Seeing that people of ages 21, 22 and even 37 diagnosed as type 1 puzzels me now.
How do they know if you are type 1 or type 2
Age doesn't come into it. Joslin a famous US specialist notes 2 peaks of incidence, one in adolescence, followed by another after the age of 40 but his figures show it occurring into the 90s.
I was 53, when diagnosed and was shocked to be admitted to hospital and told I had type 1.Even today over 5 years later,I sometimes think, maybe they got it wrong, maybe I could stop the insulin and control it with diet! (then something goes wrong and I realise that they were probably right!)
How do they diagnose ?
What they use is a certain amount of guesswork.......also known as clinical judgement.
reaction to insulin (type 1 typically needs far less for a similar amount of carbs as they haven't the insulin resistance)
blood tests. There is one that shows how much insulin you are producing and several others that show if you have various antibodies (howver some diagnosed as type 2s also have antibodies.... these are the people more likely to need insulin eventually ; conversely some obvious type 1s in all other respects don't test positive for antibodies)
Unexplained weight loss prior to diagnosis seems to happen more often in those diagnosed type 1, coupled with fairly high fasting glucose .
Just a couple of speculations :
perhaps it is really one big continuum........or several different conditions with high glucose as a symptom. The labels Type 1 and 2 don't really define things properly ...indeed even in the early 1950s Lawrence an eminent British diabetologist described 3 types of diabetics and others have described more since.