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M Koskenvuo

Publications and source records attributed to M Koskenvuo.

At least 109 records · Page 6Linked to original sources
PubMed1998

Humoral immune response to Chlamydia pneumoniae in twin discordant for smoking.

OBJECTIVES: The aim of this study was to investigate whether there is a relationship between smoking and Chlamydia pneumoniae specific antibody levels in generally healthy subjects, and whether this possible relationship is dose-dependent. DESIGN: Match pair study. SUBJECTS: The study population comprised of 111 same-gender twin pairs from the Finnish Twin Cohort who in a previous study reported the highest discordance between smoking assessed as pack-years. MAIN OUTCOME MEASURES: Smoking and background data were obtained by a questionnaire, and C. pneumoniae specific serum IgG and IgA antibodies were measured by the micro-immunofluorescence (mIF) test. RESULTS: A significantly higher proportion of men with a history of smoking had elevated levels (a titre of > or=40) of serum IgA antibodies (P=0.003), whereas in women, a significant difference between the pairs was found in the proportion of IgG seropositive (a titre of > or=128) subjects (P=0.03). Conditional logistic regression analysis revealed that the risk for elevated IgA antibodies suggestive of chronic infection was significantly increased in current or former smokers in men (odds ratio 5.0 with 95% confidence intervals of 1.45-17.3). No dose-response effect was found between smoking and IgG or IgA titres, neither even if men and women were analysed separately. CONCLUSION: Smoking was significantly associated with elevated IgA antibody levels in men, supporting indirectly the hypothesis that smoking is a contributory factor in the establishment of chronic C. pneumoniae infection.

Adult↗
PubMed1997

Magnetic fields of transmission lines and depression.

Electromagnetic fields have been suggested to contribute to the risk of depression by causing pineal dysfunction. Some epidemiologic studies have supported this possibility but have generally reported crude methods of exposure assessment and nonsystematic evaluation of depression. Using two available nationwide data sets, the authors identified from the Finnish Twin Cohort Study 12,063 persons who had answered the 21-item Beck Depression Inventory of self-rated depressive symptoms in 1990. The personal 20-year histories of exposure (i.e., distance and calculated annual average magnetic fields) before 1990 to overhead 110- to 400-kv power lines were obtained from the Finnish Transmission Line Cohort Study. The adjusted mean Beck Depression Inventory scores did not differ by exposure, providing some assurance that proximity to high-voltage transmission lines is not associated with changes within the common range of depressive symptoms. However, the risk of severe depression was increased 4.7-fold (95% confidence interval 1.70-13.3) among subjects living within 100 m of a high-voltage power line. This finding was based on small numbers. The authors recommend that attempts be made to strive for a better understanding of the exposure characteristics in relation to the onset and course of depression.

Adult↗
PubMed1997

Relation between plasma leptin levels and measures of body fat in identical twins discordant for obesity.

BACKGROUND: Plasma levels of leptin, the recently discovered satiety hormone, are associated with adiposity in humans. OBJECTIVE: To determine whether genetic factors or body fat distribution affect the association between leptin levels and obesity. PARTICIPANTS: 23 healthy identical twin pairs (9 male pairs and 14 female pairs, 33 to 59 years of age) who were discordant for obesity (average weight difference, 18 kg). MEASUREMENTS: Fasting plasma leptin levels were measured by radioimmunoassay. Distribution of abdominal fat into visceral and subcutaneous compartments was estimated by use of magnetic resonance imaging. RESULTS: Plasma leptin levels were threefold higher in obese twins than in lean twins (mean +/- SD, 18.7 +/- 12.5 micrograms/L compared with 6.4 +/- 4.8 micrograms/L; P < 0.001); a similar difference was seen when the entire study group was divided according to sex. Compared with lean twins, plasma leptin levels were 3.7-fold higher in the obese twins who had visceral fat accumulation greater than the median and 2.1-fold higher in the obese twins who had visceral fat accumulation less than the median. The intrapair differences in leptin levels correlated with the corresponding differences in percentage of body fat in women (r = 0.73; P = 0.003) but not in men and correlated with differences in visceral fat area in men (r = 0.79; P = 0.019) and women (r = 0.73; P = 0.007). In multiple regression analyses that included intrapair differences in visceral fat area and total body fat, the association between differences in visceral fat area and leptin levels was significant in men (P = 0.029) but not in women. CONCLUSIONS: Plasma leptin levels are increased in obese persons, independent of genetic background. Visceral fat may be of special importance in the regulation of leptin levels, but it is probably less important in women than in men.

Adipose Tissue↗
PubMed1997

Markers for the gene ob and serum leptin levels in human morbid obesity.

Leptin, the product of the ob gene, reduces body fat in genetically obese animals and circulates in elevated concentrations in the blood of obese patients. Polymorphic markers situated in the proximity of the human ob gene have recently been suggested to be linked to morbid obesity. We have studied the possible association between the microsatellite markers near the ob gene and morbid obesity in 252 morbidly obese patients with a mean body mass index (BMI) of 43 +/- 7 kg/m2, and 151 lean controls with a mean BMI of 22 +/- 2 kg/m2, and searched for linkage of these gene markers to obesity in 76 affected sib-pairs (BMI > or = 32). No significant association was observed between any of the eight microsatellite markers and morbid obesity, and affected-sib-pair analysis failed to show linkage of three selected ob gene markers to obesity in the sibships. There was a strong positive correlation between serum leptin levels and BMI in morbidly obese patients; a carrier status for either of the two most prevalent alleles of the microsatellite marker D7S530 in the vicinity of the ob gene was associated with serum leptin levels in the obese subjects. Two of the markers (D7S2519, D7S649) showed a significant relation to the weight-losing response to a 16-week very-low-calorie dietary intervention. We have thus been able to confirm a tight relationship between serum leptin and body mass but have found no evidence for genetic linkage of the ob gene markers to morbid obesity in a population considered to represent a genetic isolate and to be an ideal model for studies of complex disorders.

Adult↗
PubMed1997

Alzheimer's disease in twins.

Besides familial Alzheimer's disease (AD), the genetic susceptibility has also been found in sporadic cases of AD, mostly related to the apolipoprotein E polymorphism. The penetrance of AD is determined by age and probably by environmental exposure. Gene-environment interaction of a disease can be examined through studies of twins. The relative roles of genetic and environmental influences can be estimated by comparing the concordance rates between monozygotic (MZ) and dizygotic (DZ) twins. Genetic models can be used to specify contributions both from genetic as well as shared and unique environmental effects. The role of environmental factors can be investigated in the co-twin control study, either by comparing environmental exposure in MZ twins discordant for a disease or by comparing MZ twins discordant for an exposure suspected of causing a particular disease. The sampling of twin pairs AD can be carried out using voluntary recruitment, linkage of twin and hospital discharge registries or screening of twin registry population. Potential sources of biases in sampling are discussed. The majority of the published twin studies on AD are case reports or based on selected materials. In MZ pairs, the concordance rates for AD have varied between 31% and 83%. Only one co-twin control study in twins discordant for AD has been published. Published twin studies on AD are briefly reviewed.

Alzheimer Disease↗
PubMed1997

Causes of death after hip arthroplasty in primary arthrosis.

The causes of death in 1,018 patients operated on for primary osteoarthrosis with cemented total hip arthroplasty (THA) were compared with those of age- and sex-matched orthopaedic control patients and those of the general population in Finland. The mean follow-up period was 12 years for the THA patients and 11 years for the control patients. During the first 4 years after surgery, the mortality of the THA patients from circulatory diseases was significantly increased compared with that of the orthopaedic control patients; the number of deaths in patients with THA was 34 compared with 17 for orthopaedic control patients, the relative risk being 2.00 (95% confidence interval, 1.13-3.54). During the 10-year period after the surgery, the relative risk of death of the THA patients compared with the orthopaedic control patients was 1.50 for death from circulatory diseases (95% confidence intervals, 1.11-2.00), 0.42 for accidental death (95% confidence interval, 0.55-1.08), 0.74 for death from cancer, and 0.77 for death from other causes. The observed numbers of deaths from circulatory diseases or by accidents for patients with THA during a postoperative time frame of 5 to 23 years did not differ from the numbers expected for an age- and sex-matched subgroup of the Finnish population. The number of deaths from cancer was less than expected (P = .046).

Accidents↗
PubMed1997

Hostility and registered sickness absences: a prospective study of municipal employees.

BACKGROUND: Prior evidence on the relationship between hostility and minor health problems is limited to cross-sectional self-report studies. In the present study, this relationship was examined prospectively. METHODS: Hostility of 1077 municipal employees was measured by a questionnaire survey and minor health problems by using 4-year register-based absence data including medically certificated diagnoses. RESULTS: High hostility predicted a high total number of long-term sickness absence spells among men, but not among women. In separate diagnostic categories (musculo-skeletal, traumas and injuries, respiratory), hostility related positively and linearly to absences due to traumatic causes and curvilinearly (U-shape) to absences due to musculo-skeletal causes. Controlling the effects of health risk behaviour and demographic background did not significantly change these figures. However, health risk behaviour moderated the relations of hostility to overall long-term sickness absences, and to traumatic and musculo-skeletal absences, being significantly stronger in high-risk groups. No association was found between hostility and non-certificated short-term absence spells. CONCLUSIONS: The results suggest that hostility plays a role in the aetiology of minor health problems.

Absenteeism↗
PubMed1997

Are genetic determinants of weight gain modified by leisure-time physical activity? A prospective study of Finnish twins.

A large number of studies have shown that obesity is both under genetic control and influenced by several environmental factors, including energy expenditure and intake. Several studies in animals and humans have furthermore suggested that certain environmental factors, such as a high fat intake, may modify the expression of the genes responsible for weight gain. The present study examined whether physical activity, measured at the baseline examination in 1975, was likely to play a differential role in subsequent weight changes in the following 6 y in 1571 monozygotic and 3029 dizygotic, same-sex twin pairs from the Finnish Twin Cohort Study. A hierarchical multiple-regression analysis was used to test for gene-environment interactions by identifying significant three-way interactions between genetic factors, physical activity, and weight change. The results showed that associations between weight change in twin A and twin B were significantly stronger for monozygotic than for same-sex dizygotic twins at all levels of physical activity. Additionally, in the monozygotic men the strength of the association varied with physical activity level, and the association between the change in body mass index between the twin pairs with the highest physical activity level was about three times stronger (beta = 0.40) than the association in twin pairs with the lowest physical activity level (beta = 0.15, P for trend = 0.002). In pairs of dizygotic men, and in both monozygotic and dizygotic women, similarity in body mass index change was independent of physical activity level (all P > 0.14). The present study showed that genetic factors may modify the effects of physical activity on weight change, and suggests that a sedentary lifestyle may have an obesity-promoting effect in men with a genetic predisposition.

Adult↗
PubMed1997

Lifetime exercise and disk degeneration: an MRI study of monozygotic twins.

Participation in some competitive sports has been shown to increase disk degeneration; however, the long-term effects of recreational physical activities are unclear. We investigated the effects of endurance exercise and power sports on disk degeneration in monozygotic male twins with contrasting lifetime exercise histories. The effects of endurance exercise were studied in 22 discordant twin pairs (mean lifetime frequencies of 3.9 vs 1.1 times/wk), and the effects of power sports were investigated in 12 discordant pairs (2,300 vs 200 h of weightlifting). The age range of the twins was from 35 to 69 yr. No differences in MRI findings between co-twins discordant for endurance exercise were found at any of the spinal regions. Subjects with more power sport involvement had greater disk degeneration in the T6-T12 region (P < 0.03), but similar findings were not present in the lumbar spine. Controlling for recalled back injuries, occupational loading, smoking, and driving did not significantly affect the results. No signs of beneficial or harmful effects of lifetime endurance exercise on disk degeneration were seen. Increased power sport participation was associated with slightly greater disk degeneration in the lower thoracic spine, but not in the lumbar spine.

Adult↗
PubMed1997

Mortality of adults with asthma: a prospective cohort study.

BACKGROUND: Few studies have been published on the overall survival of adult patients with asthma. A cohort study was performed to assess the mortality from all causes, from chronic obstructive pulmonary disease, and from lung cancer among adult asthmatic subjects. METHODS: A population of 31,110 Finnish adult women and men, mostly twins, was studied to compare the 16 year mortality rates among asthmatic (n = 471) and non-asthmatic persons. A further 293 twin pairs, discordant for asthma, were also studied to determine whether the mortality of patients with asthma differs from that of their age matched siblings. RESULTS: Mortality from all causes was increased among asthmatic adults (age adjusted hazard ratios 1.49, 95% CI 1.09 to 2.05 for men and 1.53, 95% CI 1.10 to 2.13 for women), and mortality due to chronic obstructive pulmonary diseases was also significantly increased in asthmatic subjects. The risk of death due to lung cancer was increased in men with asthma (hazard ratio adjusted for smoking 3.19, 95% CI 1.39 to 7.31). The risk ratios found among twins discordant for asthma corresponded to those found in the whole cohort. CONCLUSIONS: Survival in adults with asthma is worse than in those without asthma. The excess deaths due to chronic obstructive pulmonary disease may explain some part of the increased mortality rates, but not all of it.

Adolescent↗
PubMed1997

Glucose metabolism in identical twins discordant for obesity. The critical role of visceral fat.

Obesity, especially intraabdominally deposited fatness, is associated with reduced insulin sensitivity. However, it is not well established whether this association is confounded by genetic factors. We studied 23 monozygous twin pairs (14 female, 9 male), 33-59 yr old, who had, on the average, 18 kg intrapair difference in body weight. A 75-g oral glucose tolerance test with glucose and insulin measurements at 30-min intervals was performed, and fat distribution was determined with magnetic resonance imaging. The pairs were divided into two groups by the gender-specific median of the abdominal visceral fat area (AVF) in the obese co-twins. In the high-AVF pairs, the mean area under curve (AUC) for glucose (mmol x min/L) was 758 vs. 968 (P = 0.001), AUC for insulin (mU x min/L) was 4320 vs. 8741 (P = 0.001), and insulin sensitivity index (mg x L x L/mmol x mU x min) was 71.5 vs. 45.9 (P < 0.001) in the lean and obese co-twins, respectively. In the low AVF pairs, the mean AUC for glucose was 669 vs. 706 (not significant), AUC for insulin was 3323 vs. 4241 (not significant), and the sensitivity index was 85.2 vs. 73.7 (P = 0.04) in the lean and obese co-twins, respectively. In subjects who are genetically identical but who are discordant for body mass, only those who differ most in visceral fat level are characterized by major alterations in insulin sensitivity and glucose tolerance.

Adipose Tissue↗
PubMed1997

Prevalence and genetics of sleepwalking: a population-based twin study.

We investigated the prevalence of sleepwalking using a well defined population previously used for epidemiologic investigations: the Finnish Twin Cohort. The study population consisted of 11,220 subjects aged 33 to 60 years, and it included 1,045 monozygotic and 1,899 dizygotic twin pairs. Questions on the frequency of sleepwalking were asked separately for occurrence in childhood and adulthood. Childhood sleepwalking was significantly more frequent in women ("often" in 2.8% of women and 2.0% of men and "sometimes" in 6.9% of women and 5.7% of men). As adults, sleepwalking had occurred in 3.9% of men and in 3.1% of women, and it was reported "weekly" in 0.4% for both genders. There was no significant difference in frequency between monozygotic and dizygotic twin individuals, either in childhood or adulthood. For sleepwalking in childhood the probandwise concordance rate was 0.55 for monozygotic and 0.35 for dizygotic pairs, and for adults, 0.32 for monozygotic, and 0.06 for dizygotic pairs. Those who reported never having walked in their sleep in childhood did so as adults rarely (0.6%), both men and women. Those who reported walking in their sleep often or sometimes in childhood did so as adults for 24.6% of men and for 18.3% of women. Of adult men sleepwalkers 88.9% had a positive history of sleepwalking in childhood, and in women, 84.5%. The proportion of total phenotypic variance attributed to genetic influences was 66% in men and 57% in women in childhood sleepwalking, and 80% in men and 36% in women in adult sleepwalking. Our results show that there are substantial genetic effects in sleepwalking in both childhood and adulthood.

Adult↗
PubMed1997

Hay fever, asthma and number of older siblings--a twin study.

BACKGROUND: It has been suggested that allergic sensitization is inversely related to the number of siblings in the family. OBJECTIVES: To study whether a similar relation can be observed for hay fever and asthma among Finnish adolescents in a population with relatively low prevalence of atopic diseases. METHODS: A questionnaire mailed to a nationwide sample of 1849 families with 16-year-old twins assessing the cumulative incidence of doctor-diagnosed hay fever and asthma among the adolescents and the number of older siblings in the family by parental report. RESULTS: The cumulative incidence of hay fever was significantly lower among the adolescents with three or more older siblings (3.9%, 95% CI = 1.2-6.5%) compared with adolescents with fewer older siblings (12.7%, 95% CI = 11.4-14.0%). There was no difference in the cumulative incidence of asthma among the adolescents according to the number of older siblings in the family. CONCLUSIONS: Large number of older siblings appears to be protective against the development of hay fever.

Adolescent↗
PubMed1996

Genetic and environmental components of interindividual variation in circulating levels of IGF-I, IGF-II, IGFBP-1, and IGFBP-3.

We assessed the magnitude of the genetic component in the variation of circulating levels of insulin-like growth factors I and II (IGF-I and IGF-II), and their binding proteins IGFBP-1 and IGFBP-3 by measuring their serum concentrations in 32 monozygotic and 47 dizygotic adult twin pairs of the same sex. The intrapair correlation for the IGF-I levels was r = 0.41 (P < 0.009) for monozygotic twins and r = 0.12 (P < 0.22) for dizygotic twins. For the IGF-II concentration the intrapair correlations were r = 0.66 (P < 0.0001) for the monozygotic and r = 0.34 (P < 0.01) for the dizygotic twins. No significant intrapair correlation was found for IGFBP-1 levels in either group. The correlations for IGFBP-3 concentration were r = 0.65 (P < 0.0001) and r = 0.23 (P < 0.06) for monozygotic and dizygotic twins, respectively. Women had higher IGF-II levels than men (635+/-175 vs. 522+/-144 microg/liter; P < 0.0001) and IGFBP-3 levels were also higher in women compared with men (5441+/-1018 vs. 4496+/-1084 microg/liter; P < 0.001). The proportion of variance attributable to genetic effects was 38% for the IGF-I concentration, 66% for the IGF-II concentration, and 60% for the IGFBP-3 concentration. No significant heritability was found for the IGFBP-1 concentrations. Our results show that, in adults, there is a substantial genetic contribution responsible for interindividual variation of the circulating levels of IGF-I, IGF-II, and IGFBP-3, but not for the IGFBP-1 levels.

Adult↗
PubMed1996

Magnetic fields of high voltage power lines and risk of cancer in Finnish adults: nationwide cohort study.

OBJECTIVE: To investigate the risk of cancer in association with magnetic fields in Finnish adults living close to high voltage power lines. DESIGN: Nationwide cohort study. SUBJECTS: 383,700 people who lived during 1970-89 within 500 metres of overhead power lines of 110-400 kV in a magnetic field calculated to be > or = 0.01 microT. Study subjects were identified by record linkages of nationwide registers. MAIN OUTCOME MEASURES: Numbers of observed and expected cases of cancer, standardised incidence ratios, and incidence rate ratios adjusted for sex, age, calendar year, and social class--for example, by continuous cumulative exposure per 1 microT year with 95% confidence intervals from multiplicative models for all cancers combined and 21 selected types. RESULTS: Altogether 8415 cases of cancer were observed (standardised incidence ratio 0.98; 95% confidence interval 0.96 to 1.00) in adults. All incidence rate ratios for both sexes combined were non-significant and between 0.91 and 1.11. Significant excesses were observed in multiple myeloma in men (incidence rate ratio 1.22) and in colon cancer in women (1.16). CONCLUSIONS: Typical residential magnetic fields generated by high voltage power lines do not seem to be related to the risk of overall cancer in adults. The previously suggested associations between extremely low frequency magnetic fields and tumours of the nervous system, lymphoma, and leukaemia in adults and breast cancer in women were not confirmed.

Adult↗
PubMed1996

Hospital care in later life among former world-class Finnish athletes.

OBJECTIVE: To investigate the use of hospital care from all causes among former top-level athletes from different vigorous sports to determine whether health benefits or adverse effects have the greater influence. DESIGN: National, population-based cohort study with a 21-year follow-up. SETTING: Finland. SUBJECTS: A total of 2049 male athletes who had represented Finland during 1920 to 1965, and 1403 male controls classified healthy at 20 years of age. MAIN OUTCOME MEASURE: In-hospital care from all causes was extracted from the national hospital discharge registry for the period 1970 through 1990 expressed as hospital days per person-years of exposure. RESULTS: Compared with controls, the rate ratios (RRs) for all-cause hospital days per person-years of exposure were lower in athletes from endurance sports (RR, 0.71; 95% confidence interval [Cl], 0.70-0.73), mixed sports (including endurance and weight training) (RR, 0.86; 95% Cl, 0.85-0.87), and power sports (RR, 0.95; 95% Cl, 0.94-0.96) (P < .001 for all comparisons) after adjustment for age and occupational group. The lower RR among athletes from endurance sports and other sports involving aerobic activity was largely explained by lower rates of hospital care for heart disease, respiratory disease, and neoplasms, but not for musculoskeletal disorders. CONCLUSIONS: Former elite athletes, particularly those in aerobic sports, use less hospital care. Other beneficial health habits are known to be associated with a physically active lifestyle.

Adult↗