This study explored the differences between bulimia nervosa (“BN,” n=22) and binge-eating disorder (“BED,” n=11) in type 1 diabetic females and the factors most predictive of poor glycemic control in patients suffering from these disorders. These two groups and a control group without eating disorders (n=32) were compared across a number of demographic, psychological, and medical variables. BN manifested significantly more severe disturbances related to eating disorders, depression, anxiety, a higher rate of co-occurring mental disorders, and poorer psychosocial functioning compared with BED. BN also showed poorer glycemic control. Multivariate analysis indicated that higher serum glycosylated hemoglobin (HbA1c) levels were most associated with the presence of severe insulin omission in type 1 diabetic females with binge eating. Clinicians may be able to determine the psychological/medical severity of illness in these patients by identifying the presence of compensatory behaviors to prevent weight gain such as severe insulin omission, as described in the DSM-IV.
In Japan, as in North America and Europe 1 and 2, development of disordered eating is not unusual in young females with type 1 diabetes 3 and 4. Although no one questions the devastating effect of eating disorders on the clinical course of diabetes 5, 6, 7, 8, 9 and 10, the clinical characteristics of these co-occurring patients have not been sufficiently clarified, making successful intervention exceedingly difficult [11]. Classification according to the severity of psychological/behavioral disturbances and medical consequences may be helpful in gaining a clearer understanding of the problems involved in treating these patients, and, thus, lead to more effective treatments.
The high prevalence of binge eating and its severe influence on metabolic control make it one of the most serious eating problems for type 1 diabetic patients 6, 11 and 12. Some binge eating type 1 diabetic patients meet the diagnostic criteria for bulimia nervosa, but others do not, mainly because of the absence of recurrent “inappropriate compensatory behavior in order to prevent weight gain” (ICB) 13 and 14. However, there has been little systematic research comparing these two groups. Only Affenito et al. [15] have reported the relationship of subclinical and clinical eating disorders to serum glycosylated hemoglobin (HbA1c) values, but they did not compare the two groups in depth from the psychological/behavioral aspect. Furthermore, they found no significant difference in glycemic control between the two groups. The main purpose of this study, therefore, is to compare females with type 1 diabetes who meet all the diagnostic criteria for bulimia nervosa to others who do not.
Recent research has reported the importance of insulin omission and its relation to disordered eating and poorer medical consequences 9, 16 and 17. Insulin omission is often used for the purpose of weight loss by females with type 1 diabetes. DSM-IV diagnostic criteria [14] for bulimia nervosa has, for the first time, accepted insulin omission for ICB, which is necessary for the diagnosis of bulimia nervosa. As there is a broad spectrum of methods for insulin omission, however, the significance of insulin omission varies in individual patients because of differences in such factors as frequency, dose, and motive. Examining these factors in type 1 diabetic patients with eating disorders appears to be important to explore the relationship between the insulin omission and the eating disorder.
Although females with type 1 diabetes and eating disorders seem to have a number of general psychological/behavioral and eating-related problems, there have been few studies comparing the magnitude of the influence of each problem on the medical consequences of their diabetes. There is a good possibility that psychological/behavioral factors proven to be highly associated with poorer glycemic control will become meaningful indices for assessment and treatment.
This study was designed to address the following questions concerning the psychological/behavioral and medical characteristics of females with type 1 diabetes and binge eating:
1.
How do those who meet DSM-IV criteria for bulimia nervosa differ from those who do not in terms of disordered eating attitudes and behaviors, general psychological disturbances, and medical consequences of diabetes?
2.
Which psychological/behavioral factors are most predictive of elevated HbA1c in females with type 1 diabetes and binge eating?
