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Abstracts

Abstracts

Angina

Angina Pectoris (1)

There has been a long-standing interest in the relationship between cardiovascular disease (CVD) and psychiatric morbidity, specifically depressive symptoms. This study suggests that functional impairment is a more important factor associated with depressive symptomatology than angina.

Portillo-CJ et al: Angina, functional impairment and physical inactivity among Mexican-American women with depressive symptoms. Prog-Cardiovasc-Nurs. 1995 Summer; 10(3): 18-25.

Angina Pectoris (2)

Tested the antioxidant hypothesis of coronary heart disease (CHD) by comparing blood antioxidants, indices of lipid peroxidation and classic (CHD) risk factors of 25 subjects with stable angina pectoris with 200 matched controls.

Angina subjects had significantly increased plasma concentrations of total cholesterol, low density lipoproteins and triglycerides.

It is unclear whether the increased oxidative stress in angina sufferers is a cause or consequence of the disease.

Beattie-JA et al: Duthie-GGm et al: Blood antioxidants and indices of lipid peroxidation in subjects with angina pectoris. Nutrition. 1994 Jul-Aug; 10(4): 313-6.

Arrhythmias

Sudden cardiac death accounts for about 50% of total coronary disease mortality in westernized industrial countries. The lack of early symptoms for this disorder makes prevention the preferred strategy. In a rat model of cardiac ischemia, dietary n-6 (sunflower seed oil) and n-3 (fish-oil) polyunsaturated fatty acids were shown to protect against arrhythmia compared with saturated fat, with greatest protection observed with fish oil. The frequency of arrhythmia was similar with monounsaturated fat from olive oil and saturated fat.

Topping-D.: Dietary fatty acids and protection against experimental cardiac arrhythmias in rats. Nutr-Rev. 1993 Sep; 51(9): 271-3.

Cardiomyopathy

Oxidative Stress

In evaluating 12 patients with idiopathic dilated cardiomyopathy between 31 and 66 years of age, 11 patients with ischemic dilated cardiomyopathy between 32 and 65 years of age and 21 healthy volunteers between 25 and 67 years of age, there was a reduction in blood glutathione, erythrocyte superoxide dismutase and membrane sulphydryl content in both groups of patients compared to controls. Erythrocyte and membrane susceptibility to peroxidation were increased in both groups with cardiomyopathy. These abnormalities may contribute to contractile dysfunction, increased incidence of fatal arrhythmias, and sudden death.

Yucel, Dogan, et al: Increased Oxidative Stress in Dilated Cardiomyopathic Heart Failure, Clinical Chemistry, 1998;44(1):148-154.

Copper

Dietary copper restriction in rats results in cardiomyopathy.

Medeiros-DM. Et al: A unified perspective on copper deficiency and cardiomyopathy [see comments]. Proc-Soc-Exp-Biol-Med. 1993 Jul; 203(3): 262-73.

Selenium

A case of selenium-deficiency myopathy, secondary to total parenteral nutrition, is presented. The literature on selenium-deficiency myopathy and cardiomyopathy is reviewed in the context of the literature concerning selenium status in numerous diseases. An hypothesis of a wider role for selenium deficiency in the pathogenesis of myopathy and cardiomyopathy is presented.

Marcus-RW.: Myopathy and cardiomyopathy associated with selenium deficiency: case report, literature review, and hypothesis. Md-Med-J. 1993 Jul; 42(7): 669-74.

Antioxidants & heart disorders

In over 87,000 US female nurses between 34 and 59 years of age, followed up for 8 years, it was found that there were 437 nonfatal myocardial infarctions and 115 coronary deaths. There was a trend for decreasing risk of coronary heart disease (CHD) with higher vitamin consumption of each of the antioxidant vitamins. In women with the highest quintile of vitamin use, compared to those who were lowest, the multivariate risk of CHD was .66 for vitamin E, .78 for beta-carotene, and .70 for total vitamin A, adjusting for other variables.

Increased dietary intake of antioxidant vitamins may be associated with a reduced risk of coronary heart disease, and supports the need for randomized trials.

Manson, J.E. et al: A Prospective Study of Antioxidant Vitamins and Incidence of Coronary Heart Disease in Women. Journal of The American College of Nutrition, October 1992;11(5):633/Abstract 119.

Congestive Heart Failure

Cardiovascular disease is the leading cause of death in the United States. Congestive heart failure (CHF) is often the result of many non-fatal heart problems. Many patients who suffer from heart failure die as a result of cardiac dysrhythmias. This article discusses the normal heart, the changes from normal seen in CHF and dysrhythmias, the medical management of these conditions, including medications used, and the implications for the dental management of these patients.

Weaver T & Eisold JF: Congestive heart failure and disorders of the heart beat. Dent Clin North Am, 40:543-61, 1996 Jul.

Coxsackie B Virus

Coxsackie B group of viruses have been long considered as the precipitating factor in heart diseases. Their association with various heart diseases especially pericarditis, myocarditis and myopericarditis is known, but now their association is also known with cardiomyopathy and ischaemic heart diseases.

Thirty patients (34.5%) were found to be having high antibody titre for at least one of coxsackie B virus group with coxsackie B3 and B4 being the two commonest types. Serum IgM immunoglobulins were raised in acute infective disorders like pericarditis, myocarditis and myopericarditis but IgG, IgA and IgM levels were normal in ischaemic heart diseases and cardiomyopathy.

Gupta HL et al., Coxsackie B virus in the etiology of heart diseases in Delhi. J Commun Dis, 27:223-8, 1995 Dec.

Dialysis

The rate of cardiovascular death, and specifically of cardiac death, in dialysis patient is excessive and comparable to that in the high-risk group of survivors of myocardial infarction.

Yet, in patients on dialysis total cholesterol, LDL cholesterol, apolipoprotein B and other indicators of coronary risk--with the exception of lipoprotein(a)--are consistently higher in survivors than in those dying from cardiovascular causes, but at least in diabetic patients on dialysis, an extremely high-risk population, lipids are predictive of cardiac death.

Malnutrition as a confounding factor might explain the inverse relation between lipid indicators and cardiac death in nondiabetic patients. Indirect arguments can be marshalled that malnutrition increases cardiac death as a consequence of low L-arginine levels and the ensuing diminished synthesis of NO.

Ritz E: Why are lipids not predictive of cardiovascular death in the dialysis patient? Miner Electrolyte Metab, 1996, 22:1-3, 9-12.

Dietary intervention

The scope for dietary intervention in general practice is substantial. The three most prevalent conditions for which general practitioners are likely to give dietary advice are hypertension, functional digestive disorders, and ischemic heart disease. As well as clinical diseases, risk factors such as raised plasma cholesterol concentrations also provide opportunities for dietary intervention. But resources are limited.

If a general practitioner or nurse spends 5 min of a 10-min consultation on dietary advice, there is 5 min less to spend on the rest of the consultation. Research studies in general practice show that small changes in plasma cholesterol concentrations can be achieved by dietary interventions.

Intensive intervention can also influence salt intake to a small extent.

However, the most important, potentially cost-effective roles for the general practitioner in health promotion are the legitimization and reinforcement of public health information by brief advice and the distribution of written material. Secondary and tertiary prevention is a priority in general practice and may entail use of drugs, but drugs are not a desirable solution for the unhealthy diets of healthy people.

Mant D: Effectiveness of dietary intervention in general practice. Am J Clin Nutr, 1997 Jun, 65:6 Suppl, 1933S-1938S.

Fatty acid oxidation

The heart is known for its ability to produce energy from fatty acids (FA) because of its important beta-oxidation equipment, but it can also derive energy from several other substrates including glucose, pyruvate, and lactate. The cardiac ATP store is limited and can assure only a few seconds of beating.

For this reason the cardiac muscle can adapt quickly to the energy demand and may shift from a 100% FA-derived energy production (after a lipid-rich food intake) or any balanced situation (e.g., diabetes, fasting, exercise). These situations are not similar for the heart in terms of oxygen requirement because ATP production from glucose is less oxygen-consuming than from FA.

Excess FA oxidation is closely related to myocardial contraction disorders characterized by increased oxygen consumption for cardiac work.

In rats, an increase in n-3 polyunsaturated FA in heart phospholipids achieved by a fish-oil diet improved the recovery of pump activity during postischemic reperfusion.

Data suggest that in addition to the amount of circulating lipids, the quality of FA intake may contribute to heart energy regulation through the phospholipid composition.

Grynberg A & Demaison, L: Fatty acid oxidation in the heart. J Cardiovasc Pharmacol, 1996, 28 Suppl 1:, S11-7.

Fetal origins of heart disease

Fetal origins (1)

Geographic, retrospective, and prospective epidemiologic studies have revealed evidence that the environment in utero is a major determinant of later degenerative disease. Observations from Britain, Sweden, Jamaica, Australia, India, and China support the hypothesis that disproportionate retardation of fetal growth results in increased blood pressure and increased risk of cardiovascular mortality.

It has been proposed that hypertension and coronary heart disease are "programmed" by nutrition status.

Langley-Evans S & Jackson A: Intrauterine programming of hypertension: nutrient-hormone interactions. Nutr Rev, 1996 Jun, 54:6, 163-9.

Fetal origins (2)

Recent finding suggest that many fetuses have to adapt to a limited supply of nutrients and in doing so they permanently change their physiology and metabolism. These 'programmed' changes may be the origins of a number of diseases in life, including coronary heart disease and the related disorders stroke, diabetes and hypertension.

Barker DJ: Fetal nutrition and cardiovascular disease in later life. Br Med Bull, 1997 Jan, 53:1, 96-108.

Fruits & Vegetables

Increased interest in the potential cardio-protective effects of fruit and vegetables is currently unsupported by systematic reviews of the reported associations of these foods with risk.

For coronary heart disease nine of ten ecological studies, two of three case-control studies and six of 16 cohort studies found a significant protective association with consumption of fruit and vegetables or surrogate nutrients.

For stroke three of five ecological studies, none (of one) case-control study and six of eight cohort studies found a significant protective association with consumption of fruit and vegetables or surrogate nutrients.

For total circulatory disease, one of two cohort studies reported a significant protective association.

Results are consistent with a strong protective effect of fruit and vegetables for stroke and a weaker protective effect on coronary heart disease.

Ness AR & Powles JW: Fruit and vegetables, and cardiovascular disease: a review. Int J Epidemiol, 26:1-13, 1997 Feb.

Global mortality

Reliable information on causes of death is essential to the development of national and international health policies for prevention and control of disease and injury. Medically certified information is available for less than 30% of the estimated 50.5 million deaths that occur each year worldwide.

98% of all deaths in children younger than 15 years are in the developing world. 83% and 59% of deaths at 15-59 and 70 years, respectively, are in the developing world. The probability of death between birth and 15 years ranges from 22.0% in sub-Saharan Africa to 1.1% in the established market economies.

Probabilities of death between 15 and 60 years range from 7.2% for women in established market economies to 39.1% for men in sub-Saharan Africa. The probability of a man or woman dying from a non-communicable disease is higher in sub-Saharan Africa and other developing regions than in established market economies.

Worldwide in 1990, communicable, maternal, perinatal, and nutritional disorders accounted for 17.2 million deaths, non-communicable diseases for 28.1 million deaths and injuries for 5.1 million deaths.

The leading causes of death in 1990 were ischaemic heart disease (6.3 million deaths), cerebrovascular accidents (4.4 million deaths), lower respiratory infections (4.3 million), diarrhoeal diseases (2.9 million), perinatal disorders (2.4 million), chronic obstructive pulmonary disease (2.2 million), tuberculosis (2.0 million), measles (1.1 million), road-traffic accidents (1.0 million), and lung cancer (0.9 million).

Five of the ten leading killers are communicable, perinatal, and nutritional disorders largely affecting children. Non-communicable diseases are, however, already major public health challenges in all regions.

Injuries, which account for 10% of global mortality, are often ignored as a major cause of death and may require innovative strategies to reduce their toll.

Murray CJ & Lopez AD: Mortality by cause for eight regions of the world: Global Burden of Disease Study. Harvard School of Public Health, Boston, Massachusetts, USA.
Lancet, 1997 May 3, 349:9061, 1269-76.

LDL & heart disease

The small LDL pattern B trait, and triglyceride rich lipoproteins, have now been established as major coronary heart disease risk factors and have been associated with its severity. The corresponding patient subgroup is at substantial coronary artery disease risk but also exhibits the best arteriographic response to treatment.

Most lipid-lowering treatments have a differential effect in LDL subclass pattern A patients compared with those with pattern B that helps explain the differential arteriographic response seen in clinical trials.

Superko HR: What can we learn about dense low density lipoprotein and lipoprotein particles from clinical trials? Curr Opin Lipidol, 7(6):363-8 1996 Dec.

Platelets & heart disease

Platelet-activating factor

Platelet-activating factor (PAF) is a potent phospholipid mediator released from inflammatory cells in response to diverse immunologic and non-immunologic stimuli. Animal studies have implicated PAF as a major mediator involved in coronary artery constriction, modulation of myocardial contractility and the generation of arrhythmias which may bear on cardiac disorders such as ischemia, infarction and sudden cardiac death.

In vivo and in vitro studies strongly suggest that PAF receptor antagonists might convey therapeutic benefits in ischemic conditions and certain arrhythmias. In addition, PAF antagonists might have a cardiac allograft-preservation effect.

Feuerstein G et al., Platelet-activating factor and cardiac diseases: therapeutic potential for PAF inhibitors. J Lipid Mediat Cell Signal, 1997 Mar, 15:3, 255-84.

Sleep disorders

Cheyne-Stokes respiration can appear during sleep in patients with chronic heart failure and is generally attributed to a tendency to hyperventilate causing PCO2 to fall below the apnea threshold.

During sleep, Cheyne-Stoke respiration was present in 50% and arterial oxygen desaturations in 54% of patients.

In advanced chronic heart failure, with optimized therapy, nocturnal Cheyne-Stokes respiration is present in half of the cases, with concomitant falls in arterial oxygen desaturation. These events were not independently predictive of mortality.

Other hemodynamic mechanisms besides reduced cardiac output are responsible for this respiratory abnormality.

Traversi E et al., Sleep disorders and breathing alterations in patients with chronic heart failure. G Ital Cardiol, 27:423-9, 1997 May.

Thyroid disorders & heart disease

Severe thyrotoxicosis can cause irreversible congestive heart failure. Investigated the coincidence of subclinical thyroid disorders and idiopathic dilated cardiomyopathy (IDC).

Thyroid sonography as well as thyroid hormone levels were measured in all patients.

Sixty-one patients (50 male, 11 female) with chronic stable IDC were included. Two out of 61 patients showed completely normal thyroid morphology and function. The other 59 patients showed either morphological or functional abnormalities or both. Of the 53 patients with morphological abnormalities 23 patients (all male) showed diffuse goiter as opposed to 29 nodular enlarged organs (24 male, 5 female). No clinically significant hypothyroidism or thyrotoxicosis was seen.

Subclinical thyroid disorders are frequently seen in patients with long-standing IDC when they live in an area of chronic iodine deficiency. This can be explained by chronic salt restriction as basic treatment for congestive heart failure.

Examination of the thyroid gland should be done routinely in patients with IDC, especially when restriction of salt intake is recommended by the treating physician.

Fruhwald FM et al., Subclinical thyroid disorders in patients with dilated cardiomyopathy. Cardiology, 1997 Mar-Apr, 88:2, 156-9.

Fish Consumption

Fish Consumption

In a study conducted on 20,000 U.S. male physicians over a period of 11 years, dietary fish intake was associated with a reduced risk of sudden death. For those who consumed fish at least once per week, the risk of death was 0.48 compared with those who consumed fish less than monthly. Dietary fish consumption and omega-3 fatty acid intake were not associated with a reduced risk of total myocardial infarction, non-sudden cardiac death, or total cardiovascular mortality.

Albert, Christine M., M.D., et al: Fish Consumption and Risk of Sudden Cardiac Death, JAMA, January 7, 1998;279(1):23-28.

LDL Cholesterol & Fatty Acids

LDL cholesterol

Fatty acids found in butter and stick margarine may increase serum LDL cholesterol and may lead to heart disease. In this study, older participants ate diets containing 30% fat from either soybean oil, semi-liquid margarine, soft margarine, shortening, stick margarine, or butter. As a result, those who had soybean-oil and semiliquid margarine had 12% and 11% decline in LDL cholesterol levels. Others who had butter and stick margarine had increased their total and LDL serum cholesterol levels. The researchers conclude that fatty acids should be consumed from vegetable oils, rather than butter and/or stick margarine.

Lichtenstein AH, Ausman LM, Jalbert SM, Schaefer EJ: Effects of different forms of dietary hydrogenated fats on serum lipoprotein cholesterol levels, N Engl J Med 1999 Jun 24;340(25):1933-40

Fatty Acids & Heart Disorders

Fatty Acids

The modern diet includes an n-6 to n-3 fatty acid ratio of 20-30:1, with the majority of n-6 fatty acids coming from vegetable oils. The traditional range throughout human evolution for the n-6 to n-3 fatty acid ratio is 1-2:1. While high n-6 fatty acid consumption leads to increases in blood viscosity, vasospasm and vasoconstriction; n-3 fatty acids have antiinflammatory, antithrombotic, antiarrhythmic, hypolipidemic, and vasodilatory properties. These properties of n-3 fatty acids help to prevent coronary heart disease and other conditions. Fish oils, green leafy vegetables, flaxseed, rapeseed, and walnuts are all good sources of n-3 fatty acids.

Simopoulos AP: Essential fatty acids in health and chronic disease, Am J Clin Nutr 1999 Sep;70(3 Suppl):560S-569S

Grapes

Grapes

A component of grape skins, resveratrol may help to prevent cardiovascular diseases caused by lipid metabolism and oxidation processes, according to this article. Red wine contains the trans-isomer of resveratrol in ranges between 0.1 and 15 mg/L. A phenolic compound and a phytoestrogen, resveratrol has been shown to modulate the metabolism of lipids, and to inhibit the oxidation of low-density lipoproteins and the aggregation of platelets. These qualities may potentially lead to the prevention of cardiovascular diseases.

Fremont L: Biological effects of resveratrol, Life Sci 2000 Jan 14;66(8):663-73

Calcium and Potassium

Calcium and Potassium

According to the authors of this review, a proper diet that meets the recommended dietary guidelines for vitamins, minerals, and macronutrients may be a good way to reduce some of the risks associated with cardiovascular disease. Recent research has focused on the relationship between dietary patterns and cardiovascular health, using randomized controlled trials that are different from earlier design methods, which are plagued with inconsistencies. The newest studies indicate that it is not only excesses of single nutrients but deficiencies in multi-nutrient combinations that have the greatest effect on dietary health. Calcium and potassium are two such nutrients that, when taken together, promote cardiovascular and overall health.

McCarron DA, Reusser ME: Are low intakes of calcium and potassium important causes of cardiovascular disease? Am J Hypertens 2001 Jun;14(6 Pt 2):206S-212S

Alcohol & heart disorders

Alcohol

Moderate alcohol consumption may lower risk factors for cardiovascular disease in postmenopausal women, according to this study. Fifty-one randomly selected postmenopausal women consumed 0 (control), 15 (one drink), and 30 (2 drinks) grams of alcohol as part of three separate eight-week studies. In each study the women consumed a controlled diet consisting of 15% protein, 53% carbohydrate, and 32% fat, with the energy provided from alcohol in the 15 gram and 30 gram studies replaced with energy from carbohydrate. Significant decreases in plasma LDL cholesterol and triacylglycerols were seen in the 15 grams of alcohol per day diet when compared to the control diet. No more significant decrease was seen in the 30 grams of alcohol per day diet, but this level of alcohol intake did produce a significant increase in apolipoprotein A-I and a decrease in apolipoprotein B. It also increased plasma HDL cholesterol from 1.40 mmol/L in the control diet to 1.48 mmol/L.

Baer DJ, Judd JT, Clevidence BA, Muesing RA, Campbell WS, Brown ED, Taylor PR: Moderate alcohol consumption lowers risk factors for cardiovascular disease in postmenopausal women fed a controlled diet, Am J Clin Nutr 2002 Mar;75(3):593-9