Adolescents self-reported sleep quality and emotional regulation: a discordant twin study.

AIM: This study explores the association between sleep quality and emotional regulation, and investigates the genetic and environmental bases of this association. METHODS: Three-hundred-eighty-two adolescent twins, from the Italian Twin Registry, and their parents filled the Youth Self-Report and Child Behavior Checklist questionnaires, from which the construct of Effortful Control (EC) was derived as a measure of emotional regulation. Twins were identified as "good" or "non-good" sleepers based on answers to the Sleep Disorders Questionnaire. EC levels were compared between same-sex sleep discordant twins. RESULTS: A significant association was detected between EC scores and sleep quality. When controlling for shared (fetal or early life) environmental factors and genetic background in the discordant twin analysis, this association weakened in dizygotic twins and disappeared in monozygotic twins. CONCLUSION: Results support the association between sleep quality and EC in adolescence; furthermore, they suggest that sleep quality and emotional regulation may depend on common genetic or environmental factors.

[Determinants of eating behaviour: the contribution of twin studies]. / Determinanti del comportamento alimentare: il contributo degli studi sui gemelli.

This review includes relevant twin studies conducted on eating habits and preferences, and on endophenotypes of disordered eating behaviour in general population, non-clinical settings. The twin study design is presented, along with its assumptions and possible applications in aetiological and public health epidemiology. Subsequently, the strategy for the search of the scientific literature and the exclusion criteria are reported. Then, the analysis of the studies included in this review is performed, with a brief description of targeted outcomes, twin model used, sample characteristics and findings. Finally, key messages emerging from the review are highlighted, emphasizing their value for bridging the current gaps in the understanding of determinants of eating behaviour and their mode of action.

An update on the Italian Twin Register: advances in cohort recruitment, project building and network development.

The Italian Twin Register has been in place for more than 10 years. Since its establishment, it has been focusing, on the one hand, on a continuous update of the existing information, and on the other hand, on new phenotypes and sample collection. Demographic data on about 140,000 twins have been updated using the municipality registries. The Italian Twin Register has been carrying out several new studies during the last few years. A birth cohort of twins, Multiple Births Cohort Study, has been started and the enrollment is ongoing. For this cohort, data on pregnancy and birth are collected, and periodical follow-ups are made. DNA is being collected for the twins and their parents. In the area of behavioral genetics, most efforts have been directed to psychological well being assessed with self-reported tools. Research on age-related traits continues with studies on arteriosclerosis development, early biomarkers in mild cognitive impairment, and the relation between lifestyle habits and mutagen sensitivity. The Italian Twin Register biobanking has grown in its size and in its know-how in terms of both technical issues and ethical procedures implementation. Furthermore, attitudes toward biobank-based research, together with willingness and motivation for donation, are being investigated. A valuable key resource for the Italian Twin Register is the possibility of linking twin data with disease registries. This approach has been yielding several important results, such as the recent study on the heritability of type 1 diabetes.