Table 4.

Clinical Preconceptions are Not Always Correct

AGE OF DIAGNOSIS: TID IS DIAGNOSED IN CHILDHOOD AND T2D IS DIAGNOSED IN ADULTHOOD.
At least 25% of people with TID are diagnosed as adults. T1D is not “juvenile” diabetes.
WEIGHT: PEOPLE WITH TID ARE THIN, AND PEOPLE WITH T2D ARE OVERWEIGHT.
At least 50% of people living with TID in the US are overweight or obese, a statistic which mirrors the general US population. Excess weight doesn’t prevent autoimmunity!
CLINICAL PRESENTATION: THE ONSET OF TID IS DRAMATIC, AND INSULIN IS IMMEDIATELY REQUIRED FOR TREATMENT.
While this is generally true, the presentation of TID tends to be less abrupt in adults (in whom beta cell destruction is more gradual). Moreover, insulin isn’t always required immediately, especially in adults or in overweight individuals, where treatments to improve insulin sensitivity such as weight loss and/or metformin, may be sufficient to control blood glucose for a limited period of time.
RESIDUAL INSULIN SECRETION: PEOPLE WITH TID HAVE AN ABSOLUTE INSULIN DEFICIENCY.
At the time of diagnosis, essentially all people with TID have clinically significant amounts of C-peptide. Furthermore, among those with > 40 years of TID, 6-16% have a non-fasting C-peptide level ≥0.017 nmol/L.
AUTOIMMUNITY: IF YOU DON’T FIND ANTIBODIES, IT’S NOT TID.
There are five well-characterized antibodies associated with TID; most commercial laboratories don’t measure all five, so the results can be misleading. In addition, up to 10% of those with newly-diagnosed TID may not have antibodies. While these individuals may have a monogenic form of diabetes (http:​//monogenicdiabetes.uchicago.edu), it is also possible that they have autoimmunity not detectable with current antibody measurements.

Sources: (5, 123, 124)

From: Changing the Course of Disease in Type 1 Diabetes

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