Thyroid disease risk varies among blacks, Asians, whites

Donald S. A. McLeod, F.R.A.C.P., M.P.H., of the QIMR Berghofer Medical Research Institute, Queensland, Australia and colleagues studied all U.S. active duty military, ages 20 to 54 years, from January 1997 to December 2011 to determine the rate of Graves disease and Hashimoto thyroiditis (a progressive autoimmune disease of the thyroid gland) by race/ethnicity. Cases were identified from data in the Defense Medical Surveillance System, which maintains comprehensive records of inpatient and outpatient medical diagnoses among all active-duty military personnel. The relationship between Graves disease and race/ethnicity has previously not been known.

During the study period there were 1,378 cases of Graves disease in women and 1,388 cases in men and 758 cases of Hashimoto thyroiditis in women and 548 cases in men. Compared with whites, the incident rates for Graves disease was significantly higher among blacks and Asian/Pacific Islanders. In contrast, Hashimoto thyroiditis incidence was highest in whites and lowest in blacks and Asian/Pacific Islanders.

The authors write that the differences in incidence by race/ethnicity found in this study may be due to different environmental exposures, genetics, or a combination of both.