Association of phthalate concentration with lung function and
FeNO level
Analysis of the association of the quartiles of phthalate metabolites
with Rrs5 (Table 2, Figure 1) indicated the quartiles of urinary
Σ4HMWP metabolites were associated with greater Rrs5
(Crude β: 0.028; 95% CI: 0.011 to 0.046; P = .001), but these
associations were not significant after adjusting for height, gender,
BMI z- score, aeroallergen sensitization, secondary smoking, and
vitamin D level. However, after adjusting for these same confounders,
Σ4HMWP was significantly associated with Rrs1 (Q1/Q4,
adjusted β: 0.047, 95% CI: 0.009 to 0.084, P = .015), Rrs2
(Q1/Q4, adjusted β: 0.046, 95% CI: 0.007 to 0.084, P = .021),
and Rrs3 (Q1/Q4, adjusted β: 0.057, 95% CI: 0.015 to 0.099, P =
0.008) (Figure 1A).
Children with higher quartiles of Σ3LMWP metabolites
(Table 2, Fig. 1) also had significantly greater Rrs5 (Crude β: 0.028,
95% CI: 0.011 to 0.045; P = .001) and this relationship remained
significant after adjustment for confounding (adjusted β: 0.020, 95%
CI: 0.005 to 0.034; P = .010). In addition, after adjusting for
confounding, quartiles of Σ3LMWP was also significantly
associated with Rrs1 (Q1/Q4, adjusted β: 0.046, 95% CI: 0.008 to 0.083,P = .018), Rrs2 (Q1/Q4, adjusted β: 0.051, 95% CI: 0.012 to
0.089, P = .010), Rrs3 (Q1/Q4, adjusted β: 0.057, 95% CI: 0.015
to 0.099, P = .008), Rrs10 (Q1/Q4, adjusted β: 0.055, 95% CI:
0.010 to 0.099, P = .016), and Rrs15 (Q1/Q4, adjusted β: 0.055,
95% CI: 0.001 to 0.109, P = .044).
After adjustment for confounding, there was a significant association in
the quartiles of urinary Σ4HMWP metabolites with FeNO
(adjusted β: 0.053, 95% CI: 0.007 to 0.099; P = 0.024), but no
significant association in the quartiles of urinary
Σ3LMWP metabolites with FeNO (Table 2).