessment for insulin resistance (HOMA-IR and HOMA-B), the quantitative insulin sensitivity check index (QUICKI), hepatic insulin sensitivity index (HISI), whole-body insulin sensitivity index (WBISI), insulinogenic index (IGI) and the levels of total cholesterol (TC), HDL, LDL-cholesterol, triglycerides (TG), apolipoprotein B (ApoB), ApoA1, lipoprotein (a) (Lp[a]), homocysteine, C-reactive protein (CRP), folic acid and vitamin B12, in 106 subjects with GD (51 with overt hyperthyroidim and 55 with euthyroidism). A 75-g OGTT was performed and blood samples were obtained every 30 min for 120 min for measurements of plasma glucose, insulin and C-peptide levels. Statistical analysis was performed with MannWhitnney and Spearmans correlation tests. Results are expressed as mean±S.D. and odds ratio. A two-tailed P<0.05 was considered significant.
Results: 94% of studied subjects were female. Mean age and BMI were similar between both groups. In hyperthyroid subjects, we found significantly higher levels of TRAb (8.3±10.7 vs 2.3±4.8 IU/ml, P<0.001), CRP (0.84±1.55 vs 0.28±0.36 mg/dl, P=0.04), and significantly lower WBISI values (5.01±3.21 vs 6.73±4.23, P=0.02). In the total group, TSH levels were negatively correlated with HOMA-IR (r=−0.22; P<0.05), IGI (r=−0.31; P<0.01) and TRAb levels (r=−0.46; P=0.02). FT3 and FT4 levels were positively correlated with HOMA-IR (r=0.28, P<0.01 and r=0.26, P=0.02, respectively) and negatively correlated with WBISI (r=−0.23; P=0.03 and r=−0.26; P=0.02, respectively). In the euthyroid group, TSH levels were positively correlated with WBISI (r=0.29; P<0.05). In the hyperthyroid group, FT3 levels were negatively correlated with HISI (r=−0.38; P=0.02), and TSH and TRAb were negatively correlated (r=−0.32; P=0.02). Conclusions: The interrelationships between thyroid function, insulin resistance and CRP translate an increased cardiovascular risk in hyperthyroidism due to Graves disease.