Environmental determinants, liver function, and high density lipoprotein cholesterol levels

Alcohol drinking patterns differentially affect central adiposity as measured by abdominal height in women and men

Alcohol drinking in light-to-moderate amounts has been associated with reduced coronary heart disease (CHD) risk. However, there is evidence that the way people consume alcohol (drinking pattern) may affect risk. Central adiposity, a known CHD risk factor may be one mechanism in the pathway between alcohol consumption and CHD risk. Our study examined whether various drinking patterns differentially affect fat distribution, particularly abdominal fat in women and men. In a randomly selected population-based cohort (n = 2343), 35-79 y old, we assessed drinking pattern as reported for the past 30 d, including beverage type and amount, frequency of consumption, percentage of time drinking while eating and number of drinks consumed/drinking day. Central adiposity was determined using an abdominal caliper to measure supine height of the abdomen. Current drinkers tended to have smaller abdominal heights than nondrinkers (women, P < 0.0001; men, P = 0.0559). For drinking pattern, frequency was inversely associated, but drinking intensity (drinks/drinking day) was positively associated with central adiposity in women (P trend for frequency, 0.0007; intensity, 0.0010) and men (P trend for frequency, 0.0005; intensity, 0.0004), even when age, education, physical activity, smoking status and amount of alcohol (g) were included in the models. When frequency and intensity were considered together, daily drinkers of <1 drink/drinking day had the smallest mean abdominal height measures with the largest measures in less than weekly drinkers who consumed 4 or more drinks/drinking day. These results support the hypothesis that drinking pattern affects the distribution of body fat, an important CHD risk factor.

Sex and time differences in the associations of non-high-density lipoprotein cholesterol versus other lipid and lipoprotein factors in the prediction of cardiovascular death (The Rancho Bernardo Study)

Non-high-density lipoprotein (HDL) cholesterol (total cholesterol [TC] minus HDL cholesterol) has been suggested as the preferred lipid fraction to predict cardiovascular disease. We compared the ability of lipids, lipoproteins, the ratio of total to HDL cholesterol (TC/HDL), and non-HDL cholesterol to predict fatal coronary heart disease (CHD) and cardiovascular disease in 1,386 women and 1,094 men (mean age 69 years). After 10 years, there were more deaths in men (n = 310) than women (n = 268), but the proportions of deaths attributed to CHD (23% and 25%, respectively) and cardiovascular disease (48% and 47%) were similar. In men, age-adjusted values for non-HDL cholesterol, TC/HDL ratio, and triglycerides each predicted a significantly increased risk of CHD and cardiovascular disease; none of these associations was independent of pack-years of smoking, systolic blood pressure, fasting plasma glucose, body mass index, and physical activity. In women, age-adjusted non-HDL cholesterol levels did not predict CHD or cardiovascular disease events before or after adjusting for these covariates and for estrogen replacement therapy. In women, only the ratio of TC to HDL cholesterol predicted CHD and cardiovascular disease deaths independent of estrogen use and other risk factors. Observed associations were sensitive to time, being evident in women at 3 and 5 years, and lost thereafter, but not apparent before 10 years in men. Thus, non-HDL cholesterol is not superior to individual lipids, lipoproteins, or their ratios in the prediction of cardiovascular death in older adults.

Dose-response relationships between drinking and serum tests in Japanese men aged 40-59 years

Alcohol intake per Japanese adult has been increasing year by year. To show biological effects of drinking, the dose-response relationships between alcohol use and serum indices were analyzed in 5919 Japanese men aged 40-59 years. The subjects were classified into nine groups: a nondrinking (ND, n = 1827) group and eight drinking (1D-8D) groups, by self-reported drinking habit. The 1D (the lightest drinking, n = 699), 5D (n = 942), and 8D (the heaviest drinking, n = 46) groups consumed alcohol less than 30 g per week, 25-30 g alcohol per day, and 100 g alcohol per day or more, respectively. Ten serum indices, total cholesterol, HDL cholesterol, triglyceride, total/HDL cholesterol ratio, LDL cholesterol, gamma-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, glucose, and uric acid, were used. The dose-response analysis was statistically controlled for age, body mass index, smoking, and habitual exercise, and showed that drinking, even a small amount of alcohol, always had both beneficial and adverse effects on humans. However, alcohol less than 30 g per day may be tolerable for middle-aged Japanese men, because it improved serum lipids profile but did not induce apparent liver cell damage, hyperglycemia, or hyperuricemia.

Total, LDL, and HDL cholesterol decrease with age in older men and women. The Rancho Bernardo Study 1984-1994

BACKGROUND

The purpose of the present study was to study the effects of age, weight change, and covariates on lipid and lipoprotein levels cross-sectionally and prospectively in an elderly population.

METHODS AND RESULTS

A community-based sample of 1041 men and 1303 women aged 50 to 93 years was studied cross-sectionally in 1984 to 1987, with follow-up of 372 men and 545 women 8 years later. In the cross-sectional study, levels of total cholesterol (TC) and LDL cholesterol (LDL-C) decreased and levels of HDL cholesterol (HDLC) increased with age in men (all P < .001) but not in women. In the prospective study, TC, LDL-C, and HDL-C levels all decreased in both men and women, in all age groups (50 to 64 years, 65 to 74 years, and > or = 75 years) and in all weight change groups (> 2.5-kg loss, change within 2.5 kg, and > 2.5-kg gain) and in all waist girth change groups, for an overall decrement of approximately 1% per year. In multiple linear regression models, change in weight was the most important independent and consistent predictor of changes in TC, LDL-C, and HDL-C. Similar results were obtained in analyses excluding subjects taking lipid-lowering drugs or estrogen and in analyses adjusted for changes in cigarette smoking, alcohol intake, physical activity, medication use, and incident myocardial infarction, cancer, or diabetes.

CONCLUSIONS

Cross-sectional decrements in TC and LDL-C with age in men are not explained by survivor bias because they are also observed prospectively. Although weight change was the most important explanatory variable, TC, LDL-C, and HDL-C levels also decreased in those who lost or gained weight. Age was not an independent predictor of change. Other prospective studies are recommended to better define the causes and consequences of cholesterol and lipoprotein changes in old age.

Association of high density lipoprotein with whole blood-associated acetaldehyde levels

We hypothesized that while moderate drinking is associated with increasing levels of high density lipoprotein (HDL) levels, excessive drinking of ethanol might, in fact, be associated with lower HDL levels and by implication increased cardiovascular risk. We therefore performed analyses of whole blood-associated acetaldehyde (WBAA) as a measure of drinking behavior and HDL on blood samples from 2780 individuals applying for life insurance. Whole blood-associated acetaldehyde correlated positively with HDL in the entire sample set throughout the range of values (R = 0.101, p = 0.0001). The relationship held for females (N = 477, p = 0.036) but was stronger for males (N = 2277, p = 0.0001). We conclude that ethanol consumption correlates positively with HDL for both males and females and that the relationship persists through higher ranges of ethanol consumption.

Association between baseline risk factors, cigarette smoking, and CHD mortality after 10.5 years. MRFIT Research Group

METHODS

The association between baseline risk factors and death from coronary heart disease (CHD) after 10.5 years was investigated for cigarette smokers and nonsmokers who entered the Multiple Risk Factor Intervention Trial (MRFIT).

RESULTS

Rates per thousand person-years of CHD mortality were higher for smokers than for nonsmokers at every level of baseline risk factors examined. There were significant associations between CHD mortality and plasma low-density lipoprotein and high-density lipoprotein cholesterol for smokers and nonsmokers. The inverse association between CHD mortality and high-density lipoprotein cholesterol was significantly stronger among nonsmokers compared with that among smokers and was attributable to a very strong association for former smokers. An inverse relationship between CHD and body mass index was evident for smokers and nonsmokers. Rates of CHD death rose sharply when levels of fasting glucose exceeded 140 mg/dl, and there was a significant association between CHD mortality and blood sugar levels for nonsmokers but not for smokers. For both smokers and nonsmokers, an inverse univariate association between alcohol consumption and CHD mortality was evident. This association, however, did not persist after adjustment for plasma high-density lipoprotein cholesterol.

CONCLUSION

Intervention on blood pressure and blood lipids is particularly important among cigarette smokers because of their increased risk of CHD death. The different associations between high-density lipoprotein cholesterol, fasting serum glucose, and CHD mortality for smokers and nonsmokers requires further investigation.

The effect of a weight reduction program on cardiovascular risk factors among overweight hypertensives in primary health care

The aim of the study was to test the effect of a nonpharmacological weight reduction program on cardiovascular risk factors among overweight hypertensives in a primary health care setting. Forty-nine overweight hypertensive patients completed the 12-month program. The patients were randomly allocated into either intervention or control groups. The examinations included interviews by a nutritionist, pertinent laboratory tests, and a medical examination. The intervention involved an individually planned energy-restricted diet of 1000-1500 kcal per day, weekly discussions, and various leaflets on diet modification and on increase of physical activity. The mean body weight was reduced by 5 kg in the intervention group, but remained unchanged in the control group. The intervention group reduced their fat intake by 14 g/day while the control group increased it by 9 g/day on the average. In the intervention group, the total serum cholesterol decreased, HDL-cholesterol increased and triglycerides decreased significantly. The systolic blood pressure fell by 8 mm Hg and 15 mm Hg in the intervention and control groups, respectively. The diastolic blood pressure fell on average by 11 mm Hg in both groups. The results demonstrate the comprehensive weight reduction program to be effective in the control of cardiovascular risk factors.

Sex differences in high density lipoprotein cholesterol among low-level alcohol consumers

The purpose of this study was to examine high density lipoprotein cholesterol (HDL-C) levels in a sample of community-living women and men who consumed 1 drink of alcohol/day or less. Self-reports of alcohol consumption and clinical assessments of plasma lipid and lipoprotein levels were obtained twice, at 12 months apart. Among men, consumption of 1 drink/day or less was unrelated to levels in HDL-C. In contrast, among women alcohol consumption throughout this relatively low consumption range was positively associated with HDL-C levels. These findings indicate that the association of alcohol and higher levels of HDL-C may occur at lower intakes of alcohol in women than in men.

Racial differences in high-density lipoprotein cholesterol and coronary heart disease incidence in the usual-care group of the Multiple Risk Factor Intervention Trial

To test the hypothesis that higher levels of high-density lipoprotein cholesterol (HDL-C) in black men than in white men may offer the former greater protection against coronary heart disease (CAD), the relation between HDL-C and 7-year incidence of CAD was examined in the 5,792 white men and in the 465 black men assigned to the usual-care group of the Multiple Risk Factor Intervention Trial. CAD events included nonfatal myocardial infarction diagnosed on the basis of serial electrocardiographic change or medical record review, and fatal CAD events including sudden CAD deaths, deaths attributed to myocardial infarction or congestive heart failure caused by CAD, and deaths associated with coronary artery bypass surgery. At baseline, mean diastolic blood pressure and prevalence of cigarette smoking were significantly higher in black men, but the reverse was true for serum cholesterol (246 vs 254 mg/dl, p less than 0.01). Mean HDL-C was higher in black men than in white men (49.3 vs 41.6 mg/dl, p less than 0.01), but low-density lipoprotein cholesterol (LDL-C) levels were similar (159 vs 160 mg/dl). An inverse association between HDL-C and socioeconomic status was observed in black men, whereas a direct association was observed in white men. During follow-up, small reductions occurred in HDL-C and LDL-C in both groups. No black men died of stroke; 16 black and 404 white men sustained CAD events (5.1 vs 10.4/1,000 person-years of risk). The black-white relative risk was 0.49 (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship of physical activity to high density lipoprotein cholesterol in postmenopausal women

The relationships of physical activity to total HDL, HDL-2 and HDL-3 cholesterol were examined in 255 white postmenopausal women, mean age, 57.6 years. Physical activity was measured by the Paffenbarger Index (a composite index of walking, stair climbing and sports in the past week); by a modified Paffenbarger which included only sport activities; and by an objective activity monitor (LSI). Depending on which activity measure was used, different univariate relationships between physical activity and the HDL-cholesterol subfractions were noted. Physical activity, as measured by sport kcal/week or by objective monitors was related to HDL-2 cholesterol [r = 0.22 (p less than 0.01)] and [r = 0.19 (p less than 0.01)], respectively, but not to HDL-3 cholesterol. Physical activity, as measured by the Paffenbarger kcal/week was only related to HDL-3 [r = 0.15 (p less than 0.05)]. Multiple regression analyses revealed that sport activity was significantly related to total HDL and HDL-2 cholesterol. Activity as measured by objective monitors was not independently related to either HDL-total or HDL-2. Activity as measured by the Paffenbarger kcal/week was an independent determinant of HDL-3, after controlling for body fatness. Insulin, caloric intake and liver function were analyzed as possible underlying mechanisms, but we could not demonstrate any mediating or interacting effect on any of these mechanisms for the association of HDL-cholesterol to physical activity.

The effects of exercise and a moderate hypercholesterolemic diet on plasma and hepatic lipoproteins in the rat

Exercise generally has been found to produce beneficial effects on plasma lipid and lipoprotein profiles, but the mechanisms involved and possible dietary interactions have not been well defined. Weanling male Fischer 344 rats were assigned to three groups: normocholesterolemic diet sedentary (NS), hypercholesterolemic diet sedentary (HS), and hypercholesterolemic diet exercised (HE). Exercise consisted of treadmill running at 1.2 to 1.4 km/h at a 9% grade, six days weekly, for a 10-week experimental period. Lipoproteins from plasma and from a recirculating in situ liver perfusion system were then isolated and analyzed. The values of several parameters for HE tended to fall intermediate between HS and NS. Final total plasma cholesterol and liver cholesterol concentrations were significantly different among all three groups (HS greater than HE greater than NS). Plasma HDL-cholesterol and phospholipids and perfusate HDL-cholesterol production rate per gram liver were all significantly lower in HS v NS, with HE lying in between. Plasma HDL protein was lower in HS than in both other groups. Plasma total triglyceride levels were significantly lowered by exercise, but neither plasma nor perfusate VLDL triglyceride levels differed significantly among the three groups. Food intakes of HE and HS rats were similar, but HE rats had significantly lower final body weights. The results suggest that (1) exercise may ameliorate many of the changes in lipoprotein and cholesterol metabolism induced by a diet containing lard and cholesterol, and (2) some of these changes may be mediated by changes in hepatic lipoprotein production.

Relation between plasma high-density lipoprotein cholesterol and sex hormone concentrations in men

High-density lipoprotein (HDL) cholesterol is inversely associated with risk of heart attack. Sex hormones have been suggested as possible factors contributing to the gender difference of coronary heart disease risk. Little is known about how endogenous sex hormone concentration might be related to HDL cholesterol. The relation was examined in 225 men participating in the Multiple Risk Factor Intervention Trial. Plasma testosterone concentration was positively correlated with HDL cholesterol and the change in testosterone concentration was also positively correlated with change in HDL cholesterol. The relation between testosterone and HDL cholesterol could not be fully explained by age, relative weight, alcohol consumption and cigarette smoking in the cross-sectional study. However, when this relation was examined longitudinally, the partial correlation between changes in testosterone and HDL cholesterol did not quite achieve statistical significance (0.05 less than p less than 0.10). The biologic process that relates HDL cholesterol to testosterone is not known. The results suggest an inverse relation between plasma estradiol concentration and low-density lipoprotein cholesterol, but no statistical significant correlation with HDL cholesterol. In addition, there was no association noted in the current research between estradiol concentrations and the known determinants of HDL cholesterol.

Menopausal estrogen use, high density lipoprotein cholesterol subfractions and liver function

Forty-eight menopausal women taking exogenous estrogen were compared with 246 postmenopausal women not on estrogen. The estrogen users had significantly higher total high density lipoprotein (HDL) (76.0 vs 61.4 mg/dl) and HDL2 (36.7 vs 23.0 mg/dl) cholesterol than the controls. There was a similar concentration of HDL3 cholesterol for the two groups (39.2 for the estrogen users and 38.4 for the controls). A dose-response was evident between the amount of daily estrogen and HDL-total and HDL2 cholesterol. The significant differences between the two groups remained after adjusting for body composition, alcohol intake, cigarette smoking and physical activity. There was a significant difference between the two groups in liver function as measured by the liver enzymes, SGOT, SGPT, with liver enzyme concentrations lower in the estrogen users. The results indicate that the increase in the total HDL cholesterol as a result of menopausal estrogen is primarily the result of increased HDL2. The increase could not be explained by alterations in hepatic microsomal activity as measured by liver enzymes since estrogen users had lower concentrations of liver enzymes than non-estrogen users.