Table 5.

Association between nicotine phenotypes and rs684513 in lifetime smokers (n = 661)

Variable	Craving			CPD			FTND
	M		SD	M		SD	M		SD
C/CG (n = 632)a	3.8		2.5	23.9		15.8	3.5		2.5
GG (n = 29)	2.7		2.7	19.4		14.7	2.3		2.2
	b	[95% CI]	p	b	[95% CI]	p	b	[95% CI]	p
Linear regression analysisb	1.19	[0.24, 2.14]	.014	4.78	[-0.87, 10.43]	.097	1.08	[0.17, 1.99]	.020

Notes: SD = standard deviation; CI = confidence interval; craving = craving scale, lifetime, with higher values indicating greater craving (range: 0–8); CPD = cigarettes per day, during period of heaviest smoking (range: 1–80); FTND = Fagerström Test for Nicotine Dependence, lifetime (range: 0–8); b = regression coefficient; p values are reported to allow evaluation of significance, using a p value of .0068 to adjust for multiple testing.

^aGenotypes CC (n = 386) and CG (n = 246) were combined into one group because means for the phenotypes were very similar: craving, CC M = 3.78 (SD = 2.55), CG M = 3.80 (SD = 2.50); CPD, CC M = 23.63 (SD = 16.09), CG M = 24.31 (SD = 15.38); FTND, CC M = 3.40 (SD = 2.51), CG M = 3.54 (SD = 2.38).

^bAdjusted for demographics: age, sex, ethnicity.