Background: Metabolic syndrome has been associated with nodular goiter. Our aim was to evaluate which metabolic parameters in elderly patients with metabolic syndrome are associated with thyroid enlargement or increased prevalence of thyroid nodules.
Methods: In this cross-sectional study, 77 patients >65 years of age with metabolic syndrome were included. We evaluated the presence of thyroid nodules and thyroid volume by ultrasonography and several biochemical, metabolic and anthropometric parameters. Only patients with thyrotropin (thyroid-stimulating hormone, TSH) levels between 0.3 and 6 mU/L were included. We further divided subjects into two groups-type 2 diabetes mellitus (T2DM) and non-T2DM and established comparisons between them.
Results: Among all parameters analyzed we found a significant correlation between glycated hemoglobin (HbA1c) and volume (r=0.261, P=0.027) or number of nodules (r=0.266, P=0.023). Neither sex, age, body mass index (BMI), metformin, nor levothyroxine use were associated with thyroid volume or nodularity. Within the whole cohort, those patients with T2DM had larger thyroid volumes compared to non-T2DM [median (confidence interval, CI) 6.976 (5.220-10.789) vs. 5.034 (3.796-6.034) mL, P<0.008). Furthermore, a larger proportion of T2DM patients presented thyroid volumes >5.8 mL [69 vs. 23%, P<0.001; odds ratio=7.25 (CI 2.04-25.56)].
Conclusions: In elderly patients with metabolic syndrome, worse metabolic control, represented by higher HbA1c levels, was found associated to increased prevalence of thyroid nodules and larger thyroid volume. Moreover, within the whole metabolic syndrome group, patients with T2DM had the largest thyroid volumes.