Helicobacter pylori infection and iron deficiency in teenage females in New Zealand.

BACKGROUND: Iron deficiency is an important problem in New Zealand children and young adults. Iron deficiency and Helicobacter pylori (H. pylori) infection are each more common in Māori and Pacific Island ethnic groups. AIMS: This study seeks to determine if H. pylori infection is associated with iron deficiency. METHODS: 792 female students from 7 Auckland high schools (median age 16 years) had H. pylori serology and tests for iron deficiency assessed by a combination of serum ferritin, iron saturation and mean cell volume. RESULTS: The prevalence of positive H. pylori serology was highest for Pacific Island students (49.0%; CI 38.0-60.0), intermediate for Māori (26.7%; CI 16.9-36.4) and Asian (24.7%; CI 12.6-36.7) and lowest for European (13.7%; 6.0-21.4) p<0.0001. Students with positive H. pylori serology had lower mean levels of iron saturation (p=0.013), but not of ferritin (p=0.068), haemoglobin (p=0.08) or mean cell volume (p=0.16), compared to those with negative serology. Positive H. pylori serology was associated with increased risk of iron deficiency (RR 1.20; CI 1.08-1.34), but not anaemia (RR 1.01; CI 0.87-1.18), after adjusting for age, ethnicity and school SES decile. CONCLUSIONS: This study indicates that H. pylori infection is associated with iron deficiency in adolescent females. There are significant differences in H. pylori serology amongst different ethnic groups in New Zealand.