Table 4.

Associations of PM₁₀, O₃, and NO₂ with fasting glucose, insulin, and HOMA indices by GSTM1, GSTT1, and GSTP1 genotypes.

Gene/genotype		Pollutant	n	Glucose						Insulin						HOMA
				Estimate (95% CI)		p-Value	p for interaction	Estimate (95% CI)		p-Value	p for interaction	Estimate (95% CI)		p-Value	p for interaction
GSTM1
Present	PM10	225	0.04	(–0.04, 0.13)	0.3019	0.0459	0.19	(–0.25, 0.64)	0.3990	0.6201	0.12	(–0.04, 0.28)	0.1488	0.4944
O3	225	0.04	(–0.10, 0.18)	0.6027	0.0112	0.19	(–0.55, 0.93)	0.6140	0.2934	0.08	(–0.18, 0.34)	0.5552	0.1647
NO2	225	0.06	(–0.02, 0.15)	0.1579	0.2187	0.14	(–0.30, 0.58)	0.5278	0.0054	0.10	(–0.06, 0.25)	0.2308	0.0137
Null	PM10	299	0.17	(0.09, 0.25)	0.0001	0.33	(–0.35, 1.02)	0.3430	0.20	(–0.03, 0.43)	0.0894
O3	299	0.30	(0.17, 0.42)	< 0.0001	1.14	(0.08, 2.19)	0.0351	0.47	(0.11, 0.83)	0.0102
NO2	299	0.14	(0.06, 0.22)	0.0006	1.27	(0.59, 1.94)	0.0003	0.45	(0.22, 0.68)	0.0002
GSTT1
Present	PM10	254	0.05	(–0.03, 0.12)	0.2449	0.1166	0.17	(–0.41, 0.75)	0.5649	0.8711	0.06	(–0.10, 0.22)	0.4812	0.3609
O3	254	0.08	(–0.03, 0.19)	0.1687	0.0151	0.59	(–0.29, 1.47)	0.1875	0.8825	0.15	(–0.09, 0.40)	0.2231	0.4358
NO2	254	0.02	(–0.05, 0.08)	0.6524	0.0020	0.44	(–0.07, 0.96)	0.0908	0.0463	0.11	(–0.03, 0.25)	0.1338	0.0028
Null	PM10	270	0.15	(0.07, 0.24)	0.0008	0.21	(–0.41, 0.83)	0.5030	0.20	(–0.03, 0.43)	0.0926
O3	270	0.29	(0.15, 0.44)	0.0001	0.77	(–0.27, 1.81)	0.1490	0.42	(0.03, 0.81)	0.0360
NO2	270	0.21	(0.12, 0.31)	< 0.0001	1.08	(0.41, 1.76)	0.0019	0.49	(0.24, 0.75)	0.0002
GSTP1
AA	PM10	345	0.09	(0.03, 0.15)	0.0052	0.9598	0.06	(–0.47, 0.59)	0.8326	0.7265	0.05	(–0.13, 0.23)	0.5758	0.3947
O3	345	0.08	(–0.02, 0.17)	0.1029	0.0006	0.15	(–0.07, 0.97)	0.7215	0.0205	0.06	(–0.22, 0.34)	0.6762	0.0036
NO2	345	0.08	(0.02, 0.14)	0.0077	0.3620	0.75	(0.24, 1.26)	0.0042	0.3848	0.26	(0.09, 0.43)	0.0034	0.4972
AG or GG	PM10	179	0.12	(0.001, 0.24)	0.0503	0.47	(–0.26, 1.20)	0.2099	0.29	(0.04, 0.54)	0.0250
O3	179	0.40	(0.20, 0.60)	0.0001	1.79	(0.58, 3.01)	0.0044	0.74	(0.32, 1.17)	0.0007
NO2	179	0.14	(0.02, 0.27)	0.0230	0.70	(–0.05, 1.44)	0.0695	0.30	(0.04, 0.56)	0.0235
At-risk genotypea
0–1	PM10	282	0.08	(0.005, 0.15)	0.0382	0.6077	0.04	(–0.37, 0.45)	0.8377	0.3584	0.06	(–0.07, 0.18)	0.3853	0.2277
O3	282	0.05	(–0.06, 0.17)	0.3625	0.0003	–0.06	(–0.69, 0.57)	0.8633	0.0860	–0.01	(–0.20, 0.19)	0.9379	0.0244
NO2	282	0.05	(–0.02, 0.12)	0.1832	0.0358	0.32	(–0.05, 0.69)	0.0943	0.0135	0.11	(–0.001, 0.23)	0.0528	0.0030
2–3	PM10	242	0.13	(0.03, 0.22)	0.0080	0.38	(–0.39, 1.15)	0.3388	0.23	(–0.04, 0.59)	0.1017
O3	242	0.35	(0.20, 0.50)	< 0.0001	1.47	(0.19, 2.74)	0.0253	0.61	(0.16, 1.06)	0.0089
NO2	242	0.19	(0.09, 0.29)	0.0003	1.28	(0.45, 2.11)	0.0027	0.51	(0.22, 0.81)	0.0006
p-Values obtained after weighting follow-up observations in the single-pollutant model of PM10, O3, and NO2 on lag day 4, lag day 5, and lag day 7, respectively. Changes in glucose, insulin, and HOMA indices by an IQR-change of PM10 (20.8 µg/m3), O3 (15.1 ppb), and NO2 (10.8 ppb) were obtained after adjusting for age, sex, BMI, cotinine level, and outdoor temperature and dew point of the day. aNumber of risky genotypes.