Clinical Features of Brittle Diabetic Patients Unresponsive to Optimized Subcutaneous Insulin Therapy (Continuous Subcutaneous Insulin Infusion)

  1. Harry Keen
  1. Unit for Metabolic Medicine, Guy's Hospital Medical School London SE1 9RT, England
  1. Address reprint requests to Dr. J. C. Pickup, Department of Chemical Pathology, Guy's Hospital Medical School, London SE1 9RT, England.


We examined the clinical features of 14 brittle diabetic patients, all of whom had failed to achieve near-normoglycemia during the ordinarily optimal treatment regimen of continuous subcutaneous insulin infusion. All patients were female. Seven patients had obvious family problems such as divorce or parental conflict. Type A (12 patients) suffered mainly from frequent, unpredictable episodes of ketoacidosis, necessitating many emergency admissions to a hospital; type B (two patients) complained of frequent, unpredictable, symptomatic hypoglycemia, short of coma and not requiring admission to a hospital. Type A brittle diabetic individuals were compared with 12 stable diabetic patients matched for age, sex, and duration of diabetes. The type A diabetic patients were young (mean age: 19.2 yr; range: 13–27 yr) with a wide range of duration of diabetes (2.5–23 yr) and brittleness (1–11 yr). Although their body mass index (BMI) was not significantly different from the stable diabetic subjects, many type A brittle patients were overweight, despite usually constant ketosis and hyperglycemia. The daily subcutaneous insulin dose was significantly higher than for stable diabetic individuals (mean ± SEM: 7.1 ± 2.6 versus 0.96 ± 0.12 U/kg), reflecting, perhaps, a subcutaneous absorption barrier in brittle patients. There was a significant correlation between age of onset of brittleness and age at menarche, with brittleness starting in most patients 2–5 yr after a normal-age menarche. This may implicate the hormonal and/or psychological changes at this time. Most type A brittle patients had secondary amenorrhea or oligomenorrhea at the time of study. Type B patients were older (32 and 38 yr) with long duration of diabetes (24 and 28 yr) and brittleness (20 and 28 yr). They were receiving a normal subcutaneous insulin dose (0.5 and 0.8 U/kg) and had a regular menses. Furthermore, brittleness appeared before menarche in these patients.

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