QUESTIONS AND ANSWERS: Type 2 Diabetes and Eating Disorders

Q. Several of my patients have type 2 diabetes (T2DM) but, unlike the case with type 1 disease, I rarely see much in the literature about T2DM and eating disorders. What do we know about T2DM and ED? (VM, Cincinnati)

A. You are right; there has long been a marked focus on T1DM. It is natural for the spotlight to remain on patients with type 1 diabetes because these patients may be especially vulnerable to over-concern about weight and shape, body dissatisfaction, preoccupation with food, and dietary restraint. Furthermore, disordered eating has been shown to increase risk for diabetic complications. However, three recent studies have added more to our knowledge about T2DM and EDs, particularly binge eating disorder (BED).

Dr. Joana Nicolau and colleagues reported the results of a study of 320 randomly selected primary care clinic or endocrine clinic patients with T2DM. After screening all subjects with the Eating Attitudes Test-26 (EAT-26) and the Questionnaire of Eating and Weight Patterns-Revised (QEWP-R), the researchers found that, overall, 14% of the volunteers also had eating disorders. The most prevalent disorder was BED, which was diagnosed in 12.2% of the subjects, based on the QEPW-R (Acta Diabetol. 2015; Apr 5. Doi 10.1007/s00592-015-0742-z. Epub before print]. Those with a positive screening for BED also were younger, had a shorter duration of T2DM symptoms, and greater body mass indexes. Among those with BED, depression and EAT scores were significantly higher.

Individuals with a positive screening for an eating disorder had higher triglyceride levels than did subjects without T2DM. In contrast, glycemic control was not different between those with and without BED.

Metabolic and immune disorders

In a second and much larger study, Dr. Anu Raevuori and colleagues at Helsinki General Hospital examined the prevalence and incidence of T2DM in 2342 patients treated for AN, BN, or BED over 16 years at Helsinki University Central Hospital’s eating disorders unit, and 9,638 matched controls; additionally, the authors examined development of autoimmune disease (Int J Eat Disord. 2014; July 25. Doi: 10.1002/eat.22334. [epub ahead of print].

The lifetime prevalence of T2DM was 5.2% among ED patients and 1.0% among controls. The prevalence was higher in male patients than in females. In terms of autoimmune disease, the authors found that 8.9% of patients with eating disorders, compared with 5.4% of control patients, had prior diagnoses of one or more autoimmune diseases. T1DM accounted for most of the increase in endocrinologic diseases, and Crohn’s disease explained most of the risk of gastroenterologic disease.

The authors suggest that their findings support a link between immunologic factors and development of eating disorders. Future studies are needed to explore the risk of autoimmune factors in individuals with eating disorders and their family members.

Depression and glycemic control

A third study evaluated the prevalence of BED in T2DM patients, in an attempt to learn more about the correlation of BED with the level of depression and glycemic control (Gen Hosp Psychiatry. 2015; 37:116). With an age range from 18 to 75 years, 81 females and 71 males with T2DM were evaluated with a Structured Clinical Interview for DSM-IV Axis I Disorder and the EAT, and depression was determined with the Beck Depression Scale. In contrast to the Nicholau study, all participants came from a diabetes clinic.

The percentage of patients found to have BED was 5.26%, or about half that of the previous study. Depression and EAT scores were higher in those with BED. Glycosylated hemoglobin A1C levels (a measure of long-term blood sugar control) did not differ between BED and non-BED participants.

Authors of all three studies remind us that it is easy to overlook underlying eating disorders in diabetic patients, particularly those with T2DM. The diagnostic workup should always include the possibility of disordered eating patterns, particularly BED.

— SC