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M Koskenvuo

Publications and source records attributed to M Koskenvuo.

At least 163 records · Page 9Linked to original sources
PubMed1991

Genetic factors in epileptic seizures: evidence from a large twin population.

The Finnish Twin Cohort study (27,776 individuals; all twins of the same sex born before 1958 and alive in 1967) detected 316 cases of epileptic seizures occurring in 310 twin pairs: 89 monozygotic pairs and 221 dizygotic pairs, including three concordant monozygotic pairs and three concordant dizygotic pairs. The ratio of the observed to expected number of concordant pairs for epileptic seizures was 5.48 (90% CL 1.5-14.2) in monozygotic and 2.12 (90% CL 0.6-5.5) in dizygotic pairs. The results suggest that 8% to 27% of the incidence of epileptic seizures is related to genetic variability. The study of environmental differences in discordant monozygotic pairs should provide insights into the etiology of this group of disorders.

Adolescent↗
PubMed1991

Exposure to organic solvents and neuropsychological dysfunction: a study on monozygotic twins.

Twenty one monozygotic twins exposed to organic solvents were compared with their non-exposed cotwins by performance in psychological tests. A further 28 monozygotic twin pairs were examined as a reference group. The study used 11 tests, 10 of which had shown an effect in previous studies on the results of exposure to solvents. Paired comparisons of the test scores showed the exposed twins to have lower performance in associative learning, digit span, and block design. These results agree with two previous studies that used a similar set of tests. Contrary to some other studies, psychomotor speed was not affected, but the results indicated a marginal effect on the control of hand movements. Further comparison of subgroups with a low and a high exposure showed the prevalence of subtle neuropsychological dysfunction to be greater among the more exposed twins.

Adult↗
PubMed1991

Impact of heredity in myopia.

A series of 109 like-sexed twin pairs in the age group 30-31 years (54 monozygotic and 55 dizygotic) with one or both members of the twins with myopia was found in the Finnish Twin Cohort. The series was based on a random sample of 1,200 twins in one age stratum of the cohort. The twins received a questionnaire on their health status with special reference to eye diseases and symptoms. The refractive status of the twin pairs was ascertained by asking the twins to send their latest prescription for glasses to the authors or the refraction was obtained from the ophthalmologists or opticians of the twins. The mean difference in refraction between the monozygotic twins was 1.19 dptr in the right eyes and 1.15 dptr in the left eyes. The difference between dizygotic pairs was 2.34 dptr in the right eyes and 2.47 dptr in the left eyes. Analysis of variance showed that the difference in refraction between the two eyes of a twin pair was not significant. The mean difference in refraction between the monozygotic twins was significantly lower than that between dizygotic twins (p less than or equal to 0.001). The intrapair variances were doubled among dizygotic twin pairs compared to monozygotic twin pairs in the male group. The intrapair variance in the female group was 4-fold among dizygotic twin pairs as compared to monozygotic twin pairs. Heritability of myopia was 0.58 (0.74 for males and 0.61 for females) when myopia was considered a dichotomous variable. This result suggests that inheritance has a substantial effect on the etiology of myopia.

Adult↗
PubMed1991

A population-based study of bronchial asthma in adult twin pairs.

Aggregation of cases of bronchial asthma in adult twin pairs was studied in the nationwide Finnish twin cohort consisting of 13,888 adult monozygotic (MZ) and same-sex dizygotic (DZ) pairs. Cases of asthma were ascertained by record-linkage from three sources of data: death certificates from the Central Statistical Office; hospital discharges from the nationwide hospital registry; and the nationwide registry for fully reimbursed medications of the Social Insurance Institution. A diagnosis of bronchial asthma in one or more of these registers was obtained for 525 (236 men and 289 women) out of 27,776 twin individuals. Among MZ pairs, ten concordant and 138 discordant pairs were identified, while among DZ pairs, 12 concordant and 343 discordant pairs were found. In the whole sample the observed-expected ratio for the number of pairs concordant for bronchial asthma was 4.30 (95 percent confidence interval [CI], 2.06 to 7.90) in MZ pairs and 2.61 (95 percent CI, 1.35 to 4.56) in DZ pairs. Using a multifactorial threshold model, we estimated the correlation in liability to asthma as 0.425 (SE = 0.07) in MZ twins and 0.247 (SE = 0.06) in DZ twins, and we obtained a heritability estimate of 35.6 percent. The data also showed a gender difference in asthma heredity, which may, however, be due to chance events affecting the distribution of concordant pairs.

Adult↗
PubMed1991

Rheumatoid arthritis in identical twins: a clinical and immunogenetic study of eight concordant pairs derived from a nationwide twin panel.

The nationwide Finnish Twin Cohort was linked with the national Sickness Insurance Register. Eight identical twin pairs concordant for rheumatoid arthritis (RA) fulfilling the American Rheumatism Association criteria were identified. All 16 cases were known to be seropositive. Four pairs had at least one additional first-degree relative with RA, and the prevalence of RA among all the first-class relatives was 9%. HLA-typing was performed for 15 patients representing the eight pairs; six pairs carried the DR4 allele, and three of these pairs were putative homozygotes. Nodules and Sjögren syndrome occurred fairly frequently (in 7 of 16 and 6 of 13 cases examined, respectively), but concordance within pairs was no higher than that expected by chance. The course of the disease was fulminant in one patient and in several others the disease had led to marked joint destructions. The findings pointed out to some intrapair similarity in the progression of the joint damage and in the type of complications caused by gold.

Adult↗
PubMed1991

Cancer risk after Mckee-Farrar total hip replacement.

Cancer incidence in 433 McKee-Farrar total hip replacement patients, operated on between 1967 and 1973, was examined for 5729 person-years, to the end of 1981. The expected number of natural deaths was slightly higher than observed, suggesting some selection of the operated patients. The risk of total cancer incidence did not increase, but the risk for site-specific cancer did because there were no cases of kidney or bladder cancer, or rare forms of cancer. The risk of leukemias and lymphomas increased, and the risk of breast cancer decreased; these results were surprisingly similar to those of a study from New Zealand. This study concluded that patients with total hip prostheses have a cancer morbidity differing from the general population. The role of chrome-cobalt-molybdenum alloy in carcinogenesis requires further investigation.

Aged↗
PubMed1991

Effects of gender and age on the heritability of body mass index.

We estimated genetic and environmental components of variance of body mass index (BMI) among 7245 same-sexed Finnish MZ and DZ twin pairs aged 18-54 years from the nationwide Finnish Twin Cohort. Age accounted for 20 per cent of variance among men and 26 per cent in women. The contributions of additive genetic effects, shared and non-shared environmental effects on BMI-variance were estimated by LISREL structural equation models. Genetic effects accounted for 72 per cent and 68 per cent of total variance in men and non-pregnant women respectively, while 28 per cent of variance among men and 32 per cent among women was due to non-shared environmental effects. This gender difference was statistically significant. Models including shared environmental effects did not improve model fits. The magnitude of the genetic component of BMI was also analysed separately for each 10-year age group. Models with age-specific parameters for genetic and environmental effects fitted significantly better than models with effects constrained to be equal over age. Our results indicate a substantial genetic component in BMI. However, the magnitude of additive genetic effects decreases with age in both genders.

Adult↗
PubMed1991

Genetics of alcoholism: effects of migration on concordance rates among male twins.

We have extended linkage of the population-based Finnish Twin Cohort to alcohol-related hospital discharge data through 1985. The sample included 10,680 individual male twins > or = age 30 at time of linkage; 269 of these twins (2.5%) had received an alcohol-related hospital diagnosis. Twin analyses confirm significant genetic variance in alcohol-related disorders, but suggest that concordance for these disorders is greater for twins living within limited geographic areas, perhaps due to restricted social mobility among those who abuse alcohol.

Adult↗
PubMed1991

1991 Volvo Award in clinical sciences. Smoking and lumbar intervertebral disc degeneration: an MRI study of identical twins.

The primary objective of this study was to determine whether disc degeneration, as assessed through magnetic resonance imaging, is greater in smokers than in nonsmokers. To control for the maximum number of potentially confounding variables, pairs of identical twins highly discordant for cigarette smoking were selected as study subjects. Data analyses revealed 18% greater mean disc degeneration scores in the lumbar spines of smokers as compared with nonsmokers. The effect was present across the entire lumbar spine, implicating a mechanism acting systemically. This investigation demonstrates the efficiency of using carefully selected controls in studying conditions of multifactorial etiology, such as disc degeneration.

Awards and Prizes↗
PubMed1991

[Interaction between the arterial wall and thrombocytes in smokers].

Smoking is per se a major risk factor in cardio-vascular diseases. It causes atherosclerosis and blockage particularly in the aorta and the leg arteries. The components of tobacco smoke damage the endothelium, increase arterial contractility, and accelerate the formation of plaque therein. The mechanisms of the effect of smoking on the genesis of atherothrombotic diseases have been studied in inter alios identical twins where the one smokes and the other does not. Smoking activates the sympathetic nerves and affects their regulation. Tobacco smokers show signs of activated thrombocyte function and increased sensitivity to vasoconstriction, which provokes a counter-reaction in the arterial walls. The observations emphasize the importance of vaso-active agents for the development and complications of atherosclerosis.

Arteriosclerosis↗
PubMed1990

Viral antibodies in multiple sclerosis. A nationwide co-twin study.

Serum viral antibody titers against 21 viruses were studied in 19 of 23 same-sex twin pairs with multiple sclerosis derived from the Finnish Twin Cohort. Thorough neurologic examinations showed two monozygotic pairs to be concordant, whereas all dizygotic pairs were discordant. Special attention was given to measles, mumps, and rubella viruses, against which the antibody levels were determined with the complement fixation, hemagglutination inhibition, hemolysis-ingel, and enzyme immunoassay methods. Epstein-Barr virus antibody levels were determined by enzyme assay. In pairwise comparisons, the measles, mumps, and Epstein-Barr virus-IgG antibody levels were more often elevated in the patients with multiple sclerosis, compared with the healthy co-twins. The same antibody levels were more often above the median in the diseased twin, compared with the healthy twin, but the difference was not significant. No human T-cell lymphotropic virus type I antibodies were found in any of the individuals examined. The total IgG, IgA, and IgM levels did not differ between the diseased and healthy subjects. The HLA types, severity of the disease, and cell-mediated immunity parameters did not influence antibody levels.

Antibodies, Viral↗
PubMed1990

Change in cohabitation and intrapair similarity of monozygotic (MZ) cotwins for alcohol use, extraversion, and neuroticism.

We have reported cross-sectional evidence that behavioral similarities of adult monozygotic (MZ) cotwins are associated with their age at initial separation and the frequency of their subsequent social interaction (Kaprio et al., 1987; Rose et al., 1988; Rose and Kaprio, 1988). Twins who separated early and twins in infrequent interaction were less alike. Data for those reports came from a 1981 survey of the Finnish Twin Cohort. The Finnish cohort had been surveyed in 1975 with a similar questionnaire, and we now report a longitudinal analysis of the 1975-1981 surveys. All cohabiting MZ cotwins, ages 18-25 at the 1975 baseline, were followed up in 1981, and pairwise similarities at baseline and follow-up were compared for three groups: MZ pairs that remained cohabiting, separated pairs in which the cotwins retained regular contact with one another, and separated cotwins whose social interactions at follow-up were infrequent. For alcohol consumption and EPI Neuroticism scores, relative similarities of the MZ cotwins at follow-up paralleled the relative frequencies of their social contact; baseline differences in resemblance for Extraversion scores preceded follow-up differences in social interaction. These findings clarify the directional nature of associations found in our cross-sectional data and provide new, more compelling evidence of effects of shared experience on sibling resemblance for some dimensions of adult behavior.

Adolescent↗
PubMed1990

Lymphocyte activation in discordant multiple sclerosis twin pairs.

Phytohemagglutinin-induced lymphocyte activation sequence was studied in monozygotic and dizygotic discordant multiple sclerosis (MS) twin pairs in a quiescent disease phase. The study group included all available 11 pairs listed in a nation-wide twin register. Lymphocyte activation markers, DNA synthesis and gamma-interferon secretion were studied using avidin-biotin-peroxidase complex (ABC) stainings, [3H]thymidine incorporation, and a solid-phase double-antibody immunoradiometric assay (IRMA), respectively. The level and kinetics of interleukin-2 receptor expression, DNA synthesis, gamma-interferon secretion, and major histocompatibility complex (MHC) locus II antigen expression were similar (Wilcoxon's test for paired samples) in both the diseased and healthy monozygotic and dizygotic twins. Our results suggest that the cell-mediated immune system may not be primarily at fault, but rather that both MS itself and its exacerbations are caused by an unknown triggering stimulus facing a properly functioning immune system.

Antigens, CD↗
PubMed1990

Body weight in the Finnish Twin Cohort.

We estimated genetic and environmental variance of BMI among 7245 non-pregnant MZ and DZ pairs of the same sex from the population-based Finnish Twin Cohort. The contributions of additive genetic effects, shared and non-shared environmental effects on age-adjusted BMI-variance were estimated by LISREL structural equation models. Genetic effects contribute 72% in men and 66.4% in non-pregnant women of total variance, while 27.8% of variance among men and 33.6% among women is due to non-shared environmental effects. Shared environmental effects were nonsignificant (0% for women and 0.2% for men). Similar values were obtained for hereditary and non-shared environmental effects, when shared environmental effects were not included in the model. The inclusion of pregnant women did not substantially change heritability estimates.

Adolescent↗
PubMed1990

Population-based twin registries: illustrative applications in genetic epidemiology and behavioral genetics from the Finnish Twin Cohort Study.

The population-based twin registries of Denmark, Finland, Norway and Sweden represent an extraordinary resource for scientific research. Although each register has its own history and composition, they share certain common qualities. All the Nordic countries have a long tradition of population registration, a high standard of living and health-related registers of high quality. The large size of the registers means that they are uniquely placed for representative studies of rare occurrences. Examples of studies that these registers make possible are illustrated with data from the Finnish Twin Cohort, which in its first phase consisted of over 17,000 like-sexed twin pairs born before 1958. It has been recently expanded to include multiple births between 1958 and 1986 (nearly 23,000 sets) and their first-degree relatives. During this period the DZ/MZ ratio decreased, while an increase in MZ twinning rates was observed between 1974 and 1986.

Adult↗
PubMed1990

Selection bias in disease-related twin studies. Data on 11,154 adult Finnish twin pairs from a nationwide panel.

The effect of migration on pairwise concordance for disease was assessed in 11,154 twin pairs of the Finnish Twin Cohort Study by comparing the pairs living in the same province to the pairs which members were living in different provinces of Finland. The cumulative incidence of psychosis and hypertension for the years 1972-1985 were analyzed. The cumulative concordance of psychosis for those MZ twin pairs living in the same province were higher than for those MZ pairs living further apart. Similar findings were found among DZ pairs for psychosis. The cumulative concordance of hypertension was only slightly higher among those MZ and DZ pairs living in the same province compared with pairs living in different provinces. These results indicate an overestimation of concordance of psychosis caused by selective migration. This bias in twin studies is likely to influence heritability estimates in a sample of limited geographical area.

Adult↗