AMSTERDAM — More than 90% of all teenagers with type 1 diabetes omit insulin doses at least occasionally in order to prevent weight gain, according to the results of an international observational study presented by Dr. Soren E. Skovlund at the annual meeting of the European Association for the Study of Diabetes.
Of concern, the practice is associated with significantly poorer glycemic control. “Screening for and dialog with adolescents about omission of insulin injections may be particularly warranted in those who exhibit concern about their weight or engage in weight-reducing activities,” said Dr. Skovlund, global director of patient-focused programs at Novo Nordisk A/S, Bagsvaerd, Denmark.
A total of 2,062 adolescents aged 11–18 years with type 1 diabetes of at least 1 year's duration completed the survey, conducted in 2005 by the Novo-Nordisk-funded Hvidoere Study Group. Respondents were from 21 centers in Europe, Australia, Japan, and North America. There was one U.S. center at Children's Hospital, Los Angeles.
The study group was 49.4% female and 50.6% male. Both genders had a mean age of 14.5 years, and mean diabetes duration of 6.3 years for the females and 5.9 years for the males. Mean body mass indices were 22.8 kg/m
Each adolescent was asked to complete an extensive questionnaire covering topics such as self-management and health behaviors, treatment goals, family dynamics, well-being and quality of life, diabetes burden, and weight perception/dieting. Also included was the question: “How often do you miss insulin to control your weight?” Possible responses were “never,” “once a month,” “once a week,” or “every day.”
The majority—91.7% of the females and 93.0% of the males—checked “once a month.” “Never” was a distant second, reported by 5.1% of females and 4.2% of males, followed by “once a week” (2.5% female/1.9% male) and “every day” (0.7% female/0.9% male).
“This was not just in general, but specifically to avoid weight gain. Clearly, people are connecting the two aspects,” Dr. Skovlund commented.
The nearly equal proportion of males and females is striking. “A lot of the insulin omission literature has focused on this being a female phenomenon. … But we have certainly also seen it in boys,” he said.
Not surprisingly, those who reported omitting insulin doses either daily or weekly (“high omitters”) had poorer metabolic control, and averaged a significant difference of half a percentage point in hemoglobin A1c values, compared with the “low omitters,” those who omitted never or monthly (8.99% female/8.61% male vs. 8.24% female/8.08% male). Insulin omission remained significantly correlated with HbA1c after controlling for age and diabetes duration, but not gender.
Insulin omission also was highly correlated with other weight-loss behaviors, such as fasting, vomiting, and use of diet pills/laxatives, as well as reduced well-being. Insulin omission was reported both by patients on multiple daily injections as well as those on insulin pumps (who made up about 20% of the overall group).
The findings are not all that surprising to pediatric endocrinologist Dr. Francine R. Kaufman, who heads the Los Angeles center: “Kids miss doses all the time. … The question is why.”
Her adolescent patient population with type 1 diabetes tends to be well educated and aware that insulin omission can control weight via glycosuria. In fact, in the United States the practice of omitting insulin by young people with type 1 diabetes in order to control weight has been dubbed “Diabulemia” and is currently a hot topic in the lay press, she noted in an interview.
But the thought process may not always be so straightforward. Rather, teens might rationalize to themselves that perhaps they didn't eat as much as they did, or that they don't need as much insulin as they actually do. “A lot of it is not totally willful, but kind of miscalculating the dose,” she remarked.