China
Africa
Explore chapters and articles related to this topic
Genetics of eating disorders
Published in Stephen Wonderlich, James E Mitchell, Martina de Zwaan, Howard Steiger, Annual Review of Eating Disorders Part 2 – 2006, 2018
Suzanne E Mazzeo, Margarita CT Slof-Op’t Landt, Eric F Van Furth, Cynthia M Bulik
A third study, conducted by Reichborn-Kjennerud and colleagues (Reichborn-Kjennerud et al. 2003), investigated gender differences in BE using the population-based Norwegian twin registry. BE was moderately heritable for both men and women (a2=.51); common environmental factors did not significantly contribute to BE. Moreover, the proportion of genetic variance in BE shared between men and women was estimated at 0.57 (95% CI 0.07-1.00), indicating that the majority of genetic risk factors for BE are shared across genders. Gender-specific factors could not, however, be ruled out entirely.
A Tight-Knit Family of Syndromes
Published in Peter Manu, The Psychopathology of Functional Somatic Syndromes, 2020
Investigators from the University of Washington, Seattle, and University of Illinois, Chicago, further expanded the body of evidence for the overlap between medically unexplained somatic syndromes in a co-twin control study that controlled the data for genetic and environmental factors (Aaron et al., 2001). The participating twins had been recruited for the CFS Twin Registry established in 1993 at the Harborview Medical Center in Seattle, Washington. Of the 632 inquiries, 454 twins returned the screening questionnaires, and 233 pairs of twins were found to have at least one member with a history of chronic fatigue. Data were collected with questionnaires designed to assess the presence of ten conditions: fibromyalgia, irritable bowel syndrome, multiple chemical sensitivity, temporomandibular disorder, interstitial cystitis, tension headache, postconcussion syndrome, chronic low back pain, chronic nonbacterial prostatitis (in males), and chronic pelvic pain (in females). A structured psychiatric interview, the Diagnostic Interview Schedule (Robins and Heizer, 1985) was administered by telephone to establish the lifetime presence of somatization disorder, major depression, dysthymia, generalized anxiety, panic, agoraphobia, post-traumatic stress disorder, mania, bipolar disorders, schizophrenia, substance use disorders, and eating disorders. Twins with a complaint of persistent tiredness were further subdivided into subsamples of twin pairs discordant for idiopathic chronic fatigue (127 pairs), chronic fatigue syndrome (22 pairs), and presumptive chronic fatigue syndrome (80 pairs) diagnosed according to standard criteria (Fukuda et al., 1994). Statistical analyses determined the prevalence of functional illnesses in twins with and without these types of chronic fatigue, and regression models were used to control for sociodemographic characteristics and nonexclusionary psychiatric morbidity (i.e., nonpsychotic and nonmelancholic major depression, dysthymia, generalized anxiety and panic disorder, somatization disorder, and post-traumatic stress disorder).
Causality in the Associations Between Exercise, Personality, and Mental Health
Published in Henning Budde, Mirko Wegner, The Exercise Effect on Mental Health, 2018
A more serious practical limitation of the twin design is that it requires access to data from a longitudinal twin registry, which is not feasible for all researchers in this field. Currently, only a few research groups have the resources to investigate causality in this specific genetically informative design. However, a different genetically informative design is becoming available through the online repositories with the results of hundreds of GWA studies (www.ebi.ac.uk/gwas/). The availability of these data on a large number of individuals makes it possible to not only test causality while controlling for latent genetic confounds, but to directly assess and hence control for the effects of specific genes. The Mendelian randomization technique has gained popularity as a means to causality testing that is in principle similar to the approach that we have used (Lawlor, Harbord, Sterne, Timpson, & Davey-Smith 2008; Davey-Smith & Hemani 2014). Instead of correlating latent genetic and environmental factors that are thought to influence two phenotypes, it is based on actual measured genetic variants. More specifically, a genetic variant that influences an exposure variable (such as exercise behavior) should also, through the causal chain, predict an outcome variable (such as mental health). The big advantage of the Mendelian randomization technique is that it is based on measured genetic variants and can be applied to any large population-based sample, whereas our methods for causality testing rely on latent (unmeasured) genetic and environmental factors that need large twin samples. The method however requires the identification of solid associations of genetic markers with the exposure variables, and this is not yet the case for most of the phenotypes concerned in this chapter. For neuroticism and extraversion, large-scale GWA analyses have been conducted, which has led to some promising results for neuroticism but no robust associations of genetic variants for extraversion (van den Berg et al. 2016; De Moor et al. 2015). For exercise behavior, robust associations with genetic markers remain to be identified (De Moor et al. 2009). It will hopefully not take long, however, for the large worldwide consortia to tackle physical activity phenotypes with a GWA approach.
Intraocular Pressure, Age, and Central Corneal Thickness in a Healthy Chinese Children Population: The Handan Offspring Myopia Study
Published in Ophthalmic Epidemiology, 2022
Qiang Zhou, Tie Ying Gao, Su Jie Fan, Yi Peng, Lei Li, Zhong Lin, Wei Han, Hai Shuang Lin, Ning Li Wang, Yuan Bo Liang
The limitation of our study is that about 30% of the eligible subjects did not participate in the study. More than half (58.9%) of these subjects had left the county for seeking higher education. 19.0% of the potential population worked outside the county for more than 6 months. That is why the sample amount in aged 15+ years old group is relative less than other age groups. The same situation also occurred in preschool children groups, because children less than 7 years old often following their parents left the county for a job. Estimates for IOP in these subgroups may not be as stable as for the rest of the population. To our best, the HOMS examined about 70% of the eligible Han Chinese offspring aged 6–18 years old of The Handan Eye Study participants living in a rural region of north China. As we have mentioned, our sample was enrolled from nature population in North China.27 The population in Guangzhou twin eye study11 was from South China. Although their twin sample was enrolled from a population-based twin registry, the population structure might different from ours. Whether our results were suit for all Chinese children need further investigation in multicenter population study in China or comparative study with other similar studies in other Chinese area in future.
Modeling the Speeded Determinants of Adolescents’ Academic and Attentional Functioning
Published in Developmental Neuropsychology, 2022
Holly N. Wakeman, Daniel R. Leopold, Richard K. Olson, Erik G. Willcutt
The twins were initially recruited from the Colorado Twin Registry, a registry based on birth records that includes information on over 90% of all twin births in Colorado. All available twins were invited to participate, yielding an unselected sample in which learning and attentional difficulties were free to vary. The twins were first assessed during the summer prior to starting kindergarten (Mage = 4.9 years). After the initial preschool assessment, participants were assessed again in the summers following kindergarten, first grade, second grade, fourth grade, and ninth grade (Mage = 15.5 years). The current analyses focus on the assessment completed at the end of ninth grade.
Lower gut microbiome diversity and higher abundance of proinflammatory genus Collinsella are associated with biopsy-proven nonalcoholic steatohepatitis
Published in Gut Microbes, 2020
Stuart Astbury, Edmond Atallah, Amrita Vijay, Guruprasad P Aithal, Jane I Grove, Ana M Valdes
Seventy-six healthy controls were included from the UK Adult Twin Registry (TwinsUK), a large cohort of volunteer adult twins from the United Kingdom hosted by the Department of Twin Research and Genetic Epidemiology at St. Thomas’ Hospital, King’s College London.55This cohort contained 13 twin pairs (9 monozygotic pairs and 4 dizygotic pairs); all others had a twin who was not included.