Childhood fish oil supplementation modifies associations between traffic related air pollution and allergic sensitisation

Table 3 Associations of lung function measurements at age 5 years in relation to weighted road density within a 50 m radius of home adjusted for potential confounders stratified by fish oil supplementation

	No fish oil supplementation				Fish oil supplementation				p-value for interaction
	N	Mean Difference	95% CI	p-value	N	Mean Difference	95% CI	p-value
log (FEV1 pre bronchodilator (L))	154	−0.04	−0.09−0.01	0.083	147	−0.04	−0.08−0.01	0.100	0.760
log (FEV1 post bronchodilator (L))	151	− 0.03	− 0.08−0.01	0.150	146	−0.03	− 0.08−0.02	0.188	0.808
log (FVC pre bronchodilator (L))	154	−0.05	−0.10−0.01	0.102	147	−0.03	−0.08−0.01	0.171	0.854
log (FVC post bronchodilator (L))	151	−0.03	−0.08−0.03	0.306	146	−0.01	−0.06−0.04	0.641	0.950
FEV1/FVC ratio pre bronchodilator	154	−0.05	−0.10−0.00	0.037	147	−0.03	−0.07−0.01	0.126	0.932
FEV1/FVC ratio post bronchodilator	151	−0.04	−0.08−0.01	0.102	146	−0.03	−0.08−0.01	0.175	0.908
pre Peak Expiratory Flow (PEF)	154	−0.05	−0.10−0.00	0.073	147	−0.03	−0.07−0.02	0.237	0.903
post Peak Expiratory Flow (PEF)	151	−0.03	−0.07−0.02	0.240	146	−0.01	−0.05−0.03	0.727	0.795
Pre forced expiratory flow at 50% vital capacity (FEF₅₀)	154	0	−0.02−0.01	0.623	147	−0.01	−0.02−0.01	0.549	0.935
Post forced expiratory flow at 50% vital capacity (FEF₅₀)	151	−0.01	−0.02−0.01	0.349	146	−0.02	−0.04−0.00	0.022	0.408
Pre forced expiratory flow at mid-expiratory phase (FEF_25–75)	102	5.30	−6.24−16.85	0.364	99	−0.32	−14.53−13.88	0.964	0.386
Post forced expiratory flow at mid-expiratory phase (FEF_25–75)	100	6.23	−6.04−18.50	0.316	98	−0.49	−14.22−13.24	0.944	0.410

All models are adjusted for age at spirometry, height at spirometry, weight at spirometry, sex, father’s education, mother’s education, environmental tobacco smoke exposure, breastfed to 6 months, any dog owned by 5 or 8 years, any cat owned by 5 or 8 years, maternal smoking in pregnancy, gas cooking at home
Interaction term of fish oil supplementation with weighted road density was added as a separate term into a random intercept Poisson model. Mean difference, Relative Risks (RRs) and 95% confidence intervals (95% CI) represent increase in risk per unit increase in weighted road density, representing 100 m local road or 33.3 m of motorway within 50 m of the home. N = number of children

ISSN: 1476-069X