Table 1.

General characteristics of the participants.

Characteristics	Case	Control	p Value
	(n = 200)	(n = 200)
Children
Age	5.55 ± 1.25	5.69 ± 0.93	0.19
Male gender (%)	116 (58.0%)	101 (50.5%)	0.10
Premature birth (<37 weeks) (%)	13 (6.5%)	19 (9.5%)	0.26
Birth body weight (gm)	3199 ± 413	3104 ± 493	0.49
Body mass index (BMI)	16.2 ± 1.90	16.0 ± 1.91	0.32
Z-score of BMI	0.18 ± 1.12	0.30 ± 1.14	0.34
Percentage of BMI	55.9 ± 31.5	59.4 ± 28.8	0.28
Urinary 8-OHdG (ng/mg Cr)	35.6 ± 27.7	26.2 ± 17.6	<0.001
Asthma (%)	49 (25.4%)	4 (2.00%)	<0.001
Allergic rhinitis (%)	99 (50.8%)	8 (4.00%)	<0.001
Night pruritus (%)	71 (35.5%)	2 (1.00%)	<0.001
Mothers
Maternal age at delivery (years)	30.0 ± 4.19	30.2 ± 4.35	0.20
Maternal education (%) *
Junior high school and below	6 (3.0%)	7 (4.0%)	0.79
Senior high school and above	191 (97.0%)	192 (96.0%)
Maternal Nationality (%) *
Taiwan	188 (96.4%)	188 (94.4%)	0.36
Foreign countries	7 (3.60%)	11 (5.60%)
Parental history of atopy (%)	63 (31.5%)	81 (40.5%)	0.26
Environment
Duration of breast feeding (%) *
No	35 (18.1%)	43 (22.2%)	0.61
<6 months	110 (57.0%)	105 (54.1%)
≥6 months	48 (24.9%)	46 (23.7%)
Daily additional supplementation of vitamin C or E intake (%)	67 (37.0%)	76 (40.4%)	0.49
Number of older siblings < 2 (%)	160 (80.0%)	170 (85.0%)	0.31
Daycare < 1-year-old (%)	59 (29.5%)	39 (19.5%)	0.02
Furry pets at home (%)	29 (14.5%)	43 (21.5%)	0.08
Carpets at home (%)	17 (8.50%)	13 (6.50%)	0.39
Fungus on house wall (%)	81 (40.5%)	73 (36.5%)	0.36
Exposures of environmental tobacco smoke (%)	112 (56.0%)	102 (51.0%)	0.24
Family income per month ($USD) (%) *
<20,000	62 (34.1%)	64 (33.5%)	0.39
20,000~33,300	51 (28.0%)	65 (34.0%)
≥33,300	69 (37.9%)	62 (32.5%)

* The sum of n may not be equal to total n due to missing values; Data were presented with mean ± standard deviation or number (%).