A systematic review of obstetric complications as risk factors for eating disorder and a meta-analysis of delivery method and prematurity

Perinatal risk factors and disordered eating in children and adolescents

OBJECTIVE

Studies have reported associations between perinatal factors (obstetric and neonatal factors) and later eating disorder risk. However, previous findings have been partly conflicting. Here, we analyzed associations between perinatal factors and disordered eating in a large cohort of Finnish children and adolescents.

METHOD

The participants were 8- to 14-year-old children and adolescents (N = 11,357) from The Finnish Health in Teens study. Disordered eating was assessed using the Children's Eating Attitudes Test (ChEAT). Perinatal data were obtained from the Finnish Birth Registry. Perinatal variables were initially analyzed using Chi-square analyses and linear regressions. Variables associated with disordered eating (p < .10) were entered into a multinomial logistic regression model. The regression analysis was conducted both including and excluding maternal BMI, as this information was missing for > 80% of the participants.

RESULTS

Of the participants, 56.6% reported disordered eating (ChEAT score ≥ 11) or partial disordered eating (1-10) symptoms. Including maternal BMI in the analyses (n = 1921), higher levels of disordered eating were independently associated with maternal pre-pregnancy BMI (OR 1.07, 95% CI [1.02, 1.12]), maternal smoking during pregnancy (OR 2.64, 95% CI [1.49, 4.68]), urgent or emergency cesarean birth (OR 2.16, 95% CI [1.10, 4.05]). Assisted reproduction was associated with lower levels of disordered eating (OR 0.39, 95% CI [0.20, 0.76]).

DISCUSSION

The results suggest that pregnancy and childbirth are vulnerable developmental periods, associated with later eating pathology. Further studies disentangling genetic and environmental mechanisms of associations between perinatal factors and later eating pathology are needed.

LEVEL OF EVIDENCE

Level III, Evidence obtained from well-designed cohort or case-control analytic studies.

Two identical twin pairs discordant for longstanding anorexia nervosa and OSFED: lived experience accounts of eating disorder and recovery processes

Research into the risk of anorexia nervosa (AN) has examined twin pairs to further the understanding of the contributions of genetics, trait inheritance, and environmental factors to eating disorder (ED) development. Investigations of twin experiences of EDs have been biologically-based and have not considered the qualitative, phenomenological aspects of twin experiences. A gap in the literature exists regarding understanding of discordant twins with EDs. This research was developed in response, with the aim to deepen understanding of AN in discordant twins and to create novel ideas for further research and testing. The case studies presented in this article provide lived experience insights of two identical discordant twin pairs: one twin pair discordant for longstanding AN and one twin pair discordant for 'atypical' AN (the twin with AN has recovered). The perspectives and experiences of each co-twin (one with AN and one without) explore a number of factors that may have contributed to twin discordance in these cases, and how each twin has responded to the impact of AN in their lives. Through use of first-person accounts in case study presentation, this article centres social justice values of lived experience leadership and involvement in research. This article aims to extend current knowledge and understanding of EDs in discordant twins, particularly regarding risk for ED development, ED duration, diagnosis and treatment, and recovery processes.

Early traumatic experiences and the hypothalamus-pituitary-adrenal axis in people with eating disorders: A narrative review

Exposure to trauma during childhood is a non-specific risk factor for psychiatric disorders, including eating disorders (EDs), over the life course. Moreover, an association between stressful life events and the onset/maintenance of EDs has been documented. Therefore, the hypothalamus-pituitary-adrenal (HPA) axis, namely the main component of the endogenous stress response system, has been proposed to be implicated in the pathophysiology of EDs. In this narrative review the current knowledge concerning the effects of early trauma exposure on the HPA axis activity and their putative role in the pathophysiology of EDs will be illustrated. Research findings corroborate the idea that childhood trauma exposure has long-lasting dysregulating effects on the activity of the HPA axis, which may contribute to the biological background of the early trauma-related risk for the development of EDs across the life span. Moreover, literature data support the existence of a "maltreated ecophenotype" in EDs characterized by specific clinic and neuroendocrine features, which may have important implications in treatment programming for such a type of patients.

Exposures during pregnancy and at birth are associated with the risk of offspring eating disorders

BACKGROUND

Eating disorders (ED) are severe psychiatric disorders, commonly debuting early. Aberrances in the intrauterine environment and at birth have been associated with risk of ED. Here, we explore if, and at what effect size, a variety of such exposures associate with offspring ED, that is, anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS).

METHODS

This population-based cohort study, conducted from September 2021 to August 2023, used Finnish national registries of all live births in 1996-2014 (N = 1,097,753). Cox proportional hazards modeling was used to compare ED risk in exposed versus unexposed offspring, adjusting for potential confounders and performing sex-stratified analyses.

RESULTS

A total of 6614 offspring were diagnosed with an ED; 3668 AN, 666 BN, and 4248 EDNOS. Lower risk of offspring AN was seen with young mothers, continued smoking, and instrumental delivery, while higher risk was seen with older mothers, inflammatory disorders, prematurity, small for gestational age, and low Apgar. Offspring risk of BN was higher with continued smoking and prematurity, while lower with postmature birth. Offspring risk of EDNOS was lower with instrumental delivery, higher for older mothers, polycystic ovary syndrome, insulin-treated pregestational diabetes, antibacterial treatment, prematurity, and small for gestational age. Sex-specific associations were found.

CONCLUSIONS

Several prenatal and at birth exposures are associated with offspring ED; however, we cannot exclude confounding by maternal BMI. Nevertheless, several exposures selectively associate with risk of either AN, BN, or EDNOS, and some are sex-specific, emphasizing the importance of subtype- and sex-stratified analyses of ED.

PUBLIC SIGNIFICANCE

We define environmental factors involved in the development of different ED, of importance as preventive measure, but also in order to aid in defining the molecular pathways involved and thus in the longer perspective contribute to the development of pharmacological treatment of ED.

Eating disorders, pregnancy and the postnatal period: a review of the recent literature

PURPOSE OF REVIEW

Eating disorders (ED) are severe psychiatric disorders that affect women in reproductive age. The purpose of this review is to provide an up-to-date overview of the impact of maternal ED on pregnancy and the postnatal period. The clinical implications for identification and management of maternal ED are also discussed.

RECENT FINDINGS

In the last 2 years, 15 articles focused on the impact of maternal ED in pregnancy and postpartum. Findings from this review indicate that around 15% of pregnant women are likely to have had an ED at some point in their lifetime, and about 5% have an ED in pregnancy. Although ED symptoms tend to decrease during pregnancy, remission is often only temporary with symptoms typically resurfacing in the postnatal period. Women with ED are prone to psychiatric comorbidities such as depression and anxiety during the perinatal period, with up to a third of women with ED reporting postnatal depression in clinical studies and prevalence ranging between 40% and 66% in general population samples. Furthermore, recent findings continue to highlight that current and prior history of maternal ED are associated with a heightened risk of adverse pregnancy and birth outcomes, most notably preterm birth and adverse birth weight outcomes.

SUMMARY

These findings continue to emphasise the clinical importance of early identification and response to maternal ED to mitigate potentially adverse maternal and infant outcomes.

Risk factors for eating disorders: an umbrella review of published meta-analyses

Objective:

To grade the evidence about risk factors for eating disorders (anorexia nervosa, bulimia nervosa, and binge eating disorder) with an umbrella review approach.

Methods:

This was a systematic review of observational studies on risk factors for eating disorders published in PubMed/PsycInfo/Embase until December 11th, 2019. We recalculated random-effect meta-analyses, heterogeneity, small-study effect, excess significance bias and 95% prediction intervals, grading significant evidence (p < 0.05) from convincing to weak according to established criteria. Quality was assessed with the Assessment of Multiple Systematic Reviews 2 (AMSTAR-2) tool.

Results:

Of 2,197 meta-analyses, nine were included, providing evidence on 50 risk factors, 29,272 subjects with eating disorders, and 1,679,385 controls. Although no association was supported by convincing evidence, highly suggestive evidence supported the association between childhood sexual abuse and bulimia nervosa (k = 29, 1,103 cases with eating disorders, 8,496 controls, OR, 2.73, 95%CI 1.96-3.79, p = 2.1 x 10-9, AMSTAR-2 moderate quality) and between appearance-related teasing victimization and any eating disorder (k = 10, 1,341 cases with eating disorders, 3,295 controls, OR 2.91, 95%CI 2.05-4.12, p = 1.8x10-9, AMSTAR-2 moderate quality). Suggestive, weak, or no evidence supported 11, 29, and 8 associations, respectively.

Conclusions:

The most credible evidence indicates that early traumatic and stressful events are risk factors for eating disorders. Larger collaborative prospective cohort studies are needed to identify risk factors for eating disorders, particularly anorexia nervosa.

The role of prenatal and perinatal factors in eating disorders: a systematic review

Numerous studies showed that factors influencing fetal development and neonatal period could lead to lasting alterations in the brain of the offspring, in turn increasing the risk for eating disorders (EDs). This work aims to systematically and critically review the literature on the association of prenatal and perinatal factors with the onset of EDs in the offspring, updating previous findings and focusing on anorexia nervosa (AN) and bulimia nervosa (BN). A systematic literature search was performed on Pubmed, PsycINFO, and Scopus. The drafting of this systematic review was conducted following the PRISMA statement criteria and the methodological quality of each study was assessed by the MMAT 2018. A total of 37 studies were included in this review. The factors that showed a more robust association with AN were higher maternal age, preeclampsia and eclampsia, multiparity, hypoxic complications, prematurity, or being born preterm (< 32 weeks) and small for gestational age or lower birth size. BN was only associated with maternal stress during pregnancy. Many methodological flaws emerged in the considered studies, so further research is needed to clarify these inconsistencies. Altogether, data are suggestive of an association between prenatal and perinatal factors and the onset of EDs in the offspring. Nevertheless, given the methodological quality of the available literature, firm conclusions cannot be drawn and whether this vulnerability is specific to EDs or mental disorders remains to be defined. Also, a strong need for longitudinal and well-designed studies on this topic emerged.

Prenatal and perinatal factors and risk of eating disorders

BACKGROUND

Among the most disabling and fatal psychiatric illnesses, eating disorders (EDs) often manifest early in life, which encourages investigations into in utero and perinatal environmental risk factors. The objective of this study was to determine whether complications during pregnancy and birth and perinatal conditions are associated with later eating disorder risk in offspring and whether these associations are unique to EDs.

METHODS

All individuals born in Denmark to Danish-born parents 1989-2010 were included in the study and followed from their 6th birthday until the end of 2016. Exposure to factors related to pregnancy, birth, and perinatal conditions was determined using national registers, as were hospital-based diagnoses of anorexia nervosa (AN), bulimia nervosa, and eating disorder not otherwise specified during follow-up. For comparison, diagnoses of depressive, anxiety, and obsessive-compulsive disorders were also included. Cox regression was used to compare hazards of psychiatric disorders in exposed and unexposed individuals.

RESULTS

1 167 043 individuals were included in the analysis. We found that similar to the comparison disorders, prematurity was associated with increased eating disorder risk. Conversely, patterns of increasing risks of EDs, especially in AN, with increasing parental ages differed from the more U-shaped patterns observed for depressive and anxiety disorders.

CONCLUSIONS

Our results suggest that pregnancy and early life are vulnerable developmental periods when exposures may influence offspring mental health, including eating disorder risk, later in life. The results suggest that some events pose more global transdiagnostic risk whereas other patterns, such as increasing parental ages, appear more specific to EDs.

Identifying psychosocial and familial correlates and the impact of the stressful life events in the onset of anorexia nervosa: Control-case study (ANOBAS): Psychosocial and familial correlates and stressful life events in AN

Anorexia nervosa (AN) is a multifactorial illness. Although several studies have determined which factors could predispose AN, few studies have determined which factors could precipitate it. What is more, it has been suggested that having experienced stressful life events (SLE) could be related to the onset of AN. The aim of this study was to explore specific psychosocial and familial correlates and the impact of SLE in the onset of AN. Following a case-control design, 40 adolescents diagnosed with AN were matched to three control groups, 40 healthy adolescents, 40 adolescents with affective disorders, 40 adolescents with asthma and their families by sex, age and socioeconomic status. Diagnostic interviews K-DSADS and questionnaires were used. The results empathised that no specific predisposing correlates were found for AN. Similarly, the increase of the amount of SLE prior to the onset is an overall characteristic for psychiatric disorders, which in AN it is only specifically related to psychological correlates, but no to cortisol. In terms of specific SLE, those related to interpersonal problems were frequent at the onset of AN. The results highlight the consequences of SLEs in the emotional well-being of the AN adolescents, that could be specific for this psychopathology.

Stress hormones and eating disorders

AIMS

The aim of this paper is to emphasize the role of stress processes in the aetiology of eating disorders.

METHODS

We have examined the literature for evidence that people with eating disorders might exhibit markers of stress and show signs of the "maltreated ecophenotype".

RESULTS

Early adversity is more common among people with binge eating behaviours. The secondary effects of malnutrition, which are mostly marked in anorexia nervosa, may be an added stressor that could also contribute to the stress related phenotype. People with eating disorders have anomalies in brain structure, reward and punishment sensitivity, and the balance between HPA and SMA function. These may be potential targets for treatment.

Prenatal and perinatal risk factors for eating disorders in women: A population cohort study

OBJECTIVE

The fetal programming model hypothesizes that developmental programming in utero and in early life induces adaptations that predetermine the adult phenotype. This study investigated whether prenatal/perinatal complications are associated with lifetime eating disorders in women.

METHOD

Participants included 46,373 adult women enrolled in the Norwegian Mother and Child Cohort Study (den norske Mor & barn-undersøkelsen [MoBa]). MoBa mothers and their mothers (MoBa grandmothers) were the focus of the current study. MoBa mothers with lifetime eating disorders were compared to a referent group.

RESULTS

MoBa mothers who weighed more at birth (birth weight, adjusted odds ratio [OR] = 1.14; 95% confidence interval [CI]: 1.10-1.19) or were born large-for-gestational-age (adjusted OR = 1.39; 95% CI: 1.27-1.52) were more likely to develop binge-eating disorder in later life. MoBa mothers who weighed less at birth were more likely to develop anorexia nervosa (birth weight, adjusted OR = 0.88; 95% CI: 0.81-0.95). Bulimia nervosa and purging disorder (PD) were not significantly predicted by the prenatal and perinatal factors examined.

DISCUSSION

Results of this study, which include the first known investigation of prenatal and perinatal factors in binge-eating disorder and PD, suggest that fetal programming may be relevant to the development of anorexia nervosa and binge-eating disorder. Future genetically informative research is needed to help disentangle whether these associations are a function of genetic influences or a true environmental fetal programming effect.

Recent Research and Personalized Treatment of Anorexia Nervosa

Recent advances in the understanding of aetiologic elements underlying anorexia nervosa have provided valuable insights and are transforming the way this illness is treated. The aim of this article is to consider how neuropsychological understanding and new research can be used to develop a more individualized and personalized approach in the management of this serious illness.

Association between maternal body mass index in early pregnancy and anorexia nervosa in daughters

BACKGROUND

The etiology of anorexia nervosa is poorly understood. Although genetic factors play a major role, maternal factors, and obstetric complications are possible environmental causes. We investigated the association between maternal overweight and obesity in early pregnancy and risk of anorexia nervosa in daughters.

METHODS

A retrospective cohort study including all live singleton females born in Sweden from 1992 through 2002. Anorexia nervosa diagnosis was identified by using the nation-wide Swedish Patient and Cause of Death Registers. Multivariable Cox hazards regression was used to estimate adjusted hazard ratios (aHRs) and 95% CIs, adjusting for confounders. Stratified Cox regressions were applied to data on siblings to adjust for unmeasured familial confounding.

RESULTS

Among 486,688 live singleton females, 2,414 (0.50%) were diagnosed with anorexia nervosa through 2012. The aHR of anorexia nervosa decreased linearly by maternal BMI (p-value for trend < .001). When compared with daughters of normal weight mothers (body mass index [BMI] 18.5-24.9), aHRs (95%CI) of anorexia nervosa were 0.74 (0.65-0.84) in daughters of overweight mothers (BMI 25-29.9) and 0.61 (0.47-0.78) in daughters of mothers with obesity Grade I (BMI 30-34.9). In sibling control analysis, no associations were observed between maternal BMI and aHRs of anorexia nervosa in offspring.

CONCLUSIONS

The rate of anorexia nervosa decreased with maternal overweight and obesity in a dose-response manner. However, the sibling control analysis suggests that these findings are not consistent with causals effects of maternal BMI on anorexia nervosa in offspring.

Maternal eating disorders and perinatal outcomes: A three-generation study in the Norwegian Mother and Child Cohort Study

Previous studies of the relationship between maternal eating disorders and adverse perinatal outcomes have failed to control for familial transmission of perinatal phenotypes, which may confound the reported association. In a unique design afforded by the Norwegian Mother and Child Cohort Study and Medical Birth Registry of Norway, we linked three generations through birth register records and maternal-reported survey data to investigate whether maternal eating disorders increase risk after parsing out the contribution of familial transmission of perinatal phenotypes. The samples were 70,881 pregnancies in grandmother-mother-child triads for analyses concerning eating disorder exposure during pregnancy and 52,348 for analyses concerning lifetime maternal eating disorder exposure. As hypothesized, eating disorders predicted a higher incidence of perinatal complications even after adjusting for grandmaternal perinatal phenotypes. For example, anorexia nervosa immediately prior to pregnancy was associated with smaller birth length (relative risk = 1.62; 95% CI [1.20, 2.14]), bulimia nervosa with induced labor (relative risk = 1.21; 95% CI [1.07, 1.36]), and binge-eating disorder with several delivery complications, larger birth length (relative risk = 1.25; 95% CI [1.17, 1.34]), and large-for-gestational-age (relative risk = 1.04; 95% CI [1.01, 1.06]). Maternal pregravid body mass index and gestational weight mediated most associations. Our results support that exposure to eating disorders increases the risk for negative health outcomes in pregnant women and their babies. (PsycINFO Database Record

Prenatal exposure to gestational diabetes mellitus as an independent risk factor for long-term neuropsychiatric morbidity of the offspring

BACKGROUND

The reported rates of gestational diabetes mellitus are constantly escalating and little is known about long-term complications in the offspring. Evidence from the field of epigenetics strongly advocates the need for research on the neuropsychiatric complications in offspring prenatally exposed to gestational diabetes mellitus.

OBJECTIVE

We sought to assess whether in utero exposure to gestational diabetes mellitus increases the risk of long-term neuropsychiatric morbidity in the offspring.

STUDY DESIGN

A population-based cohort study compared the incidence of hospitalizations due to neuropsychiatric disease between singletons exposed and unexposed to gestational diabetes mellitus. Deliveries occurred in the years 1991 through 2014 in a regional tertiary medical center. Perinatal deaths, multiple gestations, mothers with pregestational diabetes or lack of prenatal care, and children with congenital malformations were excluded from the study. A multivariate generalized estimating equation logistic regression model analysis was used to control for confounders and for maternal clusters.

RESULTS

During the study period 231,271 deliveries met the inclusion criteria; 5.4% of the births were to mothers diagnosed with gestational diabetes mellitus (n = 12,642), of these 4.3% had gestational diabetes type A1 (n = 10,076) and 1.1% had gestational diabetes type A2 (n = 2566). During the follow-up period, a significant linear association was noted between the severity of the gestational diabetes (no gestational diabetes, gestational diabetes mellitus A1, gestational diabetes mellitus A2) and neuropsychiatric disease of the offspring (1.02% vs 1.36% vs 1.68%, respectively, P < .001). A Kaplan-Meier curve demonstrated that children born to women with gestational diabetes mellitus had higher cumulative incidence of neuropsychiatric morbidity. Using a generalized estimating equation multivariable logistic regression model, controlling for time-to-event, maternal age, gestational age at delivery, maternal obesity, maternal preeclampsia and fertility treatments, maternal gestational diabetes mellitus was found to be an independent risk factor for long-term neuropsychiatric disease of the offspring (gestational diabetes mellitus A1 [adjusted odds ratio, 1.83; 95% confidence interval, 1.53-2.19] and gestational diabetes mellitus A2 [adjusted odds ratio, 1.64; 95% confidence interval, 1.18-2.27]). Within the limits of our database, our findings also point to a possible association between in utero exposure to gestational diabetes mellitus and autistic spectrum disorder of the offspring (adjusted odds ratio, 4.44; 95% confidence interval, 1.55-12.69), which was found significant also after controlling for time-to-event, maternal age, gestational age at delivery, and offspring weight at birth.

CONCLUSION

Exposure to maternal gestational diabetes mellitus is an independent risk factor for long-term neuropsychiatric morbidity in the offspring.

Childhood risk factors for lifetime bulimic or compulsive eating by age 30 years in a British national birth cohort

OBJECTIVE

To examine whether previously identified childhood risk factors for bulimia or compulsive eating (BCE) predict self-reported lifetime BCE by age 30 years in a prospective birth cohort.

METHOD

Using data from the 1970 British Cohort Study at birth, 5, and 10 years, associations between 22 putative childhood risk factors and self-reported lifetime BCE at 30 years were examined, adjusting for sex and socioeconomic status.

RESULTS

Only female sex (odds ratio (OR): 9.2; 95% confidence interval (CI): 1.9-43.7; p = 0.005), low self-esteem (OR:2.9; 95%CI: 1.1-7.5; p = 0.03) and high maternal education (OR:5.4; 95%CI: 2.0-14.8; p = 0.001) were significantly associated with higher risk of BCE, whereas high SES at 10 years was significantly protective (OR:0.2; 95%CI: 0.1-0.8; p = 0.022) of BCE in fully adjusted multivariable logistic regression analysis.

DISCUSSION

Our findings do not support a strong role for childhood weight status and eating behaviours in the development of bulimia and compulsive eating pathology, rather suggesting a focus on self esteem may have greater relative importance. Findings in relation to maternal education and SES need further exploration.

Body image and eating behavior in young adults born preterm

OBJECTIVE

Previous studies have suggested that people born preterm have increased rates of eating disorders (ED). However, a recent study suggested lower levels of ED-related symptoms in the extreme group of adults born preterm with very low birth weight (<1,500 g). We examined symptoms related to EDs in adults born early (<34 weeks of gestational age) or late (34 to <37 weeks of gestational age) preterm.

METHODS

We studied young adults (mean age 24.1 years) from two birth cohorts: ESTER (Northern Finland 1985-1989) and AYLS (Uusimaa, Finland, 1985-1986). Of the participants, 185 were born early preterm, 348 late preterm, and 637 were term-born controls (N = 1,170). They completed three subscales of the Eating Disorder Inventory (EDI)-2, including Drive for Thinness (DT), Body Dissatisfaction (BD), and Bulimia (B). Group differences were examined by linear regression.

RESULTS

Young women born early preterm scored 4.1 points (95% CI -8.0, -0.2, P =.04) lower in summed EDI subscale scores than women born at term, when adjusted for age and cohort. This difference was observed also in DT and BD but not for B subscales. The differences persisted after adjustments for current, pre- and neonatal characteristics. We did not observe differences in EDI scores among men or women born late preterm when compared to controls.

DISCUSSION

Women born early preterm have significantly fewer symptoms related to EDs in early adulthood when compared to their peers born at term, which may protect from developing an ED. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:572-580).

Pattern of mother-child feeding interactions in preterm and term dyads at 18 and 24 months

Literature on mother-child feeding interactions during the transition to self-feeding in preterm populations is lacking, particularly through observational methods. The present research study aims to look at the longitudinal patterns of mother-toddler feeding interactions, comparing preterm and full term dyads. To this end, a multi-method approach was used to collect data from 27 preterm to 20 full-term toddlers and their mothers. For each dyad, mother-child interactions were observed during the snack time at 18 and 24 months of age and then assessed through the Italian version of the Feeding Scale. Higher scores on the scale indicate a less healthy pattern of interaction. Additionally, at both points in time, mothers completed the BDI-II questionnaire as a screen for maternal depression and the child's developmental stage was assessed using the Griffiths Scales. A series of repeated measures Analysis of Variances were run to detect differences in feeding interactions between the two groups at the time of assessment. Our results show that preterm dyads report overall higher levels of maternal negative affection, interactional conflicts, and less dyadic reciprocity during the meal compared to full-term dyads. Additionally, longitudinal data show that dyadic conflict decreases in both groups, whereas the child's food refusal behaviors increase in the preterm group from 18 to 24 months. No differences were reported for both the BDI-II and the child's development for the two groups. The results reveal that regardless of maternal depression and the child's developmental stage, the two groups show different trajectories in the pattern of feeding interactions during the transition to self -feeding, at 18 and 24 months, with overall less positive interactions in preterm mother-child dyads.

Recent Advances in Developmental and Risk Factor Research on Eating Disorders

The Diagnostic and Statistical Manual of Mental Disorders (i.e., DSM-5) currently recognizes three primary eating disorders: anorexia nervosa, bulimia nervosa, and binge eating disorder. The origins of eating disorders are complex and remain poorly understood. However, emerging research highlights a dimensional approach to understanding the multifactorial etiology of eating disorders as a means to inform assessment, prevention, and treatment efforts. Guided by research published since 2011, this review summarizes recent findings elucidating risk factors for the development of eating disorders across the lifespan in three primary domains: (1) genetic/biological, (2) psychological, and (3) socio-environmental. Prospective empirical research in clinical samples with full-syndrome eating disorders is emphasized with added support from cross-sectional studies, where relevant. The developmental stages of puberty and the transition from adolescence to young adulthood are discussed as crucial periods for the identification and prevention of eating disorders. The importance of continuing to elucidate the mechanisms underlying gene by environmental interactions in eating disorder risk is also discussed. Finally, controversial topics in the field of eating disorder research and the clinical implications of this research are summarized.

Obstetric complications and eating disorders: a replication study

OBJECTIVE

To provide data about the role of obstetric complications (OCs) in a large and well-characterized sample of patients with anorexia nervosa (AN) or bulimia nervosa (BN).

METHOD

The new sample consists of 150 patients with AN and 35 patients with BN, and 73 healthy women; statistical analyses were performed on the new sample alone and on the larger sample created by merging the new dataset with the previous one (264 AN, 108 BN, and 624 healthy women). All data about OCs were collected blind to diagnostic status.

RESULTS

OC rates in the replication sample were similar to those of our previous studies. In the whole sample, the risk of developing AN was significantly associated with the occurrence and number of pregnancy, delivery, hypoxic, and dysmaturity complications. The risk of developing BN was significantly associated with dysmaturity complications. Signs of retarded fetal growth (being small and short for gestational age, short head circumference) significantly distinguished BN patients from both AN and healthy individuals. Significantly higher number of OCs were found in the binge eating/purging type of AN, in comparison with restricting AN patients.

DISCUSSION

Our study provides further evidence of the role of OCs as putative risk factors for the development of eating disorders, showing different pathways between AN and BN.

Eating disorder psychopathology, brain structure, neuropsychological correlates and risk mechanisms in very preterm young adults

This study investigates the prevalence of eating disorder (ED) psychopathology, neuropsychological function, structural brain correlates and risk mechanisms in a prospective cohort of very preterm (VPT) young adults. We assessed ED psychopathology and neuropsychological correlates in 143 cohort individuals born at <33 weeks of gestation. Structural brain correlates and risk factors at birth, in childhood and adolescence, were investigated using prospectively collected data throughout childhood/adolescence. VPT-born individuals had high levels of ED psychopathology at age 21 years. Executive function did not correlate with ED symptomatology. VPT adults presenting with ED psychopathology had smaller grey matter volume at age 14/15 years in the left posterior cerebellum and smaller white matter volume in the fusiform gyrus bilaterally, compared with VPT adults with no ED psychopathology. Caesarean delivery predicted engaging in compensatory behaviours, and severe eating difficulty at age 14 years predicted ED symptomatology in young adulthood. VPT individuals are at risk for ED symptomatology, with evidence of associated structural alterations in posterior brain regions. Further prospective studies are needed to clarify the pathways that lead from perinatal/obstetric complications to ED and relevant neurobiological mechanisms. © 2015 The Authors. European Eating Disorders Review published by John Wiley &Sons, Ltd.

Effects of obstetric complications on volume and functional connectivity of striatum in anorexia nervosa patients

OBJECTIVE

To investigate the volume and functional connectivity of dorsal and ventral striatal nuclei in anorexia nervosa (AN) and their relationship with early exposure to obstetric complications.

METHOD

Fifty-one patients with lifetime AN (35 acute, 16 recovered) and 34 healthy controls underwent high-resolution and resting-state functional magnetic resonance imaging.

RESULTS

The AN group showed reduced functional connectivity of the putamen compared with healthy women, and this reduction was more evident in patients with lifetime binge eating/purging. Both acute and recovered AN groups showed a larger left accumbens area compared with that of healthy women. The functional connectivity of bilateral nucleus accumbens and putamen showed significant negative correlations with number of obstetric complications in the AN group.

DISCUSSION

This study supports the hypothesis that AN is associated with structural and functional alterations of striatal networks, and reveals the possible role of obstetric complications in the pathogenesis of striatal dysfunction.

Prenatal and perinatal factors in eating disorders: a descriptive review

OBJECTIVE

The objective of this descriptive review is to summarize the current scientific evidence on various prenatal and perinatal exposures affecting later development of eating disorders among offspring.

METHOD

Studies were searched from PubMed database with the following keywords: eating disorders and disordered eating and anorexia nervosa and bulimia nervosa and binge eating disorder and prenatal exposure delayed effects and maternal exposure and perinatology. A comprehensive manual search, including search from the reference list of included articles, was also performed.

RESULTS

The attributable risk for prenatal and perinatal factors in anorexia nervosa (AN) is 3.6%. Numerous prenatal and perinatal factors have been associated with offspring AN, but only prematurity has been replicated in different samples. The risk of bulimia nervosa (BN) in offspring has attracted less study, and despite varying positive associations, there are no replicated findings. Higher prenatal testosterone may protect against the development of a range of disordered eating symptoms, although studies are not consistent.

DISCUSSION

Evidence in support of an effect of prenatal and perinatal factors on eating disorders or disordered eating in offspring is conflicting. If present, the overall effect appears to be relatively small, and it is likely that the early risk factors operate in conjunction with other biological, genetic, and/or environmental risk factors to bring on eating pathology. Genetically sensitive designs, such as sibling and twin studies, are needed to disentangle the different types of risk factors and ensure that prenatal/perinatal effects are "causal" rather than indications of genetic risk.

Differential methylation of the oxytocin receptor gene in patients with anorexia nervosa: a pilot study

Background and Aim

Recent studies in patients with anorexia nervosa suggest that oxytocin may be involved in the pathophysiology of anorexia nervosa. We examined whether there was evidence of variation in methylation status of the oxytocin receptor (OXTR) gene in patients with anorexia nervosa that might account for these findings.

Methods

We analyzed the methylation status of the CpG sites in a region from the exon 1 to the MT2 regions of the OXTR gene in buccal cells from 15 patients and 36 healthy women using bisulfite sequencing. We further examined whether methylation status was associated with markers of illness severity or form.

Results

We identified six CpG sites with significant differences in average methylation levels between the patient and control groups. Among the six differentially methylated CpG sites, five showed higher than average methylation levels in patients than those in the control group (64.9–88.8% vs. 6.6–45.0%). The methylation levels of these five CpG sites were negatively associated with body mass index (BMI). BMI, eating disorders psychopathology, and anxiety were identified in a regression analysis as factors affecting the methylation levels of these CpG sites with more variation accounted for by BMI.

Conclusions

Epigenetic misregulation of the OXTR gene may be implicated in anorexia nervosa, which may either be a mechanism linking environmental adversity to risk or may be a secondary consequence of the illness.