Greater early infant weight gain may reduce allergen sensitization risk
Greater weight gain in the first 15 months of life was associated with a decreased risk of allergen sensitization, according to a Singapore study.
Using data from the GUSTO* birth cohort, researchers evaluated 1,059 mothers who gave birth to full-term infants. Skin prick tests (SPTs) to inhalant and food allergens were carried out at 18 and 36 months. [BMC Pediatrics 2017;doi:10.1186/s12887-017-0890-0]
At 18 months, 13.5 percent had a positive SPT. About 4 percent had wheeze and a positive SPT, 3.9 percent had rhinitis and a positive SPT, and 6.1 percent had eczema and a positive SPT.
At 36 months, 23.5 percent had a positive SPT. Twelve percent had wheeze and a positive SPT, 12.2 percent had rhinitis and a positive SPT, and 11.5 percent had eczema and a positive SPT.
After controlling for clinical, demographic, and maternal variables and allergy history, greater weight gains between 6 and 9 months (quartile 4 [Q4], adjusted odds ratio [adjOR], 0.3, 95 percent confidence interval [CI], 0.1–0.7; p<0.01) and between 12 and 15 months (Q4, adjOR, 0.4, 95 percent CI, 0.2–0.8; p<0.01) were associated with a decreased risk of developing positive SPT at 18 months.
At 36 months, a greater weight gain between 12 and 15 months was associated with a decreased risk of positive SPT (Q4, adjOR, 0.4, 95 percent CI, 0.2–0.8; p<0.01).
There were no significant associations between weight gain at any period and wheeze, rhinitis, or eczema combined with a positive SPT at 18 or 36 months.
“The dissociation between SPT and clinical symptoms could be due to the less specific nature of clinical symptoms of rash, rhinitis, and wheezing, which could be of nonatopic origins,” said the researchers.
However, the findings were contradictory to previous studies that found no association between positive SPTs and infant weight gain. [Public Health Nutr 2014;17:2537-2545; Pediatr Allergy Immunol 2013;24:122-130; J Allergy Clin Immunol 2009;123:1312-1318; Thorax 2010;65:1099-1106]
“A possible reason for the inconsistent results … is the earlier age at which SPTs were obtained in the GUSTO cohort,” said the researchers, as most of the previous studies focused on older children.
“Allergen sensitization patterns are known to change with age. The association we observed between increased weight gain and reduced subsequent allergen sensitization may be a chance finding,” they added, hence the need for further evaluation.
Additionally, further investigation is warranted as the allergic symptoms were mostly reported by parents which could have limited the findings, noted the researchers. “It will be important to track the future development of allergic diseases and immune phenotypes in our cohort to assess whether the associations we observed persist, and whether new ones emerge at later ages,” they said.