Abstract
Objectives:
Analyze the relationship between obesity and type-2 diabetes (DM-II) and the development of differentiated thyroid cancer (DTC).
Methods:
Randomized case-controlled retrospective chart review conducted for outpatient clinic patients between January 2005 and December 2012 at an academic medical center. Forty-nine DTC patients were compared with 70 control group patients diagnosed with hyperparathyroidism with documented euthyroid state. Exposure variables consisted of the most recent body-mass index (BMI) within 6 months prior to diagnosis of DTC and any report of DM-II. Multivariate logistic regressions adjusting for sex, age, and year of body mass index (BMI) were used to assess the odds ratio of DTC with both BMI and DM-II. No interventions were performed.
Results:
Comparison of means shows BMI was greater in patients with DTC (BMI = 37.83) than controls (30.36), P < .0001, and DM-II was more frequent in patients with DTC (29%) than controls (16%), P = .08. The adjusted Odds Ratio for BMI was 1.12 (95% 1.06, 1.19, P < .0002); the DM-II adjusted Odds Ratio was 3.24 (95% 1.21, 8.70), P = .0196. A Hosmer-Ledeshow test did not detect misfit (p < .05) in either model. The C-value for the BMI model was 0.82 (bivariate = 0.81) and for the DM-II model was 0.73.
Conclusions:
Our preliminary results show that obesity, and to a slightly lesser degree DM-II, are significantly associated with DTC. BMI in particular was a strong predictive variable for DTC (C = 0.81 bivariate, C = 0.82 multivariate).