Changes in low-density lipoprotein cholesterol levels after discharge for acute myocardial infarction in a real-world patient population

Aggressively managing low-density lipoprotein cholesterol (LDL-C) after myocardial infarction (MI) is a cornerstone of secondary prevention. The changes in LDL-C after MI and the factors associated with LDL-C levels are unknown. Therefore, we directly measured fasting LDL-C levels in 797 MI patients from 24 US hospitals from 2005 to 2008. Mean LDL-C levels at discharge, 1 month, and 6 months were 95.1, 81.9, and 87.1 mg/dL, respectively. In a hierarchical, multivariable, repeated measures model, older age, male sex, and hypertension were associated with lower LDL-C levels, whereas self-reported avoidance of health care because of cost was associated with higher LDL-C. Both the presence and intensity of statin therapy at discharge were strongly associated with LDL-C levels, with adjusted mean 6-month changes of -3.4 mg/dL (95% confidence interval (CI): -12.1, 5.3) for no statins; 1.7 mg/dL (95% CI: -4.7, 8.1) for low statins; -10.2 mg/dL (95% CI: -14.5, -6.0) for moderate statins; and -13.9 mg/dL (95% CI: -19.7, -8.0) for intensive statins (P < 0.001). In conclusion, we found that greater reductions in LDL-C levels after MI were strongly associated with the presence and intensity of statin therapy, older age, male sex, hypertension, and better socioeconomic status. These findings support the use of intensive statin therapy in post-MI patients and provide estimates of the expected LDL-C changes after MI in a real-world population.

Nutritional recommendations for preventing coronary heart disease in women: evidence concerning whole foods and supplements

AIMS

Some food groups and supplements have been recommended for preventing coronary heart disease (CHD) in women. In this article, evidence on recommendations for some of these food groups (whole grains, fruits, vegetables, fish, nuts, and soy) and supplements (phytosterols, antioxidants, folic acid, and B-complex vitamins) is reviewed. Additionally, gender differences in nutritional requirements and recommendations are described.

DATA SYNTHESIS

Studies of nutrition in women and those emphasizing gender differences in nutritional requirements were selected for this review.

CONCLUSION

Observational data support the benefit of vegetables, fruits, and whole grains in CHD prevention. Trial data provide support for consuming fish at least twice a week, although women of childbearing age should limit their intake of fish that may contain high levels of mercury. Nuts are nutritious snacks but their caloric impact must be considered. Soy products do not affect low-density lipoprotein cholesterol (LDL-C) or CHD but may be beneficial in replacing high-fat meat. Foods supplemented with plant stanol/sterol-esters are recommended for reducing LDL-C. Antioxidant supplementation is not recommended for prevention of heart disease. A direct causal relationship between vitamin D deficiency and CHD has not been established. Homocysteine lowering through folic acid and B-complex vitamin supplementation has not been proven to improve CHD risk. More gender-specific analyses are needed to determine whether nutritional requirements differ between men and women.

Can 19-nortestosterone derivatives be aromatized in the liver of adult humans? Are there clinical implications?

CONTEXT

Previous studies in postmenopausal women have demonstrated that, after oral administration of norethisterone, a small proportion of the compound is rapidly converted into ethinylestradiol. The shape of the concentration - time curve suggested that this occurred in the liver. The results were confirmed by in vitro investigations with adult human liver tissue. In 2002, it was shown that, after oral treatment of women with tibolone, aromatization of the compound occurred, resulting in the formation of a potent estrogen, 7 alpha-methyl-ethinylestradiol. The result has been called into question, because the adult human liver does not express cytochrome P450 aromatase, which is encoded by the CYP 19 gene. Moreover, it has been claimed that the serum level of 7 alpha-methyl-ethinylestradiol measured by gas chromatography/mass spectrometry was an artifact.

REPLY

Aromatization of steroids is a complex process of consecutive oxidation reactions which are catalyzed by cytochrome P450 enzymes. The conversion of the natural C19 steroids, testosterone and androstenedione, into estradiol-17beta and estrone is dependent on the oxidative elimination of the angular C19-methyl group. This complex key reaction is catalyzed by the cytochrome P450 aromatase, which is expressed in many tissues of the adult human (e.g. ovary, fat tissue), but not in the liver. However, 19-nortestosterone derivatives are characterized by the lack of the C19-methyl group. Therefore, for the aromatization of these synthetic steroids, the action of the cytochrome P450 aromatase is not necessary and the oxidative introduction of double bonds into the A-ring can be catalyzed by other hepatic cytochrome P450 enzymes. The final key process in the formation of a phenolic A-ring, both in natural androgens and 19-nortestosterone derivatives, is the enolization of a 3-keto group to the C2-C3-enol or the C3-C4-enol moiety, which occurs without the action of enzymes.

CONCLUSION

19-nortestosterone derivatives (norethisterone, norethynodrel, tibolone) can readily be aromatized in the adult human liver. This leads to the formation of the potent estrogens ethinylestradiol from norethisterone or norethynodrel and 7 alpha-methyl-ethinylestradiol from tibolone. This may have clinical consequences, e.g. the elevated risk of venous thromboembolic disease in premenopausal women treated with high doses of norethisterone for bleeding disorders, or the elevated risk of stroke or endometrial disease in postmenopausal women treated with tibolone.

[Medical nutrition prevention and medical nutrition therapy of lipid metabolism disorder]

High energetic density of nutrition, insufficient physical activity and smoking are the most common causes of obesity and lipid metabolism disorders (hyperlipoproteinemia and dyslipoproteinemia). Hyperlipoproteinemia and dislipoproteinemia are mass noncommunicable diseases and at the same time they are main causes of atherosclerotic cardiovascular diseases and cerebrovascular diseases, metabolic syndrome, hepatic diseases and some localization of malignant diseases. Cardiovascular diseases and malignant diseases are the leading causes of mortality in the world. Global Strategy on Diet, Physical Activity and Health Nutrition and The Second European Action Plan for Food and Nutrition Policy represent the World Health Organisation approach in prevention of risks of development, and treatment of mass noncommunicable diseases, first of all for hyperlipoproteinemia, cardiovascular diseases and cerebrovascular diseases. According to the previously mentioned health programmes, medical nutrition therapy of hyperlipoproteinemia and dislipoproteinemia should be applied on whole population and individual level as well. Medical nutrition therapy is managed on individual level. Eminent international organizations, such as the European Society of Atherosclerosis and the American Heart Association, give priority to medical nutrition prevention and medical nutrition therapy in their guides for prevention and therapy of hyperlipoproteinemia, cardiovascular diseases and cerebrovascular diseases.

Study of resveratrol and antioxidant activity in Georgian brand red wines and a number of foreign red wines

Today wine pricing is guided by content of useful substances such as resveratrol and catechines. Resveratrol [3,4',5-trihydroxystilbene (RESV)] is a compound found in the skin of red grapes and is a constituent of red wine. Clinical investigation demonstrated that resveratrol lowers the levels of catecholamines, inhibits lipid peroxidation of low-density lipoprotein; it has anti-inflammatory, antioxidant activity etc. In Georgia the highest concentration of resveratrol has been reported in wines prepared from Saperavi grapes. Resveratrol contents and antioxidant activity of Georgian brand red wines made from Saperavi grape variety and of foreign red wines available on Georgian market were assessed and compared. It was found that resveratrol content distinguishes foreign wines, particularly the French wine from the Georgian brand red wines. The research showed that resveratrol content is higher in non-brand Kakhetian style Saperavi (6.24 mg/ml) than in European or other Georgian brand wines. Proportion of trans-resveratrol is higher in "Saperavi" by "Badagoni" (94.5%), French wine (93.83%) and Saperavi by "TbilGhvino" (93.49%). Given that trans-resveratrol is characterized by higher biological activity and medical importance than cis-resveratrol, their proportion may be an important criterion to measure healing properties of wine. In terms of antioxidant activity, Georgian wines are like foreign wines. It is concluded that Georgian brand wines with few exceptions are behind the foreign wines in several parameters. Since polyphenolic substances define wine price through their positive effects on human health, more detailed studies on polyphenolic content of Georgian wines are needed.

Treatment of diabetic dyslipoproteinemia

Diabetes mellitus, specifically type 2, is often associated with disorders in lipid metabolism. Elevated levels of plasma free fatty acids play a pivotal role by contributing significantly to insulin resistance. In addition free fatty acids promote diabetic dyslipidemia through increasing VLDL synthesis in the liver, and by virtue of cholesterylester transfer protein, modifying LDL to increase small-dense LDL subfractions and to decrease HDL cholesterol. This atherogenic lipoprotein profile (elevated triglycerides, increased small-dense low-density lipoproteins, and decreased high-density lipoproteins), contributes to the development of atherosclerosis and increases the risk of experiencing cardiovascular events, the most common cause of death in type 2 diabetes. To decrease the risk of cardiovascular disease events in diabetics, dyslipidemia needs to be treated, as evidenced from epidemiology, from intervention trials, and from subgroup analyses of large intervention trials initiated to evaluate effects of lipid lowering treatment that also included patients with type 2 diabetes. Most measures used to counteract hyperglycemia, are also prone to ameliorate dyslipidemia: dietary intervention (medical nutrition) including omega-3 fatty acids as part of lifestyle changes that also comprise cessation of smoking, increases in physical activity and reduction in body weight. In addition insulin, biguanides, acarbose and glitazones applied for glycemic control also improve diabetic dyslipidemia. Additional pharmacological treatment of dyslipidemia if persisting after glycemic control relies on different drug classes. Fibrates effectively reduce free fatty acids, fasting and postprandial lipemia, shift the distribution of LDL particles towards less dense subfractions and increase HDL cholesterol, thus particularly addressing key components of diabetic dyslipidemia. For LDL cholesterol lowering statins are mainly used that decrease LDL cholesterol levels by competitive inhibition of the HMG-CoA reductase. As type 2 diabetes is found to be associated with a two- to fourfold increase in coronary heart disease risk and as the degree of glycemia is more related to microvascular complications, correcting dyslipidemia appears to be a major task in order to reduce macrovascular events in patients with type 2 diabetes.

Preventive effects of a verapamil against tumor necrosis factor-alpha-induced shock symptoms: approached from lipoprotein metabolic disorders

We examined the role of intracellular Ca2+ in the mechanism of the preventive effects of the Ca2+-channel blocker verapamil against lipoprotein disturbances during tumor necrosis factor (TNFa)-induced shock syndrome. The heparin-releasable lipoprotein lipase (LPL) activity in plasma of TNFalpha (5 X 10(4) units/mouse, i.v.)-injected mice was markedly lower at 4 h post-intoxication than in the controls. In mice treated with verapamil (10 mg/kg, s.c.), the activity of LPL 4 h after TNFalpha injection was significantly higher than in mice treated with TNFalpha alone. On the other hand, on polyacrylamide gel disk electrophoresis, very low density lipoprotein (VLDL) and high density lipoprotein (HDL) fractions in the sera of TNFalpha-injected mice were increased and reduced, respectively, relative to the controls. The administration of verapamil clearly prevented the lipoprotein damage arising from TNFalpha challenge. We investigated whether verapamil could suppress TNFalpha generation in endotoxin-treated J774A.1 cells. Treatment with verapamil (30 microM) markedly inhibited endotoxin (1 microg/ml)-induced TNFalpha production in these cells. These findings suggest that the concentration of intracellular Ca2+ may contribute to the extent of lipoprotein disturbances in plasma, which results from LPL suppression in TNFalpha-induced shock syndrome. Verapamil may, therefore, protect against some of the various disturbances caused by changes in Ca2+ mobilization through its ability to inhibit TNFalpha production in septic shock.

Physical activity for preventing and treating obesity-related dyslipoproteinemias

PURPOSE

The clinical trial data were reviewed on effects of physical activity on obesity-related dyslipoproteinemias (specifically low HDL-cholesterol (HDL-C), elevated triglycerides (TG), and high total and LDL-cholesterol (TC and LDL-C)) in adult men and women.

METHODS

Effort was made to identify all randomized clinical trials (RCT), with exercise intervention programs of at least 4 months' duration, which had lipoprotein outcomes. Those that had both an exercise only intervention and control groups or both a diet plus exercise and identical diet only intervention groups were reviewed. Tables were developed of baseline characteristics and weight and lipoprotein changes for aerobic exercise trials by body mass index: 1) < 25.0 kg x m(-2), 2) 25.0-29.9 kg x m(2), and 3) > or = 30.0 kg x m(-2)and for studies involving resistance exercise or increased energy expenditure from daily activities versus structured exercise programs.

RESULTS

Very few RCT were found that specifically addressed the role of physical activity in preventing or treating obesity-related adverse lipoprotein levels. There was essentially no evidence found in lean or overweight men or women to support a specific role for exercise in improving undesirable lipoprotein levels; however, trial data strongly suggest that the addition of exercise to a hypocaloric, reduced-fat diet improves HDL-C and TG in men and women with generally desirable initial levels and reduces LDL-C in men and women with initially elevated LDL-C levels. The evidence is also reasonably strong that weight loss, including that achieved solely by exercise, improves HDL-C and TG in obese men, without reducing LDL-C, whereas it remains weak for women. There are also virtually no trial data to support a role for resistance exercise or an increase in daily living activities for improving obesity-related lipoproteins.

CONCLUSIONS

Current evidence from RCT is too limited to determine whether physical activity can raise low HDL-C or lower high TG or LDL-C levels in overweight and obese individuals.

Postprandial lipemia: emerging evidence for atherogenicity of remnant lipoproteins

Patients with coronary artery disease (CAD) often have increased postprandial triglyceride levels compared with healthy control subjects, and it has been demonstrated that plasma triglyceride concentration in the fed state is an independent predictor of CAD. Increased postprandial triglyceridemia is strongly associated with a constellation of potentially atherogenic and thrombogenic lipoprotein changes, including a) increase in the plasma concentration of intestinally derived chylomicrons and their remnants; b) increase in the level of hepatic very low density lipoproteins and their remnants; c) decrease in level of high density lipoprotein (HDL) cholesterol because of increase in cholesteryl transfer from HDL to postprandial triglyceride-rich lipoproteins (TRL); d) decrease in low density lipoprotein (LDL) size, associated with increased susceptibility of LDL to oxidation; and e) increase in the association of lipoprotein (a) with TRL. Postprandial TRL are potentially thrombogenic because they are associated with increased activated factor VII activity (a procoagulant effect) and increased levels of plasminogen activator inhibitor-1 (an antifibrinolytic effect). Experimental results and clinical trial data suggest that plasma accumulation of remnant lipoproteins (in the fed or fasted state) is not just an associated feature of an atherogenic lipoprotein profile but that TRL remnants themselves contribute to the pathogenesis of atherosclerosis. Diet and/or drug treatments that lower the level of TRL in the fasted state also tend to have a beneficial effect on postprandial lipoprotein levels. Thus, aerobic exercise, weight reduction and triglyceride-lowering medications all reduce postprandial triglyceridemia and have the potential to reduce the level of atherogenic remnant lipoproteins.

Exercise in the management of non-insulin-dependent diabetes mellitus

The incidence of non-insulin-dependent diabetes mellitus (NIDDM) has increased worldwide during the last decades, despite the development of effective drug therapy and improved clinical diagnoses. NIDDM is one of the major causes of disability and death due to the complications accompanying this disease. For the well-being of the patient, and from a public healthcare perspective, the development of effective intervention strategies is essential in order to reduce the incidence of NIDDM and its resulting complications. For the patient, and for society at large, early intervention programmes are beneficial, especially from a cost-benefit perspective. Physical activity exerts pronounced effects on substrate utilisation and insulin sensitivity, which in turn potentially lowers blood glucose and lipid levels. Exercise training also improves many other physiological and metabolic abnormalities that are associated with NIDDM such as lowering body fat, reducing blood pressure and normalising dyslipoproteinaemia. Clearly, regular physical activity plays an important role in the prevention and treatment of NIDDM. Since physical activity has been shown in prospective studies to protect against the development of NIDDM, physical training programmes suitable for individuals at risk for NIDDM should be incorporated into the medical care system to a greater extent. One general determinant in a strategy to develop a preventive programme for NIDDM is to establish a testing programme which includes VO2max determinations for individuals who are at risk of developing NIDDM. Before initiating regular physical training for people with NIDDM, a complete physical examination aimed at identifying any long term complications of diabetes is recommended. All individuals above the age of 35 years should perform an exercise stress test before engaging in an exercise programme which includes moderate to vigorously intense exercise. The stress test will identify individuals with previously undiagnosed ischaemic heart disease and abnormal blood pressure responses. It is important to diagnose proliferative retinopathy, microalbuminuria, peripheral and/or autonomic neuropathy in patients with NIDDM before they participate in an exercise programme. If any diabetic complications are present, the exercise protocol should be modified accordingly. The exercise programme should consist of moderate intensity aerobic exercise. Resistance training and high intensity exercises should only be performed by individuals without proliferative retinopathy or hypertension. Once enrolled in the exercise programme, the patient must be educated with regard to proper footwear and daily foot inspections. Fluid intake is of great importance when exercising for prolonged periods or in warm and humid environments. With the proper motivation and medical supervision, people with NIDDM can enjoy regular physical exercise as a means of enhancing metabolic control and improving insulin sensitivity.

[Dietary intake and hyperlipoproteinemias]

The role of nutrition on the prevalence of cardiovascular diseases is largely, but not exclusively linked to the effect of dietary intake on plasma lipids and lipoproteins. Among the regular nutrients, saturated fats, and to a lesser extent cholesterol, do raise plasma cholesterol, namely in the LDL fraction. Classical recommendations consist of reducing dietary lipids to < or = 30% and saturated fats to < or = 10% of total caloric intake. However, recent findings demonstrate that not all saturated fatty acids are exerting a similar effect on cholesterol metabolism. Likewise, whether saturated fatty acids should be most appropriately replaced by carbohydrates or monounsaturated lipids is a matter of controversy, especially when managing patients with high plasma triglycerides and/or insulin resistance. In contrast, there is currently some agreement for limiting the intake of polyunsaturated fatty acids; and for considering separately the essential n-6 or omega 6 fatty acids (largely present in many vegetable oils) and the n-3 or omega 3 derivatives (present in algae and fish oils). This leads to evaluate other properties of fatty acids (and of other dietary components) such as the capacity to modulate inflammatory responses and thrombotic reactions, as well as to influence cell sensitivity to stimuli, cell to cell communication, and cell proliferation. Finally, the confirmation that peroxidative processes are playing an important role in lipoprotein metabolism and the development of atherosclerotic lesions largely explains the present interest to antioxidants.

Is cholesterol the major lipoprotein risk factor in coronary heart disease?--a Franco-Scottish overview

There has been much debate over the past three decades concerning the role of hyperlipidaemia in coronary heart disease (CHD) and the efficacy of reducing plasma lipids levels. Although reduction in plasma cholesterol has been associated with a favourable effect on both primary and secondary CHD, there is a growing feeling that cholesterol may not be the only significant lipoprotein risk factor to be involved. Only relatively recently has the true role of triglycerides become apparent. Studies have indicated that the greatest reduction in CHD with some treatments has been found in those patients in whom high triglyceride levels accompany hypercholesterolaemia. In particular, in younger patients who have suffered a myocardial infarction, hypertriglyceridaemia is more common than hypercholesterolaemia. Nevertheless, recent large studies have shown that reduction of low-density lipoprotein (LDL) is beneficial, even in post-infarction patients with a relatively normal total cholesterol level. Furthermore, studies with fibrates and with HMG Co-A reductase inhibitors have indicated that progression of atheromatous lesions can be halted and in may cases there is evidence of regression. Continuing research on the pathophysiology of atherosclerosis, including the role of macrophages and thrombotic involvement, will further define the role of hypolipidaemics in the prevention and management of coronary heart disease.

Hyperlipoproteinemic states and ischemic heart disease

Ischemic heart disease and contributing risk factors such as the hyperlipoproteinemic states affect a great percentage of the general population. Because these disease processes can effectively place patients at risk for a life-threatening event, every health care provider must be knowledgeable, disciplined to take a thorough medical history, and prepared for emergency situations that may arise in the clinical practice of dentistry. A proactive approach to identification of risk factors and to primary prevention of ischemic heart disease not only helps to lengthen and improve the quality of patient's lives, but also ensures that necessary modifications of treatment reflect each patient's medical and pharmacologic status.

[Marine fish oil in the prevention and treatment of cardiovascular diseases]

Diets containing different ratios of omega 6: omega 3- polyunsaturated fatty acids (PUFA) were studied for their hypolipidemic, antiatherogenic, thrombolytic, and antihypertensive effects in 448 patients with coronary heart disease, familial hyperlipoproteinemia, essential hypertension. Optimizing the omega 6: omega 3-PUFA ratios in the antiatherosclerotic diet of patients with cardiovascular diseases during inpatient course treatment was found to promote the formation of combined therapeutical effects of a diet. This is caused by changes in the fatty acid composition of cytomembranes and, apparently by lipid-protein interactions that affect the activity of a complex of lipolytic membrane-binding enzymes of different types of cells.

Clustering of cardiovascular risk factors: targeting high-risk individuals

Cardiovascular risk factors have traditionally been divided into 2 categories: modifiable risk factors (smoking, hypertension, elevated cholesterol, reduced high density lipoprotein cholesterol, and diabetes), and nonmodifiable risk factors (age, gender, and hereditary factors). However, more recent data indicate clustering of several metabolic and familial factors that are often related to each other. A pattern of lipoprotein abnormalities characterized by increased hepatic production of apolipoprotein B-containing lipoprotein particles, high blood pressure, visceral obesity, and peripheral insulin resistance are identified with increasing frequency in subjects with premature coronary artery disease (CAD). The metabolic substrates for many such disorders are being uncovered, and genetic analysis of affected kindred have, often with conflicting results, suggested associations with candidate genes. In the context of a multifactorial approach, aggressive treatment of lipoprotein disorders in high-risk individuals, or in the secondary prevention of cardiovascular diseases, has resulted in a decreased rate of progression of CAD and a marked reduction in clinical events. Further work in the field of hemostatic factors has shown that fibrinogen, activated coagulation factor VII, spontaneous platelet aggregation, and elevated levels of plasminogen activator inhibitor-1 (PAI-1), are all associated with CAD. There is a strong association between lipids (especially triglyceride-rich lipoproteins) and fibrinogen, PAI-1, and activation of factor VII. In addition, vascular function, especially endothelial cell physiology, has been shown to be compromised in the presence of multiple risk factors and to be improved with intensive therapy aimed at reducing risk factors, especially plasma lipoprotein levels. The implications for clinical practice are important. In the primary prevention of cardiovascular disease, proper risk stratification must be carried out with specific attention given to lifestyle changes. Cessation of smoking and changes in diet (both qualitative and quantitative), exercise, and serenity are often required. In the prevention of cardiovascular disease in subjects at high risk, or in the secondary prevention of CAD, a clear justification exists for aggressive lifestyle changes, often coupled with lipid-lowering therapy and adequate blood pressure control. Basic research is providing us with a better understanding of the molecular interactions between lipoproteins and hemostatic factors. It is becoming increasingly necessary to develop novel pharmaceutical agents with the combined ability to reduce atherogenic lipoprotein levels while also reducing susceptibility to thrombosis.

Dyslipoproteinemia in women and the elderly

Major risk factors predict coronary risk in both women and men. It is inadvisable and unwarranted to suggest that women be excluded from cholesterol screening. In fact, what evidence is available suggests that women, similar to men, benefit from cholesterol lowering. This is not an insignificant issue. Women, similar to men, die mostly of coronary atherosclerosis, although atherosclerotic death in women occurs 5 to 10 years later than in men. There are some risk factors that are unique in women. LDL-c levels may be less predictive of risk in women than in men; HDL-c levels may be more predictive. Triglycerides are a stronger predictor of risk in women than in men. Finally, diabetes is a major risk factor in women and almost eliminates the differences in risk seen in comparing nondiabetic men and women. Exogenous gonadal hormones, both in the form of OCs and HRT, have the potential to influence coronary risk in women. In premenopausal women, use of OCs is associated with increased risk of coronary disease in women who smoke, particularly in women older than age 35. In postmenopausal women, estrogen use is generally associated with protection against coronary disease. These results may be in part due to favorable effects on circulating lipoproteins but may as well be related to the protective effects of estrogen on the arterial wall. Definitive recommendations about the use of estrogen in postmenopausal women for the primary prevention of coronary disease await the completion of clinical trials of estrogen alone and in combination with progestins. Cholesterol and its lipoprotein subfractions continue to be predictors of both morbidity and mortality in older populations. The value of cholesterol-altering therapy in older individuals is not as well established in clinical trials as in middle-aged men. Nevertheless, there is good reason to believe that the results from both primary and secondary prevention studies in younger individuals can readily be extrapolated to older individuals. In particular, individuals with symptomatic coronary disease but a relatively good prognosis should be offered the same benefits from secondary prevention as younger individuals. Thus, although data are more limited in women and the elderly than in middle-aged men, there is good reason to believe that cholesterol interventions are likely to be effective, particularly in postmenopausal women and in older individuals with established coronary disease. To withhold therapy based simply on gender or chronologic age is a mistake.

Hyperlipidemia in children

Advances toward improving cardiovascular health of tomorrow's adults lie both in acknowledging that the pathogenesis of atherosclerosis begins in childhood and in considering the influence of environmental factors on genetic endowment of risk. Based on current understanding of lipoprotein transport processes, an array of genetic disorders with various degrees of atherogenicity can be classified according to the predominant lipoprotein density class, as represented by a standard lipid profile, and then further defined by assaying apolipoproteins and their receptors, lipoprotein transport enzymes, or the respective variant genes. Alternatively, a simple and potentially cost-effective representation of multifactorial influences on lipid transport is provided by an assessment of apolipoprotein particle composition using serial immunologic precipitation of apolipoproteins while on their intact plasma lipoproteins. A comprehensive intervention strategy can be based on identification of inherited risk and the effects of nongenetic factors, which include dietary excess, inactivity, disease states, and medications.

Effect of pravastatin, a HMG CoA reductase inhibitor, on blood lipids and aortic lipidosis in cholesterol-fed White Carneau pigeons

The effect of pravastatin, an inhibitor of HMG CoA reductase, on blood lipids and aortic lipidosis was studied in young cholesterol-fed White Carneau pigeons. The birds were fed with normal ('N group', n = 20) or atherogenic diet (grains + 0.4% cholesterol + 4% lard) alone ('C group', n = 20) and in association with pravastatin ('P group', n = 20). Plasma lipids and aortic intima lipidosis were studied after 3-5 and 8-12 months of the diet. Compared to the N group, pigeons from C group exhibited hypercholesterolemia (TC = 1000 mg/dl) and hyperlipoproteinemia of which level was independent of the duration of the diet. Total VLDL (VLDL+LDL)-cholesterol and apolipoprotein-B levels rose significantly 15, 8 and 4 times, respectively, whereas HDL were increased two times (P < 0.01) in females only. Macroscopically visible intima lipidosis areas covered 40% and 80% of aortic surface after 3-5 and 8-12 months of the diet. In P group, the increase in plasma lipid values was significantly lower than in WC from C group: -40% for total cholesterol (600 mg/dl) (P < 0.01), -71% for VLDL (P < 0.001), -53% for (VLDL+LDL)-cholesterol (P < 0.01) and -54% for apo-B (P < 0.05). HDL remained as high as in C group. Consequently TC/HDL-C ratio was improved and atherogenic risk of cholesterol was reduced by 41% (P < 0.05). Intima lipidosis areas were lowered by 35% (P < 0.01). We conclude that pravastatin treatment involves (1) a decrease in hypercholesterolemia and hyperlipoproteinemia and (2) a lowering in extensiveness and severity of macroscopically visible aortic lipidosis in cholesterol-fed White Carneau pigeon.

[Modern diet for patients with hyperlipoproteinemia]

Diet is fundamental in the treatment of primary hyperlipoproteinaemias. The author outlines nutritional factors affecting serum lipoproteins. In the treatment of hypercholesterolaemia the most effective is the reduction of the intake of saturated fatty acids, it being twice as effective as the reduction of dietary cholesterol, which is necessary as well. The proportion of the saturated, poly- and monounsaturated fatty acids is recommended to be 10-10-10 percent of the overall calorie intake. Such a composition of diet has no disadvantageous effect on the level of HDL cholesterol. Of carbohydrates the consumption of sugar and alcohol should be limited in the presence of hypertriglyceridaemia and/or obesity. Water soluble dietary fibres may have a cholesterol-lowering effect. The reduction of overall calorie intake is indispensable in hyperlipoproteinaemias with obesity. As a result of the diet a 10-20 percent decrease in the level of cholesterol and--in some cases--the normalization of hypertriglyceridaemia can be expected.

[Pathophysiologic principles of metabolic syndrome. Consequences for early diagnosis and prevention]

The metabolic syndrome (syndrome X) is characterised by an association of elevated insulin levels, a tendency to obesity of the android type, a disturbance of lipid metabolism with elevated triglyceride levels and commonly associated hypertension. The underlying common cause of this syndrome appears to be insulin resistance of the skeletal muscles, which is related in particular to the non-oxidative glucose utilization on the part of the muscle. The molecular cause of this syndrome has not been clarified, but a defect in the signal transduction chain between the insulin receptor and glycogen synthase is suspected. Epidemiological studies have shown that the metabolic syndrome may be considered a preliminary stage of manifest type II diabetes. In addition, it appears to play a major role in the development of cardiovascular complications in certain high-risk groups.

Plasma lipid and lipoprotein disorders in IDDM

Abnormal lipoprotein metabolism contributes to the increased risk of premature atherosclerosis in people with insulin-dependent (type I) diabetes. Although hypertriglyceridemia is common in those with untreated IDDM, treatment with conventional insulin therapy usually restores fasting lipoprotein profiles to nondiabetic levels. Intensive insulin therapy improves glycemic control and lipoprotein concentrations, but does not ameliorate the changes in lipoprotein composition described in people with IDDM. Some of these persistent changes in lipoprotein composition have been attributed to peripheral hyperinsulinemia associated with s.c. insulin therapy. The recent availability of implantable insulin-infusion pumps for treatment of IDDM has allowed the study of the effect of i.p. insulin delivery on lipoprotein metabolism. i.p. insulin therapy is capable of maintaining near normal plasma glucose levels while reducing the peripheral hyperinsulinemia. Although results have been contradictory, studies of i.p. insulin therapy may eventually help to determine whether some of the observed changes in lipoprotein metabolism and composition in people with IDDM are due to the peripheral hyperinsulinemia associated with s.c. insulin therapy.

Lp(a): a link between thrombosis and atherosclerosis

Lipoprotein(a), or Lp(a), is a lipoprotein having lipid composition similar to that of LDL, but a protein moiety consisting of ApoB 100 linked by disulfide bridge to apo(a), a glycoprotein with structural similarity to plasminogen. Lp(a) can be both atherogenic and thrombogenic. These two actions are likely to be mutually operative, a fact that on a molar basis makes Lp(a) more of a cardiovascular pathogen than LDL.

[The atherosclerosis problem in infancy. Some considerations]

The problem of some aspects of infantile atherosclerosis is examined synthetically (period of onset, classification of hyperdyslipidemia, lipidic fractions, threshold values, variations with age) and prevention examined at length. In particular, stress is laid on a "mixed" mass screening method to prevent many subjects being untouched by targeted screening investigation.

Hyperlipoproteinemias: Part II. Screening and patient classification

The National Cholesterol Education Program recommends measuring the total nonfasting serum cholesterol in all individuals 20 years of age or older. By definition, a desirable level is less than 200 mg/dL, borderline-high is 200-239 mg/dL, and high is greater than or equal to 240 mg/dl. Subsequent classification is based on the LDL-cholesterol level with a value of less than 130 mg/dL considered to be desirable. The appropriate approach to screening for hypercholesterolemia in children and the elderly is debated and awaits definitive recommendations.

Screening, diagnosis, and management of dyslipoproteinemia in children

The authors provide an extensive and comprehensive review of dyslipoproteinemia in children. An effective program for CVD reduction in this population will include an accessible screening program to identify high-risk children, high-quality measurements of TC and LP-C, careful follow-up of screening results with multiple measurement to classify risk status and diagnose primary dyslipidemia, a key role for family and education, and consistent and long-term follow-up for diet and drug adherence, efficacy, and safety.

[Inhibitors of protein biosynthesis and development of dyslipoproteinemia in rabbits]

Acute alimentary hypercholesterolemia, developing after a single load with cholesterol, and experimental atherosclerosis, caused by long-term loading with cholesterol, were studied in young rabbits. Olivomycin, administered simultaneously with long-term cholesterol loading, and streptomycin, injected within 3 days before cholesterol loading, were used as inhibitors. These antibiotics prevented hypercholesterolemia, hyperlipoproteinemia and atherosclerosis development. The data obtained suggest that the drugs used inhibited development of atherosclerosis via selective blockade of apoB proteins synthesis in liver and intestinal tissues of the experimental animals.

Parental history of cardiovascular disease as an indication for screening for lipoprotein abnormalities in children

We studied the relationship between parental history of cardiovascular disease and risk for adverse lipid and lipoprotein levels in a total community study of 3313 children (ages 4 to 17 years, 63% white, 37% black). Older white children (11 to 17 years) with a parental history of heart attack or diabetes were 4.3 and 5.6 times, respectively, more likely to have high levels (greater than or equal to 95th percentile) of serum total cholesterol than those without such a history (all p less than 0.05). White children with a parental history of heart attack or diabetes were twice as likely to have an elevated (greater than or equal to 95th percentile) low-density lipoprotein cholesterol (LDL-C) level than those without such a history (both p less than 0.05). In contrast, parental history of cardiovascular disease did not predict elevated levels of total cholesterol or LDL-C in black children. However, older black children with a parental history of heart attack, hypertension, or diabetes were 4 1/2 to 5 times more likely to have low levels (less than or equal to 5th percentile) of high-density lipoprotein cholesterol than those without such a history (all p less than 0.05). Only 40% of white children and 21% of black children with elevated LDL-C levels had a parental history of vascular disease. These findings raise questions about the current practice of screening only children with a family history of cardiovascular disease to identify those with elevated total cholesterol and LDL-C levels.

Helsinki Heart Study. New perspectives in the prevention of coronary heart disease

The Helsinki Heart Study tested the effect of modifying plasma low density lipoprotein (LDL)- and high density lipoprotein (HDL)-cholesterol on the primary prevention of coronary heart disease in middle-aged men with non-HDL-cholesterol greater than or equal to 5.2 mmol/L (200 mg/dl). One group (2046 men) received 600mg of gemfibrozil twice daily, and the other (2035 men) received placebo. Averaged over the 5-year trial period, gemfibrozil induced mean decreases of 11% in LDL-cholesterol and 35% in triglycerides and a mean increase of 11% in HDL-cholesterol compared with placebo. These changes were accompanied by a 34% reduction (number of end-points; 56 vs 84) in the incidence of coronary heart disease. The reduction was largest in subjects with type IIB hyperlipoproteinaemia and smallest in subjects with type IIA hyperlipoproteinaemia. The changes in serum HDL- and LDL-cholesterol during the trial were associated (p less than 0.02 and p less than 0.05, respectively) with the risk of coronary heart disease in the gemfibrozil group, but not in the placebo group.

Hyperlipoproteinemia, atherosclerosis risk, and dietary management

There is new impetus for dietary intervention in response to the recent data relating levels of circulating lipids and lipoproteins to atherosclerosis risk. Certain levels of cholesterol, stratified for age and sex, are associated with "moderate" and "high" risk of atherosclerosis. Knowing the relationship of diet to lipid levels and lipid transport by the various lipoproteins enables the appropriate diagnosis and management. Dietary measures include attention to the level of calories and fat, the type of fat, cholesterol content, source of protein, the type of carbohydrate and fiber, and the level of alcohol intake. Lipid (cholesterol) screening at intervals is recommended for all adults and for children at special risk of hyperlipidemia.

[Prevention of stress dyslipidemia by adapting animals to the periodic action of hypoxia]

Emotional-painful stress in rats results in the increase of atherogenic and decrease of antiatherogenic lipoprotein fractions. Adaptation of animals to periodic intermittent hypoxia significantly enhanced the proportion of antiatherogenic lipoproteins in the blood and reduced the degree of post-stress dyslipidemia.

Frequency and clustering of nonlipid coronary risk factors in dyslipoproteinemia. The Lipid Research Clinics Program Prevalence Study

In a defined population of 4349 men and 3398 women, we evaluated the frequency and clustering of five nonlipid coronary heart disease risk factors--obesity, hypertension, sedentary lifestyle, cigarette smoking, and alcohol consumption--in nine categorical lipoprotein phenotypes--normal, types I or V, IIA, IIB, III, IV, hypoHDL (high-density lipoprotein), hypoLDL (low-density lipoprotein), and hyperHDL. This analysis indicated that compared with the normal phenotype, nonlipid coronary risk factors tend to be more frequent and thus cluster in individuals with "high risk" phenotypes, and occur somewhat less frequently in those with "low risk" phenotypes. Thus, identification of a high-risk phenotype suggests the presence of nonlipid risk factors as well, and the clinician should be alert to this possibility. A multivariable analysis of the independent associations of each of the risk factors with the lipid and lipoprotein components that define the phenotypes suggested that several behavioral risk factors may directly affect lipid and lipoprotein levels. This observation raises the possibility that certain intervention strategies, such as weight loss, smoking cessation, and regular exercise, may favorably influence dyslipoproteinemia.

[Hypertriglyceridemia in intravenous hyperalimentation with glucose. Observations on patients treated with cyclosporin-A following bone marrow transplantation]

The authors report marked hypertriglyceridaemia with peak values of up to 14 mmol/l in patients who have undergone bone marrow transplantation (BMT) and who are receiving 925 g/d glucose and 70 g/d crystalline amino acids for parenteral nutrition. Larger doses of insulin lead to only slightly better control of mean blood glucose level and to a clearly less marked increase in triglycerides (TG) in a series of patients otherwise treated identically. Only a slight increase in serum TG was seen in BMT patients receiving 325 g glucose per day. There was no increase in serum TG to values above normal in a small group of surgical patients receiving 700-900 g glucose/d and high doses of insulin. Peripheral insulin resistance is presumed to be the pathogenetic factor in this hypertriglyceridaemia, mia, which can be avoided by higher doses of insulin or decreased glucose load.

Relationship between habitual physical activity and serum lipoprotein levels in white male adolescents

It is currently thought that increased physical activity can have a positive influence on high-density lipoprotein cholesterol (HDL-C) levels in adults. However, only a limited amount of research has been directed at studying the influence of physical activity on HDL-C in adolescents. This study correlated the reported levels of physical activity, exercise capacity, physical measurements, and 48-hr dietary intake of 50 white male adolescents with their levels of HDL-C, ratio of total serum cholesterol (T.Chol) to HDL-C, and ratio of low-density lipoprotein (LDL-C) to HDL-C. Using multiple regression, age (r = -0.42) was the strongest predictor of HDL-C, followed in order by TV watched/night (r = -0.42) and height (r = -0.31) (R2 = 0.28). Age (r = 0.38) was the strongest predictor of the T.Chol/HDL-C ratio, followed by days jogged/week (r = -0.32), TV watched/night (r = 0.29), and systolic blood pressure (r = 0.30) (R2 = 0.30). The days jogged per week (r = -0.32) was the best predictor of the LDL-C/HDL-C ratio, followed in order by hours spent reading/day (r = 0.27) and systolic blood pressure (r = 0.23) (R2 = 0.23). Maximum exercise capacity was not related to these lipoprotein components. These findings suggest that the level of habitual physical activity in white male adolescents may be associated with the level of HDL-C in relation to T.Chol and LDL-C.

[Prevention and therapy of disorders of purine metabolism]

To the most important prophylactic measures for the prevention of a disturbance of the purine metabolism belong the normalisation of the body-weight, a mixed diet without protein carriers containing much purine, a regular physical activity, a life without hectic conditions as well as without an excess of conflict situations and a moderate taking of alcohol. These recommendations are of particular importance for patients endangered by gout. In patients with hyperuricaemia they form the basic treatment for the prevention of a uric arthritis, a urate nephrolithiasis and a gouty nephropathy. The clinical and paraclinical results of the directives must be continuously tested with regard to the effectiveness. To the comprehensive prophylaxis also belong the preventive measures against an associated disturbance of an associated disturbance of metabolism or concomitant disease. An additional medicamentous therapy is necessary, when the success of the basic therapy is insufficient and there are already organ manifestations of a disturbance of the purine metabolism. The application of antihyperuraemic drugs corresponding to types should be performed by uricostatic drugs, uricosuric drugs and citric acid-citrate mixtures. The approach according to a 3-step-programme is most useful. In the treatment of the concomitant diseases certain preventive measures are to be taken into consideration. The therapy of an acute attack of gout is at present without any essential problems. Patients with disturbances of the purine metabolism need a permanent care by the physician.

Lowering triglyceride values in an occupational setting

Within a multiphasic screening program it was possible to establish an effective industrial counseling program for individuals identified as potential cardiovascular risks by their serum triglyceride values. A significant reduction of serum triglyceride values was obtained even where minimal supervision was used to modify aspects of an employee's life style. A counseled group of 109 male employees, 40 years and older, with serum triglyceride levels of 200 mg. or higher per 100 ml., was matched by location and age with a control group of 135 noncounseled individuals with similarly elevated triglyceride levels. Individuals in both groups showing significant percentage reduction were those whose serum levels began above 250 mg. per 100 ml. The employees who lowered their triglyceride values most significantly were those that had dieted and were periodically counseled and checked by a physician.

[The medical practitioner facing arteriosclerotic vascular disease]

The results and validity of some of the latest and most significant epidemiological studies of the relation between risk factors and the clinical signs of arteriosclerosis are discussed, and the best rules for the prevention of arteriosclerotic vascular disease are suggested. Since primary prevention for the entire population is sound management, the practitioner should look for persons at risk, and initiate suitable hygienic, dietetic and, where necessary, pharmacological measures. This programme must not overlook secondary prevention, whose implementation demands the use of drugs (especially those that prevent the clumping of platelets). Under such conditions, ad is clear from the results of numerous multicentre studies, instigation of a multifactorial intervention has enabled the incidence of recurrences and mortality to be reduced.

Accelerated hypertriglyceridemia in patients on continuous ambulatory peritoneal dialysis - a preventable abnormality

Increasing hypertriglyceridemia is a recognised complication of CAPD. To investigate the etiology lipid clearance studies using the intravenous fat tolerance test were performed in control subjects and in uremic patients before and after six months CAPD treatment. Oral carbohydrate intake was restricted and the use of hypertonic dialysate kept to a minimum. Although serum triglycerides were elevated in the uremic patients before CAPD (3.1 +/- 0.3 mMol/L) no further increase occurred during therapy. Oral carbohydrate intake was restricted to 240-250 Gms/24 hrs and hypertonic dialysate to 5.7 +/- 4.1% of the total. There were no significant changes in fractional removal rate of lipid. Therefore further increases in serum triglycerides in CAPD may be prevented by simple dietary manoeuvres.