Eating Disorders and Type 1 Diabetes Mellitus
By Elissa Rosen, MD, CEDS-S
Type I diabetes mellitus (DMT1) is an autoimmune disease in which the immune system attacks cells in the pancreas that are responsible for making insulin leading to insulin deficiency. (1) Therefore, DMT1 treatment always involves the administration of exogenous insulin. Before getting into the rest of the blog, let’s review some basic physiology around insulin. After every meal, blood sugar or glucose levels rise. As our cells need glucose for energy, the pancreas releases insulin, which functions to “open” cells to let glucose in. In DMT1, the lack of insulin leads to a rise in blood glucose levels and essentially starvation of the body’s cells. Our body also likes to keep the level of glucose in our blood within a specified range. Blood glucose that is too high, called hyperglycemia, or too low, called hypoglycemia, can cause dangerous medical complications both in the short and long term. Now that we have covered some of the basics, let’s shift to focus on eating disorders in those with DMT1.
Terminology
The presence of any eating disorder in someone with DMT1 is often labeled as ED-DMT1 or diabulimia. (2) Neither term is present as a formal eating disorder diagnosis in any edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM V does mention the reduction or withholding of insulin as a way of decreasing weight in anorexia nervosa or as a compensatory behavior to prevent weight gain in bulimia nervosa.
ED-DMT1 can involve a full range of eating disorder symptoms, but the misuse of insulin in order to decrease weight is a common behavior in ED-DMT1. Ways to manipulate insulin include, but are not limited to: a reduction in insulin dose, reduction in frequency of administration, tampering with insulin to render it ineffective, or even the complete cessation of insulin administration. (2) Any of these actions that lead to insufficient insulin promote weight loss for several reasons. First, without insulin, glucose levels rise in the blood stream. As glucose cannot enter cells to provide needed energy, it is excreted in the urine leading to loss of essential nutrients. Second, high blood glucose pulls more water into blood vessels and both are ultimately excreted in the urine, which is known as osmotic diuresis, leading to dehydration and loss of water weight. Last, as cells are not getting glucose to perform their needed functions, the body breaks down other tissues for energy thereby causing further weight loss.
Prevalence and Risk of ED-DMT1
According to the Juvenile Diabetes Research Foundation, 1.25 million Americans are living with DMT1 and 40,000 people are diagnosed with it every year. (3) The development of eating disorders is more common in those with DMT1 than in the general population. Women with DMT1 have nearly 2.5 times the risk of developing an eating disorder compared to those without diabetes. (4) So why might this be the case? The exact answer is unknown, but here is what the research suggests. We live in a society steeped in diet culture with a heavy emphasis on body size, weight loss, and dietary restraint. On top of this already prominent diet culture, the treatment of DMT1 itself usually involves a high emphasis on meal planning, portion sizes, carbohydrate counting, and reading food labels. (2) Body weight and exercise habits are also commonly discussed and focused on by medical providers. Such an emphasis on being the so-called “perfect diabetic” can cause intensive focus on numbers (e.g., calories, body weight, etc.) which can promote rigid thinking around food and body. Something else to keep in mind is that DMT1 is commonly diagnosed during adolescence, which is already a susceptible time for eating disorder development due to the body changes associated with puberty. Weight gain can also occur with the initiation of insulin in those with DMT1, and this may be physically and emotionally distressing to some. An association may form that taking insulin equates with weight gain; therefore, not taking insulin can prevent this. (5) Rates of depression are also higher in those with DMT1, which is a risk factor for eating disorder development. (4)
Health Risks
Women with ED-DMT1 have higher hemoglobin A1c (HbA1c) values, which is a marker of glucose levels over the prior 3 months, than women with DMT1 alone. Hyperglycemia (which would lead to higher HbA1c values in the long term) is associated with both short-term health risks like diabetic ketoacidosis (DKA) and long-term health risks like destruction of the small blood vessels in the body leading to blindness, nerve damage, and kidney disease.
In a 2008 study, women with DMT1 who restricted insulin had 3 times the mortality rate compared to those who did not. (6) Insulin restriction in DMT1 is also associated with increased rates of emergency room visits, hospitalization, and diabetes-related medical complications. (4) In another study, death rates from the combination of anorexia nervosa (AN) and DMT1 were found to be 35% over the ten year study period compared to 2.5% for DMT1 alone and 6.2% for AN alone. (7)
Treatment
ED-DMT1 treatment requires a multidisciplinary treatment team to address all aspects of eating disorder and diabetes care. This should at a minimum include a therapist, dietitian, and physician all with expertise in DMT1 and eating disorders. Some studies have shown that ED-DMT1 patients have worse outcomes with standard outpatient eating disorder treatment. (4) Therefore, higher levels of eating disorder care may be necessary for ED-DMT1 treatment, though this will depend on the individual.
From a purely medical perspective, treatment of ED-DMT1 can be complicated as meal plans are often frequently changing and, as a result, so too are insulin needs. Too strict control of glucose levels can lead to hypoglycemia; therefore, so-called “permissive hyperglycemia” is often warranted. (8) Nerve damage or neuropathy can also result from lowering a chronically elevated blood sugar too quickly. ED-DMT1 also comes with increased risk of edema formation with nutritional rehabilitation. Insulin in and of itself can cause salt and water retention in the kidneys. Combine the reintroduction of appropriate amounts of insulin with the secondary hyperaldosteronism that develops due to chronic dehydration from osmotic diuresis and the edema that develops can be quite severe and often requires medical management with a specific aldosterone blocking diuretic, spironolactone.
Anyone struggling with ED-DMT1 should know that there are many compassionate professionals out there ready to help you in your recovery journey. In addition, it is important to establish care with a medical provider that is knowledgeable about the intersection of these diagnoses and can help you work towards your health-related goals in conjunction with the rest of your treatment team.
References:
1. Levitsky, L and M Misra. Epidemiology, presentation, and diagnosis of type 1 diabetes in children and adolescents. Up to Date. June 27, 2019.
2. Gaudiani, Jennifer. Sick Enough: A guide to the medical complications of eating disorders
3. Juvenile Diabetes Research Foundation. Type 1 Diabetes Facts. https://www.jdrf.org/t1d-resources/about/facts/
4. Goebel-Fabbri A, Copeland P, Touyz S, Hay P. EDITORIAL: Eating disorders in diabetes: Discussion on issues relevant to type 1 diabetes and an overview of the Journal's special issue. J Eat Disord. 2019;7:27. doi: 10.1186/s40337-019-0256-0. eCollection 2019.
5. Diabulimia Helpline: http://www.diabulimiahelpline.org/uploads/2/5/0/7/25075632/for_diabetes_professional_-_overview_of_ed_with_t1d.jpg
6. Goebel-Fabbri AE, Fikkan J, Franko DL, Pearson K, Anderson BJ, Weinger K. Insulin restriction and associated morbidity and mortality in women with type 1 diabetes. Diabetes Care. 2008 Mar;31(3):415-9. doi: 10.2337/dc07-2026. Epub 2007 Dec 10. PubMed PMID: 18070998.
7. Nielsen S, Emborg C, Mølbak AG. Mortality in concurrent type 1 diabetes and anorexia nervosa. Diabetes Care. 2002 Feb;25(2):309-12. doi: 10.2337/diacare.25.2.309. PubMed PMID: 11815501.
8. Brown C, Mehler PS. Anorexia nervosa complicated by diabetes mellitus: the case for permissive hyperglycemia. Int J Eat Disord. 2014 Sep;47(6):671-4. doi: 10.1002/eat.22282. Epub 2014 Apr 9. PubMed PMID: 24719247.