COTWIN STUDY OF THE EFFECT OF ENVIRONMENT AND DIETARY ELEMENTS ON ACQUISITION OF HELICOBACTER-PYLORI INFECTION

The rate of Helicobacter pylori infection is inversely related to soci oeconomic status, and childhood is thought to be the major acquisition period. The authors investigated the importance of childhood environm ent in the acquisition of H. pylori infection. A cross-sectional study was conducted of monozygotic and dizygotic twins who were reared apar t or reared together. Three hundred twins from a subregistry of the Sw edish Twin Registry were studied. H. pylori status was evaluated by us ing an enzyme-linked immunosorbent assay for anti-H. pylori immunoglob ulin G. Socioeconomic status during childhood was assessed on the basi s of the density of the living conditions and the economic situation o f the family that reared the twins. Current socioeconomic status was e stimated by using a scale that combined income and education. Dietary elements that were studied included fat and fiber intake and ascorbic acid consumption. The density of the childhood home was consistently f ound to be significantly associated with the acquisition of H. pylori infection (p = 0.04). Among monozygotic twins reared apart and discord ant for H. pylori status, affected twins were raised in homes under po orer socioeconomic conditions than those of their unaffected co-twins (p = 0.02). Additionally, infected twins consumed more ascorbic acid t han their unaffected co-twins(p = 0.04), The finding of an effect of s ocioeconomic status during childhood on the acquisition of H. pylori a mong monozygotic twins who were reared apart and had an identical gene tic makeup but not a common environment confirms the hypothesis that c hildhood acquisition of H. pylori infection is linked to hygiene pract ices.