October 17, 2001
Diagnosis and Symptoms
Question from Austin, Texas, USA:
Recently I’ve been reading a lot on-line about people claiming to have “converted” from type 2 to type 1 diabetes, saying that because as their diabetes progressed they eventually required insulin, thus making them type 1which doesn’t many any sense to me. Doesn’t someone still have type 2 diabetes, even if they eventually become insulin-dependent from loss of insulin production in the later stages of the disease, a sort of “burn out” of insulin production if you will? It seems that this is one more myth that is fairly wide-spread. I know that the distinctions between type 1 and type 2 are becoming less clear, but am I correct in thinking that it’s just not possible to have type 2, and then “change” to type 1 many years later? The person would still be a type 2, just on insulin.
Until relatively recently, the term Type I diabetes was used synonymously with insulin dependant diabetes in the young (IDDM), and the term Type II was kept for the much more common middle-aged overweight person with diabetes who could be controlled with diet, exercise and perhaps oral hypoglycemic agents (NIDDM), but who might eventually might require insulin. So, it is easy to see how some people with type�2 might feel that they had become type�1 when they started to need insulin even though they are still type 2.
Nowadays of course, the subdivisions of these two forms have become much more complex.and much less distinct. Type 1 for instance now comprises type�1A (autoimmune) and type�1B which has the same acute onset, but in which the antibody tests are negative. Add to this, one form of Late-onset Autoimmune Diabetes of Adulthood (LADA), some of the insulin resistance syndromes, and the occasional case that presents acutely, but ends up looking like a typical type 2. The latter group now has to include the many forms of Maturity Onset Diabetes of the Young, some cases of LADA in which antibody tests are less convincing, and of course, the rarities like mitochondrial diabetes.
One day perhaps, initial diagnosis will routinely become more precise, but for the moment, it can be an expensive process and more importantly it really doesn’t affect clinical management very much.
I hope this is of some help on a confusing theme.