Alcohol consumption and lipoprotein subclasses in older adults

CONTEXT: Limited evidence suggests that alcohol intake may be associated with lipoprotein subclass distribution, which could mediate its relationship with coronary heart disease. OBJECTIVES: The objective was to determine the relationship of alcohol intake with lipoprotein particle subclasses. DESIGN, SETTING, AND PARTICIPANTS: The study included a cross-sectional analysis of 1850 participants of the Cardiovascular Health Study aged 65 yr and older and free of clinical cardiovascular disease. MAIN OUTCOME MEASURE: Lipoprotein subclass distribution was measured with nuclear magnetic resonance spectroscopy, according to self-reported alcohol intake. RESULTS: Alcohol intake was associated with total low-density lipoprotein (LDL) particles in a U-shaped manner. Consumers of one or more drinks per week had the highest number of large LDL particles, whereas consumers of 7-13 drinks per week had the lowest number of small LDL particles. Alcohol intake was strongly positively associated with large- and medium-sized high-density lipoprotein (HDL) particles but had an inverse relationship with concentrations of small HDL particles and small- and medium-sized very-low-density lipoprotein particles. Average particle sizes of all three lipoproteins were positively associated with alcohol intake. Associations were generally stronger among women than men but in similar directions. Beverage type did not consistently modify these findings. CONCLUSIONS: Alcohol intake is associated with less total LDL particles, lower levels of small LDL, HDL, and very-low-density lipoprotein particles, and higher levels of large LDL and medium- and large-sized HDL particles in older adults free of prevalent clinical cardiovascular disease.     

Dietary fatty acids and peripheral artery disease in adults

BackgroundPeripheral artery disease (PAD) is a debilitating condition involving atherosclerosis. Although saturated, monounsaturated and polyunsaturated fatty acids have strong associations with atherosclerosis, it is unclear if diets high in these fatty acids affect PAD.MethodsWe studied 6352 adults aged 40 years and older who participated in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004. Ankle brachial index (ABI) was assessed by standardized blood pressure measurements, and we defined PAD as an ABI < 0.9. Fatty acid intake was assessed by validated 24-h dietary recall. We used multivariable linear and logistic regression to estimate associations between intakes of dietary saturated fatty acids (SFAs), monounsaturated fatty acids (MFAs), marine omega-3 fatty acids (N-3), linolenic acid (LNA), and omega-6 fatty acids (N-6) and ABI/PAD.ResultsThe prevalence and 95% confidence interval (CI) of PAD was 5.2% (95% CI 4.6–5.8).There were no associations between ABI and intakes of marine N-3 (p = 0.83) or N-6 (p = 0.19) in adjusted models. In contrast, LNA was associated with higher ABI (p = 0.04) and SFA tended to be associated with lower ABI (p = 0.06) in adjusted models. In addition, higher SFA was associated with a higher prevalence of PAD: adjusted odds ratio 1.30 (95% CI 1.01–1.67; p = 0.04) and a trend toward slower gait speed (p = 0.08).ConclusionIn this nationally representative sample, higher dietary intakes of LNA and SFAs were associated with higher and lower ABI, respectively. Prospective studies are needed to confirm the potential protective effects of dietary LNA and detrimental effects of dietary SFAs on PAD.     

Impact of diabetes on long-term survival after acute myocardial infarction: comparability of risk with prior myocardial infarction

OBJECTIVE: To determine the effect of diabetes on long-term survival after acute myocardial infarction and to compare its effect with that of a previous myocardial infarction. RESEARCH DESIGN AND METHODS: In a prospective cohort study, we followed 1,935 patients hospitalized with a confirmed acute myocardial infarction at 45 U.S. medical centers between 1989 and 1993, as part of the Determinants of Myocardial Infarction Onset Study. Trained interviewers performed chart reviews and face-to-face interviews with all patients. We analyzed survival using Cox proportional hazards regression to control for potentially confounding factors. RESULTS: Of the 1,935 patients, 320 (17%) died during a mean follow-up of 3.7 years. A total of 399 patients (21%) had previously diagnosed diabetes. Diabetes was associated with markedly higher total mortality in unadjusted (hazard ratio [HR] 2.4; 95% CI 1.9-3.0) and adjusted (1.7; 1.3-2.1) analyses. The magnitude of the effect of diabetes was identical to that of a previous myocardial infarction. The effect of diabetes was not significantly modified by age, smoking, household income, use of thrombolytic therapy, type of hypoglycemic treatment, or duration of diabetes, but the risk associated with diabetes was higher among women than men (adjusted HRs 2.7 vs. 1.3, P = 0.01). CONCLUSIONS: Diabetes is associated with markedly increased mortality after acute myocardial infarction, particularly in women. The increase in risk is of the same magnitude as a previous myocardial infarction and provides further support for aggressive treatment of coronary risk factors among diabetic patients.     

Alcohol in Moderation, Cardioprotection, and Neuroprotection: Epidemiological Considerations and Mechanistic Studies

In contrast to many years of important research and clinical attention to the pathological effects of alcohol (ethanol) abuse, the past several decades have seen the publication of a number of peer‐reviewed studies indicating the beneficial effects of light‐moderate, nonbinge consumption of varied alcoholic beverages, as well as experimental demonstrations that moderate alcohol exposure can initiate typically cytoprotective mechanisms. A considerable body of epidemiology associates moderate alcohol consumption with significantly reduced risks of coronary heart disease and, albeit currently a less robust relationship, cerebrovascular (ischemic) stroke. Experimental studies with experimental rodent models and cultures (cardiac myocytes, endothelial cells) indicate that moderate alcohol exposure can promote anti‐inflammatory processes involving adenosine receptors, protein kinase C (PKC), nitric oxide synthase, heat shock proteins, and others which could underlie cardioprotection. Also, brain functional comparisons between older moderate alcohol consumers and nondrinkers have received more recent epidemiological study. In over half of nearly 45 reports since the early 1990s, significantly reduced risks of cognitive loss or dementia in moderate, nonbinge consumers of alcohol (wine, beer, liquor) have been observed, whereas increased risk has been seen only in a few studies. Physiological explanations for the apparent CNS benefits of moderate consumption have invoked alcohol’s cardiovascular and/or hematological effects, but there is also experimental evidence that moderate alcohol levels can exert direct “neuroprotective” actions—pertinent are several studies in vivo and rat brain organotypic cultures, in which antecedent or preconditioning exposure to moderate alcohol neuroprotects against ischemia, endotoxin, β‐amyloid, a toxic protein intimately associated with Alzheimer’s, or gp120, the neuroinflammatory HIV‐1 envelope protein. The alcohol‐dependent neuroprotected state appears linked to activation of signal transduction processes potentially involving reactive oxygen species, several key protein kinases, and increased heat shock proteins. Thus to a certain extent, moderate alcohol exposure appears to trigger analogous mild stress‐associated, anti‐inflammatory mechanisms in the heart, vasculature, and brain that tend to promote cellular survival pathways.