Racial Differences in the Association Between Alcohol Drinking and Cigarette Smoking: Preliminary Findings From an Alcohol Research Program.

AIMS: Important differences have been shown in alcohol drinking and cigarette smoking prevalence, patterns and consequences among individuals from different racial backgrounds. Alcohol and nicotine are often co-used, and the association between drinking and smoking may differ between racial groups-a question explored in the present study. METHODS: Data from the NIAAA natural history and screening protocols were utilized; non-Hispanic Black and non-Hispanic White individuals were included in the analyses [N = 1692; 65.2% male; 58.3% met criteria for current alcohol use disorder (AUD); 37.8% were current cigarette smokers]. Bivariate associations between assessments related to alcohol drinking and cigarette smoking were examined, and the strength and direction of these associations were compared between the two groups. RESULTS: The sample included 796 Black and 896 White individuals. Black participants had higher frequency (P < 0.0001) and severity (P = 0.007) of AUD, as well as higher frequency (P < 0.0001) of cigarette smoking. Bivariate analyses showed that the expected positive associations between alcohol drinking and cigarette smoking, observed among White individuals, were blunted or absent among Black individuals [age at first cigarette-AUD identification test (AUDIT) score: F(1, 292) = 7.60, P = 0.006; cigarette pack years-AUDIT score: F(1, 1111) = 10.97, P = 0.001]. CONCLUSIONS: Some decoupling in the association between alcohol drinking and cigarette smoking was found among Black compared to White individuals. The sample was drawn from a specific population enrolled in alcohol research protocols, which is a limitation of the present study. These preliminary findings highlight the importance of considering racial/ethnic background in preventive and therapeutic strategies for comorbid alcohol and nicotine use.

Changes in Hemodynamic Response Function Resulting From Chronic Alcohol Consumption.

BACKGROUND: Functional MRI (fMRI) task-related analyses rely on an estimate of the brain's hemodynamic response function (HRF) to model the brain's response to events. Although changes in the HRF have been found after acute alcohol administration, the effects of heavy chronic alcohol consumption on the HRF have not been explored, and the potential benefits or pitfalls of estimating each individual's HRF on fMRI analyses of chronic alcohol use disorder (AUD) are not known. METHODS: Participants with AUD and controls (CTL) received structural, functional, and vascular scans. During fMRI, participants were cued to tap their fingers, and averaged responses were extracted from the motor cortex. Curve fitting on these HRFs modeled them as a difference between 2 gamma distributions, and the temporal occurrence of the main peak and undershoot of the HRF was computed from the mean of the first and second gamma distributions, respectively. RESULTS: ANOVA and regression analyses found that the timing of the HRF undershoot increased significantly as a function of total lifetime drinking. Although gray matter volume in the motor cortex decreased with lifetime drinking, this was not sufficient to explain undershoot timing shifts, and vascular factors measured in the motor cortex did not differ among groups. Comparison of random-effects analyses using custom-fitted and canonical HRFs for CTL and AUD groups showed better results throughout the brain for custom-fitted versus canonical HRFs for CTL subjects. For AUD subjects, the same was true except for the basal ganglia. CONCLUSIONS: These findings suggest that excessive alcohol consumption is associated with changes in the HRF undershoot. HRF changes could provide a possible biomarker for the effects of lifetime drinking on brain function. Changes in HRF topography affect fMRI activation measures, and subject-specific HRFs generally improve fMRI activation results.