Principal Components Analysis of Atopy-Related Traits in a Random Sample of Children
Table 1
Correlations between atopy-related traits in a population of 1007 children, 7–17 years of age.
Trait
Traits(1)
Principal components(2)
Summary statistics(3)
Asthma
Hay fever
Eczema
IgE
FEV1/FVC
AHR
SPT
Grass
Cat
HDM
Comp 1
Comp 2
Comp 3
Asthma
1
024
0.67
0.12
7.1 (5.7–8.9)
Hay fever
0.25
1
0.66
0.10
0.17
17.3 (15.1–19.7)
Eczema
0.10
0.14
1
0.09
0.05
0.90
22.1 (19.6–24.7)
IgE
0.20
0.32
0.17
1
0.50
0.22
0.30
35.2 (31.8–39.1)
FEV1/FVC
−0.16
−0.05
−0.01
−0.06
1
0.04
−0.62
0.20
89.4 (89.0–89.8)
AHR
0.38
0.16
0.13
0.24
−0.18
1
0.11
0.74
0.22
11.6 (9.7–13.7)
SPT
0.23
0.46
0.12
0.39
−0.05
0.20
1
0.89
0.11
−0.05
21.8 (19.4–24.5)
Grass
0.13
0.43
0.11
0.30
−0.03
0.05
0.55
1
0.69
−0.13
0.11
7.7 (6.2–9.5)
Cat
0.25
0.34
0.18
0.25
−0.03
0.25
0.50
0.32
1
0.65
0.11
0.13
6.5 (5.1–8.2)
HDM
0.24
0.32
0.20
0.30
−0.07
0.20
0.69
0.20
0.41
1
0.71
0.24
−0.18
11.8 (10.0–14.0)
(1)Significant correlations are shown in bold print. Significance level is 0.0005 when adjusting for multiple testing. (2)Varimax-rotated factor solution. (3)IgE is geometric mean (95% CI); all other values are percentages (95% CI). IgE is serum total IgE; AHR is airway hyperresponsiveness to histamine; SPT is positive skin prick test; HDM is house dust mite (D. Pteronyssinus).
