Alcohol consumption and high-density lipoprotein cholesterol in marathon runners

A history of medical reports on the Boston Marathon: 112 years and still running

INTRODUCTION/METHODS

We performed a systematic search for medical reports on the Boston Marathon, run annually since April 19, 1897 and studied medically since 1899.

RESULTS

We identified 66 articles: 25 were related to cardiology; 10, exercise physiology; 8, metabolism; 5, neurology; 4, gastroenterology; 3, hematology; 3, several disciplines; and 8, nephrology, orthopedics, and general topics. The predominance of cardiology articles reflects concerns about the cardiac risks of exercise present in the early 20th century and persistent to this day. The authors and contributors included luminaries from the medical and exercise community including Drs. Paul Dudley White, Samuel Levine, Kenneth Cooper, Paul Zoll, Ellsworth Buskirk, and David Costill. The articles identified or confirmed many of the presently accepted principles of marathon medicine.

CONCLUSIONS

Medical studies on the Boston Marathon not only provide lessons applicable to managing modern athletes but also demonstrate the interests and concerns of researchers who have used the event to study the physiology of prolonged exercise for more than a century.

Alcohol and lipids

Alcoholic fatty liver and hyperlipemia result from the interaction of ethanol and its oxidation products with hepatic lipid metabolism. An early target of ethanol toxicity is mitochondrial fatty acid oxidation. Acetaldehyde and reactive oxygen species have been incriminated in the pathogenesis of the mitochondrial injury. Microsomal changes offset deleterious accumulation of fatty acids, leading to enhanced formation of triacylglycerols, which are partly secreted into the plasma and partly accumulate in the liver. However, this compensatory mechanism fades with progression of the liver injury, whereas the production of toxic metabolites increases, exacerbating the lesions and promoting fibrogenesis. The early presence of these changes confers to the fatty liver a worse prognosis than previously thought. Alcoholic hyperlipemia results primarily from increased hepatic secretion of very-low-density lipoprotein and secondarily from impairment in the removal of triacylglycerol-rich lipoproteins from the plasma. Hyperlipemia tends to disappear because of enhanced lipolytic activity and aggravation of the liver injury. With moderate alcohol consumption, the increase in high-density lipoprotein becomes the predominant feature. Its mechanism is multifactorial (increased hepatic secretion and increased extrahepatic formation as well as decreased removal) and explains part of the enhanced cholesterol transport from tissues to bile. These changes contribute to, but do not fully account for, the effects on atherosclerosis and/or coronary heart disease attributed to moderate drinking.

Coffee Consumption, Alcohol Use, and Cigarette Smoking as Determinants of Serum Total and HDL Cholesterol in Two Serbian Cohorts of the Seven Countries Study

The associations between serum total and HDL cholesterol and three lifestyle factors—consumption of Turkish coffee, consumption of alcohol, and cigarette smoking—were examined in two Serbian cohorts of the Seven Countries Study. In 1988 and 1989, 319 men from Zrenjanin and Belgrade, 65 to 84 years old and free of myocardial infarction, participated. The men from Zrenjanin were originally working in a large cooperative, and the men from Belgrade were faculty members of the university. HDL cholesterol, alcohol consumption, and cigarette smoking were significantly higher in Zrenjanin than in Belgrade. Serum total cholesterol levels and coffee consumption were not different. ANCOVA showed that serum total cholesterol levels were 8.2% higher (P<.05) in men consuming two small cups of coffee per day compared with abstainers, and this was also seen after adjustment for cigarette smoking, age, body mass index, cohort, and alcohol consumption. In men consuming one or more alcoholic drinks per day (more than 10 g/d alcohol), HDL cholesterol levels were increased by 0.19 mmol/L (15.4%) compared with men consuming no alcohol (P<.001) . This association was stronger in the Zrenjanin cohort than in the Belgrade cohort (P<.05) . Smoking was not associated with total cholesterol or with HDL cholesterol levels. In Serbian men, boiled Turkish coffee and alcohol consumption are independently associated with serum total and HDL cholesterol levels, respectively. (Arterioscler Thromb Vase Biol. 1995;15:1793-1797.)

Correlations of alcohol consumption with related covariates and heritability estimates in older adult males over a 14- to 18-year period: the NHLBI Twin Study

Consistent maximum-likelihood heritability estimates of consumption of alcoholic beverages were observed at three separate times during a 14- to 18-year period in adult twin males initially aged 42-56 years in 1969-1973. Log transformation of the average number of drinks/week of the returnees to all three examinations was examined relative to potential covariates representing both antecedents of drinking alcohol and consequences of alcohol consumption. Significant relationships were noted for 38 of the covariates at one or more of the separate examinations, including positive correlations with smoking, coffee consumption, high-density lipoprotein cholesterol, mean corpuscular volume, systolic blood pressure, uric acid and behavioral measures, and negative correlations with blood urea nitrogen, red blood cell count, tea consumption, and tricep skinfolds. Analysis of the average alcohol consumption adjusted for nine independent covariates selected from multiple stepwise regression resulted in a modest decline in maximum-likelihood heritability estimates compared with unadjusted data, but little difference from heritability estimates obtained when abstainers from alcohol (no alcoholic beverages consumed at all three examinations) were excluded. The most striking effect of omitting abstainers from alcohol was the decline in the intraclass correlations in dizygotic twins. Bivariate analyses of alcohol and individual covariates revealed the phenotypic correlation between alcohol consumption and a measure of hostility was primarily environmental, that for high-density lipoprotein, smoking and coffee drinking with alcohol was primarily genetic, and the phenotypic correlation between alcohol consumption and mean corpuscular volume had both significant genetic and environmental correlations.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid profiles in spinal cord injury

Measurement of blood levels of total cholesterol and lipoproteins (HDL and LDL) were conducted on 96 men with spinal cord injury, 46 paraplegics and 50 quadriplegics. All these patients were studied in the stabilized phase of the disease as a follow up to the rehabilitation process. The study was designed to compare results with a normal, able bodied population and to investigate if any abnormal finding could be related to the age at onset of the spinal cord injury, the duration of the disease or the level of the lesion. Compared to the normal, able bodied population, this study indicates that patients with a spinal cord injury do not have higher levels of cholesterol or LDL, nor lower levels of HDL. Levels of total cholesterol increase with aging, as in the normal population, but have no relation to the duration of the disease or the level of the lesion. Blood levels of HDL and LDL do not seem to be related either to the duration of the disease or to the level of the lesion.

Dual tissue-specific expression of apo-AII is directed by an upstream enhancer

Apolipoprotein-AII (apo-AII) is one of a family of evolutionarily related proteins which play a crucial role in lipid transport and metabolism. The serum levels of human apo-AII have been shown to be inversely correlated to the incidence of coronary heart disease and its expression to be limited to the liver and intestine. Here we demonstrate that this dual tissue-specificity involves DNA sequences located in a 259 bp region centred 782 bp upstream from the transcription initiation site. These sequences function in an orientation-independent manner and are absolutely required for transcription from the apo-AII promoter. The regulatory region contains sequences which are homologous to the apo-AI, beta-globin and immunoglobulin gene promoters and to the immunoglobulin heavy-chain enhancer.

[Body weight, food habits and physical activity in the Swiss population: the project MONICA]

Within the framework of the first risk factor survey among the two reporting units of MONICA-Switzerland (cantons of Vaud and Fribourg; canton of Tessin), body mass index (BMI) was also analysed. One in four adults (25-74 years) presents with overweight, this proportion being even 1 in 3 among males of the canton of Tessin. However, this health risk can probably be changed, as every third female and every fifth male indicated to have modified their nutritional habits in a more healthy sense within the last 12 months preceeding the survey. On the other side, less than half of the population engages in a degree of physical activity conducive to cardiovascular prevention and reduction of overweight. In order to increase the level of physical activity in the population, it is primarily leisure time sports activities that have to be developed as only very few adults experience a heavy physical work load within their profession.

Effect of alcohol intake and exercise on plasma high-density lipoprotein cholesterol subfractions and apolipoprotein A-I in women

Abstinence from alcohol consumption for 3 weeks was followed by 3 weeks of wine intake in 18 inactive and 18 physically active premenopausal women (runners). The runners weighed less and had higher plasma high-density lipoprotein (HDL) cholesterol and lower low-density lipoprotein cholesterol levels than the inactive women. There were no differences between groups in plasma total cholesterol, triglyceride and apolipoprotein A-I concentrations. Runners had higher plasma HDL2 cholesterol concentrations than inactive women (34 +/- 17 vs 19 +/- 12 mg/dl), but HDL3 cholesterol concentration did not differ between the groups (41 +/- 10 vs 39 +/- 9 mg/dl). Addition of 35 g/day of ethanol for 3 weeks did not result in a significant change in either group for any of the variables measured. The amount of exercise appears to be a more important determinant of plasma lipoproteins and apolipoprotein A-I than alcohol intake in premenopausal women.

HDL cholesterol levels in patients with myocardial infarction and their families

The present study using a quartile distribution of myocardial infarction patients demonstrated that the first-degree relatives of the myocardial infarction patients with the lowest HDL cholesterol have similarly the lowest HDL cholesterol. Low HDL cholesterol among these relatives was not secondary to increased VLDL triglycerides, as it persisted when subjects with hyper VLDL triglycerides were excluded. Familial low HDL cholesterol could not be attributed to known environmental factors as their levels did not differ significantly between the groups compaired. There was a significant correlation between HDL cholesterol levels of the parents and that of their younger offspring. The correlation was not significant with the offspring aged 20 and over. It appeared that there was a familial trend in low HDL cholesterol levels, more apparent among the young offspring than among the adult offspring, who may possibly not share any more the parental environment for factors liable to influence HDL cholesterol. This finding is compatible with a hereditary trait.

Alcohol consumption and cardiovascular risk factors

This chapter reviews epidemiologic evidence relating alcohol consumption to the cardiovascular risk factors of high-density lipoprotein (HDL)-cholesterol and blood pressure. Alcohol consumption shows a linear dose-response relationship with HDL-cholesterol that is independent of other known determinants of HDL-cholesterol. The effect of alcohol on HDL-cholesterol appears to be reversible. The relationship of alcohol consumption to HDL-cholesterol subfractions and to the HDL apoproteins is not clear. Alcohol consumption also shows a linear dose-response relationship with blood pressure. Although the association is consistent, the estimated effect of alcohol consumption on blood pressure is small. This effect of alcohol may also be reversible. No biological mechanisms have been established for these associations. Some of the effect of alcohol on the risk of coronary heart disease may be explained by the effects of alcohol on these risk factors. It remains to be determined if alcohol also exerts an effect that is independent of these risk factors.

Alcohol, lipids and heart disease

The attenuating effect of moderate amounts of alcohol on cardiovascular morbidity and mortality has been reported by several groups of investigators at various geographic locations. At this time, the generally accepted explantation for this cardioprotective effect favors an increase in plasma high-density lipoprotein cholesterol, a factor inversely associated with the development of coronary heart disease (CHD). Other variables potentially influencing the development of CHD such as a reduced tendency for blood coagulation and increased fibrinolytic activity has been enhanced by alcohol and may be considered as possible additional mechanisms for the cardioprotective effects of the agent. Because of its addictive potential, alcohol should not be considered for treatment of CHD.

Exercise training improves lipoprotein lipid profiles in patients with coronary artery disease

The effects of endurance exercise training on plasma lipoprotein lipids were determined in 10 men, ages 46 to 62 years, with coronary artery disease (CAD). Patients maintained body weight, health-related behaviors, and stable diets throughout the program. Training was at 50% to 85% of maximal oxygen consumption (VO2 max) for 40 to 60 minutes, 3 to 5 days/week for 29 +/- 7 weeks. Training increased VO2 max (31 +/- 19%, p less than 0.001), reduced plasma cholesterol (C) (-8 +/- 4%, p less than 0.01), low-density lipoprotein-C (LDL-C) (-9 +/- 9%, p less than 0.01), and triglyceride (TG) (-13 +/- 32%, p less than 0.05) concentrations, and increased high-density lipoprotein-C (HDL-C) levels (11 +/- 13%, p less than 0.05) and HDL-C/LDL-C ratios (25 +/- 20%, p less than 0.01). Changes in LDL-C and VO2 max were correlated (r = -0.73, p +/- 0.01), while the changes in LDL-C and HDL-C each correlated inversely with pretraining lipoprotein levels (rLDL-C = -0.77, p less than 0.01; rHDL-C = -0.68, p less than 0.05). Thus potentially "antiatherogenic" benefits of exercise seem to be due to a training effect, since they correlate best with changes in VO2 max and are maximal in patients with initially low VO2 max, high LDL-C, and low HDL-C levels.

High-density lipoprotein cholesterol and liver disease

To establish whether there is any significant relationship between high-density lipoprotein cholesterol (HDLC) concentrations and biopsy-documented liver disease, 169 patients had needle biopsies, serum cholesterol, and HDLC evaluated. Twenty-four patients had serial cholesterol, HDLC, prothrombin, and aminotransferase levels and activities examined. In both men and women, HDLC decreased strikingly and significantly in acute alcoholic hepatitis and in acute viral hepatitis, compared to controls (p less than 0.001). Men and women with inactive alcoholic liver disease and chronic active hepatitis showed moderate decreased in HDLC (p less than 0.001). Patients with primary and metastatic hepatic neoplasms also had strikingly decreased HDLC (p less than 0.001). Serial testing showed an excellent direct correlation between HDLC and prothrombin activity, r values ranging from 0.71 to 0.98. Although alcohol intake is known to correlate positively with HDLC concentrations, our data shows that this association is not absolute, and in most cases is reversed once liver disease becomes apparent.

Summary estimates of cholesterol used to predict coronary heart disease

The relationships of total cholesterol and the proportion of cholesterol in individual lipoprotein classes to coronary heart disease are complex. To help simplify these relationships, cholesterol values are often combined into one summary estimate to form a single risk factor with a relationship to disease that is more easily described. Although summary estimates result in convenient expressions relating cholesterols to coronary heart disease, there is the potential for sacrificing information by ignoring the joint configuration of cholesterols that make up these estimates. We investigated the extent of this possibility for the ratio of total cholesterol to high-density lipoprotein cholesterol and the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol. The findings suggest that the summary estimates are useful expressions for combining cholesterol information and are strong predictors of coronary heart disease. Clinicians who choose to use a summary estimate for screening purposes should recognize that a single ratio estimate is not always as informative as the joint configuration of the cholesterols that make up the estimate. This possibility is most clearly exhibited for the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol, and it may become more apparent in future studies as the capabilities of exploring lipoprotein cholesterol relationships improve.

Exercise, diet, or physical characteristics as determinants of HDL-levels in endurance athletes

Serum lipids, lipoproteins, apolipoproteins, physical characteristics, and 10-day dietary records of 20 male distance runners (aged 20-42 years) were compared with those of 14 sedentary controls (aged 23-34 years). Runners had significantly greater levels (mean +/- SD) of high density lipoproteins (HDL) whether estimated as HDL-cholesterol (66 +/- 12 vs 46 +/- 10 mg/dl) or as the major HDL apolipoproteins, apoA-I (170 +/- 36 vs 124 +/- 27 mg/dl) or apoA-II (39 +/- 5 vs 34 +/- 4 mg/dl). Runners were leaner with considerably less body fat (8.3 +/- 1.7 vs 16.2 +/- 3.9%) than the sedentary men despite consuming 20% more calories. Moreover, the additional calories consumed were largely carbohydrate. This comparison illustrates that high absolute quantities of dietary carbohydrate do not depress HDL levels in lean individuals engaged in exercise training. Furthermore, the results suggest that dietary factors may be as important as exercise itself in producing the lipoprotein pattern characteristic of endurance athletes.

The relationship of exercise and diet on high-density lipoprotein cholesterol levels in women

The relationship of exercise and diet on high-density lipoprotein (HDL) cholesterol was investigated in 45 long-distance runners (LD), 49 joggers (J), and 47 inactive (I) women. Fasting plasma triglycerides (TG), HDL cholesterol, total cholesterol (TC), and percent body fat (%BF) were measured in women ages 24-58 yr. TG levels were significantly lower in LD compared to I (p less than 0.02). Although TC was not significantly different among groups, HDL-cholesterol was higher in LD (78 mg/dl) compared to J (70 mg/dl) or I (62 mg/dl) (p less than 0.001). Multiple regression analyses indicated that alterations of plasma lipids and lipoprotein levels could not be attributed to intake differences of nutrients. Distance run and %BF were the strongest predictors of HDL-cholesterol in women. LD (23 %BF) were leaner than J (26 %BF) or I (30 %BF); however, when results were adjusted for %BF, significant differences between exercise groups remained for HDL cholesterol.

Effects of drinking patterns on the relationship between alcohol an coronary occlusion

Previous reports have described an inverse relationship between alcohol consumption and the prevalence of myocardial infarction or the extent of coronary artery occlusion. The study reported here explored the relationship between patterns of alcohol intake and coronary occlusion in 526 patients who have had coronary arteriography. Patients were characterized as regular drinkers, occasional drinkers and non-drinkers. Regular drinkers were further characterized as drinking relatively consistent amounts or variable amounts. The inverse correlation between amounts of alcohol consumed and coronary occlusion found in previous studies was reaffirmed. It was also observed that the pattern of alcohol intake was related to the degree of occlusion. Higher levels of occlusion were found among non-drinkers, occasional drinkers, and regular drinkers with patterns of variable intake, while significantly lower levels of occlusion were observed for regular drinkers who drank relatively consistent amounts (P = 0.014). Furthermore, while occlusion scores were inversely correlated with amounts consumed by regular drinkers with consistent intake (P = 0.019), drinkers with variable drinking patterns had higher occlusion scores regardless of amounts consumed. Analyses of serum lipids according to drinking patterns showed a significant association between the total/HDL cholesterol ratio and drinking patterns. These findings suggest that whatever attenuating effect alcohol consumption might exert on coronary occlusion, it appears to be reversed by a variable or sporadic pattern of alcohol intake.