Biomedical subjects

L Tenkanen

Publications and source records attributed to L Tenkanen.

At least 37 records · Page 2Linked to original sources

PubMed1994

The Helsinki Heart Study: coronary heart disease incidence during an extended follow-up.

OBJECTIVES: To confirm that coronary heart disease (CHD) can be prevented by gemfibrozil treatment and to estimate the long-term effect of the treatment. DESIGN: All participants of the Helsinki Heart Study, a controlled 5-year CHD primary prevention trial with gemfibrozil and placebo, were offered gemfibrozil treatment and biannual follow-up for 3.5 more years. SETTING: By the end of the multi-clinic double-blind trial, a 34% difference in definite cardiac events (56 vs. 84; P < 0.2) had developed between the gemfibrozil and placebo groups. SUBJECTS: There were 2046 dyslipidaemic men in the gemfibrozil group at randomization, 1961 started the extended follow-up; the comparison group comprised 2035 men, and 5 years later 1928 men. INTERVENTIONS: Gemfibrozil was selected by 66.3% of gemfibrozil and 68.5% of placebo men without previous CHD end-points. MAIN OUTCOME MEASURES: Definite fatal and non-fatal CHD events are reported, possible CHD events were recorded but reported selectively. RESULTS: During the post-trial period the numbers of definite CHD events in both groups (54 vs. 47; NS) were smaller than expected without treatment, namely a reduction of around 40% for the original treatment groups. The mean incidence rates were in fact similar to that in the placebo group 5 years earlier. The post-trial CHD incidence was lowest amongst the placebo group men who later selected gemfibrozil. Cardiovascular mortality over the entire study period was similar but all-cause mortality was slightly higher amongst men of the original gemfibrozil group compared to the placebo group men (P = 0.19). CONCLUSIONS: Thus prolonged gemfibrozil treatment postpones cardiac events. This protective effect presumably involves both attenuation of atherosclerosis and mechanisms related to acute cardiac events.

Adult↗

PubMed1993

Migration to towns, occupation, smoking, and lung cancer: experience from the Finnish-Norwegian lung cancer study.

A total of 4,604 men who were interviewed in Finland in 1962 in connection with the Finnish-Norwegian lung-cancer study were followed-up for lung cancer during 1963-87 to establish why urbanized (via migration) men who smoked had a greater lung-cancer risk than native urban smokers. Exposure to occupational carcinogens was inferred from the title of the longest job held. A clear dose-response relation between occupational exposure and lung cancer was found in the urbanized but not among the native urban dwellers. The extra risk associated with migration to towns and smoking was found especially by those urbanized subjects who worked in heavily exposed industries: their lung cancer risk was more than twice that of native urban men in similar jobs, while those urbanized subjects in academic or clerical jobs showed no increased risk when compared with native urban men in corresponding work. Cardiorespiratory symptoms had a prognostic value in every residential group, but especially among the urbanized. Urbanized men who smoked and worked in heavily exposed industries, and suffered from shortness of breath, had a fourfold risk of lung cancer when compared with native urban smokers without this symptom. We conclude that although the joint effect of smoking and occupational exposure is the main explanatory factor for high risk of lung cancer in urbanized males, environmental and psychosocial factors also may have a contributory effect.

Cohort Studies↗

PubMed1993

High-density lipoprotein cholesterol elevation with gemfibrozil: effects of baseline level and modifying factors.

The effects of baseline level and modifying factors on gemfibrozil-induced high-density lipoprotein (HDL) cholesterol elevation were studied in 1028 participants with good compliance in the Helsinki Heart Study. The absolute (mmol/L) increment in HDL cholesterol was independent of baseline when the change in the placebo group (regression toward the mean) was considered. In contrast, absolute reductions in low-density lipoprotein (LDL) cholesterol and triglycerides correlated with their baselines, relative percentage changes being constant. Statistically, this could indicate differences in the mode of action of gemfibrozil: an independent and additive effect on HDL cholesterol and a multiplicative effect on LDL cholesterol and triglycerides. These differences may have a physiologic background because the main effect of gemfibrozil is in the stable HDL3 subfraction, rather than in the variable HDL2. Only 13% of the variation in gemfibrozil-induced HDL cholesterol changes were explained by modifying factors. The basic assumptions in the uses of absolute or relative changes as a measure of treatment effect are discussed.

Adult↗

PubMed1992

Chronic Chlamydia pneumoniae infection as a risk factor for coronary heart disease in the Helsinki Heart Study.

OBJECTIVE: To investigate in the prospective Helsinki Heart Study, whether chronic Chlamydia pneumoniae infection, indicated by elevated antibody titers against the pathogen, chlamydial lipopolysaccharide-containing immune complexes, or both, is a risk factor for coronary heart disease. DESIGN AND SETTING: The Helsinki Heart Study was a randomized, double-blind, 5-year clinical trial to test the efficacy of gemfibrozil in reducing the risk for coronary heart disease. Participants were randomized to receive either gemfibrozil (2046 patients) or placebo (2035 patients). Fatal and nonfatal myocardial infarction and sudden cardiac death were the main study end points. Serum samples were collected at 3-month intervals from all patients. PATIENTS: One hundred forty cardiac events occurred during the follow-up period. Serum samples from 103 case patients obtained 3 to 6 months before a cardiac end point were matched with those from controls for time point, locality, and treatment. Samples were tested for markers of chronic chlamydial infection. MEASUREMENTS: Immunoglobulin A (IgA) and G (IgG) antibodies to C. pneumoniae were measured using the microimmunofluorescence method. Lipopolysaccharide-containing immune complexes were measured using two antigen-specific enzyme immunoassays, the lipopolysaccharide-capture and immunoglobulin M (IgM)-capture methods. MAIN RESULTS: Using a conditional logistic regression model, odds ratios for the development of coronary heart disease were 2.7 (95% CI, 1.1 to 6.5) for elevated IgA titers, 2.1 (CI, 1.1 to 3.9) for the presence of immune complexes, and 2.9 (CI, 1.5 to 5.4) for the presence of both factors. If we adjusted for other coronary heart disease risk factors such as age, hypertension, and smoking, the corresponding values would be 2.3 (CI, 0.9 to 6.2), 1.8 (CI, 0.9 to 3.6), and 2.6 (CI, 1.3 to 5.2), respectively. CONCLUSION: The results suggest that chronic C. pneumoniae infection may be a significant risk factor for the development of coronary heart disease.

Adult↗

PubMed1992

Leukocytes as a coronary risk factor in a dyslipidemic male population.

The role of an elevated serum leukocyte count (WBC) as a coronary risk factor was investigated using a nested case-control design in dyslipidemic middle-aged men (n = 420) participating in the Helsinki Heart Study, a coronary primary prevention trial. Baseline WBC was significantly higher, 6.93 (2.11) x 10(9)/L in subjects with cardiac events, than in controls, 6.26 (1.88) x 10(9)/L; p less than 0.002. This association was time-dependent, however, since the difference was not significant for events occurring during the second half of the 5-year study. Using nonsmokers in the lowest WBC tertile as the reference sample, the relative risks in the highest WBC tertile were 1.86 (95% confidence intervals [CI] 0.81 to 4.28) for nonsmokers and 3.07 (95% CI 2.23 to 8.19) for smokers. Logistic regression analysis including smoking in the model disclosed an independent contribution of elevated WBC to coronary heart disease. We conclude that elevated leukocyte count was a coronary risk factor even in this dyslipidemic population.

Case-Control Studies↗

PubMed1992

Joint effects of serum triglyceride and LDL cholesterol and HDL cholesterol concentrations on coronary heart disease risk in the Helsinki Heart Study. Implications for treatment.

BACKGROUND: We studied the joint effect of baseline triglyceride and lipoprotein cholesterol levels on the incidence of cardiac end points in the trial group (n = 4,081) of the Helsinki Heart Study, a 5-year randomized coronary primary prevention trial among dyslipidemic middle-aged men. The relative risks (RR) were calculated using Cox proportional hazards models with a dummy variable technique that allows simultaneous study of subgroup combinations from the placebo and treatment groups. METHODS AND RESULTS: In the placebo group (n = 2,045), the low density lipoprotein cholesterol (LDL-C)/high density lipoprotein cholesterol (HDL-C) ratio was the best single predictor of cardiac events. This ratio in combination with the serum triglyceride level revealed a high-risk subgroup: subjects with LDL-C/HDL-C ratio greater than 5 and triglycerides greater than 2.3 mmol/l had a RR of 3.8 (95% CI, 2.2-6.6) compared with those with LDL-C/HDL-C ratio less than or equal to 5 and triglyceride concentration less than or equal to 2.3 mmol/l. In subjects with triglyceride concentration greater than 2.3 mmol/l and LDL-C/HDL-C ratio less than or equal to 5, RR was close to unity (1.1), whereas in those with triglyceride level less than or equal to 2.3 mmol/l and LDL-C/HDL-C ratio greater than 5, RR was 1.2. The high-risk group with LDL-C/HDL-C ratio greater than 5 and triglyceride level greater than 2.3 mmol/l profited most from treatment with gemfibrozil, with a 71% lower incidence of coronary heart disease events than the corresponding placebo subgroup. In all other subgroups, the reduction in CHD incidence was substantially smaller. CONCLUSIONS: Serum triglyceride concentration has prognostic value, both for assessing coronary heart disease risk and in predicting the effect of gemfibrozil treatment, especially when used in combination with HDL-C and LDL-C.

Adult↗

PubMed1991

Lifestyle determinants of HDL2- and HDL3-cholesterol levels in a hypercholesterolemic male population.

In this cross-sectional study we investigated the role of lifestyle and other factors in determining serum HDL2- and HDL3-cholesterol levels among 82 dyslipidemic (total cholesterol minus HDL-cholesterol greater than or equal to 5.2 mmol/l) middle-aged participants of the Helsinki Heart Study. Alcohol consumption correlated positively with both subfractions of HDL-cholesterol, while leisure time physical activity had a significant correlation with the HDL3-subfraction only. HDL levels were lower in smokers than in non-smokers but the differences were not statistically significant. Using the multiple linear regression model, alcohol consumption emerged as the only significant factor influencing both HDL cholesterol subfraction levels. Leisure time physical activity had an independent contribution to HDL3-level, but lifestyle variables other than alcohol consumption did not contribute significantly to HDL2-cholesterol level. The model incorporating alcohol consumption, physical activity, smoking and relative body weight explained 13.4% of the variation in HDL2 and 17.5% in HDL3-cholesterol.

Alcohol Drinking↗

PubMed1991

The Helsinki Heart Study: central findings and clinical implications.

This paper describes the central findings and discusses the clinical implications of the Helsinki Heart Study. This was a controlled primary prevention trial to test the hypothesis that using gemfibrozil to lower the concentrations of serum low density lipoprotein (LDL) and very low density lipoprotein (VLDL) and to raise that of high density lipoprotein (HDL) protects subjects against coronary heart disease.

Adult↗

PubMed1990

Lipoproteins and coronary heart disease in the Helsinki Heart Study.

The changes in serum lipids in men treated with gemfibrozil in the Helsinki Heart Study, a controlled primary prevention trial of coronary heart disease, varied according to baseline lipid levels, type of dyslipidaemia, and treatment compliance. In subjects with the best treatment compliance, gemfibrozil induced mean decreases of 14% in total cholesterol, 15% in low density lipoprotein (LDL)-cholesterol, and 45% in triglycerides, and a mean increase of 14% in high density lipoprotein (HDL)-cholesterol, compared with placebo. These changes were significantly greater than those observed in the entire cohort. There was a strong association between baseline levels and the response to treatment (expressed as the difference in mmol l-1 between the gemfibrozil- and placebo-treated groups) for LDL-cholesterol and triglycerides. In contrast, the corresponding change in HDL-cholesterol was not dependent on the baseline level. Ultracentrifuge analysis in a subsample of the cohort revealed that gemfibrozil raised the level of HDL3-cholesterol but had little effect on HDL2-cholesterol. The gemfibrozil-associated reduction in the incidence of definite coronary events varied according to lipid values at baseline and their changes during treatment. The greatest reductions were seen in subjects with low initial HDL-cholesterol and high initial triglycerides. In the gemfibrozil group, the increase in HDL-cholesterol and decrease in LDL-cholesterol were associated with significantly lower risk of coronary events.

Coronary Disease↗

PubMed1990

HDL-cholesterol as a risk factor in coronary heart disease. An update of the Helsinki Heart Study.

The aim of the Helsinki Heart Study, a 5-year primary prevention placebo-controlled study involving 4081 dyslipidaemic men (aged 40 to 55 years), was to investigate if increasing high density lipoprotein (HDL)-cholesterol plasma levels and decreasing low density lipoprotein (LDL)-cholesterol levels would reduce the incidence of coronary heart disease. Gemfibrozil 600mg twice daily was administered to induce these changes in lipoprotein levels. Baseline HDL-cholesterol levels in the study group were similar to those in the general population. Data from patients treated with placebo were analysed to investigate the influence of HDL-cholesterol levels on the incidence of coronary heart disease. Using the number of cardiac end-points per 1000 person-years to indicate the risk of coronary heart disease, it was clear that elevated HDL-cholesterol levels reduced the risk of coronary heart disease while the incidence increased at low HDL-cholesterol levels. This relationship was not altered when the effect of HDL-cholesterol levels was analysed jointly with other coronary risk factors (age, smoking or blood pressure). A weaker association was seen between LDL-cholesterol and risk of coronary heart disease, and triglycerides appeared to have no significant effect on the incidence of the disease. The data clearly suggest that HDL-cholesterol is a strong predictor of the incidence of coronary heart disease in the placebo group of the Helsinki Heart Study.

Cholesterol↗

PubMed1989

Relation between baseline lipid and lipoprotein values and the incidence of coronary heart disease in the Helsinki Heart Study.

A 34% reduction in the incidence of definite coronary heart disease events was observed in dyslipidemic men treated with gemfibrozil in the Helsinki Heart Study, a controlled 5-year, double-blind primary prevention trial for coronary heart disease. Over the entire study period, gemfibrozil therapy induced mean decreases of 10% in serum total cholesterol levels, 11% in low-density lipoprotein (LDL) cholesterol, 35% in triglyceride levels, and a mean increase of 11% in high-density lipoprotein (HDL) cholesterol level, compared with placebo. The differences in percentage changes in LDL cholesterol between gemfibrozil- and placebo-treated men varied among Fredrickson hyperlipoproteinemia types; after 1 year of treatment the difference was greatest for type IIA hyperlipoproteinemia (14 percentage units) and smallest for IIB hyperlipoproteinemia (3 percentage units). The treatment-associated changes in HDL cholesterol and triglycerides did not differ materially between the 3 hyperlipoproteinemia types, when calculated in the same way. The gemfibrozil-associated reduction in incidence of definite coronary events varied among Fredrickson types and among tertiles of baseline HDL cholesterol and triglycerides. The greatest rate reductions were seen in subjects with type IIB hyperlipoproteinemia, low initial HDL level or high initial triglycerides. These results suggest that subjects with low HDL cholesterol and type IIB hyperlipoproteinemia (and possibly type IV hyperlipoproteinemia) would benefit from treatment with gemfibrozil.

Adult↗

PubMed1987

Smoking and cardiac symptoms as predictors of lung cancer.

In 1962, a cohort of 4604 Finnish men was interviewed about their smoking habits and cardiorespiratory symptoms. The cohort was followed up for deaths and incidence of lung cancer from 1963 to 1980 in order to study the effect of smoking and cardiac symptoms on the incidence of lung cancer. When analyzed simultaneously with smoking, the symptoms of angina, possible infarction and shortness of breath were all significantly associated with increased lung cancer risk. For example, the RR of lung cancer among those with possible infarction was 2.4, when age and smoking were adjusted for, and 1.8, when additionally shortness of breath and angina-like chest pain were adjusted for. Among smokers of greater than or equal to 15 g/day, those with symptoms of angina displayed a considerable excess risk (RR 2.5). A broad range of impairments of the cardiopulmonary functions seem to be associated with the carcinogenic processes invoked by smoking.

Angina Pectoris↗

PubMed1987

The joint effect of smoking and respiratory symptoms on risk of lung cancer.

In 1962 a cohort of 4604 Finnish men were interviewed about their smoking habits and cardiorespiratory symptoms. The cohort was followed up for deaths and incidence of lung cancer from 1963 to 1980 in order to study the effect of smoking and respiratory symptoms on the risk of lung cancer. The joint effect of smoking, age and respiratory symptoms on the risk of lung cancer was studied using a log-linear modelling technique. When analysed simultaneously with smoking, the symptoms of phlegm, shortness of breath and wheezing were all significantly associated with increased lung cancer risk. The joint effect of smoking and phlegm as well as that of smoking and wheezing was close to being multiplicative. Even if smoking is a causative factor in both these symptoms and in lung cancer, the symptoms seem to have a separate role as predictors of lung cancer risk.

Age Factors↗

PubMed1987

Is smoking sufficient to explain the large difference in lung cancer incidence between Finland and Norway?

In the 1960s, lung cancer among Finnish men was about 3.5 times as common as among Norwegian men. A study by Pedersen et al. in 1962 indicated that the difference in contemporary smoking habits could account for only part of the difference in lung cancer incidence in men between the countries. In that study, smoking habits in Finland and Norway were investigated via interviews of 8,700 people from six areas of each country. For the present study the Finnish and Norwegian cancer registries have followed lung cancer morbidity in those areas. When the interval between the recording of smoking habits and lung cancer incidence was 15 years, after adjustment for age and smoking habits, the Finnish males had a relative risk between 1.1 and 1.6 compared with Norwegian men. The results suggest that, given a sufficiently long latency period, almost the entire difference between Finnish and Norwegian men could be attributed to smoking habits.

Adult↗

PubMed1987

Migration, marital status and smoking as risk determinants of cancer.

To study the importance of migration to urban area, marital status and smoking as risk factors in cancer, a cohort of 4,475 Finnish men was followed up for the occurrence of cancer during the period 1964-1980. Of particular interest was the interaction of migration or marital status with smoking. For cancers at all sites, not married urbanized smoking men had the greatest risk, followed by not married native urban smokers. This pattern was mainly due to high risk of cancers of the lung and larynx among the urbanized men, with a risk peak among urbanized not married smokers. The pattern persisted even when the amount smoked was allowed for. The importance in lung cancer epidemiology of vitamin A deficiency, occupation and psychosocial stress was discussed, and some support was found for the role of psychosocial stress in both the migration and the marital status factors.

Aged↗

PubMed1987

Testing equality of relative survival patterns based on aggregated data.

The relative survival rate is defined as the ratio of the survival rate observed in a patient group under consideration to the survival rate expected in a group of people similar to the patient group at the beginning of the follow-up interval, with respect to all possible factors (e.g., age and sex) affecting survival, except the disease under study. Survival from cancer and other chronic diseases is often measured by this quantity, which is adjusted for the effect of mortality attributable to competing risks of death. In this paper, maximum likelihood ratio tests are constructed on the basis of aggregated data for testing the equality of relative survival rates between patient groups against proportional hazards and general alternative hypotheses. The tests are applied to the Finnish nationwide data on colon cancer patients with nonlocalized tumors as reported to the Finnish Cancer Registry. Simulation studies show that the maximum likelihood ratio tests compare favorably with alternative methods proposed earlier. Moreover, the maximum likelihood ratio tests are more extensive in coverage and are based on more applicable alternative hypotheses than the other test statistics. Finally, an extension to proportional hazards regression models of the relative survival rates is suggested.

Biometry↗

PubMed1986

Neuropsychological methods in the differentiation of organic solvent intoxication from certain neurological conditions.

Neuropsychological impairment and the subjective symptoms of 21 patients with organic solvent intoxication were compared with those of patients with vertebrobasilar insufficiency (n = 16), cerebral trauma (n = 16), and headache (n = 15). The aim was to study the diagnostic efficiency of psychological methods in the neuropsychological assessment of patients with suspected solvent intoxications. Our results suggest that it is possible to differentiate between the four groups at group level; however, because of the variance in each group, no specific rule for individual diagnostics can be given. At group level, a combination of three test variables and three symptom scales yielded the most effective discrimination. Instead of the raw scores, subscores for the individual tests as well as detailed use of the symptom questionnaire were informative when the groups were compared. This approach may also be applicable to individual diagnostics.

Brain Damage, Chronic↗

PubMed1985

Sauna, dust and migration as risk factors in lung cancer among smoking and non-smoking males in Finland.

To study possible causes of the high lung cancer incidence among Finnish males, the Finnish Cancer Registry and the Cancer Registry of Norway in 1962 performed a population survey covering smoking habits, occupational and residential history and, in Finland, sauna habits. The cohort of 4,475 Finnish men has now been followed up for incidence of lung cancer in 1964-1979. The relative importance of 3 factors--sauna baths, occupational exposure to dust, and migration to urban areas--was studied in different smoking categories. Among smokers of greater than or equal to 25 g/day, takers of frequent saunas (more than once a week) displayed some excess risk (RR 1.7). In smokers an increased risk was also found among those exposed to dust (RR 1.3), and those who had migrated to urban areas (RR 1.8, when compared to native urban population). Dust exposure and migration factors act synergistically with smoking. Migration was the only factor apart from smoking to show a substantial population-attributable risk, which amounted to 10%.

Dust↗