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1.
Age Ageing ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33022060

RESUMO

BACKGROUND: dementia is associated with an excess risk of death but mortality after chronic subdural hematoma (CSDH) evacuation in older people with dementia is unknown. We assessed the association between dementia and 1-year case-fatality in older persons undergoing CSDH evacuation. METHODS: we conducted a nationwide Finnish cohort study including all older persons (≥60 years) undergoing CSDH evacuation during 1997-2014 (referred to as cases). We identified controls, without a diagnosis of CSDH, that were matched for age, sex and year of first hospitalisation with a new dementia diagnosis. We identified cases and controls with a pre-existing diagnosis of dementia. Outcome was 12-month mortality. Mortality was compared in case-only and case-control analyses. RESULTS: of 7,621 included cases, 885 (12%) had a pre-existing diagnosis of dementia. The proportion of cases increased from 9.7% in 1997-2002 to 12.2% in 2012-2014 (P = 0.038 for trend). In the case-analysis, dementia independently associated with 1-year case-fatality (dementia vs. no dementia odds ratio [OR] 1.50, 95% confidence interval [CI] 1.26-1.78). Sensitivity analysis suggested the association to be strongest for those 60-69 years old (OR 3.21, 95% CI 1.59-6.47). In the case-control matched analysis, 1-year mortality was 26% in the dementia CSDH surgery group compared to 16% in the dementia non-CSDH controls (P < 0.001). CONCLUSION: dementia is a significant risk factor for 1-year mortality after CSDH surgery in older people. The proportion of older CSDH patients having a pre-existing diagnosis of dementia is increasing. Thus, there is a need for improved evidence regarding the indications and benefits of CSDH evacuation among older persons.

3.
Stroke ; 51(10): 3018-3022, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32938311

RESUMO

BACKGROUND AND PURPOSE: One of the largest twin studies to date suggested that subarachnoid hemorrhage (SAH) is mainly of nongenetic origin, but the causal effect of environmental factors on SAH is yet unknown. We hypothesized that if only one of the twins experience fatal SAH, they do not share the most important environmental risk factor for SAH, namely smoking. If true, such finding would suggest that smoking causes SAH. METHODS: Through the nationwide cause-of-death register, we followed 16 282 same-sex twin pairs of Finnish origin from the older Finnish Twin Cohort between 1976 and 2018 and identified all participants who died from SAH. For the baseline, we collected risk factor information about smoking, hypertension, physical activity, body mass index, alcohol consumption, and education. We classified the pairs as monozygotic, dizygotic, or of unknown zygosity. We examined the within-pair risk factor differences in the pairs discordant for SAH, that is, where one twin died from SAH and the other did not. We computed both individual (whole cohort) and pairwise (discordant pair) hazard ratios and 95% CIs. RESULTS: During the 869 469 person-years of follow-up, we identified 116 discordant and 2 concordant (both died from SAH) twin pairs for fatal SAH. Overall, 25 of the discordant twin pairs were monozygotic. For the whole cohort, smoking (occasional/current) was associated with increased risk of SAH death (hazard ratio, 3.33 [CI, 2.24-4.95]) as compared with nonsmokers (never/former). In the pairwise analyses for discordant twin pairs, we found that the twin who smoked had an increased risk of fatal SAH (hazard ratio, 6.33 [CI, 1.87-21.4]) as compared with the nonsmoking twin. The association remained consistent regardless of the twin pairs' zygosity or sex. CONCLUSIONS: Our results provide strong evidence for a causal, rather than associative, role of smoking in SAH.

4.
Med Sci Sports Exerc ; 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32868581

RESUMO

PURPOSE: Greater leisure-time physical activity (LTPA) associates with healthier lives, but knowledge regarding occupational physical activity (OPA) is more inconsistent. DNA methylation (DNAm) patterns capture age-related changes in different tissues. We aimed to assess how LTPA and OPA are associated with three DNAm based epigenetic age estimates, namely DNAm Age, PhenoAge and GrimAge. METHODS: The participants were young adult (21-25-year-old, n = 285) and older (55-74-year-old, n = 235) twin pairs, including 16 pairs with documented long-term LTPA discordance. Genome-wide DNAm from blood samples was used to compute DNAm Age, PhenoAge and GrimAge Age acceleration (Acc), which describes the difference between chronological and epigenetic ages. Physical activity was assessed with sport, leisure-time and work indices based on the Baecke Questionnaire. Genetic and environmental variance components of epigenetic age Acc were estimated by quantitative genetic modelling.Epigenetic age Acc was highly heritable in young adult and older twin pairs (~60%). Sport index was associated with slower and OPA with faster DNAm GrimAge Acc after adjusting the model for sex. Genetic factors and non-shared environmental factors in common with sport index explained 1.5-2.7% and 1.9-3.5%, respectively, of the variation in GrimAge Acc. The corresponding proportions considering OPA were 0.4-1.8% and 0.7-1.8%, respectively. However, these proportions were minor (<0.5%) after adjusting the model for smoking status. CONCLUSIONS: LTPA associates with slower and OPA with faster epigenetic aging. However, adjusting the models for smoking status, which may reflect the accumulation of unhealthy lifestyle habits, attenuated the associations.

5.
BMC Public Health ; 20(1): 1373, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32907578

RESUMO

BACKGROUND: Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep duration in a population-based cohort. METHODS: Members of the Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals, response rate 89%, mean age 36 years), 1981 (24,535, 84%, 41 years), 1990 (12,450, 77%, 44 years), and 2011 (8334, 72%, 60 years). Weibull regression models were used to model the effects of follow-up time and age simultaneously. RESULTS: Sleep duration has decreased in all adult age groups and in both genders. The mean duration was in men 7.57 h in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5 min in men and 0.9 in women per year of follow-up. In the age-group 18-34 years, mean sleep length was 7.69 h in 1975 and 7.53 in 1990. Among 35-54-year-old it was 7.57 h in 1975 and 7.34 in 2011, and in the age group of 55+ year olds 7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 min or about 0.6 min per year of follow-up. CONCLUSIONS: There has been a slight decrease in mean sleep duration during the 36-year follow-up. Although the sleep duration was longer in 1970s and 1980s, the probable main cause for the change in this study population is the effect of aging.


Assuntos
Envelhecimento , Transtornos do Sono-Vigília/epidemiologia , Sono , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Finlândia/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Autorrelato , Privação do Sono , Inquéritos e Questionários , Adulto Jovem
6.
Nat Hum Behav ; 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32989287

RESUMO

Handedness has been extensively studied because of its relationship with language and the over-representation of left-handers in some neurodevelopmental disorders. Using data from the UK Biobank, 23andMe and the International Handedness Consortium, we conducted a genome-wide association meta-analysis of handedness (N = 1,766,671). We found 41 loci associated (P < 5 × 10-8) with left-handedness and 7 associated with ambidexterity. Tissue-enrichment analysis implicated the CNS in the aetiology of handedness. Pathways including regulation of microtubules and brain morphology were also highlighted. We found suggestive positive genetic correlations between left-handedness and neuropsychiatric traits, including schizophrenia and bipolar disorder. Furthermore, the genetic correlation between left-handedness and ambidexterity is low (rG = 0.26), which implies that these traits are largely influenced by different genetic mechanisms. Our findings suggest that handedness is highly polygenic and that the genetic variants that predispose to left-handedness may underlie part of the association with some psychiatric disorders.

7.
Twin Res Hum Genet ; : 1-9, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32972470

RESUMO

We explored the genetic architecture of metabolic risk factors of cardiovascular diseases (CVDs) and their clustering in Chinese boys and girls. Seven metabolic traits (body mass index [BMI], waist circumference [WC], systolic blood pressure [SBP], diastolic blood pressure [DBP], total cholesterol [TC], triglyceride [TG], and uric acid [UA]) were measured in a sample of 1016 twins between 8 and 17 years of age, recruited from the Qingdao Twin Registry. Cholesky, independent pathway, and common pathway models were used to identify the latent genetic structure behind the clustering of these metabolic traits. Genetic architecture of these metabolic traits was largely similar in boys and girls. The highest heritability was found for BMI (a2 = 0.63) in boys and TC (a2 = .69) in girls. Three heritable factors, adiposity (BMI and WC), blood pressure (SBP and DBP), and metabolite factors (TC, TG, and UA), which formed one higher-order latent phenotype, were identified. Latent genetic, common environmental, and unique environmental factors indirectly impacted the three factors through one single latent factor. Our results suggest that there is one latent factor influencing several metabolic traits, which are known risk factors of CVDs in young Chinese twins. Latent genetic, common environmental, and unique environmental factors indirectly imposed on them. These results inform strategies for gene pleiotropic discovery and intervening of CVD risk factors during childhood and adolescence.

8.
Schizophr Res ; 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32736837

RESUMO

Subclinical psychosis, including schizotypal indicators and psychotic experiences, predicts future suicidal ideation. This relationship may reflect unmeasured confounding from environmental factors, genetic factors, or both. We used a genetically-informative twin design to understand if the association between subclinical psychosis and suicidal ideation is independent of shared genetic and environmental factors. We analysed cross-sectional associations of age-22 self-reported subclinical psychosis (positive, negative, and disorganised features) with suicidal ideation in twins participating in the FinnTwin12 study (maximum n = 1213). Then, we analysed the reverse association of age-14 suicidal ideation with age-22 subclinical psychosis. Associations were studied first among individuals and then within monozygotic (MZ) and dizygotic (DZ) pairs. Individual-level analyses showed that all subclinical psychosis factors were associated with suicidal ideation. In within-pair analyses, estimates of associations were lower for MZ pairs than DZ pairs, except for the negative schizotypy-suicidal ideation association where estimates were consistent across individual-level and within-pair analyses. Findings provide evidence that the association between negative features and suicide ideation is not explained by familial factors and may be causal, though the possibility of confounding by individual-specific environmental factors and reverse causation cannot be ruled out. The relationships of positive and disorganised subclinical psychosis features with suicidal ideation cannot be explained by confounding due to environmental factors shared between siblings, but their associations may be due to shared genetic factors.

9.
J Oral Rehabil ; 47(9): 1110-1119, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32613647

RESUMO

BACKGROUND: Sleep bruxism (SB) and awake bruxism (AB) have been considered different entities, although co-occurrence between them has been shown. While genetic factors have a marked influence on phenotypic variance in liability to SB, this remains unclear for AB. AIM: To examine the degree of co-occurrence of SB and AB, and whether they have common correlates and also twin similarity of SB and AB bruxism traits by zygosity and sex. METHODS: A questionnaire was mailed to all twins born 1945-1957 in Finland in 2012 (n = 11 766). Age and sex adjusted logistic regression models were used. Twin similarity was assessed using polychoric correlations, and crosstwin-crosstrait correlations were computed. RESULTS: The response rate was 72% (n = 8410). Any SB was reported by 14.8% and ≥ 3 nights weekly by 5.0%. Percentages for any AB were 18.4% and 6.3%, respectively. There was substantial co-occurrence (29.5%) between SB and AB, and several shared correlates were found. For SB, the polychoric intra-class correlation was 0.366 in monozygotic (MZ) and 0.200 in dizygotic (DZ) pairs, without gender difference. A twofold crosstwin-crosstrait correlation was observed in MZ twins compared to DZ twins. CONCLUSIONS: The risk factor profiles of SB and AB were largely but not entirely similar. The higher correlation in MZ than in DZ pairs suggests the influence of genetic factors on both SB and AB. The higher crosstwin-crosstrait correlation in MZ than in DZ pairs suggests some degree of genetic influences shared by SB and AB.


Assuntos
Gêmeos Dizigóticos , Vigília , Finlândia , Humanos , Autorrelato , Gêmeos Monozigóticos
10.
Am J Hum Biol ; : e23470, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32638469

RESUMO

OBJECTIVES: To analyze the influence of genetic and environmental factors on the variation in somatotype, physical fitness, and their mutual associations. METHODS: Twins from 214 pairs (87 monozygotic) of the Autonomous Region of Madeira, Portugal, from 3 to 18 years of age (51% girls) were assessed in anthropometry and physical fitness tests. We estimated endomorphy, mesomorphy, and ectomorphy based on anthropometric measures and physical fitness using the Eurofit test battery. Two age categories were analyzed: children (3-11 years) and adolescents (12-18 years). Genetic and environmental variations were estimated using quantitative genetic twin modeling. RESULTS: No genetic sex differences were found, thus boys and girls were pooled in all genetic analyses. Heritability estimates were high for somatotype (a2 = 0.80-0.93), physical fitness traits (a2 = 0.67-0.83), and largely similar in children and adolescents. Positive correlations were found for ectomorphy with motor ability and cardiorespiratory endurance as well as for endomorphy and mesomorphy with muscular strength (r = 0.25-0.37). In contrast, negative associations were found for ectomorphy with muscular strength, as well as for endomorphy and mesomorphy with motor ability and cardiorespiratory endurance (-0.46 to -0.26). Twin modeling indicated that these associations were explained mostly by genetic factors in common to the two associated traits (84% or more). CONCLUSIONS: Associations between somatotype and physical fitness tests are mainly explained by common genetic background in children and adolescents. Therefore, interventions in youth should consider that a child's performance in physical fitness tests partly reflects their inherited physique.

11.
Nat Commun ; 11(1): 3519, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32665587

RESUMO

Estimates from Mendelian randomization studies of unrelated individuals can be biased due to uncontrolled confounding from familial effects. Here we describe methods for within-family Mendelian randomization analyses and use simulation studies to show that family-based analyses can reduce such biases. We illustrate empirically how familial effects can affect estimates using data from 61,008 siblings from the Nord-Trøndelag Health Study and UK Biobank and replicated our findings using 222,368 siblings from 23andMe. Both Mendelian randomization estimates using unrelated individuals and within family methods reproduced established effects of lower BMI reducing risk of diabetes and high blood pressure. However, while Mendelian randomization estimates from samples of unrelated individuals suggested that taller height and lower BMI increase educational attainment, these effects were strongly attenuated in within-family Mendelian randomization analyses. Our findings indicate the necessity of controlling for population structure and familial effects in Mendelian randomization studies.


Assuntos
Análise da Randomização Mendeliana/métodos , Índice de Massa Corporal , Epidemiologia , Feminino , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
12.
PLoS One ; 15(6): e0235049, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603369

RESUMO

BACKGROUND: Short sleep duration has been suggested to lead to insulin resistance both directly by altering glucose metabolism and indirectly through obesity. This study aims to investigate associations between nocturnal sleep duration and insulin resistance considering abdominal obesity as a mediator. METHODS: We analysed data of 3 900 children aged 2-15 years participating in the second (2009/10) and third (2013/14) examination wave of the European IDEFICS/I.Family study (hereafter referred to as baseline and follow-up). Information on nocturnal sleep duration was collected by questionnaires and age-standardised (SLEEP z-score). The homeostasis model assessment (HOMA) was calculated from fasting insulin and fasting glucose obtained from blood samples; waist circumference (WAIST) was measured with an inelastic tape. HOMA and WAIST were used as indicators for insulin resistance and abdominal obesity, respectively, and transformed to age- and sex-specific z-scores. Cross-sectional and longitudinal associations between SLEEP z-score and HOMA z-score were investigated based on a path model considering WAIST z-score as a mediator adjusting for relevant confounders. RESULTS: Cross-sectionally, baseline SLEEP z-score was negatively associated with baseline WAIST z-score (unstandardised effect estimate -0.120, 95% confidence interval [-0.167; -0.073]). We observed no direct effect of baseline SLEEP z-score on baseline HOMA z-score but a negative indirect effect through baseline WAIST z-score (-0.042 [-0.058; -0.025]). Longitudinally, there was no direct effect of baseline SLEEP z-score on HOMA z-score at follow-up but a negative indirect effect through both baseline WAIST z-score and WAIST z-score at follow-up (-0.028 [-0.040; -0.016]). CONCLUSIONS: Our results do not support the hypothesis of an association between short sleep duration and insulin resistance independent of abdominal obesity. However, longer sleep duration may exert short and long term beneficial effects on insulin resistance through its beneficial effects on abdominal obesity.


Assuntos
Resistência à Insulina , Obesidade Abdominal/epidemiologia , Sono , Adolescente , Glicemia/análise , Criança , Pré-Escolar , Estudos Transversais , Europa (Continente) , Feminino , Humanos , Insulina/sangue , Estudos Longitudinais , Masculino , Circunferência da Cintura
13.
Am J Clin Nutr ; 112(4): 956-966, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32685959

RESUMO

BACKGROUND: Obesity susceptibility genes are highly expressed in the brain suggesting that they might exert their influence on body weight through eating-related behaviors. OBJECTIVES: To examine whether the genetic susceptibility to obesity is mediated by eating behavior patterns. METHODS: Participants were 3977 twins (33% monozygotic, 56% females), aged 31-37 y, from wave 5 of the FinnTwin16 study. They self-reported their height and weight, eating behaviors (15 items), diet quality, and self-measured their waist circumference (WC). For 1055 twins with genome-wide data, we constructed a polygenic risk score for BMI (PRSBMI) using almost 1 million single nucleotide polymorphisms. We used principal component analyses to identify eating behavior patterns, twin modeling to decompose correlations into genetic and environmental components, and structural equation modeling to test mediation models between the PRSBMI, eating behavior patterns, and obesity measures. RESULTS: We identified 4 moderately heritable (h2 = 36-48%) eating behavior patterns labeled "snacking," "infrequent and unhealthy eating," "avoidant eating," and "emotional and external eating." The highest phenotypic correlation with obesity measures was found for the snacking behavior pattern (r = 0.35 for BMI and r = 0.32 for WC; P < 0.001 for both), largely due to genetic factors in common (bivariate h2 > 70%). The snacking behavior pattern partially mediated the association between the PRSBMI and obesity measures (ßindirect = 0.06; 95% CI: 0.02, 0.09; P = 0.002 for BMI; and ßindirect = 0.05; 95% CI: 0.02, 0.08; P = 0.003 for WC). CONCLUSIONS: Eating behavior patterns share a common genetic liability with obesity measures and are moderately heritable. Genetic susceptibility to obesity can be partly mediated by an eating pattern characterized by frequent snacking. Obesity prevention efforts might therefore benefit from focusing on eating behavior change, particularly in genetically susceptible individuals.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32474928

RESUMO

BACKGROUND: To conduct a comprehensive assessment of the association between aggression and academic performance in compulsory education. METHOD: We studied aggression and academic performance in over 27,000 individuals from four European twin cohorts participating in the ACTION consortium (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies). Individual level data on aggression at ages 7-16 were assessed by three instruments (Achenbach System of Empirically Based Assessment, Multidimensional Peer Nomination Inventory, Strengths and Difficulties Questionnaire) including parental, teacher and self-reports. Academic performance was measured with teacher-rated grade point averages (ages 12-14) or standardized test scores (ages 12-16). Random effect meta-analytical correlations with academic performance were estimated for parental ratings (in all four cohorts) and self-ratings (in three cohorts). RESULTS: All between-family analyses indicated significant negative aggression-academic performance associations with correlations ranging from -.06 to -.33. Results were similar across different ages, instruments and raters and either with teacher-rated grade point averages or standardized test scores as measures of academic performance. Meta-analytical r's were -.20 and -.23 for parental and self-ratings, respectively. In within-family analyses of all twin pairs, the negative aggression-academic performance associations were statistically significant in 14 out of 17 analyses (r = -.17 for parental- and r = -.16 for self-ratings). Separate analyses in monozygotic (r = -.07 for parental and self-ratings), same-sex dizygotic (r's = -.16 and -.17 for parental and self-ratings) and opposite-sex dizygotic (r's = -.21 and -.19 for parental and self-ratings) twin pairs suggested partial confounding by genetic effects. CONCLUSIONS: There is a robust negative association between aggression and academic performance in compulsory education. Part of these associations were explained by shared genetic effects, but some evidence of a negative association between aggression and academic performance remained even in within-family analyses of monozygotic twin pairs.

15.
Transl Psychiatry ; 10(1): 196, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555147

RESUMO

Genome-wide, polygenic risk scores (PRS) have emerged as a useful way to characterize genetic liability. There is growing evidence that PRS may prove useful for early identification of those at increased risk for certain diseases. The current potential of PRS for alcohol use disorders (AUD) remains an open question. Using data from both a population-based sample [the FinnTwin12 (FT12) study] and a high-risk sample [the Collaborative Study on the Genetics of Alcoholism (COGA)], we examined the association between PRSs derived from genome-wide association studies (GWASs) of (1) alcohol dependence/alcohol problems, (2) alcohol consumption, and (3) risky behaviors with AUD and other substance use disorder (SUD) criteria. These PRSs explain ~2.5-3.5% of the variance in AUD (across FT12 and COGA) when all PRSs are included in the same model. Calculations of area under the curve (AUC) show PRS provide only a slight improvement over a model with age, sex, and ancestral principal components as covariates. While individuals in the top 20, 10, and 5% of the PRS distribution had greater odds of having an AUD compared to the lower end of the continuum in both COGA and FT12, the point estimates at each threshold were statistically indistinguishable. Those in the top 5% reported greater levels of licit (alcohol and nicotine) and illicit (cannabis and opioid) SUD criteria. PRSs are associated with risk for SUD in independent samples. However, usefulness for identifying those at increased risk in their current form is modest, at best. Improvement in predictive ability will likely be dependent on increasing the size of well-phenotyped discovery samples.

16.
Eur J Sport Sci ; : 1-10, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32449485

RESUMO

It is not known whether decrease in physical activity (PA) is associated with binge drinking among former athletes. The purpose of this study was to investigate the reciprocal associations between PA and use of alcohol among former athletes and controls at four time points. Furthermore, we examined whether there were longitudinal latent profiles related to use of alcohol, smoking and PA during the follow-up. Finnish male former elite athletes (n = 1633) and matched controls (n = 1099) questionnaire-reported their PA, alcohol consumption and smoking at four time points in 1985, 1995, 2001 and 2008. Former athletes were more physically active and smoked less than controls, but in all profiles smoking decreased during the follow-up. Former athletes consumed alcohol significantly more compared to controls in 1985, especially if their athletic career had ended suddenly by sports injury. At other time points, no differences were seen. Five latent profiles were found, and there were significant differences between former athletes and controls in the probabilities to belong to four of them. PA decreased in four of five profiles, while alcohol consumption decreased or increased in some profiles. But PA did not predict later alcohol consumption at any time point. Cross-lagged path model indicated that the mutual associations of alcohol use and PA were weak at most. Although risk of excessive alcohol consumption may increase in individuals, whose athletic career has ended suddenly by sports injury, overall PA and alcohol affected each other's development only modestly among former athletes and controls during the 23-year follow-up.

17.
Twin Res Hum Genet ; 23(2): 114-115, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32450941

RESUMO

Cohort studies are essential for conducting large studies of multiple exposures and outcomes in humans. Recently, the ability to combine data from multiple cohorts in, for example, meta-analyses, and the willingness in the genetics community to collaborate to enable replication studies has led to many new insights into the genetic and environmental determinants of human health and behaviors. The contribution of Professor Nicholas Martin to the development of cohort studies, particularly of twin and twin-family studies, over a period of several decades is reviewed. He has contributed to the development and use of both Australian and international resources. The contributions of Australian twin studies to genomewide association projects are multiple, and across multiple domains, from biomarkers, lifestyle and behavior to disorders and disease.

18.
Addict Behav ; 108: 106427, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32361366

RESUMO

Depression has been suggested to hinder smoking cessation, especially when co-occurring with nicotine dependence. The study aimed to examine the longitudinal association of depressive symptoms with smoking cessation among daily smokers. The study utilized adult Finnish twin cohort where 1438 daily smokers (mean age: 38.3, range: 33-45) in 1990 were re-examined for their smoking status in 2011. We assessed baseline depressive symptoms with the Beck Depression Inventory, and the self-reported smoking status at follow-up. The methods included multinomial logistic regression and time to event analyses, adjusted for multiple covariates (age, sex, marital status, social class, heavy drinking occasions, and health status) and smoking heaviness at baseline assessed by cigarettes per day (CPD). Additionally, within-twin-pair analyses were conducted. Results indicated that moderate/severe depressive symptoms at baseline were associated with a lower likelihood of smoking cessation two decades later. Adjusting for covariates, those with moderate/severe depressive symptoms (vs. no/minimal depressive symptoms) had 46% lower likelihood of quitting (relative risk ratio, RRR = 0.54, 95% CI: 0.30-0.96). After including CPD, the association of depressive symptoms with smoking cessation attenuated modestly (RRR = 0.62, 95% CI: 0.34-1.12). Further, time to event analysis for quitting year since baseline yielded similar findings. In the within-pair analysis, depressive symptoms were not associated with quitting smoking. The results suggest that reporting more depressive symptoms is associated with a lower likelihood of smoking cessation during a 20-year period. The baseline amount of smoking and familial factors partly explain the observed association. Smoking cessation programs should monitor depressive symptoms.

19.
Neurosci Biobehav Rev ; 114: 1-11, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32325068

RESUMO

Regular physical activity (PA) offers positive effects on the human body. However, the effects of PA on cognition and in the brain are less clear. In this paper, we narratively review the relationship of PA with cognition and dementia, first from general perspective and then through genetically informed studies on the topic. Then we move on to imaging studies on exercise and brain anatomy first by presenting an overall picture of the topic and then discussing brain imaging studies addressing PA and brain structure in twins in more detailed way. Regarding PA and cognition or dementia, genetically informed studies are uncommon, even though the relationship between PA and cognitive ageing has been extensively studied. It is challenging to find twin pairs discordant for PA and dementia. Concerning brain imaging studies, among PA discordant young adult twin pairs, the more active co-twins showed larger gray matter volumes in striatal, prefrontal, and hippocampal regions and in electrophysiological studies automatic deviance-detection processes differed in brain regions involved with sensorimotor, visual and memory functions.

20.
Scand J Med Sci Sports ; 30(8): 1409-1422, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32259351

RESUMO

Motives for physical activity may vary considerably by age, sex, and the level of physical activity. We aimed to examine motives for physical activity in older men and women with different physical activity levels as well as whether genetic and/or environmental factors explain those motives. Finnish twins (mean age 72.9 years, 262 full twin pairs) self-reported their motives for physical activity. Time spent on moderate-to-vigorous physical activity was monitored using a hip-worn accelerometer. Comparisons between the different physical activity groups of older twins (n = 764-791/motive dimension) were analyzed using the Wald test, and effect sizes were calculated as Cohen's d. Quantitative genetic modeling was used to estimate genetic and environmental contributions. For both sexes, the most frequently reported motives for physical activity were physical fitness, health maintenance, and psychological well-being. Conforming to others' expectations was more important for men than for women (P < .001, Cohen's d = 0.38), while appearance (P = .001 Cohen's d = -0.24) and psychological well-being (P = .02, Cohen's d = -0.17) were highlighted by women. Most of the motive dimensions differed significantly between the physically active and inactive individuals. It was estimated that 5%-42% of the variation in motives was contributed by genetic factors and 58%-95% by environmental factors. The result that environmental factors contribute in a great deal to motives indicates that interventions to motivate physically inactive older individuals to be physically active can be successful. However, personalized interventions are needed because sex and the level of physical activity were found to be associated with older individuals' motives for physical activity.

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