Serum lipids and lipoproteins as predictors of atherosclerosis. An autopsy study

Escalation of Coronary Atherosclerosis in Younger People by Comparison of Two Autopsy Studies Conducted a Decade Apart

Introduction:

Cardiovascular disease is the most common cause of death worldwide which includes coronary heart disease (CHD) as the major contributor. The foremost cause of CHD is atherosclerosis of coronary arteries leading to angina to sudden deaths which is sharply increasing in India; sadly more in the younger people. In this study, results were compared to an autopsy result performed a decade earlier.

Aims:

Both autopsy studies were conducted to assess the frequency of coronary atherosclerosis, morphological types of lesions and the degree of stenosis in three major coronary arteries. The association of the disease to age, sex, socio-economic status, diet and obesity were studied along with correlating the severity with major risk factors such as hypertension, diabetes mellitus, hyperlipidemia and smoking.

Materials and Methods:

60 hearts in the 1st study and 120 in the 2^nd study were studied after collecting from Forensic department with details of the deceased. Hearts were dissected by Virchow's method and three major coronary arteries were studied by making serial sectioning. The atherosclerotic lesions were examined histopathologically and typed according to American Heart Association classification along with grading of the luminal stenosis.

Results:

The second study showed an alarmingly higher incidence of atherosclerosis (90.83%), especially in younger age. Compared to the older study in which 68.33% had coronary atherosclerosis. In both studies coronary atherosclerosis was more in males, severity increased with age and proximal segment of left anterior descending coronary artery was the most commonly affected part with higher grade lesions.

Conclusion:

The frequency of occurrence of coronary atherosclerosis has definitely increased steeply in the past two decades and alarmingly more in the younger people, with the severity being common in the fourth decade of life itself. There is strong positive correlation with major risk factors reiterating the importance of clinical screening and preventive programs.

Cerebrospinal fluid biomarkers of Alzheimer's disease are associated with carotid plaque score and hemodynamics in intra- and extra-cranial arteries on ultrasonography

Carotid plaque score (PS) and hemodynamic abnormalities in intra- and extra-cranial arteries are related to Alzheimer's disease (AD) progression. As these parameters are measured conveniently and non-invasively by ultrasonography, we examined their association with cerebral spinal fluid (CSF) AD biomarkers amyloid β (Aβ) and phosphorylated tau (p-tau). Carotid PS, mean flow velocity (MFV) in multiple intra- and extra-cranial arteries, CSF Aβ42 and p-tau, neurocognitive function (assessed by the Mini-Mental State Examination and Alzheimer's Disease Assessment Scale-cognitive subscale, Japanese version), and blood lipids (total cholesterol, HDL cholesterol, LDL cholesterol, and triglyceride) were measured in AD patients (n = 42), mild cognitive impairment patients (n = 20), and cognitively normal controls (n = 18). The results were also compared among groups defined by PS range. After adjusting for blood lipids as covariates, Aβ42 was higher in the PS = 1.1-2.0 mm group than in the higher PS groups (2.1-3.0, 3.1-5.0, 5.1-7.0, and >7.0 mm). However, subjects with very low PS (<1.1 mm) also had a low mean CSF Aβ42. Alternatively, CSF p-tau181 did not differ between PS groups. In multiple regression analysis, Aβ42 was not associated with MFVs; however, CSF p-tau181 showed a significant association with the MFV of the internal carotid and basilar arteries. Findings suggest that carotid plaque formation may accelerate Aβ42 deposition, although it is not necessary for deposition. Hemodynamics abnormalities may cause increased CSF p-tau181. Ultrasonographic evaluation of PS and arterial hemodynamics may be a useful noninvasive method for estimating AD pathology.

The Hypolipidemic Effect of Total Saponins from Kuding Tea in High-Fat Diet-Induced Hyperlipidemic Mice and Its Composition Characterized by UPLC-QTOF-MS/MS

Kuding tea are used as a traditional tea material and widely consumed in China. In this study, total saponins (TS) from water extract of Kuding tea was prepared by D101 macroporous resins and analyzed by UPLC-QTOF-MS/MS. Then the hypolipidemic effect of TS extract was investigated in high-fat diet-induced hyperlipidemic mice. For comprehensive identification or characterization of saponins in TS extract, 3 major saponins of Kudinoside A, Kudinoside F, and Kudinoside D were isolated and used as standards to investigate the MS/MS fragmentation pattern. As a result, 52 saponins were identified or characterized in TS extract from Kuding tea. In addition, the increased levels of mice serum TC, LDL-C, HDL-C, and atherogenic index (AI) were significantly reduced after the treatment of TS extract. Also, the liver protective effect of TS extract was obviously judged from the photographs stained with oil red-O staining. Meanwhile, TS extract significantly upregulated the expression of hepatic scavenger receptors including SR-AI, SR-BI, and CD36. Therefore, it is reasonable to assume that the overexpression of hepatic scavenger receptors was involved in the hypolipidemic effect of Kuding tea on the high-fat diet-induced hyperlipidemic mice. The TS extract could influence these scavenger receptors, and this could be the potential mechanism of TS extract from Kuding tea in the treatment of lipid disorders. These results give the evidence that the saponins in Kuding tea could provide benefits in managing hypercholesterolemia and may be a good candidate for development as a functional food and nutraceutical.

Cerebrovascular atherosclerosis correlates with Alzheimer pathology in neurodegenerative dementias

A growing body of evidence demonstrates an association between vascular risk factors and Alzheimer's disease. This study investigated the frequency and severity of atherosclerotic plaques in the circle of Willis in Alzheimer's disease and multiple other neurodegenerative diseases. Semi-quantitative data from gross and microscopic neuropathological examinations in 1000 cases were analysed, including 410 with a primary diagnosis of Alzheimer's disease, 230 with synucleinopathies, 157 with TDP-43 proteinopathies, 144 with tauopathies and 59 with normal ageing. More than 77% of subjects with Alzheimer's disease had grossly apparent circle of Willis atherosclerosis, a percentage that was significantly higher than normal (47%), or other neurodegenerative diseases (43-67%). Age- and sex-adjusted atherosclerosis ratings were highly correlated with neuritic plaque, paired helical filaments tau neurofibrillary tangle and cerebral amyloid angiopathy ratings in the whole sample and within individual groups. We found no associations between atherosclerosis ratings and α-synuclein or TDP-43 lesion ratings. The association between age-adjusted circle of Willis atherosclerosis and Alzheimer's disease-type pathology was more robust for female subjects than male subjects. These results provide further confirmation and specificity that vascular disease and Alzheimer's disease are interrelated and suggest that common aetiologic or reciprocally synergistic pathophysiological mechanisms promote both vascular pathology and plaque and tangle pathology.

Sex, race, and age distributions of mean aortic wall thickness in a multiethnic population-based sample

BACKGROUND

Reference values and age-related changes of the wall thickness of the abdominal aorta have not been described in the general population. We characterized age-, race-, and gender-specific distributions, and yearly rates of change of mean aortic wall thickness (MAWT), and associations between MAWT and cardiovascular risk factors in a multi-ethnic population-based probability sample.

METHODS

Magnetic resonance imaging measurements of MAWT were performed on 2466 free-living white, black, and Hispanic adult subjects. MAWT race/ethnicity- and gender-specific percentile values across age were estimated using regression analyses.

RESULTS

MAWT was greater in men than in women and increased linearly with age in all the groups and across all the percentiles. Hispanic women had the thinnest and black men the thickest aortas. Black men had the highest and white women the lowest age-related MAWT increase. Age, gender, ethnicity, smoking status, systolic blood pressure, low-density lipoprotein-cholesterol levels, high-density lipoprotein-cholesterol levels, and fasting glucose levels were independent predictors of MAWT.

CONCLUSIONS

Age, gender, and racial/ethnic differences in MAWT distributions exist in the general population. Such differences should be considered in future investigations assessing aortic atherosclerosis and the effects of anti-atherosclerotic therapies.

Aortic plaque imaging and monitoring atherosclerotic plaque interventions

The atherosclerotic process that results in coronary artery disease (CAD) is recognized to be a generalized process that may involve the entire vasculature. The association between CAD and atherosclerotic plaques in the thoracic aorta has often been reported using transesophageal echocardiography. An autopsy study showed plaques in the abdominal aorta, but not in the thoracic aorta, to be severe in patients with cardiac events. However, studies evaluating an association between abdominal aortic plaques and CAD are scarce. Recently, magnetic resonance imaging (MRI) has become a useful tool for the noninvasive evaluation of atherosclerotic plaques in both the thoracic and abdominal aortas. Plaques in the thoracic and abdominal aortas were found to be characteristically associated with hypercholesterolemia and smoking, respectively, suggesting different susceptibilities to risk factors. Because patients have various risk factors, it seems to be preferable to evaluate atherosclerosis in multiple vascular beds than in just 1 bed. Magnetic resonance imaging can evaluate atherosclerosis in multiple vascular beds in the same examination session. Complex aortic plaques, especially in the abdominal aorta, were found to be associated with myocardial infarction and complex coronary lesions, suggesting a link between aortic and coronary plaque instability. Aortic MRI may thus be useful for identifying vulnerable patients. Moreover, MRI is a powerful tool to serially evaluate plaque progression and regression. Intensive lipid-lowering therapy can regress aortic plaques, but the susceptibility to lipid lowering and the process of plaque regression may differ between the thoracic and abdominal aortic plaques.

Effect of bezafibrate therapy on atherosclerotic aortic plaques detected by MRI in dyslipidemic patients with hypertriglyceridemia

Fibrates reduce triglycerides (TG) and increase HDL-cholesterol levels, but there was no report showing plaque regression by fibrates. Using MRI, we investigated the effects of bezafibrate on aortic plaques in 22 dyslipidemic patients. All patients were asked to receive 400mg bezafibrate, but 8 who declined to have bezafibrate became the control group. Changes in vessel wall area (VWA) and lumen area (LA) from baseline to 1-year were evaluated. Bezafibrate reduced TG (-55%) and increased HDL-cholesterol levels (+29%). Bezafibrate reduced HDL size and increased LDL size. In thoracic plaques, bezafibrate reduced VWA (-6%, P<0.001) with no LA change, but VWA slightly progressed without bezafibrate (+5%). In abdominal plaques, bezafibrate reduced VWA (-8%, P<0.001) with LA increase (+3%, P<0.02), but VWA progressed without bezafibrate (+6%). VWA changes in thoracic and abdominal plaques correlated with TG reduction and HDL-cholesterol increase. Notably, VWA change in only abdominal plaques correlated with HDL size reduction and LDL size increase. Thus, bezafibrate induced plaque regression in thoracic and abdominal aortas with marked TG reduction and HDL-cholesterol increase, but the processes of plaque regression and vascular remodeling may differ between thoracic and abdominal aortas. However, because our study was not a controlled, randomized trial, further study is needed.

Lipids for psychiatrists - an overview

Serum cholesterol is a major risk factor for cardiovascular disease. Total cholesterol, LDL cholesterol and triglycerides are positively related to cardiovascular disease, while HDL cholesterol has an inverse relationship. Measurement of lipids is essential in individuals with established cardiovascular disease or type 2 diabetes, and may also be carried out in healthy individuals as part of cardiovascular risk assessment. Lifestyle measures are important in cardiovascular disease prevention, but the mainstay of lipid lowering therapy is appropriate use of lipid lowering drugs. Total and LDL cholesterol are the primary targets for treatment, but consideration should also be given to raising HDL cholesterol and lowering triglycerides where appropriate. Statins are the most frequently used lipid lowering agents, but there is an important place for other drugs, including ezetimibe, fibrates and nicotinic acid.

The effects of a soy rich diet on serum lipids: the Menfis randomized trial

OBJECTIVE

To assess beneficial effects of a soy rich diet on the main biomarkers of cardiovascular health in menopause, compared with the effects of the hormone replacement therapy (HRT).

METHODS

187 healthy asymptomatic postmenopausal women, aged 39-60, were recruited and randomized into three groups: a soy rich diet group, a HRT group, and a control group. Lipid profile, body mass index, blood pressure, endometrial thickness, uterine artery resistance index (RI), were evaluated in all the participants at the baseline, after 6 months, and at the end of the study.

RESULTS

After a 6-month intervention period, the lipid profile in the soy rich diet group showed a favourable outcome, similar to that observed in the HRT group, but compliance to the diet was low.

CONCLUSION

Soy products may be used in the prevention of cardiovascular risk in postmenopausal women because of their efficacy in contrasting the negative effects of menopause on the cardiovascular system, but our findings should be confirmed; moreover, suitable strategies to improve the compliance have to be considered.

Origin of atherosclerosis in childhood and adolescence

Atherosclerosis begins in childhood as deposits of cholesterol and its esters, referred to as fatty streaks, in the intima of large muscular arteries. In some persons and at certain arterial sites, more lipid accumulates and is covered by a fibromuscular cap to form a fibrous plaque. Further changes in fibrous plaques render them vulnerable to rupture, an event that precipitates occlusive thrombosis and clinically manifest disease (sudden cardiac death, myocardial infarction, stroke, or peripheral arterial disease). In adults, elevated non-HDL-cholesterol concentrations, low HDL-cholesterol concentrations, hypertension, smoking, diabetes, and obesity are associated with advanced atherosclerotic lesions and increased risk of clinically manifest atherosclerotic disease. Control of these risk factors is the major strategy for preventing atherosclerotic disease. To determine whether these risk factors also are associated with early atherosclerosis in young persons, we examined arteries and tissue from approximately 3000 autopsied persons aged 15-34 y who died of accidental injury, homicide, or suicide. The extent of both fatty streaks and raised lesions (fibrous plaques and other advanced lesions) in the right coronary artery and in the abdominal aorta was associated positively with non-HDL-cholesterol concentration, hypertension, impaired glucose tolerance, and obesity and associated negatively with HDL-cholesterol concentration. Atherosclerosis of the abdominal aorta also was associated positively with smoking. These observations indicate that long-range prevention of atherosclerosis and its sequelae by control of the risk factors for adult coronary artery disease should begin in adolescence and young adulthood.

Hyperfibrinogenemia is associated with specific histocytological composition and complications of atherosclerotic carotid plaques in patients affected by transient ischemic attacks

BACKGROUND

Epidemiological studies have demonstrated that hyperfibrinogenemia is an independent risk factor for cerebrovascular atherosclerosis. However, the underlying mechanisms are poorly understood. We studied whether hyperfibrinogenemia could modify the histological composition of atherosclerotic plaque and precipitate carotid thrombosis resulting from rupture of the plaque.

METHODS AND RESULTS

We studied the histological composition of 71 carotid atherosclerotic plaques from patients who had undergone surgical endarterectomy after a first episode of transient ischemic attack. Patients were divided into 3 groups corresponding to the tertiles of plasma fibrinogen values. Hypercholesterolemia, hypertriglyceridemia, hypertension, diabetes, and smoking habit were also assessed. At the histological analysis, plaques of patients in the highest tertile of fibrinogen (>407 mg/dL) were characterized by a high incidence of thrombosis (66.7% of cases) compared with plaques of subjects in the lower (21.7%) (P=0.002) and middle (29. 2%) (P=0.009) tertiles. Plaque rupture was significantly associated with high fibrinogen levels (54.2%, P=0.003). Multivariate logistic regression indicated that hyperfibrinogenemia was an independent risk factor for a decrease in cap thickness (P=0.0005), macrophage foam cell infiltration of the cap (P=0.003), and thrombosis (P=0. 003). When the presence of other risk factors was accounted for, hyperfibrinogenemia remained an independent predictor of carotid thrombosis with an odds ratio of 5.83, compared with other risk factors.

CONCLUSIONS

The results of the present study add to the evidence that hyperfibrinogenemia, independently of other risk factors, is associated with a specific histological composition of carotid atherosclerotic plaques that predisposes them to rupture and thrombosis.

A polymorphism of angiotensinogen gene codon 174 and coronary artery disease in Japanese subjects

The relationship between coronary artery disease (CAD) and polymorphisms of genes encoding angiotensinogen (AGT) and angiotensin converting enzyme (ACE) was analyzed in Japanese subjects. One hundred and four patients with CAD and 170 healthy subjects were enrolled in the study. CAD was defined as having a luminal diameter stenosis > or =50% in at least one of three major coronary arteries by coronary angiography. The genotypes (determined by polymerase chain reaction) of AGT gene codon 174 were not significantly associated with CAD in the total study population. However, the frequency of T/T homozygotes of AGT codon 174 was significantly higher in CAD patients compared to controls in each of three subgroups: 1) body mass index (BMI) below the median value of 24.1 kg/m2; 2) not more than two CAD risk factors out of five (hypercholesterolemia, hypertension, diabetes mellitus, smoking, and family history of CAD); and 3) the ACE I/I genotype. The M/M genotype of AGT codon 235 was negatively associated, and the ACE D/D genotype was positively associated, with CAD in the total study population. Our results indicate that the T/T genotype of AGT codon 174 may be a risk factor for CAD in Japanese individuals with low BMI, lesser CAD risk factors, or ACE I/I genotype.

Influence of risk factors on peripheral and cerebrovascular disease in men with coronary artery disease, low high-density lipoprotein cholesterol levels, and desirable low-density lipoprotein cholesterol levels. HIT Investigators. Department of Veterans Affairs HDL Intervention Trial

BACKGROUND

The Veterans Administration-HDL Intervention Trial is an ongoing, 20-center, randomized, double-blind, placebo-controlled study aiming to assess the effect of gemfibrozil-improved low high-density lipoprotein cholesterol levels on cardiovascular morbidity and mortality rates.

METHODS AND RESULTS

Eligible patients were men with low high-density lipoprotein cholesterol levels and demonstrable coronary heart disease. A total of 2531 patients (average age 63.5 years) were randomly assigned in this study, with a mean high-density lipoprotein cholesterol level of 0.83 mmol/L (32 mg/dL) and low-density lipoprotein cholesterol level of 2.87 mmol/L (111 mg/dL). Baseline data provided the opportunity to assess the interaction of several coronary heart disease risk factors and comorbid vascular diseases. Of these patients, 206 had diabetes mellitus (DM) alone, 1021 had hypertension (HTN) alone, 421 had both DM and HTN, and 883 had neither ("others"). Considering the influence of these risk factors on comorbidities independent of smoking status, patients with DM alone had a 2-fold increase in the prevalence of peripheral vascular disease and a 1.5-fold increase in congestive heart failure. Patients with HTN had a significant increase in the prevalence of cerebrovascular disease, stroke, and congestive heart failure. Patients with HTN and DM had a significant increase in all comorbidities. Smoking resulted in substantial increase of both peripheral vascular disease and cerebrovascular disease. Compared with nonsmoking patients with no DM or HTN, patients with DM and HTN and smoking had a 3-fold increase in the prevalence of peripheral vascular disease and a 3.5-fold increase in cerebrovascular disease (P < .001).

CONCLUSIONS

We conclude that DM is a strong correlate of peripheral vascular disease, hypertension of cerebrovascular disease, and that there is a strong additive effect between DM, HTN, and smoking on both.

[Wine and heart]

Many epidemiological studies have shown that moderate alcohol intake, from 10 to 30 g of ethanol a day, decreases cardiovascular mortality from atherosclerotic ischaemic heart disease and ischaemic stroke as compared to non-drinkers. This beneficial effect outweighs the risks of alcohol consumption in subgroups of people with a higher risk of atherosclerosis: the elderly, people with coronary risk factors and patients with previous coronary events. It has not been demonstrated that alcohol intake, even in moderate amounts, is beneficial for the general population, in particular, men under the age of 40 and women under 50, because it raises mortality due to other causes, especially injury, cirrhosis of the liver and some types of cancer, thereby outweighing the benefits for coronary artery disease. Thus, alcohol consumption should not be recommended as a prophylaxis for the general population. Guidelines on alcohol drinking habits--whether to continue, to start, to modify or to stop--must be given on an individual basis, taking into account the relative risks and benefits for each patient. The benefits of moderate alcohol consumption on the cardiovascular system seem to be exerted fundamentally through its effects on plasma lipoproteins, principally by raising high density lipoprotein (HDL) cholesterol and to a lesser degree, by decreasing low density lipoprotein (LDL) cholesterol. It appears to exert additional beneficial effects on the heart by decreasing platelet aggregability and by bringing about changes in the clotting-fibrinolysis system. Although there has been some debate about the relative superiority of different types of alcoholic beverages (wine, beer or hard liquor), and to a greater extent, about different types of wine, there is no current evidence of any kind of beneficial effect from other components of the beverage besides ethanol. Thus, it does not seem appropriate to recommend any particular type of alcoholic drink, except for sociocultural reasons. The added benefits from some components of different types of wine with a high antioxidant activity on plasma lipoproteins remain only an interesting hypothesis. Meanwhile, encouraging a healthy diet, flavonoid rich and with a predominance of natural ingredients (fruit, legumes, cereals and seeds), in the general population should stop the current tendency of Southern European countries from abandoning the Mediterranean diet. Because of the multifactorial nature of coronary heart disease, it is necessary to remember that atherosclerotic risk reduction is achieved by behavior modification of multiple risk factors present in individual patients and in the general population. Therefore, guidelines regarding alcohol intake should always be linked to pertinent recommendations about other atherosclerotic risk factors.

Different effects of hypertension and hypercholesterolemia on the natural history of aortic atherosclerosis by the stage of intimal lesions

To investigate the histopathologic modes of the effect of hypertension and hypercholesterolemia on atherosclerosis progression, a total of 573 male autopsied aortas, ranging from 0 to 97 years-old, were histomorphometrically compared by the status based on antemortem risk factors. Specimens were classified into four categories according to the criteria reported by the American Heart Association after histometric measurement at defined sites of the aortas. Intimal lesions progressed in the same fashion in all the risk factor groups examined; normal intima converted to fatty streak, preatheroma (characterized by microscopic extracellular lipid deposition) and then atheroma. This progression of intimal lesions correlated with age-related increases in intimal thickness independent of risk factors. Although the frequency of fatty streaks and the population of foam cells were greater in the hypercholesterolemics than in the non-risk patients, the frequencies of preatheroma and atheroma were not different between these two patient groups until patients reached the fifth decade. In contrast, the frequencies of preatheroma and atheroma were consistently greater in the hypertensives than in the other groups by the fifth decade. Hypertension was also related to intimal thickness in the younger groups. Our findings suggest that hypertension and hypercholesterolemia affect the progression of atherosclerosis differently by histopathologic stages.

Pathophysiology and inflammatory aspects of plaque rupture

Atherosclerotic plaque disruption with superimposed thrombosis is the main cause of acute coronary events. At present it is not known specifically how various risk factors influence the development and configuration of coronary plaques. The risk of plaque disruption depends more on plaque composition and vulnerability (plaque type) than on the degree of stenosis (plaque size). Lipid accumulation and chronic inflammation, particularly macrophage activities, seem to influence the development and the stability of a plaque and thus its propensity to rupture. Macrophages have the ability to secrete proteolytic enzymes and often infiltrate the region of imminent plaque rupture, and disruption may be associated with a generalized inflammatory reaction. Further, plaque disruption tends to occur at points where the plaque surface is weakest, corresponding to locations where mechanical and hemodynamic forces have their highest impact. The risk of plaque disruption is a function of both plaque vulnerability (intrinsic disease) and rupture triggers (extrinsic forces). The former predisposes the plaque to rupture; the latter may precipitate rupture. The danger of vulnerable plaques, however, is not related to disruption as such but to the resulting thrombosis. The magnitude of this thrombotic response and the ensuing flow obstruction depends on the contents and quantity of exposed thrombogenic plaque material, the degree of pre-existing stenosis, and the systemic thrombotic tendency. The thrombotic response is a dynamic process that is decisive for the clinical presentation and the outcome.

Predictors of myocardial lesions in men with minimal coronary atherosclerosis at autopsy. The Honolulu heart program

Some cardiovascular risk factors are associated with clinical coronary heart disease but not with autopsy evidence of coronary atherosclerosis. To determine whether these risk factors might operate through mechanisms other than atherosclerosis, we examined associations between cardiovascular risk factors and subsequent intramural myocardial lesions assessed by protocol autopsy between 1965 and 1984 in 120 Japanese-American men from the Honolulu Heart Program who had minimal coronary atherosclerosis (American Heart Association (AHA) panel score < 3 on scale of 1 to 7). Age-adjusted prevalence of myocardial lesions was related to smoking status (P < 0.01), as well as amount, duration, and pack-years of smoking (P < 0.03). In a multiple logistic model, smoking (20 pack-years) was directly associated and fish intake (> or = 2 times/wk) was inversely associated with myocardial lesions independently of age, cholesterol, systolic blood pressure, body mass index, alcohol, diabetes, total calories, and animal protein intake (odds ratio (OR) = 1.5, 95% confidence intervals (CI) = 1.1 to 2.0 and OR = 0.35, 95% CI = 0.2 to 0.9, respectively). The protective effect of fish intake was most evident among men who did not have hypertension at baseline. Indices of obesity, body fat distribution, and physical activity and levels of triglyceride and alcohol intake were not associated with myocardial lesions. Thus, the adverse effects of smoking and the protective effects of fish consumption may extend to individuals relatively free of coronary atherosclerosis, possibly through hemostatic mechanisms or effects on small intramural arteries.

Impaired hyperemic response of brachial artery with the presence of diabetes mellitus in patients with coronary artery disease: a preliminary study

Microvascular reactivity was assessed in reactive hyperemic response of brachial artery in 10 patients with non-insulin-dependent diabetes mellitus and 34 non-diabetic patients. Each subject was diagnosed clinically as having angina pectoris and was examined by coronary angiography. Brachial arterial flow was determined by a pulsed Doppler velocity measurement, guided by a high-resolution B-mode imaging of the forearm. Peak systolic velocity at the basal state in diabetic and non-diabetic patients was comparable (0.53 +/- 0.03 versus 0.61 +/- 0.04 m/s, respectively; P = NS). The velocity ratio of the peak systolic flow at the basal state to the maximum velocity during hyperemia of 2 min arterial occlusion tended to be less in diabetic than in non-diabetic patients (1.76 +/- 0.14 versus 2.15 +/- 0.13, respectively; P = NS). The duration of hyperemic flow was less in diabetic than in non-diabetic patients (6.7 +/- 0.7 versus 9.9 +/- 0.6 s, respectively; P < 0.02). Such alterations in reactive hyperemia may be relevant to the microvascular disorder of the peripheral vessel in the presence of diabetes mellitus.

Black-white differences in subclinical cardiovascular disease among older adults: the Cardiovascular Health Study. CHS Collaborative Research Group

Cardiovascular and all-cause mortality are higher in black than white Americans, but racial differences in clinical and subclinical cardiovascular disease (CVD) have not been examined in older adults. Clinical and subclinical CVD and its risk factors were compared in 4926 white and 244 black men and women aged 65 years and older. Black participants had lower socioeconomic status and generally higher prevalences of CVD and its risk factors, except for adverse lipid profiles. Common carotid wall thickness was greater in black than white women, and ankle-arm blood pressure ratios were lower in black women and men (p < 0.01). After adjustment for CVD risk factors, common carotid walls were significantly thicker and ankle-arm ratios were lower in blacks than whites of both sexes, while internal carotid walls were significantly thinner in black women. Racial differences in clinical and subclinical CVD in older adults are similar to those reported in younger populations and do not appear to be explained by CVD risk factors.

Body fat distribution in the Finnish population: environmental determinants and predictive power for cardiovascular risk factor levels

STUDY OBJECTIVE

The aim was to examine (1) whether health habits are associated with body fat distribution, as measured by the waist/hip girth ratio, and (2) to what extent environmental factors, including anthropometric characteristics, explain the variability in levels of cardiovascular risk factors.

DESIGN

The study was a population based cross sectional survey, conducted in the spring of 1987 as a part of an international research project on cardiovascular epidemiology.

SETTING

The survey was conducted in three geographical areas of eastern and south western Finland.

SUBJECTS

2526 men and 2756 women aged 25-64 years took part in the study, corresponding to a survey participation rate of 82%.

MEASUREMENTS AND MAIN RESULTS

In men, waist/hip ratio showed stronger associations with exercise (Pearson's r = -0.24), resting heart rate (r = 0.10), alcohol consumption (r = 0.07), smoking (r = 0.05), and education (r = -0.23) than did body mass index. Jointly, exercise, resting heart rate, alcohol consumption, education, and age explained 18% of variance in male waist/hip ratio, but only 9% of variance in male body mass index. In women, environmental factors were more predictive for body mass index than for waist/hip ratio, with age and education being the strongest determinants. Waist/hip ratio and body mass index were approximately equally strong predictors of cardiovascular risk factor levels. The additional predictive power of waist/hip ratio over and above body mass index was tested in a hierarchical, stepwise regression. In this conservative type of analysis the increase in explained variance uniquely attributable to waist/hip ratio was 2-3% for female and 1-2% for male lipoprotein levels, and less than 0.5% for female and 0-2% for male blood pressure values.

CONCLUSIONS

The distribution of abdominal obesity in Finland is significantly influenced by health habits and sociodemographic factors in both men and women. This in turn is obviously one reason for the relatively small "independent" effect of body fat distribution on cardiovascular risk factor levels.