Improved stenosis geometry by quantitative coronary arteriography after vigorous risk factor modification

A Fad too Far? Dietary Strategies for the Prevention and Treatment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years, concurrent with rising rates of obesity and other metabolic diseases. Currently, there are no FDA-approved pharmacological therapies for NAFLD, and lifestyle interventions, including weight loss and exercise, remain the cornerstones for treatment. Manipulating diet composition and eating patterns may be a sustainable approach to NAFLD treatment. Dietary strategies including Paleolithic, ketogenic, Mediterranean, high-protein, plant-based, low-carbohydrate, and intermittent fasting diets have become increasingly popular because of their purported benefits on metabolic disease. This review highlights what is currently known about these popular dietary approaches in the management of NAFLD in clinical populations with mechanistic insight from animal studies. It also identifies key knowledge gaps to better inform future preclinical and clinical studies aimed at the treatment of NAFLD.

Special Commentary: Is diet management helpful in familial hypercholesterolemia?

PURPOSE OF REVIEW

Familial hypercholesterolemia is a genetic condition where low-density lipoprotein (LDL) receptor defects cause severe elevations of LDL cholesterol. As significant LDL-lowering effects are needed, medication is considered the cornerstone of therapy, and dietary therapy has received less emphasis. This review will re-visit older studies of diet intervention and new insights from genetic and mechanistic studies to determine the value of diet management for familial hypercholesterolemia patients.

RECENT FINDINGS

Saturated fat reduction improves cardiovascular outcomes, particularly in those with genetic predisposition to risk. Secular trends in saturated fat intake may have improved familial hypercholesterolemia outcomes. Dietary mechanisms of LDL cholesterol-lowering complement pharmacologic approaches.

SUMMARY

Diet treatment adds incremental health benefit to pharmacologic treatment in familial hypercholesterolemia.

Vegetarian Dietary Patterns and Cardiovascular Disease

Cardiovascular (CV) disease (CVD) is the leading global cause of mortality, being responsible for 46% of non-communicable disease deaths. It has been estimated that about 85.6 million Americans are living with some form of CVD, which continues to rise. Healthy lifestyle choices may reduce the risk of myocardial infarction by >80%, with nutrition playing a key role. Vegetarian dietary patterns reduce CVD mortality and the risk of coronary heart disease (CHD) by 40%. Plant-based diets are the only dietary pattern to have shown reversal of CHD. Additionally, evidence suggests benefits of vegetarian dietary patterns in both the prevention and the treatment of heart failure and cerebrovascular disease. Plant-based diets are associated with lower blood pressure, lower blood lipids, and reduced platelet aggregation than non-vegetarian diets and are beneficial in weight management, reduce the risk of developing metabolic syndrome, and type 2 diabetes. They have also been shown an effective treatment method in diabetes management. Well planned vegetarian diets provide benefits in preventing and reversing atherosclerosis and in decreasing CVD risk factors and should be promoted through dietary guidelines and recommendations.

On the Cusp

A new president is stepping into leadership at the American College of Lifestyle Medicine (ACLM). Opportunities abound. The fact that both diabetes and heart disease are reversible is a message that is not reaching the majority of the general public. But times are changing and lifestyle treatment is on the cusp of being accepted as the self-evident best treatment for chronic medical conditions. ACLM is poised to be the leader in this area. Our members passion and experience are our richest resources. Each member is encouraged to be involved with the different committees of ACLM. Choices include Conference Planning, Education, Research, practice Models, Publications, Awards, Business Development, Membership Development, Strategic Partnerships, Marketing and Communications.

PET measurement of adenosine stimulated absolute myocardial blood flow for physiological assessment of the coronary circulation

Considerable awareness has been raised of late of the need to reduce radiation exposure and control costs of x-ray and radionuclide imaging procedures. PET/CT cameras are now widely available and in conjunction with appropriate radionuclides and commercially available software make quantitative measurement of absolute MBF feasible for routine clinical practice. Quantitative measurement of absolute MBF under condition of coronary vasodilation permits independent assessment of the functional status of each of the three major coronary perfusion zones and so obviates the need for rest MBF determination in the great majority of cases. Coronary microvascular function also may be assessed in this same way. Thus, the stress-only protocol with quantitative PET measurement of MBF provides essential information required for clinical decision making related to need for catheterization and intervention for patients with known or suspected ischemic heart disease. Moreover, the single PET determination of maximal MBF in contrast to the usual rest/stress procedure addresses both safety and cost concerns. The present review focuses on: (1) quantitative PET measurements of myocardial blood flow for physiological assessment of the coronary circulation and (2) the value and potential limitations of performing stress only imaging in the clinical context.

[The 2009 Nobel Prize in Medicine and its surprising message: lifestyle is associated with telomerase activity]

The 2009 Nobel Prize in Physiology and Medicine was awarded to three scientists for their pioneer research on telomeres - and the enzyme that forms them - telomerase. Their work highlighted the considerable connection between the length of telomeres and intensive changes in lifestyle and nutrition (Ornish method) as well as behavioral and psychological factors. In this review the various elements of molecular, cell biological, nutritional and lifestyle changes are introduced and discussed.

The Effectiveness and Efficacy of an Intensive Cardiac Rehabilitation Program in 24 Sites

Purpose.

The purpose of this study is to test the efficacy and effectiveness of an intensive cardiac rehabilitation program in improving health outcomes in multiple sites.

Methods.

This study employs a nonexperimental (prospective time series) design to investigate changes in cardiovascular disease in 2974 men and women from 24 socioeconomically diverse sites who participated in an intensive cardiac rehabilitation program at baseline, 12 weeks, and 1 year. Paired t-tests were used to assess differences by comparing baseline values to those after 12 weeks, baseline values to those after 1 year, and values after 12 weeks to those after 1 year.

Results.

Eighty-eight percent of patients remained enrolled in the program after 12 weeks, and 78.1% remained enrolled in the program after 1 year. Patients showed statistically significant improvements after 12 weeks in body mass index (BMI), triglycerides, low density lipoprotein cholesterol, total cholesterol, hemoglobin A1c, systolic blood pressure, diastolic blood pressure, depression, hostility, exercise, and functional capacity. These differences also remained significant after 1 year. There was additional significant improvement between 12 weeks and 1 year only in BMI, high density lipoprotein cholesterol, functional capacity, and hostility, and significant recidivism between 12 weeks and 1 year in all other measures (except triglycerides) and depression, yet improvements from baseline to 1 year remained significant in all measures (except HDL, which was unchanged) (p < .005).

Conclusions.

This intensive cardiac rehabilitation program was feasible and sustainable for most patients who enrolled and was associated with numerous subjective and objective improvements in health outcomes. It demonstrates that the intervention works when it is administered by staff at multiple clinical/community sites in four different states. These improvements were also seen in patients 65 years of age or older.

Effects of cardiovascular lifestyle change on lipoprotein subclass profiles defined by nuclear magnetic resonance spectroscopy

Background

Low-density lipoprotein (LDL) cholesterol lowering is a primary goal in clinical management of patients with cardiovascular disease, but traditional cholesterol levels may not accurately reflect the true atherogenicity of plasma lipid profiles. The size and concentration of lipoprotein particles, which transport cholesterol and triglycerides, may provide additional information for accurately assessing cardiovascular risk. This study evaluated changes in plasma lipoprotein profiles determined by nuclear magnetic resonance (NMR) spectroscopy in patients participating in a prospective, nonrandomized lifestyle modification program designed to reverse or stabilize progression of coronary artery disease (CAD) to improve our understanding of lipoprotein management in cardiac patients.

Results

The lifestyle intervention was effective in producing significant changes in lipoprotein subclasses that contribute to CAD risk. There was a clear beneficial effect on the total number of LDL particles (-8.3%, p < 0.05 compared to matched controls), small dense LDL particles (-9.5%, p < 0.05), and LDL particle size (+0.8%; p < 0.05). Likewise, participants showed significant improvement in traditional CAD risk factors such as body mass index (-9.9%, p < 0.01 compared to controls), total cholesterol (-5.5%, p < 0.05), physical fitness (+37.2%, p < 0.01), and future risk for CAD (-7.9%, p < 0.01). Men and women responded differently to the program for all clinically-relevant variables, with men deriving greater benefit in terms of lipoprotein atherogenicity. Plasma lipid and lipoprotein responses to the lifestyle change program were not confounded by lipid-lowering medications.

Conclusion

In at risk patients motivated to participate, an intensive lifestyle change program can effectively alter traditional CAD risk factors and plasma lipoprotein subclasses and may reduce risk for cardiovascular events. Improvements in lipoprotein subclasses are more evident in men compared to women.

Improvement in psychosocial functioning during an intensive cardiovascular lifestyle modification program

PURPOSE

Psychosocial factors have significant effects on development and progression of coronary artery disease (CAD), but appropriate strategies for clinical management of multiple risk factors in persons with CAD are not well defined. This study evaluated changes in psychosocial functioning in patients with cardiovascular disease participating in an intensive lifestyle modification program.

METHODS

One hundred seventy-six patients participated in a prospective, nonrandomized intervention designed to stabilize or reverse progression of CAD through dietary changes, exercise, stress management, and group support. Three examinations over the course of 1 year assessed psychosocial functioning, physiological and biochemical CAD risk factors, and risk for future coronary events.

RESULTS

Most patients showed significant improvements in mental health and quality of life as well as significant reductions in traditional CAD risk factors and cardiovascular risk. The intervention was effective in producing clinically meaningful changes in psychosocial functioning. Response rates were approximately 90% for clinical depression, 85% for stress, and 87% for mental health.

CONCLUSIONS

A comprehensive lifestyle intervention can reduce multiple psychometric risk factors and produce clinically relevant improvement in measures of depression, stress, and mental health. Cardiac rehabilitation programs that effectively address psychosocial and physiological outcomes may be valuable alternatives or supplements to pharmacologic treatments for reducing multiple psychosocial risk factors for CAD.

Comparative review of diets for the metabolic syndrome: implications for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a significant health problem and affects 70 million adults in the United States (30% of the adult population), and an estimated 20% of these individuals have the most severe form of NAFLD-nonalcoholic steatohepatitis (NASH). The mechanisms underlying disease development and progression are awaiting clarification. Insulin resistance and obesity-related inflammation, among other possible genetic, dietary, and lifestyle factors, are thought to play a key role. A program targeting gradual weight reduction and physical exercise continues to be the gold standard of treatment for all forms of NAFLD. Even though weight loss and dietary and lifestyle changes are recommended as primary treatment for fatty liver, little to no scientific evidence is available on diet and NAFLD. This article reviews the implications of current dietary approaches, including national guidelines and popular weight-loss diets, with a focus on determining the optimal diet to prescribe for NAFLD and NASH patients. The effects of macronutrient content (carbohydrate, fat, and protein ratios) and specific food components, such as soluble fiber, n-3 fatty acids, and fructose, are discussed. The premises, effects, barriers, and issues related to current dietary guidelines and specific diets are discussed, and the question, "Will it work for the pathogenesis of NAFLD and NASH? ", is addressed.

Guar Gum: A Miracle Therapy for Hypercholesterolemia, Hyperglycemia and Obesity

The number of hypercholesterolemic and hyperglycemic people is increasing rapidly in the world. The prevention against these health problems is related to a complex management of conventional and non-conventional risk factors. The inclusion of dietary fiber in the diet is the right approach to reduce these risks. Cholesterol and glucose lowering effects are most often associated with gelling, mucilaginous, and viscous fibers such as guar gum, an edible thickening agent. It has widespread applications in the food industry due to its ability to hydrate without heating. The demand for guar gum is still growing rapidly because in addition to its indispensable role in lowering serum cholesterol and glucose levels, it is also considered helpful in weight loss programs. The main thrust of therapeutic and medicinal properties lies in the soluble dietary fiber content of guar gum to improve the serum biochemical profile of human and non-human primates, reducing total serum cholesterol, triglycerides, increasing the high density lipoprotein cholesterol level, and the management of glycemic indices and obesity. Among the various intervention strategies, diet diversification is the right approach to overcome these problems. Composite flours containing wheat and legumes have proven practical uses and are being utilized in many parts of the world to improve the nutritional and functional properties of flour. The main focus of this manuscript is to review the available information on various aspects of guar gum with special reference to its effectiveness in reducing the cardiovascular disease risk, diabetes and weight loss programs.

Outcomes of comprehensive lifestyle modification in inpatient setting

OBJECTIVE

To examine the effectiveness of a 4-week inpatient non-pharmacological risk factor modification programme for individuals with the metabolic syndrome. The aim of the program was to reduce patients' over risks for stroke and myocardial infarction.

METHODS

A prospective clinical study including 2468 patients--1096 men and 1372 women--with and average age of 50 +/- 10 years. The patients were referred to the programme from primary care units and hospitals where treatment options were exhausted.

RESULTS

All risk factor levels for stroke and myocardial infarction decreased. The reduction of weight among men was 4.7 +/- 2.6 kg and 3.8 +/- 1.8 kg among women from an initial weight of 96 +/- 17 kg and 85 +/- 16 kg, respectively. The patients systolic and diastolic blood pressure decreased by 15/10 mmHg for men and 14/9 mmHg among women from initial average for the whole population of 148/90 +/- 19/11 mmHg and 146/87 +/- 19/12 mmHg, respectively. The greatest decrease in weight and blood pressure occurred in men and women with an initial body mass index of > or = 30 and with a diastolic blood pressure of > or = 90; in this group, the average reductions in weight were 5.8 +/- 2.4 kg for men and 4.4 +/- 1.7 kg for women; the reductions in systolisk/diastolisk blood pressure were 22/15 +/- 16/9 mmHg (p < 0.001) for both men and women. A reduction of medication (DDD) although not a goal was also achieved.

CONCLUSION

The results prove the value of a comprehensive and highly structured inpatient approach to lifestyle modification.

PRACTICE IMPLICATIONS

The results should give cause to trials with half-way strategies integrating features from the inpatient programme into the design of risk factor interventions.

Beneficial effects of atorvastatin on myocardial regions with initially low vasodilatory capacity at various stages of coronary artery disease

PURPOSE

The aim of this study was to analyse non-invasively the regional effect of therapy with an HMG-CoA reductase inhibitor on myocardial blood flow in patients with coronary artery disease (CAD) with special reference to segments with initially substantially impaired vasodilation.

METHODS

The study included 26 patients with untreated hypercholesterolaemia. Coronary angiography revealed CAD in nine patients with stenosis >50% and wall irregularities or minimal stenosis <30% in 17 patients. Before and 4.6+/-1.8 months after atorvastatin therapy, ( 13)N-ammonia positron emission tomography (PET) studies were performed at rest and under pharmacological stress. Minimum coronary vascular resistance (MCR) and coronary flow reserve (CFR) were determined. Segments were divided into those with normal or near-normal (MBF during adenosine > or =2.0 ml/min/g) and those with abnormal (MBF<2.0 ml/min/g) vasodilator flow response. In CAD patients, 156 segments were analysed, 85 of which had abnormal MBF; in the non-obstructive group, 59 of 297 segments had abnormal MBF.

RESULTS

LDL cholesterol decreased after atorvastatin therapy from 186+/-43 mg/dl to 101+/-26 mg/dl (p<0.001). In normal segments no significant changes in MBF, CFR and MCR were found. However, initially abnormal segments showed significant improvements in MCR (15%, p<0.0001) and MBF during adenosine (30%, p<0.0001) after therapy.

CONCLUSION

The improvement in regional coronary vasodilator function after atorvastatin in patients with coronary atherosclerosis may be caused, at least in part, by increased flow-mediated (endothelium-dependent) dilation of the total arteriolar and arterial vascular system. These data further support the concept of non-invasive management of stable CAD by statin therapy and life-style modification guided by PET.

Long-term effects of lifestyle behavior change in coronary artery disease: effects on recurrent coronary events after percutaneous coronary intervention

This study evaluated the effects of a behaviorally oriented cardiac rehabilitation and secondary prevention program on lifestyle changes and on coronary recurrence rates. Patients recently treated with percutaneous coronary intervention (PCI) were randomized to an intervention with an aggressive focus on lifestyle changes (smoking, diet, exercise, and stress; n=46) or to a standard-care control group (n=42). Results showed that the intervention group had significantly larger overall lifestyle changes than the control group after 12, 24, 36, and 60 months. The intervention group had significantly lower rates of all coronary events (acute myocardial infarction, coronary artery bypass graft, PCI, cardiac death; 30.4% vs. 53.7%), and of cardiovascular mortality (2.2% vs. 14.6%). The need for future large-scale and long-term evaluations of lifestyle-oriented secondary prevention interventions of this kind is emphasized.

Yoga: a therapeutic approach

Yoga, practiced widely in the East, is now popular in the West as part of a healthy lifestyle. This article brings a medical perspective to the practice of yoga. Selected yoga postures that are believed to benefit certain medical conditions are highlighted. In addition, the philosophy, general guidelines, and medical benefits of yoga practice are described.

Intensive lifestyle modification: impact on cardiovascular disease risk factors in subjects with and without clinical cardiovascular disease

Intensive lifestyle modification programs are intended to stabilize or promote regression of coronary artery disease; however, clinical response is often nonuniform, complicating appropriate utilization of resources and prediction of outcome. This study assessed physiological and psychological benefits to 72 persons participating in a prospective, nonrandomized, four-component lifestyle change program and compared response between patients with clinical cardiovascular disease (CVD) and patients with elevated risk factors for CVD but without clinical manifestations of disease. Subjects entering the program due to elevated risk factor levels alone demonstrated equal or greater benefit, in terms of improvement in primary CVD risk factors and reduction in measures of coronary disease risk developed in the Framingham Heart Study, than those with clinical CVD. These findings suggest that intensive lifestyle change programs may be important for primary prevention in individuals at increased risk of CVD.

Aggressive diets and lipid responses

Poor diet and physical inactivity, the two major contributors to the development of overweight and obesity, have recently been identified as the second most common actual cause of death in the United States. With the increasing awareness of the strong link between obesity and chronic disease, in particular cardiovascular disease, a myriad of diets have surfaced and many of them claim weight loss depends more on the macronutrient composition of the diet than the number of calories consumed. Long-term outcome data, particularly cardiovascular outcome data, on these diets are sparse. This article summarizes previous and recent reports of popular and aggressive diets, such as low-carbohydrate diets, low-fat diets, and very low-calorie diets, addressing their effects on weight loss and focusing on their effects on lipids and lipoproteins.

A shift in myocardial substrate, improved endothelial function, and diminished sympathetic activity may contribute to the anti-anginal impact of very-low-fat diets

A new category of anti-anginal drug - exemplified by ranolazine - is believed to work by partially inhibiting cardiac oxidation of fatty acids; oxidation of glucose requires less oxygen per mol of ATP generated, and thus is preferable to fat oxidation when oxygen availability is limiting in underperfused cardiac tissue. Unfortunately, there is no reason to believe that these drugs inhibit fat oxidation selectively in the heart; thus, chronic use of these drugs can be expected to increase body fat stores until the original rate of fat oxidation is restored by mass action - presumably negating the therapeutic benefit in angina, while exacerbating the manifold adverse effects of insulin resistance syndrome. The rational way to decrease cardiac metabolic reliance on fatty acids is to consume a very-low-fat quasi-vegan diet (i.e., 10% fat calories). Indeed, such diets are known to have a rapid and substantial therapeutic impact on anginal symptoms, while concurrently benefiting insulin sensitivity, markedly improving serum lipid profile, promoting leanness, and lessening coronary risk. A reduction in diurnal insulin secretion might also be achieved, which would be expected to decrease sympathetic activity. While reduced myocardial demand for oxygen doubtless contributes to the beneficial impact of such diets on angina, it is likely that improved cardiac perfusion consequent to improved endothelium-dependent vasodilation also plays a role in this regard. Supplemental carnitine, also beneficial in angina, appears to improve utilization of glucose in the ischemic myocardium by lowering elevated acetyl-coA levels and thereby disinhibiting pyruvate dehydrogenase. Certain other nutraceuticals may aid control of angina by improving endothelial function. In the longer term, these measures have the potential to slow or reverse the progression of stenotic lesions that underlie most cases of angina. These safe and relatively inexpensive nutritional strategies for coping with angina deserve far more attention than orthodox medical practice has thus far accorded them.

Does postprandial storage of triglycerides in endothelial cells contribute to the endothelial dysfunction associated with insulin resistance and fatty diets?

Insulin resistance syndrome is associated with endothelial dysfunction characterized by decreased nitric oxide bioactivity and subnormal endothelium-dependent vasodilation. Excessive exposure to free fatty acids (FFAs) is thought to mediate this dysfunction, at least in part, since free fatty acid overexposure, both in vivo and in vitro, decreases the capacity of endothelial cells to generate bioactive nitric oxide. Yet this endothelial dysfunction tends to correlate, not with fasting FFA levels, but with poor insulin suppressibility of FFA flux postprandially. I propose that triglycerides are synthesized and stored in endothelial cells during the postprandial period, when FFAs and insulin are jointly elevated, and that this triglyceride pool serves as a source of FFA overexposure postabsorptively--thus accounting for the endothelial dysfunction associated with insulin resistance syndrome and the role of excessive postprandial FFA flux in its induction. Since a substantial proportion of postprandial FFA flux derives, not from adipocytes, but from the fat provided by meals, these considerations may help to rationalize the documented clinical utility of very-low-fat diets for management of coronary disease.

A preliminary fast may potentiate response to a subsequent low-salt, low-fat vegan diet in the management of hypertension - fasting as a strategy for breaking metabolic vicious cycles

Although a salted diet appears to be a sine qua non for the development of essential hypertension, low-salt diets often have a modest or even negligible impact on the blood pressure of hypertensives; this suggests that salt, perhaps often acting in concert with other aspects of a modern, rich diet, may set in place certain metabolic vicious cycles that sustain blood pressure elevation even when dietary salt is eliminated. Therapeutic fasting is known to lower elevated blood pressure - presumably in large part because it minimizes insulin secretion - and may have the potential to break some of these vicious cycles. Goldhamer has recently reported that a regimen comprised of a water-only fast of moderate duration, followed by a transition to a low-fat, low-salt, whole-food vegan diet, achieves dramatic reductions in the blood pressure of hypertensives, such that the large majority of patients can be restored to normotensive status, in the absence of any drug therapy. Although long-term follow-up of these subjects has been sporadic, the available data suggest that these large reductions is blood pressure can be conserved in patients who remain compliant with the follow-up diet - in other words, a 'cure' for hypertension may be feasible. If a protein-sparing modified fast can be shown to be virtually as effective as a total fast for achieving these benefits, it may be possible to implement this regimen safely on an outpatient basis. The ability of therapeutic fasts to break metabolic vicious cycles may also contribute to the efficacy of fasting in the treatment of type 2 diabetes and autoimmune disorders. As a general principle, if a metabolic disorder is susceptible to prevention - but not reversal - by a specific diet, and therapeutic fasting has a temporary favorable impact on this disorder, then a more definitive therapy may consist of a therapeutic fast, followed up by the protective diet as a maintenance regimen.

Recurrent Ischemia in a Young Man with the Antiphospholipid Syndrome

Recurrent thromboses, cerebral disease, miscarriages, and antiphospholipid antibodies are characteristic of the antiphospholipid syndrome. A 31-year-old man presented with limb ischemic and isolated right ventricular failure. Antiphospholipid syndrome was suspected and limb salvage was accomplished by anticoagulation and tibial- to-plantar artery bypass surgery. However, recurrent ischemic episodes were successfully treated with thrombolytic therapy and anticoagulants. The surgeon should be aware that patients with antiphospholipid antibodies and lupus anticoagulant antibodies have a high propensity for recurrent arterial thromboses and should use multiple therapeutic approaches to effect successful long-term limb salvage.

Lipoproteins, nutrition, and heart disease

This article reviews the current status of our knowledge of lipoproteins, nutrition, and coronary heart disease (CHD). Special emphasis is placed on CHD risk assessment, dietary intervention studies, diet-gene interactions, and current dietary guidelines and the contributions of my laboratory to these areas. CHD remains a major cause of death and disability, and risk factors include age, sex, hypertension, smoking, diabetes, elevated serum LDL cholesterol, and low HDL cholesterol. Emerging independent risk factors include elevated serum concentrations of lipoprotein(a), remnant lipoproteins, and homocysteine. The cornerstone of CHD prevention is lifestyle modification. Dietary intervention studies support the concepts that restricting saturated fat and cholesterol and increasing the intake of essential fatty acids, especially n - 3 fatty acids, reduces CHD risk. The variability in LDL-cholesterol response to diet is large, related in part to APOE and APOA4 genotype. The use of antioxidants in intervention studies has not been shown to reduce CHD risk. Compliance with dietary recommendations remains a major problem, and directly altering the food supply may be the most effective way to ensure compliance. The available data indicate that the recommendation to use fats, oils, and sugars sparingly for CHD prevention should be modified to a recommendation to use animal, dairy, and hydrogenated fats; tropical oils; egg yolks; and sugars sparingly and to increase the use of vegetables, fruit, and whole grains.

Physical activity and exercise training prescriptions for patients

The dominant outcome from exercise prescription is an increase in various markers of exercise capacity. A very large group of studies have demonstrated that the VO2max is increased in response to exercise performed according to well-accepted principles of exercise prescription. Other markers of exercise capacity, such as the VT, also improve substantially following exercise training. Finally, improvement in exercise capacity is generally related to improved quality of life, particularly in patients with exercise capacity limited by various disease processes. Beyond the specific physiologic gains from training, exercise contributes to a better overall clinical outcome. Although there are few data conclusively demonstrating that exercise independently causes favorable changes in other risk factors, it should be recognized that exercise can contribute indirectly to modulation of other risk factors. Exercise represents positive health advice. Since most of our other recommendations to patients are in the nature of negative advice (e.g., don't smoke, don't eat high-fat foods), and since people are infamous for ignoring negative advice, the value of using a positive recommendation that may indirectly lead the patient to discontinue bad behaviors can hardly be overstated.

Dietary advice given by a dietitian versus other health professional or self-help resources to reduce blood cholesterol

BACKGROUND

The average level of blood cholesterol is an important determinant of the risk of coronary heart disease. Blood cholesterol can be reduced by dietary means. Although dietitians are trained to provide dietary advice, for practical reasons it is also given by other health professionals and occasionally through the use of self-help resources.

OBJECTIVES

To assess the effects of dietary advice given by a dietitian compared with another health professional, or the use of self-help resources, in reducing blood cholesterol in adults.

SEARCH STRATEGY

We searched The Cochrane Library (to Issue 2 1999), MEDLINE (1966 to January 1999), EMBASE (1980 to December 1998), Cinahl (1982 to December 1998), Human Nutrition (1991 to 1998), Science Citation Index, Social Sciences Citation Index, hand searched conference proceedings on nutrition and heart disease, and contacted experts in the field.

SELECTION CRITERIA

Randomised trials of dietary advice given by a dietitian compared with another health professional or self-help resources. The main outcome was difference in blood cholesterol between dietitian groups compared with other intervention groups.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed study quality.

MAIN RESULTS

Eleven studies with 12 comparisons were included, involving 704 people receiving advice from dietitians, 486 from other health professionals and 551 people using self-help leaflets. Four studies compared dietitian with doctor, seven with self-help resources, and one compared dietitian with nurse. Participants receiving advice from dietitians experienced a greater reduction in blood cholesterol than those receiving advice only from doctors (-0.25 mmol/L (95% CI -0.37, -0.12 mmol/L)). There was no statistically significant difference in change in blood cholesterol between dietitians and self-help resources (-0.10 mmol/L (95% CI -0.22, 0.03 mmol/L)). No statistically significant differences were detected for secondary outcome measures between any of the comparisons with the exception of dietitian versus nurse for HDLc, where the dietitian groups showed a greater reduction (-0.06 mmol/L (95% CI -0.11, -0.01)). No significant heterogeneity between the studies was detected.

REVIEWER'S CONCLUSIONS

Dietitians were better than doctors at lowering blood cholesterol in the short to medium term, but there was no evidence that they were better than self-help resources. The results should be interpreted with caution as the studies were not of good quality and the analysis was based on a limited number of trials. More evidence is required to assess whether change can be maintained in the longer term. There was no evidence that dietitians provided better outcomes than nurses.

Diet and coronary heart disease: clinical trials

Dietary intervention trials using coronary heart disease (CHD) mortality and morbidity as endpoints have demonstrated that restriction of dietary total and saturated fat or replacement of the latter with polyunsaturated fatty acids (PUFAs), in particular n-3 PUFAs, is of great benefit with respect to CHD risk. This is likewise the case for intervention trials using angiographic endpoints, with many studies showing that such diets not only retard progression of coronary atherosclerosis but can cause regression as well. The role that antioxidants, such as vitamin E, may play in the development and progression of CHD is less clear. The results of large-scale clinical trials evaluating the effect of vitamin E supplementation on CHD risk do not support the concept that this agent is cardioprotective. The purpose of this report is to review dietary intervention trials that support a direct relationship between diet, lipoproteins, and CHD risk.

Complementary alternative medicine in health and mental health: implications for social work practice

This article describes the increasing use of complementary alternative medicine (CAM) in this country and its implications for social work practice, education, research and policy in the health care field. Descriptive examples of CAM treatment modalities are provided along with their underlying rationale, common uses and available empirical support. It is concluded that patients will be better served by social workers who have knowledge of CAM treatment modalities. Furthermore, the need for further research on the efficacy of many CAM treatments and the certification of CAM treatment providers is discussed.

Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity

Amino acids modulate the secretion of both insulin and glucagon; the composition of dietary protein therefore has the potential to influence the balance of glucagon and insulin activity. Soy protein, as well as many other vegan proteins, are higher in non-essential amino acids than most animal-derived food proteins, and as a result should preferentially favor glucagon production. Acting on hepatocytes, glucagon promotes (and insulin inhibits) cAMP-dependent mechanisms that down-regulate lipogenic enzymes and cholesterol synthesis, while up-regulating hepatic LDL receptors and production of the IGF-I antagonist IGFBP-1. The insulin-sensitizing properties of many vegan diets--high in fiber, low in saturated fat--should amplify these effects by down-regulating insulin secretion. Additionally, the relatively low essential amino acid content of some vegan diets may decrease hepatic IGF-I synthesis. Thus, diets featuring vegan proteins can be expected to lower elevated serum lipid levels, promote weight loss, and decrease circulating IGF-I activity. The latter effect should impede cancer induction (as is seen in animal studies with soy protein), lessen neutrophil-mediated inflammatory damage, and slow growth and maturation in children. In fact, vegans tend to have low serum lipids, lean physiques, shorter stature, later puberty, and decreased risk for certain prominent 'Western' cancers; a vegan diet has documented clinical efficacy in rheumatoid arthritis. Low-fat vegan diets may be especially protective in regard to cancers linked to insulin resistance--namely, breast and colon cancer--as well as prostate cancer; conversely, the high IGF-I activity associated with heavy ingestion of animal products may be largely responsible for the epidemic of 'Western' cancers in wealthy societies. Increased phytochemical intake is also likely to contribute to the reduction of cancer risk in vegans. Regression of coronary stenoses has been documented during low-fat vegan diets coupled with exercise training; such regimens also tend to markedly improve diabetic control and lower elevated blood pressure. Risk of many other degenerative disorders may be decreased in vegans, although reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke. By altering the glucagon/insulin balance, it is conceivable that supplemental intakes of key non-essential amino acids could enable omnivores to enjoy some of the health advantages of a vegan diet. An unnecessarily high intake of essential amino acids--either in the absolute sense or relative to total dietary protein--may prove to be as grave a risk factor for 'Western' degenerative diseases as is excessive fat intake.

Occlusions of epicardial arteries might not directly induce symptoms in ischemic heart disease

It is accepted that primary occlusions of epicardial arteries by thromboses, stenotic coronary artery disease (CAD), and spasm directly induce symptoms in ischemic heart disease (IHD). Because of this acceptance, there has been little interest in alternate mechanisms for IHD--as the spasm of resistance vessel (S-RV) concept of IHD, which asserts that S-RV directly induces symptoms in IHD. To stimulate interest in the S-RV concept, evidence against the primacy of occlusions of epicardial arteries was presented, as well as evidence for this position to provide a balanced discussion; while the evidence was mixed, overall findings appeared to weigh significantly against the primacy of occlusions of epicardial arteries. Also, the S-RV concept was discussed; the discussion included presenting the theory's explanations for events in epicardial arteries, with the aim of demonstrating that the concept provides more consistent explanations than the standard position. It is suggested that there is sufficient information to warrant renewed consideration of the S-RV concept.

Complex systems model of dietary choice with implications for improving diets and promoting vegetarianism

An important step toward improving nutrition and promoting vegetarianism in the general population is to understand how consumers make dietary choices. Researchers from many clinical and social sciences are interested in dietary choice but have not combined their research into a comprehensive model to explain consumer actions. No one model has offered a good explanation for the fact that, although many people successfully change their diet significantly (often toward health-improving, plant-based diets) and are happy with the change, the public and health professionals often perceive dietary change as being difficult and unlikely to succeed. I have termed these observations "the paradox of dietary change." The present computer model uses the emerging science of complex systems analysis, which offers an intuitive method for studying evidence about dietary choice from many fields, including public health, clinical science, economics, sociology, marketing, and genetics, and for combining individual choice with social interaction. The results suggest an explanation for the paradox and methods for helping society shift toward healthier and more plant-based diets. In particular, they suggest how and why major changes might be easier to make than incremental ones, and why this makes dietary change seem more difficult to consumers than it actually is.

Vegetarian diet: panacea for modern lifestyle diseases?

We review the beneficial and adverse effects of vegetarian diets in various medical conditions. Soybean-protein diet, legumes, nuts and soluble fibre significantly decrease total cholesterol, low-density lipoprotein cholesterol and triglycerides. Diets rich in fibre and complex carbohydrate, and restricted in fat, improve control of blood glucose concentration, lower insulin requirement and aid in weight control in diabetic patients. An inverse association has been reported between nut, fruit, vegetable and fibre consumption, and the risk of coronary heart disease. Patients eating a vegetarian diet, with comprehensive lifestyle changes, have had reduced frequency, duration and severity of angina as well as regression of coronary atherosclerosis and improved coronary perfusion. An inverse association between fruit and vegetable consumption and stroke has been suggested. Consumption of fruits and vegetables, especially spinach and collard green, was associated with a lower risk of age-related ocular macular degeneration. There is an inverse association between dietary fibre intake and incidence of colon and breast cancer as well as prevalence of colonic diverticula and gallstones. A decreased breast cancer risk has been associated with high intake of soy bean products. The beneficial effects could be due to the diet (monounsaturated and polyunsaturated fatty acids, minerals, fibre, complex carbohydrate, antioxidant vitamins, flavanoids, folic acid and phytoestrogens) as well as the associated healthy lifestyle in vegetarians. There are few adverse effects, mainly increased intestinal gas production and a small risk of vitamin B12 deficiency.

Improvement of impaired myocardial vasodilatation due to diffuse coronary atherosclerosis in hypercholesterolemics after lipid-lowering therapy

BACKGROUND

Diminished myocardial vasodilatation (MVD) in hypercholesterolemics without overt coronary stenosis has been reported. However, whether the diminished MVD of angiographically normal coronary arteries in hypercholesterolemics can be reversed after lipid-lowering therapy is not known.

METHODS AND RESULTS

A total of 27 hypercholesterolemics and 16 age-matched controls were studied. All patients had >1 normal coronary artery, and those segments that were perfused by anatomically normal coronary arteries were studied. Myocardial blood flow (MBF) was measured during dipyridamole loading and at baseline using positron emission tomography and 13N-ammonia, after which MVD was calculated before and after lipid-lowering therapy. Total cholesterol was significantly higher in hypercholesterolemics (263+/-33.8) than in controls (195+/-16.6), and it normalized after lipid-lowering therapy (197+/-19.9). Baseline MBF (ml. min-1. 100 g-1) was comparable among hypercholesterolemics (both before and after therapy) and controls. MBF during dipyridamole loading was significantly lower in hypercholesterolemics before therapy (189+/-75.4) than in controls (299+/-162, P<0.01). However, MBF during dipyridamole loading significantly increased after therapy (226+/-84.7; P<0.01). MVD significantly improved after therapy in hypercholesterolemics (2.77+/-1.35 after treatment [P<0.05] versus 2. 02+/-0.68 before treatment [P<0.01]), but it remained significantly higher in controls (3.69+/-1.13, P<0.01). There was a significant relationship between the percent change of total cholesterol and the percent change of MVD before and after lipid-lowering therapy (r=-0. 61, P<0.05).

CONCLUSIONS

Diminished MVD of anatomically normal coronary arteries in hypercholesterolemics can be reversed after lipid-lowering therapy.

Multifactorial evaluation of a program for lifestyle behavior change in rehabilitation and secondary prevention of coronary artery disease

A comprehensive, multifactorial lifestyle behavior change program was developed for rehabilitation and secondary prevention of subjects with coronary artery disease. The purpose of the present report is to describe this intervention model and to analyze results achieved in a first group of consecutive participants. Main inclusion criteria for the 292 subjects were a recent history of acute myocardial infarction, coronary artery bypass surgery, or percutaneous transluminal coronary angioplasty. The program commenced with a 4-week residential stay, with the focus on health education and the achievement of behavior change in major lifestyle areas. During the year of follow-up a systematic maintenance program included regular contact with a nurse. Morbidity and mortality was low. Self-reported quality of life improved and there were significant improvements in blood lipids, exercise capacity and body mass index. There were also significant changes both in psychological variables such as Type A behavior, anger, hostility, and in major lifestyle areas such as stress reactions, diet, exercise and smoking. These changes compared favorably with data from relevant samples from the Swedish normal population. This program had a considerable effect on a number of important factors for rehabilitation and secondary prevention of coronary artery disease.

Effects of short-term treatment of hyperlipidemia on coronary vasodilator function and myocardial perfusion in regions having substantial impairment of baseline dilator reverse

BACKGROUND

We tested the hypothesis that correction of hyperlipidemia improves coronary vasodilator response and maximal perfusion in myocardial regions having substantial impairment of pretreatment vasodilator capacity.

METHODS AND RESULTS

Measurements of myocardial blood flow were made with PET [13N]ammonia in 12 patients with ischemic heart disease (11 men; age, 65+/-8 years [mean+/-SD]) at rest and during adenosine at 70 and then 140 microg . kg-1 . min-1 for 5 minutes each before and approximately 4 months after simvastatin treatment (40 mg daily). Simvastatin reduced LDL (171+/-13 before versus 99+/-18 mg/dL after simvastatin, P<0.001) and increased HDL (39+/-8 versus 45+/-9 mg/dL, P<0.05). Myocardial segments were classified on the basis of pretreatment blood flow response to 140 microg . kg-1 . min-1 adenosine as normal (flow >/=2 mL . min-1 . g-1) or abnormal (flow <2 mL . min-1 . g-1). In normal segments, baseline myocardial blood flow (0.95+/-0.32) increased (P<0.001) at both low- (1.62+/-0.81) and high- (2.63+/-0.41) dose adenosine and was unchanged both at rest and with adenosine after simvastatin. In abnormal segments, myocardial blood flow at rest (0. 73+/-0.19) increased at low- (1.06+/-0.59, P<0.02) and high- (1. 29+/-0.33, P<0.01) dose adenosine. After simvastatin, myocardial blood flow increased more compared with pretreatment at both low- (1. 37+/-0.66, P<0.05 versus pretreatment) and high- (1.89+/-0.79, P<0. 01 versus pretreatment) dose adenosine.

CONCLUSIONS

Short-term lipid-lowering therapy increases stenotic segment maximal myocardial blood flow by approximately 45%. The mechanism involves enhanced, flow-mediated dilation of stenotic epicardial conduit vessels and may account at least in part for the efficacy of lipid lowering in secondary prevention trials and in reducing ischemic episodes in ambulatory patients.

Diet, lipoproteins, and coronary heart disease

Current dietary recommendations to decrease coronary heart disease (CHD) risk in the general population include reduction of total fat intake to less than or equal to 30% of energy, saturated fat to less than 10% of energy, and dietary cholesterol to less than 300 mg/day. Further restrictions in saturated fat to less than 7% of energy and in dietary cholesterol to less than 200 mg/day are indicated for those individuals with elevated low-density lipoprotein (LDL) cholesterol concentrations. Under controlled conditions, such diets reduce LDL cholesterol by 15% to 20%. However, in the out-patient setting, only 5% to 10% reductions in LDL cholesterol have been achieved, and large variability in dietary response is observed due to differences in compliance, as well as to genetic heterogeneity. This article reviews epidemiologic studies and dietary intervention trials that support a direct relationship between diet, lipoproteins, and CHD risk, with the ultimate goal of providing a framework for dietary management of the hyperlipidemic patient.