Alcohol and atherosclerosis

Contribution of metabolic risk factors and lifestyle behaviors to cardiovascular disease: A mendelian randomization study

BACKGROUND AND AIMS

Etiologic associations between some modifiable factors (metabolic risk factors and lifestyle behaviors) and cardiovascular disease (CVD) remain unclear. To identify targets for CVD prevention, we evaluated the causal associations of these factors with coronary artery disease (CAD) and ischemic stroke using a two-sample Mendelian randomization (MR) method.

METHODS AND RESULTS

Previously published genome-wide association studies (GWASs) for blood pressure (BP), glucose, lipids, overweight, smoking, alcohol intake, sedentariness, and education were used to identify instruments for 15 modifiable factors. We extracted effects of the genetic variants used as instruments for the exposures on coronary artery disease (CAD) and ischemic stroke from large GWASs (N = 60 801 cases/123 504 controls for CAD and N = 40 585 cases/406 111 controls for ischemic stroke). Genetically predicted hypertension (CAD: OR, 5.19 [95% CI, 4.21-6.41]; ischemic stroke: OR, 4.92 [4.12-5.86]), systolic BP (CAD: OR, 1.03 [1.03-1.04]; ischemic stroke: OR, 1.03 [1.03-1.03]), diastolic BP (CAD: OR, 1.05 [1.05-1.06]; ischemic stroke: OR, 1.05 [1.04-1.05]), type 2 diabetes (CAD: OR, 1.11 [1.08-1.15]; ischemic stroke: OR, 1.07 [1.04-1.10]), smoking initiation (CAD: OR, 1.26 [1.18-1.35]; ischemic stroke: OR, 1.24 [1.16-1.33]), educational attainment (CAD: OR, 0.62 [0.58-0.66]; ischemic stroke: OR, 0.68 [0.63-0.72]), low-density lipoprotein cholesterol (CAD: OR, 1.55 [1.41-1.71]), high-density lipoprotein cholesterol (CAD: OR, 0.82 [0.74-0.91]), triglycerides (CAD: OR, 1.29 [1.14-1.45]), body mass index (CAD: OR, 1.25 [1.19-1.32]), and alcohol dependence (OR, 1.04 [1.03-1.06]) were causally related to CVD.

CONCLUSION

This systematic MR study identified 11 modifiable factors as causal risk factors for CVD, indicating that these factors are important targets for preventing CVD.

Body mass index is associated with brain metabolite levels in alcohol dependence--a multimodal magnetic resonance study

BACKGROUND

Recent studies demonstrated that alcohol dependence and excessive alcohol consumption are associated with increased rates of obesity. In healthy light-drinkers, we and others have observed associations between elevated body mass index (BMI) and reductions in brain volumes, lower concentrations of N-acetyl-aspartate (NAA, marker of neuronal viability) and choline-containing compounds (Cho, involved in membrane turnover), and lower glucose utilization, particularly in frontal lobe-a brain region that is particularly vulnerable to the effects of alcohol dependence. Here, we evaluated whether BMI in alcohol-dependent individuals was independently associated with regional measures of brain structure, metabolite concentrations, and neocortical blood flow.

METHODS

As part of a study on the effects of alcohol dependence on neurobiology, we analyzed retrospectively data from 54 alcohol-dependent males, abstinent from alcohol for about 1 month and with BMI between 20 and 37 kg/m(2) by structural MRI, perfusion MRI (blood flow), and proton magnetic resonance spectroscopic imaging.

RESULTS

After correction for age, smoking status, and various measures of alcohol consumption, higher BMI was associated with lower concentrations of NAA, Cho, creatine and phosphocreatine (Cr, involved in high energy metabolism), and myo-inositol (m-Ino, a putative marker of astrocytes) primarily in the frontal lobe, in subcortical nuclei, and cerebellar vermis (p < 0.004). Regional brain volumes and perfusion were not significantly related to BMI. Furthermore, comorbid conditions, clinical laboratory measures, and nutritional assessments were not significant predictors of these MR-based measures.

CONCLUSIONS

The results suggest that BMI, independent of age, alcohol consumption, and common comorbidities, is related to regional NAA, Cho, Cr, and m-Ino concentrations in this cohort of alcohol-dependent individuals. Additionally, as some common comorbid conditions in alcohol dependence such as cigarette smoking are associated with BMI, their associations with regional brain metabolite levels in alcohol-dependent individuals may also be influenced by BMI.

The relationships of sociodemographic factors, medical, psychiatric, and substance-misuse co-morbidities to neurocognition in short-term abstinent alcohol-dependent individuals

Co-morbidities that commonly accompany those afflicted with an alcohol use disorder (AUD) may promote variability in the pattern and magnitude of neurocognitive abnormalities demonstrated. The goal of this study was to investigate the influence of several common co-morbid medical conditions (primarily hypertension and hepatitis C), psychiatric (primarily unipolar mood and anxiety disorders), and substance use (primarily psychostimulant and cannabis) disorders, and chronic cigarette smoking on the neurocognitive functioning in short-term abstinent, treatment-seeking individuals with AUD. Seventy-five alcohol-dependent participants (ALC; 51+/-9 years of age; three females) completed comprehensive neurocognitive testing after approximately 1 month of abstinence. Multivariate multiple linear regression evaluated the relationships among neurocognitive variables and medical conditions, psychiatric, and substance-use disorders, controlling for sociodemographic factors. Sixty-four percent of ALC had at least one medical, psychiatric, or substance-abuse co-morbidity (excluding smoking). Smoking status (smoker or nonsmoker) and age were significant independent predictors of cognitive efficiency, general intelligence, postural stability, processing speed, and visuospatial memory after age-normed adjustment and control for estimated pre-morbid verbal intelligence, education, alcohol consumption, and medical, psychiatric, and substance-misuse co-morbidities. Results indicated that chronic smoking accounted for a significant portion of the variance in the neurocognitive performance of this middle-aged AUD cohort. The age-related findings for ALC suggest that alcohol dependence, per se, was associated with diminished neurocognitive functioning with increasing age. The study of participants who demonstrate common co-morbidities observed in AUD is necessary to fully understand how AUD, as a clinical syndrome, affects neurocognition, brain neurobiology, and their changes with extended abstinence.

The atherogenic and metabolic impact of non-HDL cholesterol versus other lipid sub-components among non-diabetic and diabetic Saudis

Background

Several trials from different populations have reported that non-high density lipoprotein cholesterol (non-HDL-C) has more predictive power than low-density lipoprotein cholesterol (LDL-C) in detecting coronary heart disease (CHD) and none in any Arab community whose propensity to develop CHD is higher compared to other ethnicities. This study aims to determine and compare the impact of non-HDL-C versus other lipid parameters, in predicting coronary heart disease among diabetic versus non-diabetic adult Saudis and identify the lipid parameters which make a significant contribution in the development of coronary heart disease, diabetes mellitus, and metabolic syndrome. 733 adult Saudis were recruited and divided into groups of diabetics and non-diabetics. Each participant completed a questionnaire, underwent physical exam including 12-L ECG, and submitted a fasting blood sample where glucose and lipid parameters were analyzed using routine procedures.

Results

462 subjects (age 45.03 ± 11.52; BMI 28.91 ± 6.07) were classified non-diabetics while the remaining 271 (age 52.73 ± 11.45, BMI 30.15 ± 6.62) were diabetics. 99 out of 465 (21.3%) of non-diabetics had CHD and 114 out of 271 (52.5%) in the diabetics. Non-HDL cholesterol was the best predictor among the non-diabetics (odds-ratio 2.89, CI 1.10–7.58, p-0.03). Total cholesterol was the highest single predictor for the development of CHD among the lipids (odds-ratio 1.36, CI 0.68–2.71, p-0.39) but HDL-cholesterol although small was significant (odds-ratio 0.52, CI 0.27–0.99, p-0.05).

Conclusion

This study supports the use of non-HDL cholesterol as the more practical and reliable target for lipid lowering therapy among the Saudi population.