Risk factors for anorexia nervosa and bulimia nervosa in Japan and compared to a U.S. sample

OBJECTIVE

This study provides the first systematic investigation of environmental exposure to putative psychosocial risk factors for eating disorders in individuals with AN and BN in Japan. It also provides a comparison of risk factors for the development of AN and BN in Japan versus the United States.

METHOD

Participants in Japan were 96 women with a current DSM-IV AN or BN primary diagnosis (AN, n = 60; BN, n = 36) and 57 women with no current psychiatric diagnosis (NC group). Participants in the United States were 137 women with a current DSM-IV AN or BN primary diagnosis (AN-U.S., n = 71; BN-U.S., n = 66). A standardized semi-structured interview retrospectively assessed exposure to risk factors prior to first symptom onset, which were analyzed using General Linear Model analyses.

RESULTS

Perfectionism and negative affectivity, family relationship issues, and, to a lesser degree, parental psychopathology predicted the emergence of AN and BN in Japan. Physical and sexual abuse and family eating and weight concerns were not significant risk factors in Japan. Compared to their respective diagnostic U.S. groups, the Japanese AN group reported higher levels of individual mental health factors and lower levels of family dieting and family overweight, and the Japanese BN group reported higher levels on individual mental health factors, lower exposure to problems with their parents, and lower exposure to family weight and eating concerns.

DISCUSSION

These country-specific data from Japan contribute to an increasingly nuanced and global understanding of risk factors for eating disorders.

Clinical presentation and outcome of avoidant/restrictive food intake disorder in a Japanese sample

We conducted a study of the clinical presentation and outcome in patients with avoidant/restrictive food intake disorder (ARFID), aged 15-40years, and compared this group to an anorexia nervosa (AN) group in a Japanese sample. A retrospective chart review was completed on 245 patients with feeding and eating disorders (FEDs), analyzing prevalence, clinical presentation, psychopathological properties, and outcomes. Using the DSM-5 criteria, 27 (11.0%) out of the 245 patients with a FED met the criteria for ARFID at entry. All patients with ARFID were women. In terms of eating disorder symptoms, all patients with ARFID had restrictive eating related to emotional problems and/or gastrointestinal symptoms. However, none of the ARFID patients reported food avoidance related to sensory characteristics or functional dysphagia. Additionally, none of them exhibited binge eating or purging behaviors, and none of them reported excessive exercise. The ARFID group had a significantly shorter duration of illness, lower rates of admission history, and less severe psychopathology than the AN group. The ARFID group reported significantly better outcome results than the AN group. These results suggest that patients with ARFID in this study were clinically distinct from those with AN and somewhat different from pediatric patients with ARFID in previous studies.

Serum Lipid Levels in Patients with Eating Disorders

Objective To evaluate some risk factors for cardiovascular diseases in feeding and eating disorders, the degree of lipid abnormalities was investigated in a large Japanese cohort of different groups of feeding and eating disorders, according to the Japan Atherosclerosis Society Guidelines for the Prevention of Atherosclerotic Cardiovascular Diseases 2012 (JAS Guidelines 2012). Methods Participants in the current study included 732 women divided into four groups of feeding and eating disorders: anorexia nervosa, restricting type (AN-R); anorexia nervosa, binge-eating/purging type; bulimia nervosa (BN); and binge-eating disorder (BED). We measured the serum levels of total cholesterol, high-density-lipoprotein (HDL) cholesterol, and triglyceride in these participants. Low-density-lipoprotein (LDL) cholesterol and non-HDL cholesterol levels were also calculated. Results The concentrations of LDL cholesterol and non-HDL cholesterol were widely distributed in all groups. When the LDL cholesterol risk was defined as ≥120 mg/dL and the non-HDL cholesterol risk as ≥150 mg/dL, according to the JAS Guidelines 2012, the proportion of LDL cholesterol risk ranged from 29.6% (BN) to 38.6% (AN-R), and the proportion of non-HDL cholesterol risk ranged from 17.8% (BN) to 30.1% (BED). Conclusion The present findings suggest the existence of LDL cholesterol risk and non-HDL cholesterol risk in all groups of eating disorders. Given the chronicity of this condition, the development of elevated concentrations of LDL cholesterol and non-HDL cholesterol at an early age may increase the risk of cardiovascular diseases.

Relationship between duration of illness and cardiac autonomic nervous activity in anorexia nervosa

Background

The mortality rate associated with anorexia nervosa (AN) is high, and death is mainly attributable to cardiac events. A wide range of autonomic nervous system disturbances may be mechanisms underlying the increased cardiovascular mortality and sudden death of patients with AN. Heart rate variability (HRV) has been proven to be a reliable noninvasive method for quantitative assessment of sympathetic and parasympathetic regulation of heart rate (HR). The longer the duration of illness of AN patients, the higher the mortality rate. However, there have been few reports on the relationship between the duration of illness and HRV in AN. Hence, the aims of this study were to compare the cardiac autonomic nervous activity (CANA) of female patients with AN and age-matched female controls and to evaluate the relationship between the duration of illness and the CANA of the AN patients.

Methods

We studied 14 female patients with AN and 22 age-matched healthy women. Beat-to-beat heart rate variability, recorded in a supine position, was investigated using power spectral analysis.

Result

Mean heart rate was positively correlated with normalized high-frequency (HF: 0.15 to 0.40 Hz) power and negatively correlated with the low-frequency (LF: 0.04 to 0.15 Hz)/HF power (LF/HF) ratio of the controls. On the other hand, duration of illness was negatively correlated with normalized HF power and positively correlated with the LF/HF ratio of the AN patients.

Conclusions

These results suggest that, given that the LF/HF ratio is an estimate of cardiac sympathovagal balance, anorectic patients with a long illness duration display lower vagal tone (parasympathetic withdrawal) and high sympathetic tone.