Premorbid body weight predicts weight loss in both anorexia nervosa and atypical anorexia nervosa: Further support for a single underlying disorder.

OBJECTIVE: For adolescents, DSM-5 differentiates anorexia nervosa (AN) and atypical AN with the 5th BMI-centile-for-age. We hypothesized that the diagnostic weight cut-off yields (i) lower weight loss in atypical AN and (ii) discrepant premorbid BMI distributions between the two disorders. Prior studies demonstrate that premorbid BMI predicts admission BMI and weight loss in patients with AN. We explore these relationships in atypical AN. METHOD: Based on admission BMI-centile < or ≥5th, participants included 411 female adolescent inpatients with AN and 49 with atypical AN from our registry study. Regression analysis and t-tests statistically addressed our hypotheses and exploratory correlation analyses compared interrelationships between weight loss, admission BMI, and premorbid BMI in both disorders. RESULTS: Weight loss in atypical AN was 5.6 kg lower than in AN upon adjustment for admission age, admission height, premorbid weight and duration of illness. Premorbid BMI-standard deviation scores differed by almost one between both disorders. Premorbid BMI and weight loss were strongly correlated in both AN and atypical AN. DISCUSSION: Whereas the weight cut-off induces discrepancies in premorbid weight and adjusted weight loss, AN and atypical AN overall share strong weight-specific interrelationships that merit etiological consideration. Epidemiological and genetic associations between AN and low body weight may reflect a skewed premorbid BMI distribution. In combination with prior findings for similar psychological and medical characteristics in AN and atypical AN, our findings support a homogenous illness conceptualization. We propose that diagnostic subcategorization based on premorbid BMI, rather than admission BMI, may improve clinical validity. PUBLIC SIGNIFICANCE: Because body weights of patients with AN must drop below the 5th BMI-centile per DSM-5, they will inherently require greater weight loss than their counterparts with atypical AN of the same sex, age, height and premorbid weight. Indeed, patients with atypical AN had a 5.6 kg lower weight loss after controlling for these variables. In comparison to the reference population, we found a lower and higher mean premorbid weight in patients with AN and atypical AN, respectively. Considering previous psychological and medical comparisons showing little differences between AN and atypical AN, we view a single disorder as the most parsimonious explanation. Etiological models need to particularly account for the strong relationship between weight loss and premorbid body weight.

Reasons for admission and variance of body weight at referral in female inpatients with anorexia nervosa in Germany.

BACKGROUND: Body mass index (BMI) at hospital admission in patients with anorexia nervosa (AN) represents a prognostic marker for mortality, chronicity and future body weight. The current study focused on the associations between BMI standard deviation score (BMI-SDS) at admission and reasons for seeking inpatient treatment. Further interest was given to the relationship between premorbid weight and weight at admission, as well as the effect of both weight at referral and reasons for admission on treatment outcome. METHODS: Data ascertained in the German Register of Children and Adolescents with AN were analysed to assess the parental and patient overlap for 23 predefined reasons for admission, using factor analyses and regressions models. RESULTS: Complete parent-patient data sets were available for 360 patients out of 769. The highest consensus rates between parents and patients were obtained for weight and eating behavior related reasons and hyperactivity. Based on factor analysis, four factors emerged. Premorbid BMI-SDS, age and 'low body weight' as stated by patients or parents explained almost 40% of the variance of the BMI-SDS at admission. CONCLUSIONS: Results underscore the relevance of age and premorbid BMI for BMI at admission. Only single reasons for admission explained further variance, with 'low body weight' having the largest effect. Approximately 40% of the variance of BMI-SDS was explained. For the first time, the effect of premorbid BMI for BMI at admission was robustly demonstrated in a multicenter study. Of the variance in BMI-SDS at discharge, our model could explain 37%, with reasons for admission having a small effect. Further investigation of the reasons for admission would be worthwhile to improve treatment and prognosis.

Age dependency of body mass index distribution in childhood and adolescent inpatients with anorexia nervosa with a focus on DSM-5 and ICD-11 weight criteria and severity specifiers.

Both DSM-5 and ICD-11 have provided weight cut-offs and severity specifiers for the diagnosis of anorexia nervosa (AN) in childhood, adolescence and adulthood. The aims of the current study focusing on inpatients aged < 19 years were to assess (1) the relationship between age and body mass index (BMI; kg/m2), BMI-centiles, BMI-standard deviation scores (BMI-SDS) and body height-SDS at referral, (2) the percentages of patients fulfilling the DSM-5 and ICD-11 weight criteria and severity categories for AN, and (3) the validity of the AN severity specifiers via analysis of both weight related data at discharge and inpatient treatment duration. The German Registry for Anorexia Nervosa encompassed complete data sets for 469 female patients (mean age = 15.2 years; range 8.9-18.9 years) with a diagnosis of AN (n = 404) or atypical AN (n = 65), who were ascertained at 16 German child and adolescent psychiatric hospitals. BMI at referral increased up to age 15 to subsequently plateau. Approximately one tenth of all patients with AN had a BMI above the fifth centile. The ICD-11 specifier based on a BMI-centile of 0.3 for childhood and adolescent AN entailed two equally sized groups of patients. Discharge data revealed limited validity of the specifiers. Height-SDS was not correlated with age thus stunting had no impact on our data. We corroborate the evidence to use the tenth instead of the fifth BMI-centile as the weight criterion in children and adolescents. Weight criteria should not entail major diagnostic shifts during the transition from adolescence to adulthood. The severity specifiers based on BMI or BMI-centiles do not seem to have substantial clinical validity.

Incontinence and constipation in adolescent patients with anorexia nervosa-Results of a multicenter study from a German web-based registry for children and adolescents with anorexia nervosa.

OBJECTIVE: Nocturnal enuresis (NE), daytime urinary incontinence (DUI), and fecal incontinence (FI) are common disorders in childhood and are frequently accompanied by comorbid psychiatric disorders. Despite a high association between urinary and fecal incontinence with psychiatric and neurodevelopmental disorders, research on comorbidity between incontinence and anorexia nervosa (AN) remains scarce. Yet, it is well known that somatic consequences of AN include metabolic and gastrointestinal disorders. The study sought to assess the prevalence of incontinence and constipation in children and adolescents with AN and to examine associations of these two symptoms with body weight at admission and with BMI changes during inpatient treatment. METHODS: Data collected between 2015 and 2017 by a multicenter German web-based registry for AN were analyzed. Three hundred and forty-eight patients with AN (96.3% female, mean age = 15.1 ± 1.8 years) were assessed regarding AN subtype, psychiatric comorbidity, body weight, incontinence, and constipation. RESULTS: Overall, 27.6% of patients had constipation, 1.8% had NE and 1.8% DUI. Prevalence of constipation did not significantly differ between AN subtypes. Constipation did not lead to any significant differences in weight/BMI changes during inpatient treatment. DISCUSSION: This is the largest study of incontinence and constipation in patients with AN, so far. Our results indicate that constipation is highly prevalent in adolescent patients with AN and reflects a clinically relevant condition. Despite, patients with AN do not have an increased prevalence of incontinence compared with the general population. Future studies should include medical examinations like ultrasound and physical examination of the lower abdomen to evaluate the severity of constipation.

Clinical Characteristics of Inpatients with Childhood vs. Adolescent Anorexia Nervosa.

We aimed to compare the clinical data at first presentation to inpatient treatment of children (<14 years) vs. adolescents (≥14 years) with anorexia nervosa (AN), focusing on duration of illness before hospital admission and body mass index (BMI) at admission and discharge, proven predictors of the outcomes of adolescent AN. Clinical data at first admission and at discharge in 289 inpatients with AN (children: n = 72; adolescents: n = 217) from a German multicenter, web-based registry for consecutively enrolled patients with childhood and adolescent AN were analyzed. Inclusion criteria were a maximum age of 18 years, first inpatient treatment due to AN, and a BMI <10th BMI percentile at admission. Compared to adolescents, children with AN had a shorter duration of illness before admission (median: 6.0 months vs. 8.0 months, p = 0.004) and higher BMI percentiles at admission (median: 0.7 vs. 0.2, p = 0.004) as well as at discharge (median: 19.3 vs. 15.1, p = 0.011). Thus, in our study, children with AN exhibited clinical characteristics that have been associated with better outcomes, including higher admission and discharge BMI percentile. Future studies should examine whether these factors are actually associated with positive long-term outcomes in children.

Seasonal variation of BMI at admission in German adolescents with anorexia nervosa.

OBJECTIVE: Recent preliminary studies indicated a seasonal association of BMI at admission to inpatient treatment for anorexia nervosa (AN), indicating lower BMI in the cold season for restrictive AN. An impaired thermoregulation was proposed as the causal factor, based on findings in animal models of AN. However, findings regarding seasonality of BMI and physical activity levels in the general population indicate lower BMI and higher physical activity in summer than in winter. Therefore, we aimed to thoroughly replicate the findings regarding seasonality of BMI at admission in patients with AN in this study. METHOD: AN subtype, age- and gender-standardized BMI scores (BMI-SDS) at admission, mean daily sunshine duration and ambient temperature at the residency of 304 adolescent inpatients with AN of the multi-center German AN registry were analyzed. RESULTS: A main effect of DSM-5 AN subtype was found (F(2,298) = 6.630, p = .002), indicating differences in BMI-SDS at admission between restrictive, binge/purge and subclinical AN. No main effect of season on BMI-SDS at admission was found (F(1,298) = 4.723, p = .025), but an interaction effect of DSM-5 subtype and season was obtained (F(2,298) = 6.625, p = .001). Post-hoc group analyses revealed a lower BMI-SDS in the warm season for restrictive AN with a non-significant small effect size (t(203.16) = 2.140, p = .033; Hedges'g = 0.28). Small correlations of mean ambient temperature (r = -.16) and daily sunshine duration (r = -.22) with BMI-SDS in restrictive AN were found. However, the data were widely scattered. CONCLUSIONS: Our findings are contrary to previous studies and question the thermoregulatory hypothesis, indicating that seasonality in AN is more complex and might be subject to other biological or psychological factors, for example physical activity or body dissatisfaction. Our results indicate only a small clinical relevance of seasonal associations of BMI-SDS merely at admission. Longitudinal studies investigating within-subject seasonal changes might be more promising to assess seasonality in AN and of higher clinical relevance.

First Sociodemographic, Pretreatment and Clinical Data from a German Web-Based Registry for Child and Adolescent Anorexia Nervosa.

OBJECTIVE: The first web-based registry for childhood and adolescent anorexia nervosa (AN) in Germany was established to systematically collect demographic and clinical data. These data as well as information on how young individuals with AN can find access to healthcare services are presented. METHOD: Patients´ data from child and adolescent psychiatry departments of 12 university hospitals and two major nonuniversity hospitals in Germany were collected between January 2015 and December 2016. All patients met the ICD-10 diagnostic criteria for (atypical) AN. Sociodemographic data, type and amount of healthcare utilization before admission, and clinical data at admission and discharge were compiled. RESULTS: 258 patients with a mean age of 14.7 years and a mean BMI at admission of 15.3 kg/m2 were included. The parents and patients had a higher educational level than the general German population. More than 80 % of the patients reported having utilized healthcare before hospitalization. The mean duration of outpatient treatment before hospitalization was 7 months. CONCLUSIONS: There seem to be major barriers to specialist treatment for young patients with AN in Germany, which should be analyzed in future studies.

[The inpatient treatment of patients with anorexia nervosa in German clinics]. / Die Versorgung von Kindern und Jugendlichen mit Anorexia nervosa in deutschen Kliniken.

Objective: The medium- and long-term effects and side effects of inpatient treatment of patients with anorexia nervosa is still a matter of debate. The German S3-guidelines underline the importance of providing specialized and competent treatment. In this article we focus on the inpatient service structure in German child and adolescent psychiatric clinics with regard to their diagnostic and therapeutic concepts. Methods: A self-devised questionnaire was sent to 163 German child and adolescent psychiatric clinics. The questionnaire focused on the characteristics of the respective clinic as well as its diagnostic and therapeutic strategies. Results: All clinics with an inpatient service for patients with anorexia nervosa (N = 84) provide single-therapy, family-based interventions and psychoeducation. A target weight is defined in nearly all clinics, and the mean intended weight gain per week is 486 g (range: 200 g to 700 g/week; SD = 117). Certain diagnostic tests and therapeutic interventions are used heterogeneously. Conclusions: This is the first study investigating the inpatient service structure for patients with anorexia nervosa in German clinics. Despite the provision of guideline-based therapy in all clinics, heterogeneous approaches were apparent with respect to specific diagnostic and therapeutic concepts.