August 5, 2013
Does Type 2 Diabetes Have Subclasses?
Before getting started on this topic, I must state that these are my opinions only, based on my reading and are no way official opinions. While some people have been alluding to sub groups or subclasses of people with type 2 diabetes, I believe the evidence is mounting for more people to come out in support of this idea. We now know that ethnicity is a factor and I am not sure how to list the young type 2's that have more deadly type of diabetes than children with type 1.
I personally feel that an apples to apples comparison is not totally accurate for those adolescent and young adults with type 2 diabetes, but I could be in error. “The study population was derived from the Royal Prince Alfred Hospital Diabetes Database and focused on individuals diagnosed with diabetes between the ages of 15 and 30 years. Records were matched with the Australian National Death Index to establish mortality outcomes for all subjects until June 2011. Clinical and mortality outcomes in 354 patients with type 2 diabetes (mean age at diagnosis, 25.6 years) were compared primarily with 470 patients with type 1 diabetes with a similar age of onset (mean age at diagnosis, 22.0 years) to minimize the confounding effect of age on outcome; disease duration was 11.6 vs 14.7 years.”
While type 1 diabetes is generally considered a more severe type of diabetes, the results highlight that young people with type 2 diabetes have double the risk of dying when compared to those with type 1 diabetes and after a much shorter duration of having diabetes.
Therefore, I would think this should be considered one subclass of type 2 diabetes. Studies are finally being done to compare how different ethnicities are affected by type 2 diabetes. While much more study is need for those in Africa, they tend to have a lower insulin sensitivity, but seem to compensate by releasing greater amounts of insulin.
Among those of East Asian origin, they have very good insulin sensitivity, but seem to have a harder time releasing insulin when it is needed. This means in the clinical settings, they develop diabetes more easily and do so at a lower BMI. Because East Asians have more difficulty releasing insulin, generally they need to start insulin therapy at an earlier stage of diabetes.
Caucasians fall between the two extremes in both insulin release and insulin sensitivity. Now in addition to the above subclasses there are probably more that have not been studied, such as the Eskimos and American Indians, but until there are studies verifying this, we can only guess. I would even hazard a guess that the African Americans could also be a subclass separate in part from those from Africa itself.
I also believe that even among Americans, there could be several subclasses of type 2 because we have thin type 2's and obese type 2's. We have many people that are able to manage their diabetes with nutrition and exercise and others that have a difficult time even on low levels of medication.
Will we have any discussion within the ADA about this? I highly doubt this and would be more inclined to believe that with the current attitude of physicians wanting cut and died answers, that it will require a much stronger voice than mine to give them a wake up call. Plus, with their conflicts of interest, unless some of their corporate sponsors raise the question, this will never see the light of day in the American Diabetes Association discussions.