Table 4.

Multiple regression analysis between multiple variables (age, body mass index, education, smoking years, cigarettes per day, pack/years, nicotine dependence, carbon monoxide in exhaled air and respiratory variables) and saccharin transit time test (minutes).

	Smokers								Non-smokers
	Men (n = 33)				Women (n = 37)				Men (n = 32)				Women (n = 37)
	β	95% CI		p	β	95% CI		p	β	95% CI		p	β	95% CI		p
		Lower limit	Upper limit			Lower limit	Upper limit			Lower limit	Upper limit			Lower limit	Upper limit
Age	0.07	−0.22	0.36	0.63	−0.01	−0.28	0.26	0.94	0.41	−0.17	0.99	0.16	0.07	−0.31	0.45	0.73
BMI	0.03	−0.48	0.43	0.90	−0.40	−0.74	−0.06	0.02a	0.38	−0.64	1.40	0.45	−0.00	−0.41	0.40	0.98
Education	0.20	−0.69	0.29	0.41	−0.29	−0.64	0.05	0.09	0.11	−0.97	1.18	0.84	−0.63	−1.29	0.03	0.06
Smoking years	0.02	−0.24	0.28	0.87	0.16	−0.05	0.37	0.14	–	–	–	–	–	–	–	–
Cigarettes per day	0.07	−0.10	0.23	0.40	−0.02	−0.17	0.12	0.74	–	–	–	–	–	–	–	–
Pack/years	0.03	−0.08	0.14	0.57	0.01	−0.12	0.15	0.85	–	–	–	–	–	–	–	–
Nicotine dependence	0.20	−0.61	1.02	0.61	−0.27	−1.02	0.47	0.46	–	–	–	–	–	–	–	–
COex (% Hb)	1.18	−3.6	1.26	0.33	−2.47	−4.75	−0.19	0.04a	4.40	−8.47	17.27	0.49	−1.03	−6.80	4.75	0.72
FVC (% of predicted)	0.14	−0.38	0.10	0.25	−0.04	−0.18	0.11	0.59	−0.29	−0.50	−0.09	0.01a	0.08	−0.07	0.23	0.30
FEV1 (% of predicted)	0.11	−0.35	0.13	0.37	0.00	−0.14	0.15	0.98	−0.31	−0.55	−0.08	0.01a	0.13	−0.02	0.28	0.09
FEV1/FVC	0.06	−0.31	0.43	0.76	0.25	−0.13	0.63	0.19	0.28	−0.29	0.84	0.32	0.42	−0.05	0.88	0.08
PEF (% of predicted)	0.09	−0.23	0.05	0.21	−0.06	−0.16	0.05	0.27	−0.14	−0.37	0.08	0.20	0.08	−0.04	0.20	0.18
FEF25–75% (% of predicted)	0.01	−0.11	0.12	0.92	0.03	−0.04	0.10	0.37	0.01	−0.13	0.15	0.87	0.09	0.01	0.16	0.03a

Hb, hemoglobin; FVC, forced vital capacity; FEV₁, forced expiratory volume in one second; PEF, peak expiratory flow; FEF_25–75%, forced expiratory flow between 25% and 75%.

^ap < 0.05.