Sex effect on growth faltering in an indigenous ethnic minority population of infants in Israel

Objective: We examined sex effects on growth faltering in an indigenous population of Bedouin Arab infants born in Israel, an economically developed country. Design: Retrospective cohort study. Height-for-age Z-score (HAZ) at age 6, 12, 18 and 24 months was calculated for full-term, normal-birth-weight Bedouin infants born during years 2000-2009 and attending maternal and child health (MCH) clinics. Multivariate linear regression analysis (MLRA) was used to calculate the association between sex and HAZ, controlling for year of birth, birth weight (BW) and residence by type of settlement (established settlement (ES); non-established settlement (NES)). Setting: Bedouin are an indigenous poor community of semi-nomadic Arabs, with the highest infant mortality rate in Israel. Fifty per cent of Bedouin infants live in NES with inadequate access to running water, electricity, and rubbish and sewage disposal. All Bedouin receive free well-baby care in community-based MCH clinics. Participants: Full-term, normal Bedouin infants (n 5426) born during 2000-2009 and attending computerized MCH clinics who had growth measurements at age 6, 12, 18 and 24 months. Results: At all ages, girls had significantly higher mean HAZ than boys (P < 0.05). Increasing birth year, residence in ES and increasing BW were positively associated with HAZ (P < 0.05) at all ages. In MLRA controlling for birth year, BW and type of settlement, sex still had a significant effect, with lower HAZ among boys at 6, 12, 18 and 24 months of age (P < 0.001 at all ages). Conclusions: Our results indicated that sex effects on growth faltering can occur in an indigenous population with low socio-economic status within an economically developed country.