Objectives: To evaluate the prevalence of goiter and nodular disease in patients with class III obesity, and to correlate results with serum leptin levels and insulin resistance (IR) parameters.
Subjects and methods: A cross-sectional study was performed to assess thyroid ultrasound (US) patterns, HOMA-IR, serum leptin, and TSH levels in obese patients and controls.
Results: Thyroid volume was positively correlated with body mass index (BMI) (r = 0.240, p = 0.039) and with HOMA-IR (r = 0.329; p < 0.01). Thyroid US patterns were similar between groups. However, when data from the male group was considered, greater thyroid volume was detected in the obese group compared with controls (10.8 vs. 8.5 cm³; p = 0.04). Also, nodules were more frequently detected (67% vs. 18%), as were nodules requiring FNAB (33.3% vs. 0%, p ≥ 0.05-0.09), in this group.
Conclusion: Although IR did not correlate directly with the presence of nodules, the results support the hypothesis of a direct association between insulin resistance and thyroid volume.