Table 3 Clinical and diagnostic features of diabetes in youth
From: Challenges in diagnosis and management of diabetes in the young
| Â | Type 1 diabetes | Type 2 diabetes | Monogenic diabetes | FCPD |
|---|---|---|---|---|
Age at onset | Any age after 6Â months; most common in childhood and early adolescence | Adolescence and young adulthood; onset in children becoming more common, although unusual before puberty | Any age; usually presents before 25Â years of age; Hyperglycemia in GCK defects can be present from birth | Usually in the 2nd decade |
Family history of diabetes | Usually sporadic (>85Â %) | Strongly positive; usually on both sides of the family | Positive for at least three generations, on one side of the family | Unusual |
Overweight/obesity | Occurs at frequency similar to general population | Common | Occurs at frequency similar to general population | Usually lean |
Markers of insulin resistance | Unusual | Common | Unusual | Unusual |
C-peptide levels | Low or undetectable, particularly after 2 to 3Â years of diagnosis | May be supranormal, normal or low | Usually lower than normal | Low |
Islet autoantibodies | Present in majority of patients | Usually absent | Usually absent | Usually absent |