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Biomedical subjects

E B Schmidt

Publications and source records attributed to E B Schmidt.

At least 19 recordsLinked to original sources
PubMed2001

Marine n-3 fatty acids, wine intake, and heart rate variability in patients referred for coronary angiography.

BACKGROUND: Dietary n-3 polyunsaturated fatty acids (PUFAs) derived from fish may reduce the incidence of sudden cardiac death (SCD). In addition, wine drinking is suggested to have a protective effect against cardiovascular death. METHODS AND RESULTS: We included 291 patients referred for coronary angiography in whom ischemic heart disease was suspected and all of whom completed a food questionnaire regarding fish and wine intake. The n-3 PUFA composition of granulocyte membranes and of adipose tissue was measured. In addition, 24-hour heart rate variability (HRV) was analyzed. Fish intake was positively associated with the level of n-3 PUFAs in adipose tissue. Significant positive correlation coefficients were found between HRV indices and the levels of n-3 PUFAs in granulocytes. Wine intake was also significantly positively related to HRV, but the patients with the highest wine intake also had the highest intake of fish, as documented by a high n-3 PUFA content in adipose tissue. Multiple linear regression analysis revealed that traditional factors such as treatment with ss-blockers, smoking, age, and previous myocardial infarction were independently related to HRV, and furthermore that n-3 PUFAs (but not wine intake) were significantly independently associated with HRV. CONCLUSIONS: The close positive association between n-3 PUFAs and HRV in patients suspected of having ischemic heart disease may indicate a protective effect of n-3 PUFAs against SCD. This may partly explain the reduction in SCD observed in humans with a modest intake of n-3 PUFA. Wine intake was also positively correlated with HRV, but this correlation was no longer significant after controlling for the cellular level of n-3 PUFA.

Aged↗
PubMed2000

N-3 fatty acids from fish and coronary artery disease: implications for public health.

OBJECTIVE: To review and discuss the effect of n-3 polyunsaturated fatty acids (PUFA) from fish in the prevention and, primarily, in the treatment of coronary artery disease (CAD). DESIGN: Overview of the literature. SETTING: Denmark. RESULTS: There is good evidence that fish consumption may reduce the risk of CAD. CONCLUSIONS: Fish can be recommended to reduce the risk of CAD both in healthy subjects and in patients with a high risk of CAD or with documented CAD. The use of fish oil concentrates can not be recommended in general, but may be considered in patients after a myocardial infarction or in patients with hypertriglyceridaemia. An increased intake of n-3 polyunsaturated fatty acids from fish may have substantial implications for public health and health economy by decreasing the risk of coronary events and sudden cardiac death.

Coronary Disease↗
PubMed2000

Alpha-linolenic acid and heart rate variability.

BACKGROUND AND AIM: The marine long-chained n-3 polyunsaturated fatty acids seem to have antiarrhythmic effects in humans. Similar effect has also been postulated for alpha-linolenic acid, a plant-derived polyunsaturated fatty acid--from the n-3 family. The purpose of the study was to examine the relation between the content of alpha-linolenic acid in cell membranes and the risk of malignant arrhythmias as assessed by determination of heart rate variability (HRV). METHODS AND RESULTS: Patients at high risk of sudden cardiac death (52 with a previous myocardial infarction and 29 with chronic renal failure on dialysis) were enrolled as well as 64 healthy volunteers. The cell membrane content of alpha-linolenic acid was analyzed by gas chromatography and related to 24-hour HRV, which was measured in all subjects. No correlations were found between levels of alpha-linolenic acid and 24-hour HRV. CONCLUSION: The present study was unable to demonstrate a positive correlation between cell membrane levels of alpha-linolenic acid and HRV. Our results suggest that alpha-linolenic acid per se is devoid of an antiarrhythmic effect, though this effect could arise from its conversion to the longer chained n-3 PUFA, usually derived from fish.

Aged↗
PubMed1999

Heart rate variability and plasma lipids in men with and without ischaemic heart disease.

Decreased 24-h heart rate variability (HRV) is associated with increased coronary mortality. The objective of this study was to examine the relation between plasma lipids and HRV (1) in men with a previous myocardial infarction (MI) and left ventricular dysfunction and (2) in healthy men. Forty seven men (mean age 63 years) with a previous MI and a left ventricular ejection fraction < or = 0.40 and 38 healthy men (mean age 37 years) were included. A 24-h Holter recording and fasting blood samples were performed in all the subjects. Plasma total-cholesterol and low-density-lipoprotein (LDL)-cholesterol were inversely correlated with 24-h HRV in both groups. Plasma cholesterol remained significantly inversely correlated to the 24-h HRV in a stepwise multiple regression analysis. The men were dichotomized according to the mean plasma cholesterol in the study population which was 6.2 mmol/l in patients with a previous M1, and 5.2 mmol/l in the group of healthy men. In both groups, men with plasma cholesterol levels above the mean had the lowest HRV. In conclusion, the data suggest, that hypercholesterolaemia is associated with a decreased 24-h HRV in men with and without ischaemic heart disease, suggesting an increased risk of sudden cardiac death.

Adult↗
PubMed1999

Heart rate variability and fatty acid content of blood cell membranes: a dose-response study with n-3 fatty acids.

BACKGROUND: Dietary intake of long-chain n-3 polyunsaturated fatty acids (PUFA) may protect against sudden cardiac death, an event that may be predicted by measurement of heart rate variability (HRV). OBJECTIVE: The objectives of this study were to 1) examine the correlations between the content of fatty acids in blood cell membranes (platelets and granulocytes) and HRV in healthy subjects, and 2) assess the effect on HRV of dietary intervention with n-3 PUFA in different doses. DESIGN: Sixty healthy volunteers (25 women and 35 men) were randomly assigned to 3 treatment groups in a double-blind design. Subjects received a daily supplement of either 6.6 g n-3 PUFA, 2.0 g n-3 PUFA, or placebo (olive oil). A 24-h Holter recording was obtained for each subject before supplementation and after 12 wk of supplementation; the 24-h HRV was then related to the content of fatty acids in granulocytes and platelets. RESULTS: Before supplementation, positive correlations were observed in men between the content of docosahexaenoic acid in cell membranes and HRV indexes (r = 0.50, P < 0.01), whereas such correlations were not found in women. Dietary intervention revealed a dose-dependent effect of n-3 PUFA on HRV in men, whereas no effect was found in women. CONCLUSION: The study showed a beneficial effect of n-3 PUFA on HRV in healthy men, suggesting an antiarrhythmic effect of n-3 PUFA. No such effect was observed in healthy women.

Adult↗
PubMed1998

Heart rate variability and n-3 fatty acids in patients with chronic renal failure--a pilot study.

Patients with chronic renal failure (CRF) often have autonomic cardiac dysfunction, which can be assessed by measuring heart rate variability (HRV). This dysfunction prediposes the patients to sudden cardiac death. This study describes 24-hour HRV in patients with CRF compared to HRV in patients with a previous myocardial infarction (MI). Furthermore, associations between HRV in patients with CRF and the content of n-3 polyunsaturated fatty acids (PUFA) in cell membranes were examined, because n-3 PUFA may improve HRV. Twenty-nine patients with CRF treated with dialysis were enrolled. A 24-hour Holter recording was obtained at baseline and the HRV variables, RR (= mean of all normal RR intervals during the 24-hour recording) and SDNN (= standard deviation of all normal RR intervals in the entire 24-hour recording) were analyzed. Also, granulocyte fatty acid composition was determined. The patients were allocated to dietary supplementation with either 5.2 g of n-3 PUFA or a placebo oil (olive oil) daily for 12 weeks in a double-blind design. At the end of the supplementation period the Holter recording and blood sampling were repeated. At baseline the CRF patients' mean SDNN ws 86 ms compared to 118 ms (p < 0.01) in patients with a previous MI. After supplementation with either n-3 PUFA or placebo a highly significant correlation was observed between the content of n-3 PUFA in cell membranes and HRV (r = 0.71, p < 0.01). Furthermore, when the patients were dichotomized according to their mean SDNN, it was found, that those with the highest SDNN had a higher content of n-3 PUFA in cell membranes compared to those with the lowest SDNN (7.8% vs 4.2%, p < 0.05). In conclusion, HRV was decreased in CRF patients indicating a cardiovascular autonomic dysfunction. The positive correlation between the n-3 PUFA content in cell membranes and HRV suggests that the effects of an increased intake of n-3 PUFA in CRF patients should be further studied.

Cell Membrane↗
PubMed1997

[n-3 polyunsaturated fatty acids, heart rate variability and ventricular arrhythmias in post-AMI-patients. A clinical controlled trial].

There is evidence for an antiarrhythmic effect of n-3 polyunsaturated fatty acids (n-3 PUFA) in animals. The aim of the present study was to investigate the effect of dietary n-3 PUFA on ventricular arrhythmias and heart rate variability (HRV) in patients with a previous myocardial infarction. Fifty-five patients were randomized to receive either 5.2 g of n-3 PUFA daily for 12 weeks or placebo in a double blind, placebo-controlled study. Prior to randomization a 24-hour Holter recording was obtained, and this was repeated at the end of the study. The major end-points were the number of ventricular extrasystoles (VE)/24 hours and the 24-hour HRV. A non-significant decrease in VE/24 hours was found in both the n-3 PUFA group and among controls after dietary supplementation, whereas HRV significantly increased after n-3 PUFA compared to both baseline values (p = 0.04) and to controls (p = 0.01). The present study therefore supports the hypothesis that n-3 PUFA may have an anti-arrhythmic effect in humans.

Aged↗
PubMed1997

Fish consumption, n-3 fatty acids in cell membranes, and heart rate variability in survivors of myocardial infarction with left ventricular dysfunction.

To elucidate a possible antiarrhythmic effect of long-chained n-3 polyunsaturated fatty acids, heart rate variability was assessed in 52 patients with a previous myocardial infarction and left ventricular dysfunction. The content of n-3 polyunsaturated fatty acids in platelets was closely associated with the patient's fish-consuming habits, and a significant positive correlation was observed between the n-3 fatty acid docosahexaenoic acid and heart rate variability.

Aged↗
PubMed1997

Homocysteine in Greenland Inuits.

Patients with homozygous homocystinuria are at greatly increased risk for development of atherosclerosis and thrombosis (1). Elevated plasma levels of homocysteine (HCY) are caused by reduced enzymatic catabolism or reduced enzymatic remethylation of HCY, due to either hereditary enzyme defects or to nutritional deficiencies of vitamins functioning as cofactors. However, several recent studies have suggested that persons with mildly elevated plasma levels of HCY also are at increased risk for coronary heart disease. (2-4). There are some indications that dietary n-3 polyunsaturated fatty acids (PUFAs) may offer protection against coronary heart disease (5-6). Several mechanisms may be involved, including beneficial effects of n-3 PUFAs on plasma lipids, platelet and leukocyte reactivity, blood pressure and vasoreactivity (7). Interestingly, Olszewski el al. recently found HCY-levels to be lowered 36% in 15 type IIa or IIb hyperlipemic men by n-3 PUFA supplementation. A possible beneficial effect of n-3 PUFA on the incidence of coronary heart disease was initially suggested from studies in Greenland Inuits by our group (8). We therefore investigated plasma levels of homocysteine in a group of traditionally living Greenland Inuits with a diet consisting mainly of marine food and with a very high content of n-3 PUFAs.

Adult↗
PubMed1997

n-3 fatty acids do not decrease plasma endothelin levels in healthy individuals.

The effect of three different doses of n-3 polyunsaturated fatty acids (PUFA) on endothelin-1 (ET-1) was studied. Study 1 included 40 healthy volunteers randomized to a single supplement of 20 g of n-3 or n-6 PUFA. Plasma ET-1 was measured 14 h after ingestion, and no changes in plasma ET-1 after intake of n-3 PUFA were observed, compared to baseline values. In study 2, 32 subjects had 0.65 g of n-3 PUFA or a fat mixture per day for 12 weeks. No changes in plasma ET-1 were found after the oil supplements. Finally, 22 persons had 4 g of n-3 PUFA for 6 weeks. A significant increase in plasma ET-1 was seen in this group after the supplement. Thus, n-3 PUFAs do not lower plasma levels of ET-1, the most potent vasoconstrictor known.

Adult↗
PubMed1996

No effect of a very low dose of n-3 fatty acids on monocyte function in healthy humans.

There is some evidence that intake of sea food rich in n-3 polyunsaturated fatty acids (PUFA) may protect against coronary heart disease (CHD). Thus, even very low daily amounts of n-3 PUFA below 0.5 g have been reported to reduce the incidence of CHD, although it is unknown by what mechanisms this may occur. Monocytes are of major importance in atherogenesis, and we therefore studied the effect of a daily supplement with 0.65 g of n-3 PUFA for 12 weeks on monocyte function in a randomized placebo-controlled trial of 32 healthy subjects. No effect of dietary n-3 PUFA could be demonstrated on monocyte chemotaxis, on chemiluminescence, or on formation of cytokines and leukotriene B4 from activated monocytes.

Adult↗
PubMed1995

n-3 polyunsaturated fatty acids: update 1995.

Epidemiologic and biochemical studies have suggested an anti-inflammatory effect of n-3 fatty acids. Beneficial therapeutic effects reported from small patient groups need to be confirmed in large-cohort controlled clinical trials. There is a growing number of clinical trials of n-3 fatty acid supplementation in disease. Clinical benefits have been moderate in patients with rheumatoid arthritis and with arterial hypertension. Clearly negative results have been reported during the past 2 years for patients with lupus nephritis and for patients with psoriasis or with atopic dermatitis. Such trials have now been completed. For patients with coronary artery disease following coronary angioplasty, earlier results of a large meta-analysis, could not be confirmed. For patients with IgA-nephropathy and for patients following kidney transplantation, a clear benefit was seen in patients receiving fish oil. These promising results are currently pursued in follow-up phase III clinical trials.

Animals↗
PubMed1995

The effect of n-3 fatty acids on neutrophil chemiluminescence.

The effect of dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) on the production of free oxygen radicals from activated neutrophils was investigated in healthy subjects, using chemiluminescence. In the first study 22 persons were give 4 g n-3 PUFAs daily for 6 weeks. There was a median reduction of chemiluminescence from neutrophils stimulated with opsonized zymosan of 37% (p < 0.001). The median content of eicosapentaenoic acid in platelets, used as an indicator for cellular fatty acid profile, increased from 0.70 to 2.80% (p < 0.001), and there was a significant negative correlation between the chemiluminescence signal and the content of eicosapentaenoic acid in platelets (p < 0.001). In a second, low-dose study 24 persons were allocated to daily supplementation with either 0.65 g n-3 PUFAs or with a control oil for 6 weeks. Compared to the control group there was a median reduction of 38 and 44% in chemiluminescence from neutrophils stimulated with opsonized zymosan and phorbol,12-myristate,13-acetate (PMA), respectively. Neither of these differences, however, was statistically significant. These findings lend support for a possible role of n-3 PUFAs in the management of inflammatory disorders.

Adult↗