Table 4.

Geometric mean for nicotine equivalents^* (95% confidence limits) by CYP2A6 activity level

	Nicotine Metabolite Ratio †					Caffeine Metabolite Ratio †
	≤ Median		> Median		p-valuea	≤ Median		> Median		p-valuea
Age- and Urine Volume- Adjusted Means	n	Mean (95% CI)	n	Mean (95% CI)		n	Mean (95% CI)	n	Mean (95% CI)
Female
All ‡	142	28.2 (25.4–31.2)	153	34.7 (31.5–38.4)	0.005	138	29.3 (26.4–32.6)	157	33.4 (30.3–36.9)	0.08
Native Hawaiian	45	28.6 (23.0–35.6)	54	37.7 (31.0–45.8)	0.06	42	32.0 (25.5–40.2)	57	34.3 (28.3–41.7)	0.65
White	33	33.5 (27.3–41.0)	66	38.7 (33.5–44.8)	0.25	36	32.1 (26.3–39.3)	63	39.8 (34.3–46.3)	0.10
Japanese American	64	23.7 (20.9–26.8)	33	28.4 (24.0–33.7)	0.09	60	23.5 (20.8–26.7)	37	28.2 (24.0–33.2)	0.08
Male
All ‡	151	36.8 (32.8–41.4)	139	39.2 (34.7–44.3)	0.48	154	32.7 (29.2–36.6)	136	45.0 (39.9–50.8)	0.0002
Native Hawaiian	49	38.7 (30.9–48.5)	44	46.1 (36.3–58.4)	0.30	50	34.1 (27.5–42.2)	43	53.7 (42.6–67.7)	0.01
White	39	40.0 (32.7–48.9)	60	47.0 (40.5–54.5)	0.20	38	41.2 (34.0–50.0)	61	46.5 (39.9–54.1)	0.34
Japanese American	63	31.3 (26.3–37.4)	35	25.8 (19.9–33.5)	0.22	66	25.9 (21.8–30.8)	32	38.6 (30.1–49.6)	0.01
Multivariate-Adjusted Means§
Female
All‡		28.4 (25.8–31.4)		34.4 (31.3–37.9)	0.01		29.9 (27.1–33.0)		32.8 (29.8–36.1)	0.20
Native Hawaiian		28.4 (23.0–35.0)		37.9 (31.5–45.7)	0.04		32.7 (26.3–40.7)		33.9 (28.1–40.8)	0.81
White		33.7 (27.8–41.0)		38.6 (33.5–44.4)	0.27		33.0 (27.1–40.0)		39.3 (34.0–45.4)	0.16
Japanese American		23.9 (21.2–27.0)		27.9 (23.6–32.9)	0.15		23.9 (21.1–27.1)		27.5 (23.5–32.3)	0.17
Male
All‡		36.9 (32.8–41.5)		39.2 (34.6–44.3)	0.51		32.9 (29.4–36.8)		44.7 (39.7–50.5)	0.0004
Native Hawaiian		39.1 (31.2–49.1)		45.5 (35.8–57.9)	0.37		34.2 (27.5–42.7)		53.4 (42.1–67.8)	0.01
White		40.5 (32.9–49.8)		46.7 (40.1–54.3)	0.29		40.8 (33.5–49.7)		46.8 (40.1–54.5)	0.29
Japanese American		31.1 (26.1–37.0)		26.4 (20.3–34.2)	0.31		26.4 (22.2–31.4)		37.2 (28.8–47.9)	0.03

^*Nicotine equivalents is the sum of urinary total nicotine, total cotinine, and total trans-3′-hydroxycotinine in nmol/mL.

^†Medians were based on all participants, and median values are 0.73 and 1.27 for nicotine metabolite ratio and caffeine metabolite ratio, respectively.

^‡Further adjusted for race.

^§Further adjusted for cigarettes per day and calorie-adjusted caffeine intake by multiple covariance analysis.

^aP-values were obtained in a model comparing nicotine equivalents as a continuous variable (with the independent variables described in the table) between low and high nicotine metabolite ratio or caffeine metabolite ratio, for each subgroup analysis.