Neighborhood socio-economic characteristics, African ancestry, and Helicobacter pylori sero-prevalence
The authors recently reported high Helicobacter pylori sero-prevalence among African-Americans of high African ancestry. We sought to determine whether neighborhood-level socio-economic characteristics are associated with H. pylori prevalence and whether this helps explain the link between African ancestry and H. pylori.
Antibodies to H. pylori proteins were assessed in the serum of 336 African-American and 329 white Southern Community Cohort Study participants. Prevalence odds ratios (ORs) and 95 % confidence intervals (CIs) for CagA+ and CagA- H. pylori were calculated using polytomous logistic regression in relation to 10 Census block group-level measures of socio-economic status.
After adjusting for individual-level characteristics, three neighborhood-level factors were significantly inversely related to CagA+ H. pylori: percent completed high school; median house values; and percent employed (comparing highest to lowest tertile, OR, 0.47, 95 % CI, 0.26-0.85; OR, 0.56, 95 % CI, 0.32-0.99; and OR, 0.59, 95 % CI, 0.34-1.03, respectively). However, accounting for these measures did not attenuate the association between African ancestry and CagA+ H. pylori, with African-Americans of low, medium, and high African ancestry maintaining two-, seven-, and ninefold increased odds, respectively, compared to whites.
Neighborhood-level measures of education, employment, and house values are associated with CagA+ H. pylori sero-prevalence, but do not explain the persistent strong relationship between African ancestry level and CagA+ H. pylori. The findings suggest that neighborhood socio-economic status can help to highlight high-risk areas for prevention and screening efforts and that the link between African ancestry and H. pylori may have a biological basis.