Study protocol of comprehensive risk evaluation for anorexia nervosa in twins (CREAT): a study of discordant monozygotic twins with anorexia nervosa.

BACKGROUND: Anorexia nervosa (AN) is a severe disorder, for which genetic evidence suggests psychiatric as well as metabolic origins. AN has high somatic and psychiatric comorbidities, broad impact on quality of life, and elevated mortality. Risk factor studies of AN have focused on differences between acutely ill and recovered individuals. Such comparisons often yield ambiguous conclusions, as alterations could reflect different effects depending on the comparison. Whereas differences found in acutely ill patients could reflect state effects that are due to acute starvation or acute disease-specific factors, they could also reflect underlying traits. Observations in recovered individuals could reflect either an underlying trait or a "scar" due to lasting effects of sustained undernutrition and illness. The co-twin control design (i.e., monozygotic [MZ] twins who are discordant for AN and MZ concordant control twin pairs) affords at least partial disambiguation of these effects. METHODS: Comprehensive Risk Evaluation for Anorexia nervosa in Twins (CREAT) will be the largest and most comprehensive investigation of twins who are discordant for AN to date. CREAT utilizes a co-twin control design that includes endocrinological, neurocognitive, neuroimaging, genomic, and multi-omic approaches coupled with an experimental component that explores the impact of an overnight fast on most measured parameters. DISCUSSION: The multimodal longitudinal twin assessment of the CREAT study will help to disambiguate state, trait, and "scar" effects, and thereby enable a deeper understanding of the contribution of genetics, epigenetics, cognitive functions, brain structure and function, metabolism, endocrinology, microbiology, and immunology to the etiology and maintenance of AN.

The Uppsala-Stockholm Assisted Reproductive Techniques (UppStART) study.

PURPOSE: The Uppsala-Stockholm Assisted Reproductive Techniques (UppStART) study is a prospectively recruited sample of couples undergoing assisted reproduction in Stockholm and Uppsala county in Sweden. The study was initiated to (1) investigate possible changes in the epigenetic profile of infants inferred through the ART procedures and their consequence and (2) to assess the impact of lifestyle and health exposures on treatment outcome. PARTICIPANTS: Recruitment took place between September 2011 and December 2013, and in vitro fertilisation (IVF) cycles initiated and pregnancies conceived during this time were followed until December 2014. The cohort includes 971 participants (n= 514 women; n= 457 men), and 129 pregnancies were achieved from the first IVF cycle included in the study. FINDINGS TO DATE: Self-reported demographic, health and lifestyle data were collected from a baseline questionnaire, and to assess changes to lifestyle, a follow-up questionnaire was issued at the time of oocyte retrieval, and at subsequent IVF cycles. Questionnaire data were linked to data extracted from medical records. Biological samples were collected at baseline: blood for extraction of serum, plasma and DNA, morning and evening saliva samples for cortisol measurement and at delivery including samples of maternal blood, placenta and amniotic fluid, and cord blood for epigenetic analysis. FUTURE PLANS: Through the unique identification number assigned to each Swedish citizen at birth or immigration, UppStART study participants will be linked to the Swedish population-based national and quality registers to provide data from prenatal, obstetrical, neonatal and infant care, and subsequent updates will provide data on childhood health and educational outcomes. Collaboration and use of UppStART data is encouraged, and more information about access can be found at www.ki.se/meb/uppstart.