Insulin-dependent diabetes mellitus (IDDM) is one of the most common chronic illnesses of childhood and adolescence in North America. 1 Although most young patients with IDDM are healthy, up to 40 percent eventually have diabetes-related microvascular complications. 2, 3 The risk is greater in those whose diabetes is poorly controlled. 4 Eating behavior is categorized under three commonly selected categories. 4 Highly disordered eating is defined as the occurrence of one or more of the following forms of disordered behavior at least twice per week: binge eating, omission or under dosing of insulin to promote weight loss, self-induced vomiting, or use of laxatives. 4 Moderately disordered eating is defined as the occurrence of one or more of these forms of disordered behavior at least twice per month, but less than twice per week.
4 Nondisordered eating is defined as the absence of disordered behavior or its occurrence less than twice per month. 4 Up to one third of young women with IDDM have eating disturbances, 5 which may affect the management of diabetes. Treatment of type 1 diabetes involves constant monitoring of food intake. In addition, the good glycemic control necessary to reduce the risk of long-term complications is associated with weight gain. 6 In young women, these two factors, along with individual, family and social factors, can lead to an increased incidence of eating disorders, which can disrupt glycemic control and increase the risk of long-term complications. 6, 7, 8 The coexistence of eating disorders and diabetes is associated with non-cooperation with treatment for diabetes, 7 omission or under dosing of insulin to induce glycosuria and promote weight loss, 8 and impaired metabolic control; 8 however, long-term effects of disordered eating on complications of diabetes are not known.
Nevertheless, it is still determined that disordered eating behavior is associated with microvascular complications in young women with IDDM. From June to December 1988 (base line), 121 girls and women 12 to 18 years old were invited to participate in a self-reported survey of eating attitudes and behavior. 7 These girls and women had previously diagnosed IDDM and were being followed in the diabetes clinic of the Hospital for Sick Children in Toronto. This represented all girls and women in this age group who attended the clinic during this period, except for one patient with cerebral palsy. Between July 1992 and January 1994 (follow-up), all of the participants were contacted again. Approximately one third were still attending the diabetes clinic, and the remainder had been referred to an adult treatment setting.
Between study entry and follow-up, the research group did not have any contact with the study participants, except that one provided medical care for some of the patients at the clinic and another saw several patients for psychiatric assessment. The treatment for patients at the diabetes clinic between study entry and follow-up included regular quarterly visits and IDDM management in a multidisciplinary setting. It was also clinical practice to recommend a psychosocial assessment for patients with persistently high hemoglobin A 1 c levels or disturbed eating attitudes and behavior. During the follow-up interval, twenty-one patients reported that they had been assessed or treated for one or more of the following: an eating disorder (9), depression (9), family problems (2) and other mental problems (4). At base line and follow-up, demographic and clinical information was collected, height and weight were measured and body-mass index was calculated. Self-reported episodes of ketoacidosis and severe hypoglycemia in the preceding year were documented.
A behavior related to eating and weight self-administered questionnaire was given at base line and follow-up. This questionnaire, which obtains information about eating habits from the previous three months, was changed to include diabetes-related items, including omission or under dosing insulin to promote weight loss. The patients either completed the questionnaire during their clinical visits or completed it at home and returned it by mail. Even with reminder calls, some questionnaires (eight at base line and nine at follow-up) were not returned. Hemoglobin A 1 c was measured at base line and follow-up. Also, the urinary albumin excretion rate, a predictor of diabetic neuropathy, was determined at follow-up in both 1 and 24 hour urine samples; however, the results from the 24-hour samples were used as the most reliable measurement.
9 Microalbuminuria was defined as an albumin excretion rate of at least 15 but less than 200 nanograms per minute, and microalbuminuria as a rate of at least 200 nanograms per minute. 9 Diabetic retinopathy was detected at follow-up by a retinal specialist who did not know the person's eating habits, hemoglobin A 1 c levels, or urinary albumin excretion rate. The level of retinopathy was derived by giving a greater weight to the eye with the higher level. 10 With this classification, level 10 indicates no diabetic retinopathy; level 20, very mild retinopathy; level 30, mild nonproliferative retinopathy; levels 40 to 55 moderate-to-severe nonproliferative retinopathy; and level 60 or higher, mild to high risk proliferative retinopathy. 10 The results then showed that 107 (88 percent) of the 121 eligible girls and women participated at base line because 8 did not return their questionnaires and 6 refused to participate. Then, 91 (85 percent) of these 107 girls participated at follow-up because 2 did not return their questionnaires and 5 could not be located.
The characteristics of the patients at base line and follow-up are shown in Table 1. 11 Also, the 16 patients who participated at base line but not at follow-up did not differ from the 91 who completed both assessments, in terms of age, age at onset of diabetes, duration of diabetes, hemoglobin A 1 c values, BMI and eating status at base line. Among the 11 patients who refused to participate or failed to return their questionnaires at follow-up, 9 were classified as having highly disordered eating and 2 had moderately disordered eating. The prevalence and persistence of disordered eating behavior are shown in Table 2. Intentional omission or under dosing of insulin and dieting for weight loss increased in frequency from base line to follow-up. Binge eating, self-induced vomiting, and dieting for weight loss tended to continue at follow-up if they were not present at base line.
Also, at base line, 9 of the 91 young women met the criteria for highly disordered eating, 17 met the criteria for moderately disordered eating and 65 met the criteria for nondisordered eating. The nine patients with highly disordered eating did not differ from the others in age, but in duration of diabetes (9+/-4 vs. 6+/-4 years). Table 2 also suggested that disordered-eating status tended to persist over time because of the 26 patients with highly or moderately disordered eating at base line, 16 remained in these categories and 10 improved. Of the 65 patients with nondisordered eating at base line, 14 had disordered eating at follow-up. At base line, the patients with highly disordered eating had a substantially higher hemoglobin A 1 c value than those with moderately disordered eating and nondisordered eating.
Among the 14 patients who had constant disordered eating behavior and whose hemoglobin A 1 c values were measured at follow-up, the values were similarly high at both assessments. In the nine patients whose eating status improved, so did their hemoglobin A 1 c and decreased from 9. 7+/-2. 2 to 7. 6+/-1. 4 percent.
71 of the 91 women had ophthalmologic examinations at follow-up and 24 of the 71 were found to have some degree of retinopathy. Sixteen had mild retinopathy, eight patients had nonproliferative retinopathy and one had advanced pre proliferative retinopathy in one eye and early proliferative in the other. Urinary albumin excretion was measured in 72 of the 91 patients at follow-up. Twelve had microalbumuria (range, 15 to 66 nanograms per minute) and three had macroalbumuria (range, 222 to 427 nanograms per minute). This association between disordered-eating status at base line and diabetes-related microvascular complications at follow up is shown in Table 3.
Results show that retinopathy was more common in patients with disordered eating at base line, but abnormal urinary albumin excretion was not. Therefore, the most striking finding of this study is that some degree of retinopathy was present at follow-up in more than 85% of young women with IDDM who had highly disordered eating at base line, as compared with 43% in those with moderately disordered eating. Only 24% of those, however, with nondisordered eating had some degree of retinopathy. Furthermore, disordered-eating status accounted for more of the explained variance in a model predicting retinopathy than did duration of diabetes, an established risk factor for microvascular complications. 4 Also, the average length of diabetes in the patients may not have been long enough for neuropathy to occur in enough patients to suspect an association with disordered-eating status.
The limitations of the study, however, include incomplete participation in the follow-up medical examinations, limited reliability on the honesty of the self-report assessment, and absence of base line evaluations of microvascular complications. This study, therefore, confirmed that in young women with diabetes, eating disorders do persist, to increase in frequency throughout adolescence, and to be predictors of poor metabolic control and their related complications. The increased prevalence of behavior designed to promote weight loss at follow-up is not surprising because more of the patients had reached the aged where eating disorders were at a higher risk. Also, apart from dieting to lose weight, intentional omission or under dosing of insulin was the most common means of inducing weight loss.
Prevention and early treatment of eating disorders in young women are important to prevent long-term complications and mortality. The health risk of these conditions is increased when they are associated with diabetes because of their effect on metabolic control and metabolic complications. In diabetic women with diabetes, the increased focus on eating and the weight gain associated with good glycemic control likely increase their susceptibility to abnormal eating. Although there is an emphasis on keeping weight down, a healthy diet should be stressed. Good nutritional counseling to help patients avoid weight gain and family counseling to improve communication between patients and their families may help decrease the risk. Intentional insulin omission is a frequent means of preventing weight gain or increasing weight loss in adolescent females with type 1 diabetes.
Eating disorders should be suspected in patients with recurrent ketoacidosis or poor glycemic control that is resistant to attempts at improvement. Treatment includes decreasing dietary restraint, promoting healthy eating and either psychiatric counseling or psychologic intervention, or both. It is always important to remember that an eating disorder can be hidden easily and for many years, usually until the consequences are irreversible. 1. Dash AL.
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