Comorbidity between types of eating disorder and general medical conditions

Inpatient admissions and mortality of anorexia nervosa patients according to their preceding psychiatric and somatic diagnoses

OBJECTIVE

Anorexia nervosa (AN) is associated with increased risk of mortality, but little is known about the risk of inpatient admissions and mortality outcomes in individuals with diagnoses of both AN and other psychiatric and somatic conditions. We aimed to investigate the inpatient admissions and mortality among people with AN and other diagnosed conditions using Danish national registers.

METHOD

This retrospective cohort study included individuals diagnosed with AN in Denmark, born 1977-2010. We identified other mental and somatic conditions in this population. We used Cox proportional hazards regression to estimate the risk of inpatient admission and mortality, focusing on (i) the number of other diagnosed conditions, and (ii) specific combinations of conditions diagnosed prior to the AN diagnosis. Categories of inpatient admissions considered were due to: (i) AN, (ii) any psychiatric disorder, and (iii) any somatic disorder. Additionally, competing risks survival analysis was used to calculate the cumulative incidence of inpatient admission and all-cause mortality over the follow-up period.

RESULTS

The study population included 11,489 individuals. The most common conditions individuals had prior to their AN diagnosis were other eating disorders (34.5%) and anxiety disorders (32.7%). During the follow-up, 3184 (27.7%), 4604 (40.1%), and 6636 (57.8%) individuals were admitted for AN, any psychiatric disorder, and any somatic disorder, respectively; and in total 106 (0.9%) died. The risk of all outcomes was highest among those who had received a higher number of other diagnoses. For most combinations, the risks of admission and mortality were increased.

DISCUSSION

Our study presents the prevalence of other conditions in patients with AN in Denmark and elucidates their association with higher rates of inpatient admission and mortality. Our findings highlight the need for comprehensive, multidisciplinary care of patients with AN considering the spectrum of other diagnosed conditions to improve health outcomes.

The United Kingdom Eating Disorders Genetics Initiative

OBJECTIVE

The United Kingdom Eating Disorders Genetics Initiative (EDGI UK), part of the National Institute for Health and Care Research (NIHR) Mental Health BioResource, aims to deepen our understanding of the environmental and genetic etiology of eating disorders. EDGI UK launched in February 2020 and is partnered with the UK eating disorders charity, Beat. Multiple EDGI branches exist worldwide. This article serves the dual function of providing an in-depth description of our study protocol and of describing our initial sample including demographics, diagnoses, and physical and psychiatric comorbidities.

METHOD

EDGI UK recruits via media and clinical services. Anyone living in England, at least 16 years old, with a lifetime probable or clinical eating disorder is eligible to sign up online: edgiuk.org. Participants complete online questionnaires, donate a saliva sample for genetic analysis, and consent to medical record linkage and recontact for future studies.

RESULTS

As of September 2022, EDGI UK recruited 7435 survey participants: 98% female, 93.1% white, 97.8% cisgender, 65.9% heterosexual, and 52.1% have a university degree. Over half (57.8%) of these participants have returned their saliva DNA kit. The most common diagnoses are anorexia nervosa (48.3%), purging disorder (37.8%), bulimia nervosa (37.5%), binge-eating disorder (15.8%), and atypical anorexia nervosa (7.8%).

CONCLUSION

EDGI UK is the largest UK eating disorders study and efforts to increase its diversity are underway. It offers a unique opportunity to accelerate eating disorder research. Researchers and participants with lived experience can collaborate on projects with unparalleled sample size.

PUBLIC SIGNIFICANCE STATEMENT

Eating disorders are debilitating and costly for society but are under-researched due to underfunding. EDGI UK is one of the largest eating disorder studies worldwide with ongoing recruitment. The collected data constitute a resource for secondary analysis. We will combine data from all international EDGI branches and the NIHR BioResource to facilitate research that improves our understanding of eating disorders and their comorbidities.

Risk factors for anorexia nervosa: A population-based investigation of sex differences in polygenic risk and early life exposures

OBJECTIVE

To examine sex differences in risk factors for anorexia nervosa (AN).

METHOD

This population-based study involved 44,743 individuals (6,239 AN cases including 5,818 females and 421 males, and 38,504 controls including 18,818 females and 19,686 males) born in Denmark between May 1981 and December 2009. Follow-up began on the individual's sixth birthday and ended at AN diagnosis, emigration, death, or December 31, 2016, whichever occurred first. Exposures included socioeconomic status (SES), pregnancy, birth, and early childhood factors based on data from Danish registers, and psychiatric and metabolic polygenic risk scores (PRS) based on genetic data. Hazard ratios were estimated using weighted Cox proportional hazards models stratified by sex (assigned at birth), with AN diagnosis as the outcome.

RESULTS

The effects of early life exposures and PRS on AN risk were comparable between females and males. Although we observed some differences in the magnitude and direction of effects, there were no significant interactions between sex and SES, pregnancy, birth, or early childhood exposures. The effects of most PRS on AN risk were highly similar between the sexes. We observed significant sex-specific effects of parental psychiatric history and body mass index PRS, though these effects did not survive corrections for multiple comparisons.

CONCLUSIONS

Risk factors for AN are comparable between females and males. Collaboration across countries with large registers is needed to further investigate sex-specific effects of genetic, biological, and environmental exposures on AN risk, including exposures in later childhood and adolescence as well as the additive effects of exposures.

PUBLIC SIGNIFICANCE

Sex differences in the prevalence and clinical presentation of AN warrant examination of sex-specific risk factors. This population-based study indicates that the effects of polygenic risk and early life exposures on AN risk are comparable between females and males. Collaboration between countries with large registers is needed to further investigate sex-specific AN risk factors and improve early identification of AN.

Risk of somatic diseases in patients with eating disorders: the role of comorbid substance use disorders

AIMS

Eating disorders (EDs) and substance use disorders (SUDs) often co-occur, and both involve somatic diseases. So far, no study has considered whether comorbid SUDs may impact somatic disease risk in patients with EDs. Therefore, this study aimed to examine the impact of comorbid SUDs on the risk of 11 somatic disease categories in patients with anorexia nervosa (AN), bulimia nervosa (BN) and unspecified eating disorder (USED) compared to matched controls.

METHODS

A retrospective cohort study was conducted using Danish nationwide registries. The study population included 20 759 patients with EDs and 83 036 controls matched on month and year of birth, sex and ethnicity. Hazard ratios (HRs) were calculated to compare the risk of being diagnosed with a somatic disease (within 11 categories defined by the ICD-10) following first ED diagnosis (index date) between ED patients and controls both with and without SUDs (alcohol, cannabis or hard drugs).

RESULTS

The ED cohort and matched controls were followed for 227 538 and 939 628 person-years, respectively. For ED patients with SUDs, the risk pattern for being diagnosed with different somatic diseases (relative to controls without SUDs) varied according to type of ED and SUD [adjusted HRs ranged from 0.95 (99% CI = 0.57; 1.59) to 4.17 (2.68, 6.47)]. The risk estimates observed among ED patients with SUDs were generally higher than those observed among ED patients without SUDs [adjusted HRs ranged from 1.08 (99% CI = 0.95, 1.22) to 2.56 (2.31, 2.84)]. Abuse of alcohol only had a non-synergistic effect on six disease categories in AN patients and five in BN and USED patients. Abuse of cannabis (with/without alcohol) had a non-synergistic effect on five disease categories in AN and BN patients and two in USED patients. Abuse of hard drugs (with/without alcohol or cannabis) had a non-synergistic effect on nine disease categories in AN patients, eight in BN patients and seven in USED patients.

CONCLUSIONS

The present study documents non-synergistic but not synergistic harmful somatic consequences of SUDs among patients with different EDs, with AN and hard drugs being the most predominant factors. Hence, EDs and SUDs did not interact and result in greater somatic disease risk than that caused by the independent effects. Since EDs and SUDs have independent effects on many somatic diseases, it is important to monitor and treat ED patients for SUD comorbidity to prevent exacerbated physical damage in this vulnerable population.

Increased risk of somatic diseases following anorexia nervosa in a controlled nationwide cohort study

OBJECTIVE

To assess the risk of somatic diseases in connection with anorexia nervosa (AN).

METHOD

This matched cohort study was based on Danish registries of all patients born 1961-2008 with a first-time diagnosis of AN in 1994-2018 at age 8-32 and matched controls without an eating disorder. For 13 somatic disease categories, time from inclusion date to time of first somatic diagnosis, accounting for censoring, was studied by use of time-stratified Cox models.

RESULTS

A total of 9985 AN patients born 1961-2008 and 49,351 controls were followed for a median (interquartile range) of 9.0 (4.4-15.7) years. During the first 2 years after entry there was a 60% higher hazard for any somatic disease among patients with AN than among controls, while the ratio from three to 11 years was reduced to 1.18. Regardless of age at diagnosis, the hazard among patients and controls were no different at approximately a decade after diagnosis of AN and the cumulative risk for patients for 12 of 13 disease categories was always higher or no less that for controls. For all disease categories, the hazard ratio (HR) was higher when close to entry. For most disease categories, age at diagnosis of AN did not modify the effect.

DISCUSSION

While around 90% of all individuals had any somatic disease at the end of follow-up, the cumulative incidence over time was higher for patients with AN than for controls. Large HRs were seen in the early years after diagnosis during which patients require extensive medical interventions.

PUBLIC SIGNIFICANCE

Based on Danish registries, a large sample of almost 10,000 patients with AN born 1961-2008 and almost 50,000 matched controls were followed for a median of 9 years. While around 90% of all individuals had any somatic disease at the end of follow-up, the cumulative incidence over time was higher for patients with AN than for controls.

Eating disorders in the U.S. Medicare population

OBJECTIVE

The social and economic burden of eating disorders is significant and often financially devastating. Medicare is the largest public insurer in the United States and provides coverage for older adults and some disabled individuals. This study explores prevalence, sociodemographic and clinical characteristics, and health care spending for Medicare enrollees with eating disorders.

METHOD

A cross-sectional study was conducted with the nationally representative 20% sample of 2016 Medicare inpatient, outpatient, carrier, and home health fee-for-service claims and Medicare Advantage encounter records. Sociodemographic characteristics and comorbid somatic conditions were compared between individuals with versus without an eating disorder diagnosis. Mean spending was compared overall and separately for inpatient, outpatient, home health, and pharmacy claims.

RESULTS

The sample included 11,962,287 Medicare enrollees of whom 0.15% had an eating disorder diagnosis. Compared to those without a 2016 eating disorder diagnosis, a greater proportion of individuals with an eating disorder were female (73.8% vs. 54.3%), under age 65 (41.6% vs. 15.5%), and dually eligible for Medicaid due to disability or low-income qualification (48.0% vs. 19.6%). Individuals with eating disorders had higher rates of comorbid conditions, with the greatest differences in cardiac arrythmias (35.3% vs. 19.9%), arthritis (40.1% vs. 26.6%), and thyroid conditions (32.2% vs. 19.4%). Spending was higher for enrollees with eating disorders compared to those without overall ($29,456 vs. $7,418) and across settings.

DISCUSSION

The findings establish that eating disorders occur in the Medicare population, and that enrollees with these illnesses have risk factors associated with significant healthcare spending and adverse health outcomes.