Metabolic and biochemical effects of low-to-moderate alcohol consumption

Abstract

Background: Alcohol consumption has multiple biochemical consequences. Only a few of these are useful as diagnostic markers, but many reflect potentially harmful or beneficial effects of alcohol. Average consumption of 2 to 4 drinks per day is associated with lower overall or cardiovascular mortality risk than either lower or higher intake. We have analyzed the dose-response relationships between reported alcohol consumption and 17 biomarkers, with emphasis on intake of up to 3 drinks per day.

Methods: Biochemical tests were performed on serum from 8,396 study participants (3,750 men and 4,646 women, aged 51 ± 13 years, range 18 to 93) who had provided information on alcohol consumption in the week preceding blood collection.

Results: Gamma glutamyl transferase, alanine aminotransferase, aspartate aminotransferase, carbohydrate-deficient transferrin, urate, ferritin, and bilirubin showed little or no change with alcohol consumption below 2 to 3 drinks per day, but increased with higher intake. High-density lipoprotein cholesterol and albumin showed increasing results, and insulin showed decreasing results, across the entire range of alcohol use. Biphasic responses, where subjects reporting 1 to 2 drinks per day had lower results than those reporting either more or less alcohol use, occurred for triglycerides, glucose, C-reactive protein, alkaline phosphatase, and butyrylcholinesterase. Increasing alcohol use was associated with decreasing low-density lipoprotein cholesterol (LDL-C) in younger women, but higher LDL-C in older men.

Conclusions: Some markers show threshold relationships with alcohol, others show continuous ones, and a third group show biphasic or U-shaped relationships. Overall, the biochemical sequelae of low-to-moderate alcohol use are consistent with the epidemiological evidence on morbidity and mortality.

Figure 1

Effects of alcohol on log10GGT, log10ALT, log10AST; adjusted for sex, age, BMI and smoking. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 2

Effects of alcohol on CDT, urate, log10Ferritin; adjusted for sex, age, BMI and smoking. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 3

Effects of alcohol on HDL-C, LDL-C, log10Triglyceride; adjusted for sex (except for LDL-C), age, BMI and smoking. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 4

Effects of alcohol on glucose, log10Insulin; adjusted for sex, age, BMI, smoking and time since last meal. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 5

Effects of alcohol on log10CRP, alkaline phosphatase, butyrylcholinesterase; adjusted for sex, age, BMI and smoking. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 6

Effects of alcohol on albumin, log10Bilirubin, urea; adjusted for sex, age, BMI and smoking. Points and error bars show mean ± SEM. The arrow shows the reference group and stars indicate the groups which are significantly different from it after allowing for multiple comparisons (p < (0.05/6) = 0.0083).

Figure 7

Associations between alcohol intake and calculated LDL-C in men and women. In each panel, the results are divided by age of the subjects, into those aged less than 50 and those aged 50 or more. Error bars show standard errors. Linear regression showed significant effects of alcohol only in the older men (p = 0.0045) and younger women (p = 7.86 × 10⁻⁹).