Trends and racial/ethnic disparities in gluten-sensitive problems in the United States: findings from the National Health and Nutrition Examination Surveys from 1988 to 2012.

OBJECTIVES: Racial disparities in the prevalence of celiac disease (CD) and the number of people without CD avoiding gluten (PWAG) in the United States are unknown. We aimed to describe racial differences in the prevalence of CD and PWAG, and evaluate the trends of CD in the noninstitutionalized civilian adult population of the US between 1988 and 2012. METHODS: A population-based cross-sectional study was conducted using data from the National Health and Nutrition Examination Surveys (NHANES) from 1988 to 1994, 1999 to 2004, and 2009 to 2012. Serum samples from the NHANES participants were tested for CD serology, which included IgA tissue transglutaminase (tTG IgA) and, if findings were abnormal, for IgA endomysial antibodies. Information about adherence to a gluten-free diet was obtained by means of an interviewer administered questionnaire. RESULTS: In NHANES 2009-2012, the adjusted prevalence of CD was significantly higher (P < 0.0001) among non-Hispanic whites (1.0%) than among non-Hispanic blacks (0.2%) and Hispanics (0.3%), whereas the adjusted prevalence of PWAG was signifi cantly higher (P = 0.01) in blacks (1.2%) as compared with Hispanics (0.5%) and whites (0.7%). The seroprevalence of CD in adults aged 50 years and older increased from 0.17% (95% confidence interval (CI) 0.03-0.33) in 1988-1994 to 0.44% (95% CI 0.24-0.81) in 2009-2012 (P < 0.05). CONCLUSIONS: The overall prevalence of CD increased between 1988 and 2012 and is signifi cantly more common in whites. In addition, a higher proportion of individuals maintaining a gluten-free diet in the absence of a diagnosis of CD are blacks.