HDL, HDL2, and HDL3 subfractions, and the risk of acute myocardial infarction. A prospective population study in eastern Finnish men

BACKGROUND. We investigated the association of cholesterol concentrations in serum high density lipoprotein (HDL) and its subfractions HDL2 and HDL3 with the risk of acute myocardial infarction in 1,799 randomly selected men 42, 48, 54, or 60 years old. METHODS AND RESULTS. Baseline examinations in the Kuopio Ischaemic Heart Disease Risk Factor Study were done during 1984-1987. In Cox multivariate survival models adjusted for age and examination year, serum HDL cholesterol of less than 1.09 mmol/l (42 mg/dl) was associated with a 3.3-fold risk of acute myocardial infarction (95% confidence intervals [CI], 1.7-6.4), serum HDL2, cholesterol of less than 0.65 mmol/l (25 mg/dl) was associated with a 4.0-fold risk of acute myocardial infarction (95% CI, 1.9-8.3), and serum HDL3 cholesterol of less than 0.40 mmol/l (15 mg/dl) was associated with a 2.0-fold (95% CI, 1.1-4.0) risk of acute myocardial infarction. Adjustments for obesity, ischemic heart disease, other cardiovascular disease, maximal oxygen uptake, systolic blood pressure, antihypertensive medication, serum low density lipoprotein cholesterol, and triglyceride concentrations reduced the excess risks associated with serum HDL, HDL2, and HDL3 cholesterol in the lowest quartiles by 52%, 48%, and 41%, respectively. Additional adjustments for alcohol consumption, cigarettes smoked daily, smoking years, and leisure time energy expenditure reduced these excess risks associated with low HDL, HDL2, and HDL3 cholesterol levels by another 26%, 24% and 21%, respectively. CONCLUSIONS. Our data confirm that both total HDL and HDL2 levels have inverse associations with the risk of acute myocardial infarction and may thus be protective factors in ischemic heart disease, whereas the role of HDL3 remains equivocal.     

High-density lipoprotein, low-density lipoprotein and coronary artery disease

Lipoprotein cholesterol data from the Framingham Heart Study show that low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels are important in determining risk for coronary artery disease (CAD). Increased LDL and decreased HDL cholesterol levels are associated with an increase in CAD. Such relations are independent of the usual coronary risk factors, such as cigarette use and hypertension. A 1% greater LDL value is associated with slightly more than a 2% increase in CAD over 6 years; a 1% lower HDL value is associated with a 3 to 4% increase in CAD. Even at total cholesterol levels less than 200 mg/dl, lower HDL levels are associated with increased myocardial infarction rates in both men and women. Death from CAD is increased when HDL levels are low, but there is no such relation between HDL level and cancer death. Triglyceride levels were associated with CAD in Framingham men and women, but the association was no longer significant in men after adjustment for HDL levels. The major determinants for greater HDL levels in Framingham participants included female sex, estrogen use, leanness, greater alcohol intake, exercise, abstinence from smoking and lack of diuretic or beta-blocker use.     

Serum lipoproteins in patients with myocardial infarction

The lipid and lipoprotein profile was examined in male patients with acute myocardial infarction (AMI) at the time of infarction (group A) and in male patients who had survived AMI 2-3 years before the study (group B), and compared to that of healthy controls. The myocardial infarction (MI) patients exhibited similar total cholesterol and LDL-cholesterol levels as the controls. However, the LDL mass concentration was higher in patients than in controls (P less than 0.01 for group A, P less than 0.001 for group B). In composition, patients' LDL in both groups was rich in protein and triglycerides but poor in cholesterol. The compositional changes in patient LDL were evident at all levels of LDL-cholesterol. The mean total HDL and HDL2 mass concentrations were lower in patients than in controls (P less than 0.001 for both groups), but there was no difference in HDL3 levels. Upon admission to hospital the patients with AMI at the time of examination (group A) had higher serum total triglyceride concentration than controls, but on the fasting morning samples serum triglyceride and VLDL lipid levels did not differ between patients and controls. Patients who had survived AMI 2-3 years prior to study (group B) exhibited higher serum total triglyceride and VLDL levels than the control subjects. On stepwise discriminant analysis, HDL2 protein concentration was the single best variable for distinguishing between patients and controls. The most powerful discriminatory parameter was the HDL/LDL protein ratio or the HDL2/LDL protein ratio.     

The Framingham Offspring Study: a commentary. 1980

Forty-three of 1,312 men aged 35 to 54 years in the Framingham Offspring Study had clinically recognized coronary heart disease at the initial examination. Twenty-six men in this group had previously had a myocardial infarction. Of 1,296 women in the same age range, only 11 had coronary disease and 3 a prior myocardial infarction. The prevalence of coronary heart disease in men was strongly associated with age, smoking, high density lipoprotein (HDL), low density lipoprotein (LDL) and total cholesterol using univariate analyses. When multivariate logistic regression analysis was used, age, smoking and HDL and LDL cholesterol retained their significant association with coronary heart disease. The total cholesterol/HDL cholesterol ratio was also strongly associated with coronary heart disease in the multivariate analysis. It is concluded that both HDL and LDL cholesterol are strongly and independently associated with the prevalence of coronary heart disease, whereas the level of very low density lipoprotein cholesterol makes no statistically significant independent contribution.     

Effect of smoking habit on age-related changes in serum lipids: a cross-sectional and longitudinal analysis in a large Japanese cohort

To observe the effect of smoking habit on age-related serum lipid levels, we examined a large cohort of Japanese cross-sectionally and longitudinally. The participants included 103,648 Japanese men and women 17-94 years of age, who had received annual health examinations from 1989 to 2003. In cross-sectional analysis, total and LDL cholesterol levels of smokers were lower than those of nonsmokers up to an elderly age in men and up to middle age in women. Smoking was associated with decreased HDL cholesterol levels up to the 65-74 years age group in men and 55-64 years in women. The triglyceride levels were higher in smokers in both genders than those of nonsmokers below 55-64 years. In the longitudinal analysis, although smoking was associated with lower total and LDL cholesterol up to 60 years of age in women, beyond the sixties an inverted association was observed. The associations of smoking with lower LDL cholesterol levels in men and lower HDL cholesterol in both genders were fairly consistent at any given age. The increase of triglyceride levels in female smokers remained rather constant between 25 and 75 years, whereas the increase in triglyceride levels in male smokers was greater with older ages up to middle age. These results suggest that the effect of smoking on the serum lipid levels is dependent on age and gender.     

Relation of parental history of early myocardial infarction to the level of apoprotein B in men

The relations between parental history of early myocardial infarction and plasma lipids and apoproteins have been examined in a population of 4045 middle-aged (20 to 60 years old) working men at the initial examination of the Paris Prospective Study 2. Subjects with a history of myocardial infarction, angina pectoris, or peripheral arterial disease or those treated with hypolipidemic drugs were excluded from the analysis. The numbers of subjects with a paternal or maternal history of early myocardial infarction were 123 and 30, respectively. After adjustment for age, cigarette consumption, alcohol consumption, and body mass index, subjects with parental history of myocardial infarction had higher levels of total cholesterol (p less than .01), low-density lipoprotein (LDL) cholesterol (p less than .01), and apoprotein B (APOB) (p less than .0001) and a lower level of high-density lipoprotein (HDL) cholesterol (p less than .05) than subjects with no parental history of myocardial infarction. On the other hand, apoprotein A1 (APOA1) and triglyceride levels were not different between the two groups. The ratios of HDL/total cholesterol and APOA1/APOB were also lower in presence of parental myocardial infarction (p less than .001 and p less than .01, respectively). When a discriminant analysis was performed, only APOB level was related to parental myocardial infarction. The results for paternal and maternal history were very similar and were grouped for the analysis. We conclude that part of the known relationship between parental history of myocardial infarction and coronary heart disease could be mediated by an increased APOB level.     

Prevalence of coronary heart disease in the framingham offspring study: Role of lipoprotein cholesterols

Forty-three of 1,312 men aged 35 to 54 years in the Framingham Offspring Study had clinically recognized coronary heart disease at the initial examination. Twenty-six men in this group had previously had a myocardial infarction. Of 1,296 women in the same age range, only 11 had coronary disease and 3 a prior myocardial infarction. The prevalence of coronary heart disease in men was strongly associated with age, smoking, high density lipoprotein (HDL), low density lipoproteln (LDL) and total cholesterol using univariate analyses. When multivariate logistic regression analysis was used, age, smoking and HDL and LDL cholesterol retained their significant association with coronary heart disease. The total cholesterol/HDL cholesterol ratio was also strongly associated with coronary heart disease in the multivariate analysis. It is concluded that both HDL and LDL cholesterol are strongly and independently associated with the prevalence of coronary heart disease, whereas the level of very low density lipoprotein cholesterol makes no statistically significant independent contribution.     

5-year incidence of atherosclerotic vascular disease in relation to general risk factors, insulin level, and abnormalities in lipoprotein composition in non-insulin-dependent diabetic and nondiabetic subjects

The 5-year incidence of myocardial infarction and claudication was examined in a group of middle-aged patients (n = 133, 70 men and 63 women) with newly diagnosed non-insulin-dependent diabetes and nondiabetic control subjects (n = 144, 62 men and 82 women). The effects of general risk factors, plasma insulin level, and lipoprotein abnormalities on the incidence of myocardial infarction and claudication were also evaluated by univariate analyses in both diabetic patients and nondiabetic subjects and by multivariate analyses combining both groups. The age-adjusted incidence of myocardial infarction was higher both in diabetic men (19.4%) and diabetic women (11.0%) than in nondiabetic men (3.2%, p = 0.009) and nondiabetic women (3.0%, p = 0.047). Similarly, the age-adjusted incidence of claudication was higher among the diabetic patients (20.3% vs. 8.0% for men, p = 0.06; 21.8% vs. 4.2% for women, p = 0.003). None of the general risk factors (i.e., low density lipoprotein [LDL] cholesterol, blood pressure, smoking, and high density lipoprotein [HDL] cholesterol) showed an association with the risk of myocardial infarction either in the diabetic or nondiabetic groups of subjects, but an ischemic electrocardiographic abnormality at the baseline examination predicted myocardial infarction in diabetic men. In univariate analyses in diabetic subjects, high serum total cholesterol, low HDL cholesterol, high very low density lipoprotein (VLDL) cholesterol, and high total, LDL and VLDL triglycerides, and in nondiabetic subjects, high VLDL cholesterol and LDL triglycerides were associated with the appearance of claudication. In multivariate analyses including both diabetic and control subjects, only diabetes had an independent association with myocardial infarction, whereas smoking, high LDL triglycerides or VLDL cholesterol, and high fasting plasma insulin showed independent relations to claudication. The present results indicate that changes in lipoprotein composition characteristic of non-insulin-dependent diabetes are atherogenic and increase the risk of atherosclerotic vascular disease. Furthermore, high plasma insulin might also be involved in atherogenesis, independent of lipoprotein abnormalities.     

Treatment of older persons with hypercholesterolemia with and without cardiovascular disease

Hypercholesterolemia is a risk factor for new coronary events in older men and women. Secondary prevention trials have demonstrated in persons with coronary artery disease (CAD) and hypercholesterolemia that statin drugs reduced in older persons all-cause mortality, cardiovascular mortality, coronary events, coronary revascularization, stroke, and intermittent claudication. Statins have also been shown to slow progression of coronary atherosclerotic plaques in persons with CAD, to reduce restenosis after coronary stent implantation, and to decrease myocardial ischemia in persons with CAD. Older men and women with CAD, prior atherothrombotic brain infarction, peripheral arterial disease, or extracranial carotid arterial disease and a serum low-density lipoprotein (LDL) cholesterol level higher than 125 mg/dl despite diet should be treated with statin drug therapy to lower the serum LDL cholesterol level below 100 mg/dl. Primary prevention trials have shown that statins were also effective in reducing cardiovascular events in older persons with hypercholesterolemia. On the basis of data from the Air Force/Texas Coronary Atherosclerosis Prevention Study, the physician should consider using statins in persons aged 65-80 years without cardiovascular disease with a serum LDL cholesterol level above 130 mg/dl and serum high-density lipoprotein cholesterol level below 50 mg/dl.     

Influence of high-density lipoprotein cholesterol and rheological factors on the sex difference in cardiovascular disease

BACKGROUND: It is well established that the incidence of cardiovascular disease among men is higher than that among women. OBJECTIVE: To determine whether differences between men and women in terms of a range of conventional and rheological risk factors could explain this sex difference. DESIGN: This was a population-based cohort study (the Edinburgh Artery Study). METHODS: Men and women aged 55-74 years (n = 1592) were selected at random from the general population of Edinburgh and followed up for 5 years. Baseline cardiovascular risk factors were measured and related to incidence of disease among men and women. RESULTS: Men had higher levels of cigarette smoking, haematocrit and blood viscosity and lower levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and plasma fibrinogen than did women. The incidences of cardiovascular events among men and women were 48.3 and 26.1 per 1000 person-years, respectively. Adjustment for level of HDL cholesterol reduced the male:female ratio for sex-specific incidence rates of cardiovascular events from 1.80 [95% confidence interval (CI) 1.43-2.27] to 1.34 (95% CI 1.04-1.73). This reduction was partially reversed after further adjustment for the other cardiovascular risk factors. The impact of blood viscosity, plasma viscosity and plasma level of fibrinogen on the risk of cardiovascular disease was higher for men than it was for women (multivariate relative risk for blood viscosity were 1.24, 95% CI 1.08-1.43, for men and 0.81, 95% CI 0.61-1.06, for women). CONCLUSIONS: Levels of HDL cholesterol levels in women being higher than those in men may explain some, but not all, of the sex difference in incidence of cardiovascular disease. Greater susceptibility of men to rheological factors might also be important.     

Serum cholesterol is a risk factor for myocardial infarction in elderly men and women: the Rotterdam Study

OBJECTIVE: To investigate the associations of serum total and HDL cholesterol with the risk of myocardial infarction in men and women of 55 years and over. DESIGN: The Rotterdam Study is a population-based prospective cohort study. In total 2453 men and 3553 women of 55 years and older were included in this study. The mean duration of follow-up was 4 years. MAIN OUTCOME MEASURES: Relative risks were estimated with Cox's proportional-hazard analysis. Cholesterol was analysed as a continuous variable and in sex-specific quartiles. RESULTS: In subjects aged 55 years and older the relative risk of myocardial infarction was 1.9 in men (95% confidence interval 1.1-3.3) and 3.2 in women (1.5-6.4) in the highest compared to the lowest serum total cholesterol quartile (Q4 vs. Q1). In men and women of 70 years and older, total cholesterol remained an important risk factor for myocardial infarction (Q4 vs. Q1 relative risk 3.2; 1.3-7.7 and 2.9; 1.3-6.6, respectively). For HDL cholesterol, the relative risk in the highest compared to the lowest quartile (Q4 vs. Q1) was 0.5 in men (0.3-0.9) and 0.4 in women (0.2-0.9). HDL cholesterol was a weaker predictor in men after the age of 70 (Q4 vs. Q1 0.8; 0.3-2.1). In women of 70 years and older the relative risk was also not significant (Q4 vs. Q1 0.6; 0.3-1.3), although the trend over the quartiles was still significant. CONCLUSION: Serum total cholesterol remains an important risk factor for myocardial infarction in men and women aged 70 years and older, whilst HDL cholesterol at older age remains important in women only.     

Population correlates of plasma fibrinogen and factor VII, putative cardiovascular risk factors.

Recent prospective investigations have reported that higher plasma fibrinogen concentrations and higher factor VII coagulant activity are associated with greater risk of cardiovascular disease. To discover what characteristics may influence fibrinogen and factor VII, we analyzed data from the Atherosclerosis Risk in Communities Study obtained from over 12,000 men and women, aged 45-64 years, from four communities in December 1986 to June 1989. Fibrinogen was higher in blacks than whites and in women than men; in general, it increased with age, smoking, body size, diabetes, fasting serum insulin, LDL cholesterol, lipoprotein(a), leukocyte count, and menopause, and it decreased with ethanol intake, physical activity, HDL cholesterol, and female hormone use. Factor VII was higher in women than men and, in women, increased with age; in both sexes, it increased with body size, triglycerides, LDL cholesterol, and HDL cholesterol, and it decreased with ethanol intake. These findings indicate that elevations in fibrinogen and factor VII may be modifiable through appropriate lifestyle changes.     

Acute changes in lipid, lipoprotein, apolipoprotein, and low-density lipoprotein particle size after an endurance triathlon

The effect of an endurance triathlon (2.4-mile swim, 112-mile bicycle ride, 26.2-mile run, in succession) on plasma total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I and B levels, and LDL particle size was determined in 34 male and six female participants 6 to 12 hours before and immediately after the completion of the triathlon. Plasma TG decreased significantly (70% decrease) in both men and women. In men the change in plasma TG was inversely associated with baseline TG values (P less than .0001). Plasma TC and LDL cholesterol did not change significantly in male athletes but decreased significantly in women. A significant increase in HDL cholesterol was observed in both men (18% increase, P less than .0001) and women (5% increase, P less than .01). In men the increase in HDL cholesterol was inversely correlated with the decrease in triglycerides (P less than .0002). Plasma apo A-I levels increased significantly only in the male group (P less than .005), whereas plasma apo B levels decreased significantly in both men and women (P less than .0005). LDL particle size increased in seven males, whereas in the remaining males and all females no change in LDL size was observed. The increase in LDL particle size in these seven subjects was associated with a greater decline in plasma TG compared with the remaining men (P less than .005) and women (P less than .03). These results indicate that prolonged strenuous physical exercise can induce acute modifications of plasma lipoproteins, which may in part be related to enhanced lipolysis.     

Plasma lipoproteins in healthy octogenarians: lack of reduced high density lipoprotein cholesterol levels: results from the Framingham Heart Study

Genetic low density lipoprotein (LDL) deficiency and high density lipoprotein (HDL) excess have been associated with enhanced longevity. This investigation assessed the prevalence of lipoprotein abnormalities in octogenarians free of clinical evidence of cardiovascular disease (CVD) in the Framingham Heart Study. Plasma lipid and lipoprotein cholesterol determinations were carried out by standard techniques between 1971 and 1974. Participants who were free of clinical evidence of CVD in an examination approximately 10 years later (1981 to 1982) had their lipoprotein values tabulated based on the earlier examination. There were 106 women and 57 men who met these criteria, with mean ages of 83.3 and 82.9 years, respectively, at examination 16 (called cases). Mean levels (+/- SEM) of LDL cholesterol in cases were 152 +/- 3 mg/dL for women, and 147 +/- 5 mg/dL for men. For HDL cholesterol, these values were 57 +/- mg/dL for women and 46 +/- 2 mg/dL for men. These values were not statistically different from those of other study subjects (who did not meet the CVD criteria or were decreased) or middle-aged controls. In contrast, HDL cholesterol levels below the tenth percentile of normal were not observed in any male cases and in only 1.0% of female cases (P less than .05) as compared with observations in control subjects. The data are consistent with the concept that there is not an overrepresentation of either decreased LDL cholesterol or elevated HDL cholesterol values in subjects who subsequently become healthy octogenarians, but that these subjects are exceedingly unlikely to have reduced HDL cholesterol levels.     

Differences in apolipoproteins and low-density lipoprotein subfractions in postmenopausal women on and off estrogen therapy: results from the Framingham Offspring Study

The use of estrogens by postmenopausal women has been associated with reduced risk of coronary artery disease (CAD) in some studies, possibly due to favorable effects of estrogens on plasma lipoproteins. In order to examine such effects, we studied 180 postmenopausal women from the Framingham Offspring Study, selected by type of menopause (natural or oophorectopic) and estrogen use. We determined fasting plasma total cholesterol, triglyceride, very-low-density lipoprotein (VLDL) cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and apolipoprotein (apo) A-l and B concentrations, as well as LDL particle size (LDL 1 to LDL 6). Apo A-l levels were significantly (P less than .005) higher, and diastolic blood pressure and glucose levels were significantly (P less than .05) lower in postmenopausal women taking estrogen regardless of type of menopause. HDL cholesterol levels were also higher in women taking oral estrogens, but differences were significant only for the oophorectomized group (P less than .02). Total cholesterol, VLDL cholesterol, and LDL cholesterol levels were significantly lower (P less than .01) in women with natural menopause who were taking estrogens than in women with natural menopause not taking this medication. No significant differences between estrogen users and nonusers were found with regard to triglyceride levels or LDL particle score, in either the natural menopause or oophorectomy groups. These data indicate that estrogen use in postmenopausal women is associated with significantly elevated plasma apo A-l levels and decreased LDL cholesterol concentrations.     

Serum apolipoproteins AI and B and lipoproteins in middle aged men with and without previous myocardial infarction

The serum high density lipoprotein (HDL) subfractions, HDL2, and HDL3, and serum apolipoprotein AI and B (apo AI and B) were evaluated as potential indicators of the risk of ischaemic heart disease in men aged less than 60 years who had previously had a myocardial infarction and in controls with a similar socioeconomic background who had no history of myocardial ischaemia. Discriminant analysis confirmed that the combination of serum cholesterol, triglycerides, and total HDL cholesterol distinguished poorly between patients and controls. The best single discriminating variable was apo B. Stepwise discriminant analysis showed that this discrimination could be improved to a small extent by combining apo B with apo AI and parental history, but nothing was gained by measurement of serum cholesterol triglycerides, very low density lipoprotein cholesterol, low density lipoprotein cholesterol, HDL cholesterol, HDL2 or HDL3 cholesterol. Significantly more patients than controls with type IV hyperlipoproteinaemia had raised concentrations of serum apolipoprotein B, but the frequency of raised apolipoprotein B concentrations was no greater in patients with type IV hyperlipoproteinaemia than in those with normal serum lipids. The value of apo B as an indicator of cardiovascular risk should be assessed in prospective studies.     

Differences in low density lipoprotein subfractions and apolipoproteins in premenopausal and postmenopausal women

Postmenopausal or oophorectomized women are at higher risk for the development of coronary artery disease than are premenopausal women. These differences in risk may be due to alternations in plasma lipoproteins modulated by hormonal changes. Plasma cholesterol, triglyceride, lipoprotein cholesterol, and apolipoprotein A-I and B (apoB) concentrations, as well as low density lipoprotein (LDL) particle size (LDL 1-7), as assessed by 2-16% polyacrylamide-agarose gradient gel electrophoresis, were determined in 87 premenopausal and 43 postmenopausal women. All were participants in the Framingham Offspring Study, were gynecologically normal, and were not taking any hormones. The postmenopausal women had significantly (P less than 0.05) higher plasma LDL cholesterol concentrations than did the premenopausal women. Plasma triglyceride, total cholesterol, very low density lipoprotein cholesterol, and apoB levels were higher, and apoA-I and high density lipoprotein cholesterol were lower in the postmenopausal group, but these differences were not significant at P less than 0.05. The postmenopausal women were likely to have small LDL particles compared to premenopausal women. Controlling for age and body mass index effects significantly reduced the differences in total cholesterol, LDL cholesterol, apoB, and LDL particle size and broadened the differences in apoA-I and high density lipoprotein cholesterol. These data indicate that menopause is positively correlated with LDL cholesterol (P less than 0.05) and decreased LDL particle size (P less than 0.05) after adjusting for significant covariates.     

Serum apolipoproteins AI and B and lipoproteins in middle aged men with and without previous myocardial infarction.

The serum high density lipoprotein (HDL) subfractions, HDL2, and HDL3, and serum apolipoprotein AI and B (apo AI and B) were evaluated as potential indicators of the risk of ischaemic heart disease in men aged less than 60 years who had previously had a myocardial infarction and in controls with a similar socioeconomic background who had no history of myocardial ischaemia. Discriminant analysis confirmed that the combination of serum cholesterol, triglycerides, and total HDL cholesterol distinguished poorly between patients and controls. The best single discriminating variable was apo B. Stepwise discriminant analysis showed that this discrimination could be improved to a small extent by combining apo B with apo AI and parental history, but nothing was gained by measurement of serum cholesterol triglycerides, very low density lipoprotein cholesterol, low density lipoprotein cholesterol, HDL cholesterol, HDL2 or HDL3 cholesterol. Significantly more patients than controls with type IV hyperlipoproteinaemia had raised concentrations of serum apolipoprotein B, but the frequency of raised apolipoprotein B concentrations was no greater in patients with type IV hyperlipoproteinaemia than in those with normal serum lipids. The value of apo B as an indicator of cardiovascular risk should be assessed in prospective studies.     

Triglyceride levels and the risk of coronary artery disease: a view from Australia.

A prospective study of cardiovascular disease in elderly Australians commenced in 1988 in Dubbo, New South Wales. The study population comprised 1,237 men and 1,568 women aged > or = 60 years. The prevalence rates of coronary artery disease (CAD) and putative risk factors were examined cross-sectionally in the baseline data. The age-standardized rate of CAD was 23.8/100 men and 18.1/100 women. In a univariate analysis, the major risk factors for CAD were hypertension, diabetes, family history, reduced high-density lipoprotein (HDL) cholesterol levels, and increased triglyceride levels. The prevalence rate of CAD was examined in those with low-density lipoprotein (LDL):HDL ratios < 5.0 or > 5.0. Most notably in women, the CAD rate was 16/100 with an LDL.HDL ratio < or = 5.0 and 28/100 with an LDL.HDL ratio > 5.0. In the latter group, the rate was 21/100 in those with triglycerides < or = 2.3 mmol/liter and 36/100 in those with triglycerides > 2.3 mmol/liter. In a multiple logistic model that controlled for many potential risk factors or confounding variables, CAD in men was significantly predicted by age, hypertension (odds ratio = 1.40), family history (odds ratio = 2.05), and low HDL cholesterol (odds ratio = 0.78). Significant predictors in women were age, years of education (odds ratio = 0.82), hypertension (odds ratio = 1.45), family history (odds ratio = 1.77), serum triglycerides (odds ratio = 1.30), and low HDL cholesterol (odds ratio = 0.73). An independent gradient of CAD risk with increasing triglyceride levels and a similar gradient with decreasing HDL cholesterol levels were found in women.(ABSTRACT TRUNCATED AT 250 WORDS)     

The distribution of plasma lipoproteins in middle-aged male runners.

Stimulated by increasing evidence of an inverse relationship between plasma high-density lipoprotein cholesterol level and frequency of coronary heart disease, we determined concentrations of fasting plasma cholesterol, triglyceride, and lipoproteins in 41 very active men (running greater than 15 miles/wk for the previous year) 35-59 years of age (mean age, 47) and in a comparison group of men of similar age, randomly selected from three northern California communities. The runners had significantly (p less than 0.05) decreased mean plasma triglyceride (70 versus 146 mg/100 ml), total plasma cholesterol (200 versus 210 mg/100 ml), and low-density lipoprotein (LDL) cholesterol (125 versus 139 mg/100 ml) concentrations, and a higher mean level of high-density lipoprotein (HDL) cholesterol (64 versus 43 mg/100 ml) than the comparison group (n equals 147 for HDL and LDL; n equals 743 for total cholesterol and triglycerides). These very active men exhibited a plasma lipoprotein profile resembling that of younger women rather tan of sedentary, middle-aged men. This characteristic, and apparently advantageous, pattern could be only partially accounted for by differences in adiposity between runners and control subjects.