Differentiating NIDDM-Y from IDDM in youth is a diagnostic challenge.
Serum insulin levels at diagnosis may help differentiate between NIDDM
-Y and IDDM if the level is elevated, but the serum insulin level is l
ow or undetectable in 45% of patients with NIDDM-Y. Islet-specific ant
ibodies may be present in serum at diagnosis, and ketosis or ketoacido
sis may occur. For our patients, clinical features are most helpful in
differentiating NIDDM-Y from IDDM and include ethnic background, age
and gender at diagnosis (approximately 80% of First Nation patients fr
om northern Manitoba are adolescent females), presence of obesity and
acanthosis nigricans, lack of symptoms or weight loss, and strong fami
ly history of NIDDM.