Background: Sporadic nodular goiter is a common problem in the United States and significant compressive symptoms may occur with progression to a critical size.
Methods: Potential epidemiological variables associated with the development of large unilateral (> or = 50 g) and bilateral (> or = 100 g) nodular goiter were investigated including: age, gender, race, body mass index (BMI), family history of thyroid disease, pregnancy at time of diagnosis, insurance status, and tobacco or alcohol use. Data were obtained from an IRB-approved thyroid database and retrospective chart review of consecutive patients operated on for nodular goiter from 1990 through 2005. A univariate and multivariate analysis of epidemiological variables in patients with "large" versus "small" nodular goiter was completed.
Results: Of the 488 patients operated on for nodular goiter, 113 (23%) were classified as "large," 43 with unilateral (mean 106 +/- 72 g) and 70 with bilateral enlargement (mean 173 +/- 92 g) and 375 (77%) were classified as "small," 179 with unilateral (18 +/- 10 g) and 196 with bilateral (37 +/- 24 g) enlargement. Based on univariate analysis, African-American race, age > or = 40 years, BMI > or = 30 kg/m2, and lack of insurance were associated with an increased risk of large nodular goiter (P < or = 0.001), whereas alcohol use was protective (P = 0.002). A multivariate analysis revealed that African-American race [adjusted odds ratio (adj. OR) 3.3, 95% CI = 2.0-5.4], age > or = 40 years (adj. OR 2.1, 95% CI = 1.2-3.8), and BMI > or = 30 kg/m2 (adj. OR 2.5, 95% CI = 1.5-4.0) were independently associated with large nodular goiter. No significant differences were observed in gender, family history of thyroid disease, pregnancy, or tobacco use (P > 0.1).
Conclusions: African-American race, obesity, and increasing age are independent risk factors for the development of large nodular goiter. These results may be helpful in determining how best to monitor patients with nodular goiter, with earlier intervention to help prevent progressive enlargement and its sequelae.