Search PubMed⌕ Search

Biomedical subjects

J Virtamo

Publications and source records attributed to J Virtamo.

At least 19 recordsLinked to original sources
PubMed1995

Effects of alpha-tocopherol and beta-carotene supplements on cancer incidence in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study.

The Alpha-Tocopherol Beta-Carotene (ATBC) Cancer Prevention Study was a placebo-controlled, randomized intervention trial testing the hypothesis that beta-carotene and alpha-tocopherol (vitamin E) supplements prevent lung and other cancers. The study is predicated on a substantial body of evidence supporting a role in cancer prevention for these micronutrients. Based on the 2 x 2 factorial study design, 29,133 eligible male cigarette smokers aged 50-69 y were randomly assigned to receive beta-carotene (20 mg), alpha-tocopherol (50 mg), beta-carotene and alpha-tocopherol, or placebo daily for 5-8 y. Capsule compliance was high (median = 99%). beta-Carotene treatment did not result in a decrease in cancer at any of the major sites but rather in an increase at several sites, most notably lung, prostate, and stomach (number of cases 474 compared with 402, 138 compared with 112, and 70 compared with 56, respectively). The vitamin E group had fewer incident cancers of the prostate and colorectum compared with the group not receiving vitamin E (number of cases 99 compared with 151 and 68 compared with 81, respectively), but more cancers of the stomach (70 compared with 56). In contrast to these intervention-based findings for beta-carotene and vitamin E supplements, we observed lower lung cancer rates in men with higher amounts of both serum and dietary beta-carotene and vitamin E at baseline.

Aged↗
PubMed1992

Serum beta-carotene before and after beta-carotene supplementation.

A two-month double-blind, placebo-controlled supplementation study of oral beta-carotene (20 mg daily) was conducted. Two hundred and twenty two 30-69 year old men were randomized into either a beta-carotene or placebo group, and serum samples were obtained at baseline, follow-up (2 months), and up to 12 weeks post-supplementation. Serum beta-carotene increased on average 10-fold in the beta-carotene group, from 0.53 +/- 0.32 mumol/l (mean +/- SD) at baseline to 4.99 +/- 2.47 mumol/l at follow-up (P less than 0.0001), and beta-carotene levels remained elevated up to 12 weeks post-supplementation (0.61 +/- 0.15 mumol/l). No changes in serum retinol, alpha-tocopherol, or total cholesterol were observed. At baseline, serum beta-carotene levels were positively correlated with dietary beta-carotene (r = 0.29) and inversely correlated with body mass index and serum gamma-glutamyltransferase (r = -0.33 and r = -0.40, respectively). The inverse association with body mass index and serum gamma-glutamyltransferase persisted during active supplementation, whereas the positive association with dietary beta-carotene disappeared. In multivariate analysis, serum cholesterol was also positively associated with serum beta-carotene levels both before and after supplementation. Baseline serum beta-carotene was the factor most strongly associated (positively) with serum beta-carotene after supplementation. Our study highlights the importance of several factors which affect serum beta-carotene.

Administration, Oral↗
PubMed1991

Dietary cholesterol, fatty acids, and the risk of lung cancer among men.

The relation between dietary cholesterol and fatty acids and the incidence of lung cancer was studied among 4,538 Finnish men aged 20-69 years and initially free of cancer. During 20 years of follow-up, 117 lung cancer cases were diagnosed. Cholesterol intake was not associated with lung cancer risk, the age-, smoking-, and energy-adjusted relative risk between the lowest and highest tertiles being 1.0 [95% confidence interval (CI) = 0.6-1.9]. The intake of saturated fatty acids was nonsignificantly related with lung cancer incidence, the relative risk for the lowest compared with the highest tertile being 1.6 (CI = 0.8-3.2). The association was stronger among smokers than among nonsmokers, the relative risks being 2.1 (CI = 1.0-4.3) and 1.3 (CI = 0.4-4.1), respectively. The relative risk among smokers, however, decreased to 1.5 after adjustment for the amount they smoked. In the total cohort, there was a significantly elevated risk of lung cancer among men with a high intake of butter, one of the main sources of saturated fatty acids, the relative risk being 1.9 (CI = 1.1-3.2). The present data do not confirm previous results suggesting that dietary cholesterol predicts the occurrence of lung cancer among men. The association between intake of saturated fatty acids and lung cancer observed in the present study may be partly due to heavy smoking among high consumers of saturated fat.

Adult↗
PubMed1990

Effect of sampling site on fatty acid composition of human breast adipose tissue.

The effect of sampling site and proximity of malignant tumor on the relative fatty acid composition of human breast adipose tissue was studied in 10 cases of breast cancer. The four anatomic quadrants of breast did not statistically significantly differ from each other in relation to any of the 30 fatty acids studied. Proximity of the malignant tumor did not affect the relative fatty acid composition of fat when compared with more distant sampling sites. Representative samples of breast adipose tissue for fatty acid composition analysis can be obtained from tissue adjacent to the tumor.

Adipose Tissue↗
PubMed1990

Variability in nutrient and food intakes among older middle-aged men. Implications for design of epidemiologic and validation studies using food recording.

The authors conducted a dietary methodology study in 1984 in Finnish men aged 55-69 years in order to validate two dietary assessment instruments being used in the US-Finland Alpha-Tocopherol, Beta-Carotene Lung Cancer Prevention Trial. Twelve 2-day food records collected from 162 men over a 6-month period, including every day of the week, served as the reference measure. This report focuses on three important questions for investigating diet and disease relations: 1) How many days are necessary to classify "usual" intake? 2) Is there loss as a result of using consecutive days? 3) Which days are necessary for assessment and classification of "usual" diet? A repeated-measures regression model was used to estimate the variance components and the effects of consecutive days, weekday (weekday vs. weekend), and season. Correlations between the averages of different numbers of days of food records and "true" usual intake were examined along with the resulting attenuations in relative risk. Results suggest that 7-14 days are required to adequately classify most individuals into categories of intake for most nutrients and some foods. There appears to be some loss of information from using consecutive days rather than days further apart. Weekday/weekend differences in mean intakes are slight, and the rank ordering of individuals appears to be preserved. A moderate seasonal effect is shown for classification of fruits, but only a slight one is seen for micronutrients and berries. Implications for the design of epidemiologic and validation studies are discussed.

Aged↗
PubMed1988

Reproducibility and validity of dietary assessment instruments. I. A self-administered food use questionnaire with a portion size picture booklet.

A self-administered food use questionnaire which included 276 food items and mixed dishes and a portion size picture booklet with 122 photographs was developed for a large lung cancer intervention trial among approximately 27,000 Finnish men aged 50-69 years. The reproducibility and validity of this questionnaire were studied from March to October 1984. In the reproducibility study, 121 men aged 55-69 years completed the questionnaire three times, at three-month intervals. The intraclass correlations varied from 0.56 for vitamin A to 0.88 for alcohol, with most falling between 0.60 and 0.70. In the validity study, 190 men of similar age kept food consumption records for 12 two-day periods, distributed evenly over a period of six months, and filled in the questionnaire both before and after this period. Correlations between nutrient intake values from the food records and the food use questionnaires ranged from 0.40 for selenium to 0.80 for alcohol. Among subjects who belonged to the lowest quintile on the basis of the food record measurement, an average of 51 per cent fell into the same quintile and 76 per cent fell into the lowest two quintiles when they were categorized on the basis of the food use questionnaire. Findings were similar for the upper tail of the distribution. These data indicate that the self-administered food use questionnaire is useful for measuring individual or group intakes for a variety of nutrients.

Aged↗
PubMed1988

Reproducibility and validity of dietary assessment instruments. II. A qualitative food frequency questionnaire.

The reproducibility and validity of a food frequency questionnaire designed to measure intakes of total fat, saturated and polyunsaturated fats, vitamins A, C, and E, selenium, and dietary fiber were tested from March to October 1984 among 297 Finnish men aged 55-69 years. The questionnaire asked about consumption of 44 food items. In the reproducibility study, 107 subjects filled in the questionnaire three times, at three-month intervals. Intraclass correlations varied from 0.52 for vitamin A to 0.85 for polyunsaturated fat. In the validity study, 190 subjects kept food consumption records for 12 two-day periods distributed evenly over a period of six months and filled in the questionnaire both before and after this period. Correlations between the nutrient intake values from the food records and those from the food frequency questionnaires ranged from 0.33 for selenium to 0.68 for polyunsaturated fat. On the average, 40-45% of the subjects in the lowest and highest quintiles based on food records were in the same respective quintiles when assessed by the food frequency questionnaire, and 70-75% were in the two lowest and two highest questionnaire quintiles, respectively. The food frequency questionnaire and a quantitative food use questionnaire tested in the same study were compared. Use of these two instruments in large-scale epidemiologic studies is discussed.

Ascorbic Acid↗
PubMed1988

Saliva concentrations of some selected proteins and glycoprotein markers in man after supplementary intake of beta-carotene.

Vitamin A has profound effects on cell biology, morphology and function of excretory cells. In the present study we investigated the effect of supplementation with beta-carotene (provitamin A) on the secretion of salivary glycoproteins and some antibacterial components. Eighty-nine men, drawn from a larger double-blind pilot study among Finnish men of a high socio-economic standard, participated in this study which lasted for 60 days. The men were allocated either to beta-carotene supplementation of 20 mg a day or to placebo treatment. At the end of the study samples of stimulated whole and parotid saliva were collected and examined for total protein as well as hexosamine, sialic acid, thiocyanate and the activity of salivary peroxidase. The secretion rate of whole saliva was calculated and the activities of lysozyme, a bacteria aggregating glycoprotein (BAGP) and secretory IgA were measured in parotid saliva. Significantly higher levels of beta-carotene, but not retinol, were found in serum and whole saliva in the beta-carotene group compared to the placebo group. Retinol or beta-carotene could not be detected in parotid saliva. No difference was found either in saliva secretion rate or in the composition of whole or parotid saliva between the beta-carotene and the placebo group.

Adult↗
PubMed1987

Serum selenium and risk of cancer. A prospective follow-up of nine years.

The association between serum selenium concentration and the risk of cancer was studied in 1110 men aged 55 to 74 years in two rural areas of Finland. The men were followed-up prospectively for 9 years and there were 109 new cases of cancer, with the cases of the first follow-up year excluded. The serum selenium concentrations were adjusted for age, area, smoking, serum cholesterol, and alcohol intake. The patients had a slightly lower adjusted mean serum selenium than the subjects without cancer at the end of the follow-up (+/- standard error of mean) 53.9 +/- 1.5 and 55.3 +/- 0.5 micrograms/l, respectively. The relative risks of cancer were essentially the same when these were calculated in the tertiles of the serum selenium distribution. Thirty-seven men had a history of cancer at baseline or had cancer diagnosed during the first follow-up year and their adjusted mean serum selenium was 49.4 +/- 2.6 micrograms/l, which was significantly lower (P less than 0.05) than that of the subjects without cancer during the follow-up.

Aged↗
PubMed1985

Serum selenium and the risk of coronary heart disease and stroke.

The association between serum selenium concentration and five-year risk of cardiovascular disease was studied in 1,110 men aged 55 to 74 years in two rural areas of Finland. In the total cohort, all-cause and cardiovascular deaths were associated significantly with serum selenium of less than 45 micrograms/liter, an adjusted relative risk of 1.4 (95% confidence interval (Cl), 1.0-2.0, p less than 0.05) and 1.6 (95% Cl, 1.1-2.3, p less than 0.05), respectively. Among men free of coronary heart disease at the outset, these associations were of similar magnitude but did not attain statistical significance. Among men free of stroke at the outset, low serum selenium was associated significantly with stroke mortality, an adjusted relative risk of 3.7 (95% Cl, 1.0-13.1). The associations of coronary deaths and myocardial infarctions with low serum selenium were nonsignificant.

Aged↗
PubMed1983

Serum HDL cholesterol in a high coronary risk population in eastern Finland.

The serum high density lipoprotein (HDL) and total cholesterol levels and their determinants were explored in a random population sample from eastern Finland, an area with an exceptionally high mortality and morbidity from coronary heart disease (CHD). A total of 1792 persons aged 14-65 years were studied. Serum HDL cholesterol was determined in one series by using an enzymatic method after precipitation by dextran-magnesium chloride. The mean serum HDL cholesterol was 1.41 mmol/l in men and 1.62 mmol/l in women. Although a multivariate linear regression model explained 21% (for men) and 28% (for women) of the variation in serum total cholesterol, the same variables were able to account for only 9 and 4%, respectively, of the variation in serum HDL cholesterol. Among men, obesity and the daily consumption of tobacco products were inversely associated and the weekly consumption of beer and age were directly associated with serum HDL cholesterol and the serum HDL cholesterol/total cholesterol ratio.

Adolescent↗
PubMed1982

Plasma prekallikrein, kallikrein inhibitors, kininogen and lipids during gemfibrozil treatment in type II dyslipidaemia.

The effects of gemfibrozil on plasma prekallikrein, kallikrein inhibitors, kininogen and plasma lipids were investigated in 31 male subjects having either type IIA or IIB dyslipidaemia. During gemfibrozil use, plasma prekallikrein and kininogen were increased significantly while kallikrein inhibitors increased only slightly. Total cholesterol and triglycerides decreased while HDL cholesterol was increased. Changes in prekallikrein and HDL cholesterol were correlated, whereas no other significant correlations between changes in lipid and kinin parameters were seen. The observed changes in prekallikrein and kininogen possibly indicate a shift in the thrombo-haemorrhagic balance in favour for increased fibrinolysis. If so, the effects of gemfibrozil in prevention and management of atherosclerosis would not be solely due to correlation of the dyslipidaemia but also to protection against the accelerated coagulation tendency seen in type II dyslipidaemia.

Adult↗
PubMed1980

Hypertension control in North Karelia before the intervention of the North Karelia Project.

The baseline survey of the North Karelia Project was carried out to measure the level of cardiovascular risk factors in the target population. These data on the prevalence, detection and treatment of hypertension obtained in the survey were utilized in planning the main programme. The survey was carried out in 1972 and 4275 persons aged from 25 to 59 (6.5% random sample) were examined. The prevalence of hypertension was high--21% of women and 15% of men were judged as being in need of treatment for hypertension. The blood pressure level of men was higher than that of women below 45 years of age, but in all age groups women were more often undergoing treatment. Although majority of people had had their blood pressure checked recently, only half of those who were aware of hypertension had ever been under treatment, and at the time of examination only 13% of those men and 10% of those women had restored normotension. Only one-fifth and one-third of the women who had used drugs had been under treatment for more than 5 years. Thus, the need to provide a systematic hypertension control scheme in North Karelia was urgent, as described in many other communities in the developed world. The main reason for this lies in the inability of the health care system which has not been able to maintain patients on long-term follow-up and treatment.

Adult↗