Prevalence of diabetes mellitus in patients with newly evaluated papillary thyroid cancer

BACKGROUND: This study investigates whether diabetes mellitus is a risk factor for the development of papillary thyroid cancer, using an age-, gender-, and race-matched analysis. METHODS: We retrospectively reviewed the charts of 1559 patients with newly evaluated thyroid cancer over a 4-year period at our institution and identified 1313 patients (84%) with papillary thyroid carcinoma. Characteristics of patients with diabetes versus those without diabetes were compared with a chi-square test for categorical variables and the Wilcoxon Rank Sum test for numeric variables. The prevalence of diabetes among patients with papillary thyroid carcinoma at our institution was compared (using an age-, gender-, and race-matched analysis) with that expected based on data from the continuous National Health and Nutrition Examination Survey (NHANES) from the same time period. RESULTS: For patients with papillary thyroid carcinoma, the median age was 47 years; 74% were female; 83% were white; and the prevalence of diabetes was 8%. Among those with diabetes, 92% had type 2 diabetes, and 24% were treated with insulin. Risk factors for diabetes included age and race. The prevalence of diabetes among patients with papillary thyroid carcinoma of all ages versus that among patients from NHANES of all ages was not significantly different (RR 1.07, CI 0.88 - 1.28). The prevalence of diabetes among patients with papillary thyroid cancer who were 44 years of age or younger versus that among patients from NHANES who were 44 years of age or younger, however, was significantly increased (RR 2.32, CI 1.37 - 3.66). There was no significant difference when subgroup analysis was performed by gender or race. CONCLUSIONS: We found an increased prevalence of diabetes in patients with papillary thyroid carcinoma who were 44 years of age or younger.