Association between celiac disease and iron deficiency in Caucasians, but not non-Caucasians

Abstract

Background & aims: Celiac disease is an increasingly recognized disorder in Caucasian populations of European origin. Little is known about its prevalence in non-Caucasians. Although it is thought to be a cause of iron-deficiency anemia, little is known about the extent to which celiac disease contributes to iron deficiency in Caucasians, and especially non-Caucasians. We analyzed samples collected from participants in the Hemochromatosis and Iron Overload Screening study to identify individuals with iron deficiency and to assess the frequency of celiac disease.

Methods: We analyzed serum samples from white men (≥25 y) and women (≥50 y) who participated in the Hemochromatosis and Iron Overload Screening study; cases were defined as individuals with iron deficiency (serum ferritin level, ≤12 μg/L) and controls were those without (serum ferritin level, >100 μg/L in men and >50 μg/L in women). All samples also were analyzed for human recombinant tissue transglutaminase immunoglobulin A; positive results were confirmed by an assay for endomysial antibodies. Patients with positive results from both celiac disease tests were presumed to have untreated celiac disease, and those with a positive result from only 1 test were excluded from analysis. We analyzed HLA genotypes and frequencies of celiac disease between Caucasians and non-Caucasians with iron deficiency.

Results: Celiac disease occurred in 14 of 567 cases (2.5%) and in only 1 of 1136 controls (0.1%; Fisher exact test, P = 1.92 × 10(-6)). Celiac disease was more common in Caucasian cases (14 of 363; 4%) than non-Caucasian cases (0 of 204; P = .003). Only 1 Caucasian control and no non-Caucasian controls had celiac disease. The odds of celiac disease in individuals with iron deficiency was 28-fold (95% confidence interval, 3.7-212.8) that of controls; 13 of 14 cases with celiac disease carried the DQ2.5 variant of the HLA genotype.

Conclusions: Celiac disease is associated with iron deficiency in Caucasians. Celiac disease is rare among non-Caucasians-even among individuals with features of celiac disease, such as iron deficiency. Celiac disease also is rare among individuals without iron deficiency. Men and postmenopausal women with iron deficiency should be tested for celiac disease.

Figure 1

Schema for detection of celiac disease status

Figure 2

Results of serologic testing for celiac disease in Caucasian and non-Caucasians

Figure 3

Percentage of positive celiac serology in iron-deficient cases versus iron-replete controls. Fisher’s exact test (p = 1.96×10⁻⁶).

Figure 4

Positive celiac serology in Caucasians and non-Caucasians. All individuals with celiac disease were Caucasian (15/1094); celiac disease was absent in non-Caucasians (0/609, Fisher’s exact test p = 0.002).