Low-moderate arsenic exposure and respiratory in American Indian communities in the Strong Heart Study

Table 5 Weighted Mean Difference (95% Confidence Interval) of Lung Function at Visit 2 (1993–1995) by Urinary Arsenic Concentration at Baseline (1989–1991)

	N	Inorganic Plus Methylated Arsenic Species μg/g creatinine				P-trend^d
	N	Tertile 1 ≤7.0^b	Tertile 2 7.1–13.9^b	Tertile 3 ≥14.0^b	75th vs. 25th Percentile^c	P-trend^d
FEV1, % predicted
All	2132	0 (Ref)	0.92 (−0.52, 2.37)	−1.64 (−3.60, 0.32)	−1.39 (−2.51, −0.25)	0.02
Healthy^a	1367	0 (Ref)	0.67 (−0.86, 2.19)	−0.49 (−2.58, 1.61)	0.85 (0.27, 2.74)	0.80
FVC, % predicted
All	2132	0 (Ref)	2.09 (0.72, 3.47)	−1.01 (−2.85, 0.83)	−1.13 (−2.21, − 0.05)	0.04
Healthy^a	1367	0 (Ref)	1.15 (− 0.23, 2.53)	− 0.73 (− 2.60, 1.14)	0.70 (0.24, 2.02)	0.50
FEV1/FVC (%)
All	2132	0 (Ref)	−0.62 (−1.26, 0.002)	− 0.16 (− 1.01, 0.69)	0.09 (− 0.46, 0.66)	0.74
Healthy^a	1367	0 (Ref)	− 0.31 (− 0.85, 0.25)	0.26 (− 0.49, 1.01)	1.21 (0.76, 1.94)	0.42
FEV1, mL
All	2132	0 (Ref)	0.007 (−0.04, 0.06)	−0.09 (− 0.15, − 0.03)	−0.07 (− 0.11, − 0.03)	< 0.001
Healthy^a	1367	0 (Ref)	0.003 (− 0.05, 0.06)	−0.06 (− 0.14, 0.01)	−0.03 (− 0.07, − 0.003)	0.07
FVC, mL
All	2132	0 (Ref)	0.06 (−0.004, 0.11)	−0.10 (− 0.17, − 0.02)	−0.07 (− 0.12, − 0.03)	0.001
Healthy^a	1367	0 (Ref)	0.02 (− 0.05, 0.09)	−0.09 (− 0.19, − 0.0001)	−0.05 (− 0.10, − 0.004)	0.03

Adjusted for age, sex, education, site, smoking status, smoking pack-year, eGFR, tuberculosis, and BMI
^aHealthy: FEV1/FVC > 0.70 & FVC > 80% predicted
^bTertiles are range; calculated based on overall population; sum of inorganic and methylated species μg/g creatinine
^cComparison of the 75th and 25th percentiles (interquartile range) of the sum inorganic and methylated urinary arsenic concentrations (16.7 vs. 5.8 μg/g creatinine)
^dP-trend calculated modeling log-arsenic as continuous

ISSN: 1476-069X