Abstracts

Antioxidants & Stroke

Examined the effect of fruit and vegetable intake on risk of stroke among middle-aged men over 20 years of follow-up. (-The Framingham Study.)

Intake of fruits and vegetables may protect against development of stroke in men.

Gillman-MW. et al: Protective effect of fruits and vegetables on development of stroke in men. JAMA. 1995 Apr 12; 273(14): 1113-7.

Community program

Community Program (Japan)

(1) To demonstrate the importance of nutrition, especially sodium restriction and increased potassium and protein intakes, in the prevention of hypertension and stroke in a pilot study involving senior citizens.

(2) To design a population-based intervention in the Shimane Prefecture of Japan concerning dietary factors such as low sodium and high potassium, protein, magnesium, calcium and dietary fibre in the prevention of stroke.

Yamori-Y & Horie-R.: Community-based prevention of stroke: nutritional improvement in Japan [see comments]. Health-Rep. 1994; 6(1): 181-8.

Fetal influences & Stroke

Recent findings suggest that many human 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 later life, including coronary heart disease and the related disorders: stroke, diabetes and hypertension.

Barker-DJ.: The Wellcome Foundation Lecture, 1994. The fetal origins of adult disease. Proc-R-Soc-Lond-B-Biol-Sci. 1995 Oct 23; 262(1363): 37-43.

Folate & Stroke

Folate (1)

A serum folate concentration < or = 9.2 nmol/L has been associated with elevated levels of plasma homocyst(e)ine. Elevated homocyst(e)ine levels have been associated with ischemic stroke in case-control studies; however, the results from prospective studies have been equivocal.

Giles-WH. et al: Serum folate and risk for ischemic stroke. First National Health and Nutrition Examination Survey epidemiologic follow-up study. Stroke. 1995 Jul; 26(7): 1166-70.

Folate (2)

Folic acid, a water-soluble vitamin, has been used since the 1940s to treat some cases of macrocytic anemia without neurologic disease. Folate deficiency is best diagnosed with red blood cell folate levels along with macrocytosis and/or megaloblastic anemia.

Elevations in homocysteine levels, a metabolite intimately associated with folate, are also being found with increasing regularity in those with cardiovascular diseases. Homocysteine levels are reduced by folic acid administration. Therefore, there is some biologic plausibility that folate supplements may prevent heart disease, stroke, and peripheral arterial disease.

Controlled trials should take place before widespread food supplementation with folate is carried out on a large scale because of the possibility of outbreaks of permanent B12-related neurologic damage in those with undiagnosed pernicious anemia.

Malnutrition & Stroke

Malnutrition has received little attention in acute stroke, although it represents a risk of decreased immunity and nosocomial infections.

Malnourished patients showed higher stress reaction and increased frequency of infections and bedsores in comparison with the appropriately nourished group.

Protein-energy malnutrition after acute stroke is a risk factor for poor outcome. Early appropriate enteral caloric feeding did not prevent malnutrition during the first week of hospitalization.

Davalos-A. et al: Effect of malnutrition after acute stroke on clinical outcome. Stroke. 1996 Jun; 27(6): 1028-32.

Milk & Stroke

Evidence suggests that dietary calcium is protective against hypertension. This report examines whether the effect has an influence on thromboembolic stroke.

Men who were nondrinkers of milk experienced stroke at twice the rate of men who consumed 16 oz/d or more (7.9 versus 3.7 per 100, respectively).

Data suggest that consumption of milk in older middle age is not harmful, and when combined with a banced diet, weight control, and physical activity, reductions in the risk of stroke may occur.

Abbott-RD et al: Effect of dietary calcium and milk consumption on risk of thromboembolic stroke in older middle-aged men. The Honolulu Heart Program. Stroke. 1996 May; 27(5): 813-8.

Nutritional assessment & Stroke

Contents:

Nutritional assessment
Nutritional status

Nutritional assessment

To test the prognostic role of nutritional variables as a component of geriatric multidimensional assessment and to study the effect of hospitalization on nutritional status.

Nutritional status deteriorates during the hospital stay, mostly in physically dependent patients.

Antonelli-Incalzi-R. Et al: Nutritional assessment: a primary component of multidimensional geriatric assessment in the acute care setting. J-Am-Geriatr-Soc. 1996 Feb; 44(2): 166-74.

Nutritional status

Stroke (Ischemic) initiates numerous pathophysiological processes and each of them can be dangerous.

Developed an algorithm for diagnosis of the nutritional state.

Patients were found to show a slight protein catabolism and nutritional stress (aminograms, stress index, nutritional percentage of complications, nitrogen balance, CRP, prealbumin).

Necessity of an early diagnosis of nutritional deficiency and disorders of protein metabolism in STROKE patients is discussed.

Enteral and parenteral nutrition are discussed.

Vavrouskova J et al., Nutritional status in patients with stroke. Diagnosis, therapy and its monitoring. Vnitr Lek, 42(10):669-75 1996 Oct.

Body size & Stroke

Body size & fat distribution

Evidence for an association between general obesity and risk of stroke is weak. However, abdominal obesity may be more closely related to stroke risk.

Examined the association of body mass index and abdominal obesity (waist/hip ratio) with stroke incidence in 28,643 US male health professionals, aged 40-75 years in 1986, who had no history of cardiovascular disease or stroke.

In 5 years of follow-up, there were 118 cases of stroke, of which 80 were ischemic.

Compared with men in the lowest quintile of body mass index, men in the highest quintile had an age-adjusted relative risk of stroke of 1.3.

In contrast, the age-adjusted relative risk for extreme quintiles of waist/hip ratio was 2.3.

There was a weaker relation with waist circumference alone, with men in the highest quintile (> 40.2 inches) having a relative risk of 1.52 compared with men in the lowest quintile (< or = 34.5 inches).

Results suggest that abdominal obesity, but not elevated body mass index, predicts risk of stroke in men.

Walker SP et al., Body size and fat distribution as predictors of stroke among US men. Am J Epidemiol, 144(12):1143-50 1996 Dec 15.

Homocysteine & Stroke

Hyperhomocysteinemia is a condition which, in the absence of kidney disease, indicates a disrupted sulfur amino acid metabolism, either because of vitamin (folate, B12 and B6) deficiency or a genetic defect.

Epidemiological evidence suggests that mild hyperhomocysteinemia is associated with increased risk of arteriosclerotic disease and stroke.

The relationship between hyperhomocysteinemia and thrombosis has been investigated in 10 studies involving a total of 1200 patients and 1200 controls. Eight of these studies demonstrated positive association with odds ratios that ranged from 2 to 13. This association was enhanced by including a methionine loading test.

There is some evidence which suggests that hyperhomocysteinemia and APC resistance have a synergistic effect on the onset of thrombotic disease.

Selhub J & D'Angelo A: Hyperhomocysteinemia and thrombosis: acquired conditions. Thromb Haemost, 78(1):527-31 1997 Jul.

Risk factors for Stroke

Geographical differences in stroke mortality are not fully explained by population variations in blood pressure and antihypertensive treatment.

Factors connected with health and nutrition in early life may be related to stroke morbidity and mortality. Body height is a sensitive marker for socioeconomic conditions, but results are conflicting as to whether height is associated with stroke.

Investigated stroke incidence in relation to height and classic cardiovascular risk factors.

Height was inversely related to stroke in a dose-response manner. Per 5-cm increase in height, the age-adjusted risk of stroke was 25% lower in women and 18% lower in men.

Systolic blood pressure and daily smoking were positively associated with stroke in both sexes, while serum triglyceride level was a significant risk factor in women only (relative risk per 1 mmol/L, 1.3).

Factors influencing early growth as well as adult lifestyle factors contribute to cerebrovascular disease in adult age.

Njlstad I et al., Body height, cardiovascular risk factors, and risk of stroke in middle-aged men and women. A 14-year follow-up of the Finnmark Study. Circulation, 94(11):2877-82 1996 Dec 1.

Vitamin C & Stroke

Contents:

Vitamin C
Vitamin C & beta-carotene

Vitamin C

To determine whether vitamin C status, as measured by dietary intake and plasma ascorbic acid concentration, is related to mortality from stroke and coronary heart disease in people aged 65 and over.

In elderly people vitamin C concentration, whether measured by dietary intake or plasma concentration of ascorbic acid, is strongly related to subsequent risk of death from stroke but not from coronary heart disease.

Gale-CR.: Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly people [see comments]. BMJ. 1995 Jun 17; 310(6994): 1563-6.

Vitamin C & beta-carotene

Investigated dietary antioxidants (vitamin C and beta-carotene) and 30-year risk of stroke incidence and mortality [Chicago Western Electric Study].

During 46, 102 person-years of follow-up, 222 strokes occurred; 76 of them were fatal. After adjustment for age, systolic blood pressure, cigarette smoking, body mass index, serum cholesterol, total energy intake, alcohol consumption, and diabetes, relative risks for nonfatal and fatal strokes in highest versus lowest quartiles of dietary beta-carotene and vitamin C intake were 0.84 and 0.71, respectively.

There was a modest decrease in risk of stroke with higher intake of beta-carotene and vitamin-C intake. It does not follow, necesasrily, that high intake of antioxidant vitamins decreases risk of stroke.

Daviglus ML et al., Dietary vitamin C, beta-carotene and 30-year risk of stroke: results from the Western Electric Study. Neuroepidemiology, 16(2):69-77 1997.

Vitamin E & Stroke

Changes in oxidative stress status play an important role in tissue injury associated with ischemia -- reperfusion events such as those that occur during stroke and myocardial infarction.

Endothelial cells (EC) from human saphenous vein and aorta were incubated for 22 h and found to take up vitamin E from media containing 0-60 mM vitamin E in a dose-dependent manner.

Saphenous EC supplemented with 23 mM vitamin E produced less H2O2 than unsupplemented controls, both at normoxic condition [supplemented: 4.9 +/- 0.05 vs. control: 10.9 +/- 1.3 pmol/min/10(6) cells] and following hypoxia/reoxygenation [supplemented: 6.4 +/- 0.78 vs. control: 17.0 +/- 2.7 nmol/min/10(6) cells].

In contrast, aortic EC, which were found to have higher superoxide dismutase and catalase activity than EC from saphenous vein, did not produce any detectable levels of H2O2.

Following hypoxia/reoxygenation, the concentration of vitamin E in supplemented saphenous EC was 62% lower than cells maintained at normoxia [0.19 +/- 0.03 vs. 0.5 +/- 0.12 nmoles/10(6) cells]; in aortic EC vitamin E content was reduced by 18% following reoxygenation [0.86 +/- 0.16 vs. 0.70 +/- 0.09 nmoles/10(6) cells].

Therefore, enrichment of vitamin E in EC decreases H2O2 production and thus may reduce the injury associated with ischemia-reperfusion events.

Martin A et al., Effect of vitamin E on hydrogen peroxide production by human vascular endothelial cells after hypoxia/reoxygenation. Free Radic Biol Med, 20(1):99-105 1996.

Dietary Fat & Stroke

Dietary Fat and stroke

This study, based on the evaluation of 832 men, suggests that saturated fat and monounsaturated fat are associated with a reduced risk of ischemic stroke in men. The 832 men were between 45 and 65 years of age, and were free from cardiovascular disease at baseline in 1966-1969. It was found that over 24 hours, an average of 114 g total fat were consumed (39% of energy), with 15% of that coming from saturated fat, 16% from monounsaturated fat, and 5% from polyunsaturated fat. The risk of ischemic stroke declined across the increasing quintile of total fat, saturated fat, and monounsaturated fat, but not polyunsaturated fat. Measures that can be taken for the prevention of stroke include avoidance of cigarettes, prevention and control of diabetes and hypertension, and treatment of atrial fibrillation.

Gillman, Matthew W., M.D., et al: Inverse Association of Dietary Fat With Development of Ischemic Stroke in Men, JAMA, December 24/31, 1997;278(24):2145-2150.

Low Magnesium Levels

Low Magnesium Levels

According to this study, chronic exposure to alcohol can reduce levels of magnesium, thereby increasing the risk of hemorrhagic stroke. In rats chronically infused for 7 and 14 days with 30% ethanol, brain intracellular free Mg2+ fell 33-39%, brain mitochondrial cytosolic phosphorylation potential fell 31-48%, and brain phosphocreatine fell approximately 15%. Magnesium ATP concentration fell by almost 20% accompanied by a 35% to 40% rise in free ADP concentration. Systemic administration of 4 g/kg ethanol into the 7- and 14-day chronic ethanol animals resulted in a 9- and 12-fold increase in hemorrhagic stroke mortality, respectively, compared to controls.

Altura, Burton M.: Continuous Osmotic Minipump Infusion of Alcohol Into Brain Decreases Brain [Mg2+] and Brain Bioenergetics and Enhances Susceptibility to Hemorrhagic Stroke: An In Vivo 31P-NMR Study, Alcohol, 1998;15(2):113-117.

Vinpocetine

Vinpocetine

According to this study conducted on rats, vinpocetine (extracted from periwinkle seeds), may reduce the oxidative neuronal damage associated with ischemic injury (stroke) and other neurological disorders. Rats were treated with ascorbate/Fe2+, and this treatment resulted in an increase in oxygen consumption, and thiobarbituric reactive substance (TBARS) formation. Administration of vinpocetine inhibited this oxygen consumption and TBARS formation, and led to a decrease in reactive oxygen species formation.

Santos MS, Duarte AI, Moreira PI, Oliveira CR: Synaptosomal response to oxidative stress: effect of vinpocetine, Free Radic Res 2000 Jan;32(1):57-66

Iron

Iron

High body stores of iron may contribute to stroke progression and early neurologic deterioration, according to this study conducted on 100 stroke patients. Measurements were taken on patients who had suffered a stroke within less than 24 hours for ferritin, total iron, and glutamate concentrations in plasma and CSF. Plasma ferritin concentrations were significantly higher in patients with progressing stroke, than in those with nonprogressing stroke. Plasma ferritin concentrations were also directly associated with early neurologic worsening.

Davalos A, Castillo J, Marrugat J, Fernandez-Real JM, Armengou A, Cacabelos P, Rama R: Body iron stores and early neurologic deterioration in acute cerebral infarction, Neurology 2000 Apr 25;54(8):1568-74

Dairy Food Consumption

Dairy Food Consumption

High dietary consumption of dairy products may reduce the risk of stroke and counter high blood pressure, according to this study. The author attributes this to the fact that dairy products contain three minerals, including calcium, magnesium, and potassium, that contribute to the reduction of blood pressure and decrease the risk of stroke. The author also notes that recent studies have indicated that dairy products may help reduce platelet aggregation and insulin resistance, which are two other factors associated with stroke.

Massey LK: Dairy food consumption, blood pressure and stroke, J Nutr 2001 Jul;131(7):1875-8