Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high ... more Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estimate the genetic correlations of BMI from infancy to adulthood and compared them to the genetic correlations of height. Methods We pooled individual level data from 25 longitudinal twin cohorts including 38,530 complete twin pairs and having 283,766 longitudinal height and weight measures. The data were analyzed using Cholesky decomposition offering genetic and environmental correlations of BMI and height between all age combinations from 1 to 19 years of age. Results The genetic correlations of BMI and height were stronger than the trait correlations. For BMI, we found that genetic correlations decreased as the age between the assessments ...
We tested the causality between education and smoking using the natural experiment of discordant ... more We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs. Similarly, education levels were higher among former smoking than among currently smoking co-twins, and this difference was larger within DZ pairs. Our results support the hypothesis of a causal effect of education on both current smoking status and smoking cessation. However, the even greater intra-pair differences within DZ pairs, who share only 50% of their segregating genes, provide evidence that shared genetic factors also contrib...
Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finlan... more Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finland Department of Physical Education and Sport, University of Madeira, Funchal, Portugal Center for the Interdisciplinary Study of Gerontology and Vulnerability, University of Geneva, Geneva, Switzerland Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country UPV/EHU, Leioa, Spain Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal ISOPlexis Genebank, University of Madeira, Funchal, Portugal Human Genetics Laboratory, University of Madeira, Funchal, Portugal Physical Activity, Sports & Health Research Group, Department of Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Department of Public Health, University of Helsinki, Helsinki, Finland De...
Social Psychiatry and Psychiatric Epidemiology, 2021
Purpose Sense of coherence (SOC) represents coping and can be considered an essential component o... more Purpose Sense of coherence (SOC) represents coping and can be considered an essential component of mental health. SOC correlates with mental health and personality, but the background of these associations is poorly understood. We analyzed the role of genetic factors behind the associations of SOC with mental health, self-esteem and personality using genetic twin modeling and polygenic scores (PGS). Methods Information on SOC (13-item Orientation of Life Questionnaire), four mental health indicators, self-esteem and personality (NEO Five Factor Inventory Questionnaire) was collected from 1295 Finnish twins at 20–27 years of age. Results In men and women, SOC correlated negatively with depression, alexithymia, schizotypal personality and overall mental health problems and positively with self-esteem. For personality factors, neuroticism was associated with weaker SOC and extraversion, agreeableness and conscientiousness with stronger SOC. All these psychological traits were influence...
We investigated the heritability of educational attainment and how it differed between birth coho... more We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural–geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a2 = 0.43; 0.41–0.44), but also environmental variation shared by co-twins was substantial (c2 = 0.31; 0.30–0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900–1949 (a2 = 0.44; 0.41–0.46) than in the later cohorts born in 1950–1989 (a2 = 0.38; 0.36–0.40), with a corresponding lower influence of comm...
The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) projec... more The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and leng...
Journal of epidemiology and community health, 2018
Previous studies have found depression to be negatively associated with the prognosis of both car... more Previous studies have found depression to be negatively associated with the prognosis of both cardiovascular disease (CVD) and cancer, but this may partly reflect reverse causality. We limited the possibility of reverse causality by measuring depression before the first diagnosis of CVD or cancer. We used an 11% longitudinal random sample of the Finnish population aged 25 years or older who are residents of Finland for at least 1 year between 1987 and 2007, with an 80% oversample of those who died during this period. Those who had their first incidence of coronary heart disease (CHD) (n=107 966), stroke (n=68 685) or cancer (n=113 754) between 1998 and 2012 were followed up for cause-specific mortality from the date of diagnosis until the end of 2012. Depression was defined as having antidepressant purchases two to three calendar years before the incidence. Logistic and Cox regression models were used to examine short-term and long-term mortality by depression status. Long-term mort...
DESCRIPTION ABSTRACT Noise sensitivity is a common trait which increases the harmful health effec... more DESCRIPTION ABSTRACT Noise sensitivity is a common trait which increases the harmful health effects of noise. It has been associated with impaired somatic health, anxiety and poor sleep quality. Self-assessed poor health is a strong predictor of early retirement. This study is based on the Finnish Twin Cohort. Questionnaire data of a sample of 706 Finnish twin individuals (age range, 31 to 65 years) with record linkage to information on DP during 16 years of follow-up were analyzed using individual and pairwise Cox proportional hazards models. Noise sensitivity increased the risk of DP (hazard ratio = 1.41, 95% CI 1.03-1.93) among all participants. In within-pair analyses, noise sensitivity increased significantly the risk of DP among all twin pairs (OR 1.80, 95% CI 1.08-3.06) and among female twin pairs (OR 2.63, 95% CI 1.12-6.85). Thus noise sensitivity may be a potential risk factor for disability retirement. It is associated with DP independently of familial background and genet...
Aims: There is a need to better understand work incapacity due to musculoskeletal disorders (MSD)... more Aims: There is a need to better understand work incapacity due to musculoskeletal disorders (MSD) and the factors that contribute to being granted disability pension (DP) with such disorders. A twin cohort study would serve a powerful tool responding to this knowledge gap by providing information on factors affecting DP when controlling for family background. The purpose was to investigate the incidence of and risk factors for DP due to any MSD ( n = 1,819) and specifically due to osteoarthritis (OA, n = 677) in a twin cohort of 24,043 people over a 30-year follow-up. Methods: Data on twin pairs from a mailed questionnaire during the baseline year of 1975 were followed up with register data regarding DP, emigration, old-age pension, and death. For statistical analysis, univariate and multivariate Cox proportional hazard ratios were estimated. Results: Baseline musculoskeletal pain, frequency of use of analgesics, body mass index, and chronic diseases, as well as education and social...
ObjectiveA low socio-economic status (SES) is related to less healthy dietary habits, but the rea... more ObjectiveA low socio-economic status (SES) is related to less healthy dietary habits, but the reasons for this remain unclear. We examined whether the absolute or relative importance of various food choice motives contributed to SES disparities in vegetable/fruit and energy-dense food intake.DesignWe analysed cross-sectional data from the FINRISK Study 2007 by means of structural equation modelling and used a shortened version of the Food Choice Questionnaire to assess the absolute importance of health, pleasure, convenience, price, familiarity and ethicality motives. We calculated the relative importance of each motive by dividing the participant's rating of it by his/her mean score on all motives. Dietary intake was measured with an FFQ.SettingA population-based survey in Finland.SubjectsMen (n 1691) and women (n 2059) aged 25–64 years.ResultsHigher education and income were related to a greater vegetable/fruit intake (β = 0·12, P < 0·001), while education was associated ne...
To investigate whether stability or changes in smoking predict disability pension (DP) due to low... more To investigate whether stability or changes in smoking predict disability pension (DP) due to low back diagnoses (LBD) and musculoskeletal diagnoses (MSD) after taking familial confounding into account using a co-twin design. Longitudinal smoking patterns and multiple covariates in a population-based cohort of 17,451 Finnish twins (6959 complete pairs) born before 1958 were surveyed through questionnaires in 1975 and 1981. The outcome data were collected from the national pension registers until the end of 2004. Cox proportional hazards regression models were used for statistical analyses. Disability pension due to low back diagnoses was granted to 408 individuals and disability pension due to musculoskeletal diagnoses to 1177 individuals during the follow-up of 23 years. Being a persistent smoker (current smoker both 1975 and 1981) predicted a significantly increased risk for disability pension (hazard ratio 1.69, 95% confidence interval 1.46, 1.97) compared to those individuals who had never smoked. The association remained when several confounding factors, including familial factors, were taken into account. Persistent smoking predicts early disability pension due to musculoskeletal diagnoses and low back diagnoses independently from numerous confounding factors, including familial effects shared by the co-twins.
Pain is known to play an important role in the pathway to becoming work disabled, in particular f... more Pain is known to play an important role in the pathway to becoming work disabled, in particular for award of disability pensions (DP) due to musculoskeletal diagnoses (MSD). This prospective cohort study investigated MSD-related pain stability and/or changes as predictors for DP during a 23-year follow-up. Additionally confounding factors were examined to elucidate whether familial effects (including genetics and family background) or socioeconomic status, other pain, or use of medication would affect the associations between pain and DP. Data were available on 11,224 twins (4399 complete pairs) born before 1958 surveyed through questionnaires about background factors and musculoskeletal (low back, neck, and shoulder) pain impairing work ability in 1975 and 1981. The follow-up data were collected from pension registers until 2004. Cox proportional hazards regression models were used. During the 23-year follow-up, 508 DPs due to MSD, 166 DPs due to osteoarthritis (OA), and 162 DPs due to low back diagnoses (LBD) were granted. Musculoskeletal pain impairing work ability both measured at 1 time point and 6 years apart, and either 1 pain location or multiple locations, predicted increased risk for DP due to MSD, OA, and LBD. The associations were independent of familial confounding factors and of several influential background factors, including headache; migraine; use of analgesics, hypnotics, or tranquillizers; life satisfaction; and education and marital status. This study concluded that musculoskeletal pain impairing work ability is an early and direct predictor for DP due to MSD, OA, and LBD.
Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high ... more Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estimate the genetic correlations of BMI from infancy to adulthood and compared them to the genetic correlations of height. Methods We pooled individual level data from 25 longitudinal twin cohorts including 38,530 complete twin pairs and having 283,766 longitudinal height and weight measures. The data were analyzed using Cholesky decomposition offering genetic and environmental correlations of BMI and height between all age combinations from 1 to 19 years of age. Results The genetic correlations of BMI and height were stronger than the trait correlations. For BMI, we found that genetic correlations decreased as the age between the assessments ...
We tested the causality between education and smoking using the natural experiment of discordant ... more We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs. Similarly, education levels were higher among former smoking than among currently smoking co-twins, and this difference was larger within DZ pairs. Our results support the hypothesis of a causal effect of education on both current smoking status and smoking cessation. However, the even greater intra-pair differences within DZ pairs, who share only 50% of their segregating genes, provide evidence that shared genetic factors also contrib...
Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finlan... more Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finland Department of Physical Education and Sport, University of Madeira, Funchal, Portugal Center for the Interdisciplinary Study of Gerontology and Vulnerability, University of Geneva, Geneva, Switzerland Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country UPV/EHU, Leioa, Spain Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal ISOPlexis Genebank, University of Madeira, Funchal, Portugal Human Genetics Laboratory, University of Madeira, Funchal, Portugal Physical Activity, Sports & Health Research Group, Department of Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Department of Public Health, University of Helsinki, Helsinki, Finland De...
Social Psychiatry and Psychiatric Epidemiology, 2021
Purpose Sense of coherence (SOC) represents coping and can be considered an essential component o... more Purpose Sense of coherence (SOC) represents coping and can be considered an essential component of mental health. SOC correlates with mental health and personality, but the background of these associations is poorly understood. We analyzed the role of genetic factors behind the associations of SOC with mental health, self-esteem and personality using genetic twin modeling and polygenic scores (PGS). Methods Information on SOC (13-item Orientation of Life Questionnaire), four mental health indicators, self-esteem and personality (NEO Five Factor Inventory Questionnaire) was collected from 1295 Finnish twins at 20–27 years of age. Results In men and women, SOC correlated negatively with depression, alexithymia, schizotypal personality and overall mental health problems and positively with self-esteem. For personality factors, neuroticism was associated with weaker SOC and extraversion, agreeableness and conscientiousness with stronger SOC. All these psychological traits were influence...
We investigated the heritability of educational attainment and how it differed between birth coho... more We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural–geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a2 = 0.43; 0.41–0.44), but also environmental variation shared by co-twins was substantial (c2 = 0.31; 0.30–0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900–1949 (a2 = 0.44; 0.41–0.46) than in the later cohorts born in 1950–1989 (a2 = 0.38; 0.36–0.40), with a corresponding lower influence of comm...
The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) projec... more The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and leng...
Journal of epidemiology and community health, 2018
Previous studies have found depression to be negatively associated with the prognosis of both car... more Previous studies have found depression to be negatively associated with the prognosis of both cardiovascular disease (CVD) and cancer, but this may partly reflect reverse causality. We limited the possibility of reverse causality by measuring depression before the first diagnosis of CVD or cancer. We used an 11% longitudinal random sample of the Finnish population aged 25 years or older who are residents of Finland for at least 1 year between 1987 and 2007, with an 80% oversample of those who died during this period. Those who had their first incidence of coronary heart disease (CHD) (n=107 966), stroke (n=68 685) or cancer (n=113 754) between 1998 and 2012 were followed up for cause-specific mortality from the date of diagnosis until the end of 2012. Depression was defined as having antidepressant purchases two to three calendar years before the incidence. Logistic and Cox regression models were used to examine short-term and long-term mortality by depression status. Long-term mort...
DESCRIPTION ABSTRACT Noise sensitivity is a common trait which increases the harmful health effec... more DESCRIPTION ABSTRACT Noise sensitivity is a common trait which increases the harmful health effects of noise. It has been associated with impaired somatic health, anxiety and poor sleep quality. Self-assessed poor health is a strong predictor of early retirement. This study is based on the Finnish Twin Cohort. Questionnaire data of a sample of 706 Finnish twin individuals (age range, 31 to 65 years) with record linkage to information on DP during 16 years of follow-up were analyzed using individual and pairwise Cox proportional hazards models. Noise sensitivity increased the risk of DP (hazard ratio = 1.41, 95% CI 1.03-1.93) among all participants. In within-pair analyses, noise sensitivity increased significantly the risk of DP among all twin pairs (OR 1.80, 95% CI 1.08-3.06) and among female twin pairs (OR 2.63, 95% CI 1.12-6.85). Thus noise sensitivity may be a potential risk factor for disability retirement. It is associated with DP independently of familial background and genet...
Aims: There is a need to better understand work incapacity due to musculoskeletal disorders (MSD)... more Aims: There is a need to better understand work incapacity due to musculoskeletal disorders (MSD) and the factors that contribute to being granted disability pension (DP) with such disorders. A twin cohort study would serve a powerful tool responding to this knowledge gap by providing information on factors affecting DP when controlling for family background. The purpose was to investigate the incidence of and risk factors for DP due to any MSD ( n = 1,819) and specifically due to osteoarthritis (OA, n = 677) in a twin cohort of 24,043 people over a 30-year follow-up. Methods: Data on twin pairs from a mailed questionnaire during the baseline year of 1975 were followed up with register data regarding DP, emigration, old-age pension, and death. For statistical analysis, univariate and multivariate Cox proportional hazard ratios were estimated. Results: Baseline musculoskeletal pain, frequency of use of analgesics, body mass index, and chronic diseases, as well as education and social...
ObjectiveA low socio-economic status (SES) is related to less healthy dietary habits, but the rea... more ObjectiveA low socio-economic status (SES) is related to less healthy dietary habits, but the reasons for this remain unclear. We examined whether the absolute or relative importance of various food choice motives contributed to SES disparities in vegetable/fruit and energy-dense food intake.DesignWe analysed cross-sectional data from the FINRISK Study 2007 by means of structural equation modelling and used a shortened version of the Food Choice Questionnaire to assess the absolute importance of health, pleasure, convenience, price, familiarity and ethicality motives. We calculated the relative importance of each motive by dividing the participant's rating of it by his/her mean score on all motives. Dietary intake was measured with an FFQ.SettingA population-based survey in Finland.SubjectsMen (n 1691) and women (n 2059) aged 25–64 years.ResultsHigher education and income were related to a greater vegetable/fruit intake (β = 0·12, P < 0·001), while education was associated ne...
To investigate whether stability or changes in smoking predict disability pension (DP) due to low... more To investigate whether stability or changes in smoking predict disability pension (DP) due to low back diagnoses (LBD) and musculoskeletal diagnoses (MSD) after taking familial confounding into account using a co-twin design. Longitudinal smoking patterns and multiple covariates in a population-based cohort of 17,451 Finnish twins (6959 complete pairs) born before 1958 were surveyed through questionnaires in 1975 and 1981. The outcome data were collected from the national pension registers until the end of 2004. Cox proportional hazards regression models were used for statistical analyses. Disability pension due to low back diagnoses was granted to 408 individuals and disability pension due to musculoskeletal diagnoses to 1177 individuals during the follow-up of 23 years. Being a persistent smoker (current smoker both 1975 and 1981) predicted a significantly increased risk for disability pension (hazard ratio 1.69, 95% confidence interval 1.46, 1.97) compared to those individuals who had never smoked. The association remained when several confounding factors, including familial factors, were taken into account. Persistent smoking predicts early disability pension due to musculoskeletal diagnoses and low back diagnoses independently from numerous confounding factors, including familial effects shared by the co-twins.
Pain is known to play an important role in the pathway to becoming work disabled, in particular f... more Pain is known to play an important role in the pathway to becoming work disabled, in particular for award of disability pensions (DP) due to musculoskeletal diagnoses (MSD). This prospective cohort study investigated MSD-related pain stability and/or changes as predictors for DP during a 23-year follow-up. Additionally confounding factors were examined to elucidate whether familial effects (including genetics and family background) or socioeconomic status, other pain, or use of medication would affect the associations between pain and DP. Data were available on 11,224 twins (4399 complete pairs) born before 1958 surveyed through questionnaires about background factors and musculoskeletal (low back, neck, and shoulder) pain impairing work ability in 1975 and 1981. The follow-up data were collected from pension registers until 2004. Cox proportional hazards regression models were used. During the 23-year follow-up, 508 DPs due to MSD, 166 DPs due to osteoarthritis (OA), and 162 DPs due to low back diagnoses (LBD) were granted. Musculoskeletal pain impairing work ability both measured at 1 time point and 6 years apart, and either 1 pain location or multiple locations, predicted increased risk for DP due to MSD, OA, and LBD. The associations were independent of familial confounding factors and of several influential background factors, including headache; migraine; use of analgesics, hypnotics, or tranquillizers; life satisfaction; and education and marital status. This study concluded that musculoskeletal pain impairing work ability is an early and direct predictor for DP due to MSD, OA, and LBD.
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Papers by Karri Silventoinen