Twin Res Hum Genet
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Multicenter Study Clinical Trial
Protective and Harmful Effects of Physical Activity for Low Back Pain: A Protocol for the AUstralian Twin BACK Pain (AUTBACK) Feasibility Study.
Low back pain (LBP) is a major health problem globally, but approaches to prevention are not yet clearly identified because modifiable risk factors are not well established. Although physical activity is one promising modifiable risk factor, it is still not known what types and doses of physical activity are protective or harmful for LBP. The aim of this study is to establish the feasibility of a definitive cohort study that will investigate the effects of different types and doses of physical activity on the risk of developing recurrent LBP while accounting for genetic factors. ⋯ We will keep records of the recruitment rate, follow-up rate, and completeness of data. Barriers to completing the study will be investigated. The results of this study will inform the design and implementation of a future definitive study, which will help to clarify the effects of different types and doses of physical activity on the risk of developing recurrent LBP.
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A complex interrelation exists between change in depression symptomatology and cognitive decline. Studies indicate either that depression is a direct risk factor for cognitive change over time, or vice versa. Longitudinal twin studies provide the possibility to unravel cause and effect of correlated traits. ⋯ There was a considerable decline in the mean cognitive performance over 10 years, whereas the mean affective depression symptoms score was stable and with no genetic contribution to any individual change. Additionally, we saw a small but significant cross-trait correlation at both occasions (-0.11 and -0.09, respectively), but cross-trait cross-occasion analysis revealed no evidence that either of the two traits predicts the other over a 10-year interval. Thus, our study was not able to detect any causal association between change in depressive symptomatology and cognitive decline in middle-aged and elderly people over a 10-year interval.
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Multicenter Study Clinical Trial
A discordant monozygotic-twin approach to potential risk factors for chronic widespread pain in females.
Chronic widespread pain (CWP) is a common disorder affecting up to 15% of the general population. The objective of the present study was to explore the role of previously reported psychosocial and interpersonal risk factors on variation in CWP by investigating CWP discordant monozygotic (MZ) twins. This approach allows separation of cause and effect relationships, albeit imperfectly, as well the control for critical confounding variables such as common environment or genetics. ⋯ Of the variables showing significant links with CWP in the univariate individual-level analyses, including age, AS, and emotional intelligence, only emotional intelligence turned out to an independent predictor to the pathogenesis of CWP in both the individual level and discordant MZ analyses. These data indicate that in women having identical genetic risk, emotional intelligence seems to play a key role, although of small effect, in the development and/or maintenance of CWP. It further seems that many of the previously reported risk factors for CWP suffer from genetic confounding.
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Comparative Study
The genetic basis for cognitive ability, memory, and depression symptomatology in middle-aged and elderly chinese twins.
The genetic influences on aging-related phenotypes, including cognition and depression, have been well confirmed in the Western populations. We performed the first twin-based analysis on cognitive performance, memory and depression status in middle-aged and elderly Chinese twins, representing the world's largest and most rapidly aging population. The sample consisted of 384 twin pairs with a median age of 50 years. ⋯ The model also estimated weak but significant inverse genetic correlation for depression with cognition (-0.31) and memory (-0.28). No significant unique environmental correlation was found for depression with other two phenotypes. In conclusion, there can be a common genetic architecture for cognitive ability and memory that weakly correlates with depression symptomatology, but in the opposite direction.
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The present study is the first behavioral genetic investigation of the Dark Triad traits of personality, consisting of Machiavellianism, narcissism, and psychopathy, and the variable of mental toughness, reflecting individual differences in the ability to cope when under pressure. The purpose of this investigation was to explore a potential explanation for the success of individuals exhibiting the Dark Triad traits in workplace and social settings. Participants were adult twins who completed the MACH-IV, the Narcissistic Personality Inventory, and the Self-Report Psychopathy Scale assessing Machiavellianism, narcissism, and psychopathy, respectively, as well as the MT48, measuring mental toughness. ⋯ Bivariate behavioral genetic analyses of the data were conducted to assess the extent to which these significant phenotypic correlations were attributable to common genetic and/or common environmental factors. Results indicate that correlations between narcissism and mental toughness were attributable primarily to common non-shared environmental factors, correlations between Machiavellianism and mental toughness were influenced by both common genetic and common non-shared environmental factors, and the correlations between psychopathy and mental toughness were attributable entirely to correlated genetic factors. Implications of these findings in the context of etiology and organizational adaptation are discussed.