. 2012 Oct 4;34(1):93–101. doi: 10.1093/carcin/bgs306

Table IV.

NNN levels were significantly higher in smokers with slower CYP2A6 activity when tobacco consumption was controlled for

A: Smokers	B	β	95% CI	P
Plasma NMR: R ² = 0.30, P < 0.001
TNE (increasing, per nmol)	0.01	0.53	0.010,0.019	0.001
NMR (slower strata)	0.41	0.17	0.023,0.791	0.038
Age (increasing)	0.01	0.08	–0.006,0.020	0.297
CYP2A6 genotype: R ² = 0.33, P < 0.001
TNE (increasing, per nmol)	0.01	0.52	0.010,0.018	0.001
CYP2A6 genotype (reduced)	0.6	0.24	0.212,0.979	0.003
Age (increasing)	0.00	0.03	–0.011,0.015	0.730
B: Commercial smokeless tobacco
Plasma NMR: R ² = 0.36, P < 0.001
TNE (increasing, per nmol)	0.01	0.63	0.007,0.015	0.001
NMR (slower strata)	0.41	0.18	–0.067,0.887	0.091
Age (increasing)	0.00	–0.02	–0.021,0.017	0.825
CYP2A6 genotype: R ² = 0.33, P < 0.001
TNE (increasing, per nmol)	0.01	0.58	0.007,0.014	0.001
CYP2A6 genotype (reduced)	–0.06	–0.03	–0.544,0.418	0.793
Age (increasing)	–0.01	–0.05	–0.025,0.015	0.612

B is the unstandardized coefficient. β is the standardized coefficient (i.e. standardized to a variance of 1). The B and β provided refer to the variables listed in brackets beside each categorical predictor. The NNN levels were log-transformed to obtain a normal distribution.