Table 2.

Association of serum cadmium with PRISm, NHANES 2007–2012¹

Exposure	Serum cadmium (ug/L)
	Odds ratio (95% confidence interval)
All individuals (n = 8324)
Quartile 1 (< 0.19 ug/L)	1.00
Quartile 2 (0.19–0.29 ug/L)	1.033 (0.768, 1.390)
Quartile 3 (0.29–0.52 ug/L)	1.302 (0.985, 1.720)
Quartile 4 (≥ 0.52 ug/L)	1.695 (1.293, 2.221) **
p-trend	< 0.0001
Never/former smokers (n = 6076)
Quartile 1 (< 0.14 ug/L)	1.00
Quartile 2 (0.14–0.26 ug/L)	2.088 (1.162, 3.750) *
Quartile 3 (0.26–0.37 ug/L)	2.314 (1.265, 4.234) **
Quartile 4 (≥ 0.37 ug/L)	2.517 (1.376, 4.604) **
p-trend	0.0077
Current smokers (n = 1694)
Quartile 1 (< 0.57 ug/L)	1.00
Quartile 2 (0.57–0.93 ug/L)	1.483 (0.835, 2.633)
Quartile 3 (0.93–1.45 ug/L)	1.478 (0.830, 2.633)
Quartile 4 (≥ 1.45 ug/L)	2.201 (1.265, 3.830) **
p-trend	0.0020

BMI, body mass index; PIR: poverty income ratio; PRISm, preserved ratio impaired spirometry; NHANES, National Health and Nutrition Examination Survey. ¹ All models were adjusted: age, gender, race/ethnicity, BMI, PIR, health insurance, sedentary activity, history of childhood diseases (emphysema, bronchitis, or asthma), diabetes, and occupational exposure to mineral dusts, organic dusts or exhaust fumes. Subgroup analysis according to smoking status. p-Value: ^* p < 0.05, ^** p < 0.01