TABLE 1.

Median (IQR) Serum Cotinine (ng/mL), Median (SD) eGFR (mL/min per 1.73 m2), and Tobacco Smoke Exposure Status by Participant Characteristics in US Adolescents 12 to 17 Years of Age

	Overall (N = 7516)		Unexposed (N = 2897)	SHS (N = 3692)	Active Smoking (N = 927)
	Median eGFR (IQR)	Median Serum Cotinine (IQR)	Weighted %	Weighted %	Weighted %
Overall	96.8 (85.4–109.0)	0.07 (0.03–0.59)
Gender
Boy	92.9 (81.8–105.4)	0.09 (0.03–0.72)	37.1	48.1	14.8
Girl	99.9 (90.0–112.0)	0.06 (0.02–0.49)	43.4	43.0	13.6
Age, y
12–13	106.7 (96.3–119.4)	0.05 (0.02–0.33)	43.4	53.0	13.6
14–15	96.2 (86.4–106.4)	0.07 (0.02–0.51)	42.9	44.2	12.9
16–17	88.23 (78.9–99.1)	0.11 (0.03–1.58)	34.0	40.2	25.8
Ethnicity
White	96.3 (85.6–107.7)	0.08 (0.02–1.14)	56.2	34.7	1.0
African American	92.3 (81.4–104.4)	0.23 (0.05–1.03)	45.8	40.2	14.0
Mexican	102.1 (89.7–116.4)	0.04 (0.02–0.13)	40.5	42.8	16.7
Other	99.1 (86.4–112.8)	0.05 (0.02–0.37)	22.3	68.2	9.5
Education
<High school	98.1 (85.5–111.2)	0.02 (0.04–0.21)	31.5	52.0	16.5
High school	96.9 (84.9–109.0)	0.04 (0.19–1.24)	26.4	55.8	17.8
>High school	96.2 (85.7–108.1)	0.14 (0.04–0.98)	49.6	38.7	11.7
BMI (percentile)
Normal weight (≤84)	96.1 (85.0–108.5)	0.05 (0.02–0.45)	43.1	42.7	14.2
Overweight (85–94)	97.1 (85.8–108.3)	0.06 (0.02–0.57)	35.2	49.0	15.8
Obese (≥95)	97.4 (85.7–110.0)	0.08 (0.03–0.65)	33.9	53.4	12.7
Birth weight
Normal weight (≥2500 g)	101.5 (90.5–112.8)	0.05 (0.22–0.37)	44.0	48.0	8.0
Underweight (<2500 g)	99.2 (88.5–112.0)	0.10 (0.03–0.67)	38.3	53.6	8.1

SHS, secondhand smoke.