Nonobese, Nonketotic Childhood-Onset Diabetes: Look for Lipodystrophies.

Abstract

Diabetes in children and youth poses a unique diagnostic and therapeutic challenge. Although type 1 and type 2 diabetes are undoubtedly the most frequently encountered forms of diabetes, other forms are not uncommon in this age-group. Many young patients with so-called “specific types of diabetes due to other causes” may be misdiagnosed as having type 1 or type 2 diabetes because of a lack of awareness of the various diagnostic possibilities (1). The group of patients with other forms of diabetes constitutes <5% of all patients diagnosed with diabetes before the age of 25 years and includes a variety of conditions (2). Lipodystrophy, a group of disorders characterized by loss or abnormal distribution of body fat, is associated with insulin resistance and resultant abnormal glucose homeostasis. Depending on the extent of the loss of adipose tissue, these rare disorders are divided into three subgroups: generalized, partial, and localized. Barring the localized form, the other variants are associated with profound metabolic dysfunction. These disorders can be inherited or can be acquired secondary to a number of infectious or immunological diseases and can potentially be associated with diabetes. Patients with lipodystrophies are often misdiagnosed as having type 2 diabetes and occasionally as having type 1 diabetes. The prevalence of partial lipodystrophy was found to be 0.79% in patients initially misdiagnosed as having type 2 diabetes (3). We describe here two patients with childhood-onset diabetes secondary to congenital lipodystrophies and discuss their clinical and diagnostic features. ### Case 1 A 6-year-old girl born of a consanguineous union had been detected to have diabetes while undergoing evaluation for failure to gain weight. She was placed on insulin by her primary care physician and referred to us for unsatisfactory glycemic control despite receiving a high dosage of insulin (3.7 units/kg; total daily dose: 52 units). She did …