Biomedical subjects

G Alfthan

Publications and source records attributed to G Alfthan.

At least 19 recordsLinked to original sources

PubMed2005

Homocysteine as a risk factor for CVD mortality in men with other CVD risk factors: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study.

OBJECTIVE: Based on case-control and prospective studies elevated blood total homocysteine (tHcy) has been suggested to be an independent risk factor for cardiovascular diseases (CVD). The purpose of the study was to explore the joint effect of increased serum tHcy concentration and other risk factors on the risk of CVD mortality in middle-aged men without a history of heart disease or stroke. DESIGN: A prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. SETTING: Eastern Finland. Subjects. A total of 802 men aged 46-64 years, examined in 1991-93. MAIN OUTCOME MEASURES: CVD mortality event. RESULTS: The mean serum tHcy concentration was 10.8 micromol L(-1) (SD 3.3). During the average follow-up time of 10.8 years 50 men experienced a CVD death. The hazard rate ratio for CVD mortality was 1.80 (95% confidence interval: 1.02-3.19) in men in the highest serum tHcy third versus lower thirds after adjustment for cardiovascular risk factors. Furthermore, elevated serum tHcy concentration appeared to increase the risk of CVD death in men who smoke or who have high circulating concentrations of serum total or LDL cholesterol, apo-B apolipoprotein or plasma fibrinogen. CONCLUSION: We conclude that homocysteine may increase the risk of CVD mortality in middle-aged men from Eastern Finland, and it may especially increase the risk when present with other risk factors for CVD.

Biomarkers↗

PubMed2003

Folate intake, plasma folate and homocysteine status in a random Finnish population.

OBJECTIVE: To assess the folate status of Finnish adults using plasma folate and homocysteine as biomarkers and to evaluate dietary and supplementary folate intakes. MATERIALS AND METHODS: Plasma folate, vitamin B(12) and total homocysteine (tHcy) were determined in a random sample of 643 subjects aged 25-74 y living in the Helsinki area. The methylenetetrahydrofolate reductase (MTHFR)-genotypes were analyzed from a subsample (n=394). Dietary intake data by 24 h recall and use of vitamin supplements were collected. RESULTS: Plasma folate was normal (>/=5 nmol/l) in 99% of subjects and optimal (>/=8 nmol/l) in terms of a minimum tHcy in 90%. Mean plasma folate of non-supplement users was 13.7 and 12.9 nmol/l and tHcy 11.3 and 9.2 micro mol/l for men and women, respectively. Elevated tHcy (>14 micro mol/l) was found in 11% of subjects. Homozygote frequency for MTHFR genotype TT was 5.0% and their plasma tHcy was 14.8 micro mol/l compared to the mean of the other subjects, 10.5 micro mol/l, P<0.05. The mean dietary folate intake was 241 micro g/day (29 micro g/MJ of energy) for men and 205 micro g/day (33 micro g/MJ) for women, respectively. The main dietary sources of folate were vegetables 12%, wholemeal ryebread 11%, fruits 10%, and potato 10%. Regular supplement users (n=97) received on average 207 micro g folic acid per day from supplements. CONCLUSIONS: The folate status of Finnish adults seems to be adequate according to energy adjusted folate intake, plasma folate and homocysteine. The MTHFR homozygote frequency was low compared to other countries. Regular use of supplementary folic acid less than 300 micro g increased plasma folate, but supplemental folic acid over 300 micro g was required to lower tHcy values significantly.

Adult↗

PubMed2003

Consumption of black currants, lingonberries and bilberries increases serum quercetin concentrations.

OBJECTIVE: To study serum quercetin concentrations of subjects consuming berries or habitual Finnish diets. DESIGN: Randomized parallel dietary intervention. SUBJECTS: Forty healthy men (age 60 y). INTERVENTION: Twenty subjects consumed 100 g/day of berries (black currants, lingonberries and bilberries) for 8 weeks. Twenty subjects consuming their habitual diets served as controls. Fasting blood samples were obtained 2 weeks prior to the study, at baseline, and at 2, 4 and 8 weeks. Intake of quercetin was assessed from 3 day food records collected at baseline and at 8 weeks. RESULTS: The serum quercetin concentrations were significantly higher in the subjects consuming berries compared to the control group (P=0.039 ANCOVA with repeated measures). During the berry consumption period the mean serum concentrations of quercetin ranged between 21.4 and 25.3 micro g/l in the berry group, which was 32-51% higher compared with the control group. According to 3 day food records, there was no difference in quercetin intake at baseline, but at 8 weeks the intake was 12.3+/-1.4 mg/day (mean+/-s.e.m.) in the berry group and 5.8+/-0.6 mg/day in the control group (P=0.001). CONCLUSIONS: The results indicate that the berries used in this study are a good source of bioavailable quercetin.

Analysis of Variance↗

PubMed2002

Plasma concentrations of the flavonoids hesperetin, naringenin and quercetin in human subjects following their habitual diets, and diets high or low in fruit and vegetables.

OBJECTIVES: To determine the fasting plasma concentrations of quercetin, hesperetin and naringenin in human subjects consuming their habitual diets, and diets either high or low in fruit and vegetables. To investigate whether plasma concentrations of flavanones can serve as biomarkers of their intake. DESIGN: This was a cross-over, strictly controlled dietary intervention consisting of a 2 week baseline period, and two 5 week dietary periods with a 3 week wash-out period in between. The low-vegetable diet contained few fruit and vegetables and no citrus fruit. The high-vegetable diet provided various fruits and vegetables daily including on average one glass of orange juice, one-half orange and one-half mandarin. SUBJECTS: Thirty-seven healthy females. RESULTS: The high-vegetable diet provided 132 mg of hesperetin and 29 mg of naringenin. The low-vegetable diet contained no flavanones. The mean plasma hesperetin concentration increased from 12.2 nmol/l after the low-vegetable diet to 325 nmol/l after the high-vegetable diet. The respective increase for naringenin was from <73.5 nmol/l for all subjects to a mean value of 112.9 nmol/l. The mean plasma quercetin concentration was 52 nmol/l after the baseline period, during which habitual diets were consumed, and it did not change significantly during the intervention. Interindividual variation in the plasma levels of hesperetin and naringenin was marked and, after the baseline and wash-out periods, and the low-vegetable diet, a majority of the samples had plasma flavanone levels below the limit of detection. After the high-vegetable diet, hesperetin and naringenin were detectable in 54 and 22% of all samples. Quercetin was detectable in nearly all samples after all study periods. CONCLUSION: Hesperetin, naringenin and quercetin are bioavailable from the diet, but the plasma concentrations of hesperetin and naringenin are poor biomarkers of intake.

Adult↗

PubMed2002

Risk factors for cryptogenic ischaemic stroke.

This case-control study was designed to identify risk factors for cryptogenic brain infarction. We assessed the frequency of prothrombotic states, homocysteine, lipoprotein (a) [Lp(a)] and other lipids and the apolipoprotein E phenotype together with conventional risk factors in 46 patients (19 women and 27 men) with cryptogenic brain infarction aged from 15 to 60 years and in 104 community-based controls. Multivariate odds ratios (ORs) for risk factors and 95% CIs were calculated by logistic regression. Hypertension (OR 4.5; 95% CI, 1.5-13.2; P = 0.006), current smoking (OR 2.9; 95% CI, 1.2-6.8; P = 0.012), low HDL cholesterol (HDL-C) (OR 5.4; 95% CI, 1.1-25.5; P = 0.035) and high clotting factor VIII activity (OR 3.6; 95% CI, 1.1-12.2; P = 0.041) were variables associated with cryptogenic brain infarction. These risk factors were not equally frequent in women and men. Low HDL-C and high factor VIII activity in the women, and hypertension, current smoking and a low level of plasma folate in the men were risk factors for cryptogenic stroke. Several of the observed risk factors for cryptogenic brain infarction were lifestyle-associated, which emphasizes the role of health education in addition to pharmacological treatment in the prevention of stroke.

Adolescent↗

PubMed2002

Multiserotype enzyme-linked immunosorbent assay as a diagnostic aid for periodontitis in large-scale studies.

Periodontitis is a common chronic oral infection caused by gram-negative bacteria, including Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Periodontitis evokes inflammatory host response locally in the periodontium but also systemically. The systemic humoral antibody response against oral pathogens can conveniently be measured by an immunoassay. The aim of the study was to measure serum immunoglobulin G class antibodies against A. actinomycetemcomitans and P. gingivalis by an enzyme-linked immunosorbent assay (ELISA) in which mixtures of several serotypes of the pathogens were used as antigens to avoid biasing of the results in favor of a particular strain. For A. actinomycetemcomitans the antigen consisted of six strains representing serotypes a, b, c, d, and e and one nonserotypeable strain. In the P. gingivalis ELISA, antigens representing serotypes a, b, and c were used. Serum samples from 90 subjects, including 35 samples from patients with diagnosed periodontitis, 10 samples from periodontally healthy controls, and 45 samples from randomly selected apparently healthy volunteers (referred to as "healthy subjects"), were tested. For both pathogens the antibody levels (means +/- standard deviations) of the patients--xpressed as area under the dilution curve--were significantly higher than those for healthy controls or healthy subjects, with values for A. actinomycetemcomitans and P. gingivalis, respectively, as follows: patients, 22.60 +/- 9.94 mm(2) and 26.72 +/- 11.13 mm(2); healthy controls, 9.99 +/- 3.92 mm(2) and 6.90 +/- 3.38 mm(2); and healthy subjects, 16.85 +/- 6.67 mm(2) and 8.51 +/- 4.23 mm(2). The serotype mixture ELISA is suitable for measuring antibodies against periodontal pathogens in large epidemiological studies in order to evaluate the role of periodontitis as a risk factor for other diseases.

Adult↗

PubMed2001

Hyperhomocystinemia: a risk factor or a consequence of coronary heart disease?

BACKGROUND: Mild hyperhomocystinemia has been suggested as an indicator of an increased risk of cardiovascular disease. OBJECTIVE: To examine whether serum homocysteine concentration is a predictor of coronary heart disease (CHD) events. METHODS: A case-control study, nested in a population-based cohort study was used. During a follow-up of 13 years, 166 major coronary events (death from CHD or nonfatal myocardial infarction) occurred in men with evidence of heart disease at baseline and 272 events in men without a history of heart disease. Two controls per case were selected by individual matching. RESULTS: Among men with known heart disease at baseline, the relative risk (95% confidence interval) of CHD events adjusted for age, smoking, hypertension, diabetes mellitus, serum cholesterol level, body mass index, and alcohol consumption was 2.23 (95% confidence interval, 1.03-4.85) in the highest serum homocysteine quintile compared with the lowest quintile. Among the men free of heart disease at baseline, the corresponding relative risk was 0.90 (95% confidence interval, 0.51-1.60). CONCLUSIONS: This prospective study does not support the hypothesis that a high concentration of serum homocysteine is a risk factor for coronary events in a population free of heart disease. However, it does suggest that mild hyperhomocystinemia predicts secondary coronary events in men with heart disease, possibly as a consequence of atherosclerotic changes.

Case-Control Studies↗

PubMed2001

Homocysteine and major coronary events: a prospective population study amongst women.

OBJECTIVES: To study serum homocysteine concentration for its prediction of major coronary heart disease events amongst women. DESIGN: A case-control study nested within a follow-up study. Subjects. A total of 74 and 75 major coronary events (coronary deaths or nonfatal myocardial infarction) which occurred in women with and without known heart disease, respectively, during a 13-year follow-up and two individually matched controls per case. Main outcome measure. Major coronary event. RESULTS: Amongst women with baseline heart disease, the relative risk (95% CI) of such events, adjusted for age, smoking, hypertension, diabetes, serum cholesterol and body mass index, was 3.32 (1.05-10.5) in the highest homocysteine quintile compared with the lowest quintile. Amongst women free of heart disease at baseline, the corresponding relative risk value was 0.77 (0.24-2.45). CONCLUSIONS: This prospective study support the hypothesis that homocysteine is a risk factor for coronary events in women with heart disease.

Adult↗

PubMed2001

Polymorphisms of key enzymes in homocysteine metabolism affect diet responsiveness of plasma homocysteine in healthy women.

High plasma total homocysteine (tHcy), low dietary intake of folate and other B vitamins, and genetic polymorphisms related to metabolism of homocysteine may interactively contribute to the risk of cardiovascular disease. We investigated whether known mutations in genes regulating homocysteine metabolism affect the responsiveness of serum folate and plasma tHcy to high intake of natural folate from food. Healthy females (n = 37) aged 22-57 y volunteered to participate in a crossover dietary intervention with two 5-wk diet periods (low and high folate diets). Concentrations of serum and RBC folate, serum vitamin B-12 and plasma tHcy were measured at baseline and at the end of each diet period. The prevalences of C677T transition of methylenetetrahydrofolate reductase (MTHFR) gene, 844ins68 of cystathionine beta-synthase (CBS) gene and A2756G mutation of methionine synthase (MS) gene were determined. Compared with the low folate diet, the high folate diet increased the serum folate concentration by 85% (P < 0.001), 77% (P < 0.001) and 55% (P < 0.05) in the subjects with the genotypes C/C (n = 19), C/T (n = 13) and T/T (n = 5), respectively, of the MTHFR gene. Also, the plasma tHcy of the subjects with the genotypes C/C, C/T and T/T was decreased by 11% (P < 0.001), 15% (P < 0.01) and 18% (P < 0.05), respectively, during the high folate diet period. The subjects carrying the G2756 allele of the MS gene (n = 15) had a more extensive reduction (P < 0.05) of plasma tHcy during the high folate diet period than the subjects with the genotype A/A (n = 22). The 844ins68 of CBS gene did not affect plasma tHcy concentrations or diet responsiveness. In conclusion, diet responsiveness of plasma homocysteine may be genetically regulated.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2001

Plasma kinetics and urinary excretion of the flavanones naringenin and hesperetin in humans after ingestion of orange juice and grapefruit juice.

The flavanones naringenin and hesperetin exhibit estrogenic, anticarcinogenic and antioxidative properties. Orange juice and grapefruit juice contain high amounts of these compounds, and therefore their intake from the diet can be relatively high. No data are available regarding plasma concentrations or plasma kinetics of flavanones. The objectives of this study were to develop methods allowing the analysis of naringenin and hesperetin from plasma and urine and to study their plasma kinetics and urinary excretion. We also wanted to assess whether plasma or urine flavanone concentrations can be used as biomarkers of intake. Healthy volunteers ingested orange juice (five women and three men) or grapefruit juice (two women and three men) once (8 mL/kg). Eleven blood samples and urine were collected between 0 and 24 h after juice administration. Flavanones were analyzed by HPLC with electrochemical detection. Naringenin and hesperetin were bioavailable from the studied juices, but interindividual variation in bioavailability was remarkable. The resulting plasma concentrations were comparatively high, and the peak plasma concentrations (C(max)) were 0.6 +/- 0.4 micromol/L (means +/- SD) for naringenin from orange juice and 6.0 +/- 5.4 micromol/L for naringenin from grapefruit juice. The corresponding value for hesperetin from orange juice was 2.2 +/- 1.6 micromol/L. The elimination half-lives were between 1.3 and 2.2 h, and therefore plasma concentrations reflect short-term intake. The relative urinary excretion varied depending on the flavanone source and dose and was 30.2 +/- 25.5% and 1.1 +/- 0.8% for naringenin from grapefruit juice and orange juice, respectively, and 5.3 +/- 3.1% for hesperetin from orange juice. The considerable difference in the relative urinary excretion of naringenin from the two juices was most likely caused by dose-dependent renal clearance rather than differences in bioavailability (as indicated by the similar C(max)-to-dose ratios). The results indicate that urine flavanone concentrations are not good biomarkers of dietary intake. We conclude that because of the relatively high concentrations of flavanones in plasma after ingestion of orange juice or grapefruit juice, considerable health effects could ensue in individuals consuming them regularly.

Adult↗

PubMed2000

Pharmacokinetics of quercetin from quercetin aglycone and rutin in healthy volunteers.

BACKGROUND: Quercetin is a flavonoid with a wide range of biological activities. It mainly occurs in plants as glycosides, such as rutin (quercetin rutinoside) in tea. Quercetin and rutin are used in many countries as vasoprotectants and are ingredients of numerous multivitamin preparations and herbal remedies. OBJECTIVES: The primary objective was to characterise and compare the absorption and the pharmacokinetics of quercetin from quercetin aglycone and rutin. A secondary objective was to investigate which forms of quercetin are present in plasma. METHODS: In this double blind, diet-controlled, two-period cross-over study, 16 healthy volunteers received three different doses of quercetin and rutin orally. The doses corresponded to 8 mg, 20 mg and 50 mg quercetin aglycone. Blood samples were obtained between 0 h and 32 h post-dose. RESULTS: The overall kinetic behaviour of quercetin differed remarkably after ingestion of quercetin aglycone or rutin. The mean area under the plasma concentration-time curve from 0 h to 32 h [AUC(0-32)] and maximum plasma concentration (Cmax) values of the two treatments were similar. However, time to reach Cmax (tmax) was significantly shorter after the quercetin aglycone treatment than after the rutin treatment (1.9, 2.7 and 4.8 versus 6.5, 7.4 and 7.5 h, for doses 1, 2 and 3, respectively). Also, the absorption of quercetin from quercetin aglycone was predictable and inter-individual variation was small. In contrast, after ingestion of rutin, inter-individual variations in AUC(0-32) and Cmax values were considerable and seemed to be associated with gender and use of oral contraceptives. Quercetin and rutin were found in plasma as glucuronides and/or sulfates of quercetin and as unconjugated quercetin aglycone, but no rutin was detected. CONCLUSIONS: In clinical trials, studying the effects of quercetin from rutin, bioavailability must be taken into consideration and plasma quercetin concentrations monitored. Whether our results apply to other glycosidic drugs as well, especially other rutosides, should be investigated.

Administration, Oral↗

PubMed2000

Relation of inflammation to vascular function in patients with coronary heart disease.

Endothelium plays a pivotal role in the regulation of vascular relaxation. Inflammation may in turn induce endothelial dysfunction and thus increase the risk of atherothrombosis. We investigated 31 men with angiographically verified coronary heart disease, aged 57. 7+/-5.3 years, in regard to endothelium-dependent, acetylcholine-induced, and to endothelium-independent, sodium nitroprusside-induced vasodilatation in the forearm vasculature by strain-gauge plethysmography. Logistic regression analysis served to determine the relation between forearm vascular function and the inflammatory factors measured, concentration of C-reactive protein, subtypes of peripheral blood T-lymphocytes, and other factors potentially affecting endothelial function (lipoprotein and glucose levels). Concentration of C-reactive protein was an independent determinant of endothelium-dependent vascular function (P<0.001 for low dose acetylcholine, P=0.01 for high dose acetylcholine). Other determinants of endothelium-dependent vascular dysfunction were CD8-lymphocytes expressing ICAM-1 (P=0.001), antibodies to oxidized low-density lipoprotein (P<0.001), and body weight (P=0.007). The present data showed an association between inflammatory risk factors linked to atherothrombosis and endothelial dysfunction in coronary heart disease patients. It is possible that endothelial dysfunction in coronary heart disease patients is related to the chronic inflammation or infection coexisting with atherosclerosis.

Aged↗

PubMed2000

Toenail selenium and breast cancer-a case-control study in Finland.

OBJECTIVE: Low levels of selenium have been associated with a higher risk of cardiovascular diseases and cancer in humans. Since 1984, selenium supplementation through fertilizers has been employed in Finland to increase the very low concentration of selenium in the nation's food supply. As a result, the selenium concentration of Finnish foods became one of the highest in Europe. A decade after selenium supplementation began, the association between toenail selenium and the risk of breast cancer was examined. DESIGN: Case-control study. SETTING: Eastern Finland. SUBJECTS: 289 pre- and postmenopausal breast cancer cases and 433 community controls. The diagnosis was unknown at the time the toenail samples were collected. RESULTS: The mean toenail selenium concentration was 0.80 mg/kg in premenopausal cases and 0.84 mg/kg in premenopausal controls: and 0. 77 mg/kg in postmenopausal cases and 0.80 mg/kg in postmenopausal controls. The odds ratio (OR) comparing the highest with the lowest quintiles of toenail selenium concentration was 1.1 (95% CI 0.4-3.2) in premenopausal women and 0.7 (95% CI 0.3-1.5) in postmenopausal women. The intake of retinol, beta-carotene, vitamin E and vitamin C did not change the association between toenail selenium and breast cancer. CONCLUSIONS: A decade after selenium supplementation, selenium seems not to be an important factor in the etiology of breast cancer, neither in premenopausal nor postmenopausal women. SPONSORSHIP: This work was supported by the EVO funds from the Kuopio University Hospital and by research grants from the Academy of Finland, Yrjö Jahnsson Foundation and Juho Vainio Foundation. European Journal of Clinical Nutrition (2000) 54, 98-103

Adult↗

PubMed2000

Cardiovascular risk factor changes in Finland, 1972-1997.

BACKGROUND: The cardiovascular risk factor levels of the population have been assessed in Finland since 1972. In the beginning the surveys were done to evaluate the North Karelia Project, which was a community-based preventive programme. A national cardiovascular disease (CVD) prevention strategy was developed and implemented during the late 1970s. Subsequently, a national cardiovascular risk factors monitoring system was developed to assess the effectiveness of the national strategy. METHODS: Cross-sectional population samples were studied in 1972 and 1977 in North Karelia and Kuopio provinces in eastern Finland. An area in southwestern Finland was included in 1982, followed by the Helsinki metropolitan area in 1992 and Oulu province in northern Finland in 1997. A total of 19 761 men and 20 761 women aged 30-59 participated in the six surveys (1972, 1977, 1982, 1987, 1992, 1997). RESULTS: The serum cholesterol levels of both genders have continuously declined. Systolic blood pressure levels have declined since 1972, but no further decline in diastolic blood pressure was found in 1997. Smoking prevalence among men continued to decline mainly due to an increase in the percentage of never-smokers. For the first time the increase in smoking prevalence among women levelled off and started to decline, mainly because the number of female quitters had increased. CONCLUSIONS: These data suggest that the cardiovascular health programme in Finland has succeeded in decreasing the general risk factor level of the population.

Adult↗

PubMed2000

Serum selenium, serum alpha-tocopherol, and the risk of rheumatoid arthritis.

Antioxidant micronutrients have been hypothesized to provide protection against rheumatoid arthritis. We investigated serum selenium and serum alpha-tocopherol for their prediction of subsequent development of rheumatoid arthritis in a case-control study nested within a Finnish cohort of 18,709 adult men and women who had neither arthritis nor a history of it at the baseline examination in 1973-1978; by late 1989, 122 had developed rheumatoid arthritis. Of the incident cases, 34 were rheumatoid factor-negative. Three controls per each incident case were individually matched for sex, age, and municipality. Serum selenium and alpha-tocopherol concentrations were measured from stored serum samples collected at baseline. Serum selenium was inversely related to subsequent occurrence of rheumatoid factor-negative but not rheumatoid factor-positive rheumatoid arthritis. The relative risks, adjusted for smoking and serum total cholesterol, for the highest relative to the lowest tertile of serum selenium, were 0.16 [95% confidence interval (CI) = 0.04-0.69] for rheumatoid factor-negative and 0.96 (CI = 0.49-1.90) for rheumatoid factor-positive rheumatoid arthritis. During the first 10 years of follow-up, the relative risk for rheumatoid arthritis for the highest compared with the lowest tertile of serum alpha-tocopherol was 0.44 (CI = 0.19-0.99). No association was found for longer follow-up periods. Low selenium status may be a risk factor for rheumatoid factor-negative rheumatoid arthritis, and low alpha-tocopherol status may be a risk factor for rheumatoid arthritis independently of rheumatoid factor status.

Adult↗

PubMed2000

Selenium depletion in hemodialysis patients treated with polysulfone membranes.

BACKGROUND/AIMS: Epidemiological, animal and human studies have indicated that selenium deficiency is a risk factor for death from malignant diseases. The mechanisms that could modify selenium status may, therefore, be of particular interest in hemodialysis patients, considering their high cancer mortality rates. We aimed at evaluating the effect of hemodialysis with polysulfone membranes on selenium status. METHODS: Twenty- eight chronically dialyzed patients and 32 age-matched healthy controls were enrolled in the study. Serum and dialysis fluid selenium concentrations, serum total protein, and hemoglobin concentrations and serum glutathione peroxidase activity were determined before and after the hemodialysis procedure. RESULTS: The (mean +/- SD) serum selenium and total protein concentrations and glutathione peroxidase activities were significantly (p < 0.05) higher in healthy controls (75.9 +/- 8.3 microg/l, 78 +/- 6 g/l, and 23.8 +/- 4.8 mU/20 microl, respectively) than in the patients. There was no significant difference between serum selenium concentration before (63.6 +/- 11. 6 microg/l) and after (64.4 +/- 11.4 microg/l) hemodialysis sessions, although hemoglobin and total serum protein concentrations and serum glutathione peroxidase activities increased (from 98.5 +/- 1.3 to 114.8 +/- 1.5 g/l, from 64 +/- 8 to 71 +/- 9 g/l, and from 16.8 +/- 1.8 to 18.9 +/- 1.9 mU/20 microl, respectively) significantly (p < 0.05) during hemodialysis, indicating hemoconcentration. The selenium concentration doubled, and protein appeared in the dialysates during dialysis session. The correlation of the selenium concentrations with the protein concentrations in the dialysate is significant (p < 0.01) with a Spearman R value of 0.97. CONCLUSION: The results of the present study suggest that selenium is lost through the pores of polysulfone membranes during hemodialysis which is associated with their protein permeability.

Adult↗

PubMed2000

Selenium supplementation of children in a selenium-deficient area in China: blood selenium levels and glutathione peroxidase activities.

Keshan disease is a cardiomyopathy restricted to the endemic areas of China and seen in residents having an extremely low selenium (Se) status. Prophylactic administration of sodium selenite has been shown to decrease significantly the incidence of acute and subacute cases. The aim offthe study was to assess the relative bioavailability of selenite versus organic Se-yeast in a Se-deficient area in China with a randomized double-blind double-dummy design. Healthy children (n=30) between 14 and 16 yr of age were randomized into three equal groups receiving either 200 microg/d selenite Se or 200 microg/d Se-yeast or placebo for 12 wk. Blood was drawn at baseline, 4, 8, and 12 wk and 4 wk postsupplementation. The plasma Se concentration (mean +/- SD) was 0.16+/-0.03 micromol/L at baseline. Selenite and Se-yeast supplementation increased plasma Se to plateau values, 1.0+/-0.2 and 1.3+/-0.2 micromol/L, respectively. In red cells, Se-yeast increased the selenium level sixfold and selenite threefold compared to placebo. The relative bioavailability of Se-yeast versus selenite measured as glutathione peroxidase (GSHPx) activity was similar in plasma, red blood cells, and platelets. GSHPx activity reached maximal levels in plasma and platelets of 300% and 200%, respectively, after 8 wk compared to the placebo group, but continued to increase in red cells for 16 wk. Our study showed that although both forms of Se were equally effective in raising GSHPx activity, Se-yeast provided a longer lasting body pool of Se. Se-yeast may be a better alternative to selenite in the prophylaxis of Keshan disease with respect to building up of body stores.

Adolescent↗

PubMed1999

[Plasma homocysteine concentration in healthy middle-aged men and its presumed association with cardiovascular mortality].

It has recently become clear that hyperhomocysteinemia is an independent risk factor for vascular diseases. The plasma homocysteine concentrations of 71 healthy men (aged 40-49) living in Hungary were compared with those of randomly selected healthy age-matched men (n = 260) living in 11 different countries. The association between the mean plasma homocysteine concentration and reported cardiovascular mortality was analyzed in the respective countries. In Hungary the mean (+/- SD) plasma homocysteine concentration was 10.6 +/- 4.3 mumol/l. In the 11 other countries the mean (+/- SD) plasma homocysteine concentration ranged from 7.1 +/- 1.4 mumol/l (Schleiz, Germany, n = 20) to 10.7 +/- 2.1 mumol/l (Kuopio, Finland, n = 20). There was a significant correlation (r = 0.71, p < 0.005) between the plasma homocysteine concentration and male cardiovascular mortality in there countries. The strength of the correlation between the male plasma homocysteine concentration and cardiovascular mortality suggests that homocysteine may be an important factor in the variation of cardiovascular mortality between populations. The mean plasma homocysteine concentrations were the highest in the Hungarian (Budapest and Pest county) and the Finnish (Kuopio) groups but cardiovascular mortality is higher in Hungary than in Finland, referring to the pivotal role of other cardiovascular risk factors for the Hungarian population.

Adult↗