Body mass index and physical activity in early childhood are associated with atopic sensitization, atopic dermatitis and asthma in later childhood

Table 4 The adjusted odds ratios of asthma in adolescence in 617 Norwegian children by weight/BMI SDS and physical activity after backward stepwise selection of potential confounders (one model for each predictor variable)

Predictor	Outcome variable (final analyses)
Predictor	Asthma ever by first follow-up^a				Current asthma at second follow-up^b
Age	n	OR	95 % CI	LR-p	n	OR	95 % CI	LR-p
Weight SDS
Birth	580	0.93	(0.72, 1.20)	0.587	439	0.95	(0.71, 1.27)	0.716
BMI SDS
3 months	520	0.88	(0.64, 1.21)	0.437	411	0.96	(0.67, 1.38)	0.835
6 months	536	1.06	(0.79, 1.41)	0.707	425	0.86	(0.61, 1.20)	0.370
1 year	536	1.00	(0.76, 1.32)	0.998	424	0.78	(0.57, 1.08)	0.127
4 years^c	454	1.09	(0.80, 1.47)	0.596	361	0.91	(0.63, 1.32)	0.627
First follow-up^d	558	1.02	(0.79, 1.33)	0.849	426	1.10	(0.81, 1.49)	0.561
Second follow-up^d	N.A.	N.A.	N.A.	N.A.	421	1.25	(0.90, 1.72)	0.176
Physical activity
At 3–6 years^e	454			0.014	361			0.475
Normal	275	1.00	Reference		220	1.00	Reference
Low	57	3.61	(1.56, 8.36)		48	1.92	(0.66, 5.59)
High	122	1.34	(0.61, 2.97)		93	1.40	(0.55, 3.55)
At 6–10 years^f	558			0.038	426			0.177
Normal	351	1.00	Reference		274	1.00	Reference
Low	92	2.52	(1.24, 5.12)		69	1.98	(0.80, 4.85)
High	115	1.02	(0.46, 2.28)		83	1.97	(0.83, 4.67)

First follow-up: 10.8 years (girls) and 11.8 years (boys); Second follow-up: 12.8 years (both sexes)
Italics numbers indicate statistically significant results
n number of participants, OR Odds ratio, CI confidence interval, LR-p likelihood ratio-test p-value refers to predictor only, BMI body mass index (kg/m²), SDS standard deviation score, N.A. not applicable
^aAfter stepwise backward selection, adjusted for sex, gestational age, mother’s preeclampsia and asthma
^bAfter stepwise backward selection, adjusted for sex, mother’s preeclampsia and mother’s asthma
^cAlso adjusted for physical activity at 3–6 years
^dAlso adjusted for physical activity at 6–10 years
^eAlso adjusted for BMI SDS at 4 years
^fAlso adjusted for BMISDS at the first follow-up

ISSN: 2045-7022