Among people with diabetes, there’s a danger that too much insulin can lower blood sugar levels too far, which can lead to coma in severe cases. While this is nearly always an accidental mishap, in rare instances it may be intentional.

Recurrent episodes of so-called hypoglycemic coma among teens may be a red flag for deliberate self-administration of large doses of insulin, French investigators report.

Dr. Pierre Bougneres and colleagues at Saint Vincent de Paul Hospital in Paris investigated 322 cases of recurring hypoglycemic coma since 1990 in 149 adolescents with type 1 diabetes.

According to the team’s report in the medical journal Diabetes Care, 19 patients had a very unusual frequency of coma. Sixteen of these patients (15 girls and 1 boy), at the time of the event or over the next several years, admitted to surreptitious self-administration of insulin.

Seven of these young people admitted to using insulin to deliberately induce coma, in one case to attempt suicide. Five of the patients had significant familial difficulties, including incest, hidden abortion, and alcoholism.

Another five teens injected secretive doses of insulin, apparently in response to strong parental pressure to bring down blood sugar levels because of unreasonable fears of future blindness.

The remaining four patients used secret injections to mask periods in which they had skipped their usual injections.

Bougneres’ team advises doctors that “all children with more than two repeated comas within a 3-month period should immediately be hospitalized to allow in-depth discussions with physicians, nurses, and psychiatrists after the physician has made clear that secret self-administration of insulin is suspected.”

SOURCE: Diabetes Care, February 2006.