Table 4.

Smoking status and total and regional gray matter volumes, stratified by alcohol use, in the CARDIA brain MRI cohort

	Alcohol non-users			Low/high-risk alcohol users
	βa	95% CI	p	βa	95% CI	p
Total GM
Never-smokers	Ref.			Ref.
Former-smokers	−2.32	−8.79, 4.15	0.48	−2.69	−7.63, 2.24	0.28
Current smokers	3.28	−5.53,12.09	0.46	−12.01	−18.54, −5.48	0.0003
Frontal GM
Never-smokers	Ref.			Ref.
Former-smokers	−0.48	−3.31, 2.17	0.72	−1.56	−3.62, 0.49	0.14
Current smokers	1.60	−2.01, 5.21	0.38	−3.57	−6.28, −0.85	0.01
Temporal GM
Never-smokers	Ref.			Ref.
Former-smokers	−0.48	−2.76, 1.79	0.68	−1.51	−3.25, 0.24	0.09
Current smokers	0.24	−2.86, 3.34	0.88	−4.14	−6.45, −1.84	0.0005
Occipital GM
Never-smokers	Ref.			Ref.
Former-smokers	−0.57	−2.07, 0.93	0.46	0.66	−0.46, 1.78	0.25
Current smokers	−0.01	−2.06, 2.03	0.99	−1.22	−2.70, 0.27	0.11
Parietal GM
Never-smokers	Ref.			Ref.
Former-smokers	−0.04	−1.69, 1.61	0.96	−0.19	−1.49, 1.11	0.77
Current smokers	1.15	−1.10, 3.40	0.32	−0.84	−2.56, 0.88	0.34
Amygdala
Never-smokers	Ref.			Ref.
Former-smokers	−0.02	−0.11, 0.07	0.64	−0.02	−0.09, 0.04	0.50
Current smokers	−0.02	−0.14, 0.10	0.75	−0.10	−0.18, −0.01	0.03
Insula
Never-smokers	Ref.			Ref.
Former-smokers	−0.13	−0.554 0.30	0.56	−0.16	−0.47, 0.16	0.32
Current smokers	0.34	−0.25, 0.92	0.26	−0.70	−1.12, −0.28	0.001
Entorhinal cortex
Never-smokers	Ref.			Ref.
Former-smokers	0.04	−0.06, 0.15	0.43	−0.06	−0.14, 0.02	0.15
Current smokers	−0.10	−0.25, 0.05	0.18	−0.06	−0.17, 0.04	0.26
Cingulate
Never-smokers	Ref.			Ref.
Former-smokers	−0.24	−0.89, 0.42	0.48	0.004	−0.52, 0.53	0.99
Current smokers	−0.15	−1.05, 0.75	0.74	−1.17	−1.87, −0.48	0.001

^aCoefficients estimated using fully-adjusted linear regression models including age, sex, education, race, study center, total intracranial volume, hypertension, diabetes, history of vascular disorders, BMI, high cholesterol, respiratory illness, FEV₁, depressive symptoms, and illicit drug use