Diabetes type 1 or 2 - how does it matter -

Hi everyone,

Please excuse my lack of knowledge: I am over 50 years old and new to insulin and was told by my endo to use insulin, does it make me type 1 or type 2? I am on 3 units of Lantus and 2-3 units of Novolog as needed to cover the blood sugar rise after meals. I asked if my pancreas were making insulin. The doctor wanted to subject me to the 75g OGTT. It sounds irresponsible because 75g of glucose would probably send my blood sugar to 300. Could a fasting C peptide test indicate if my body is still producing insulin?

Hello IH378. I am about your age as well. I was first diagnosed as a type 2 back in 2005. I was on meds up until April, when the meds just were not cutting it. Endo, took me off the meds and placed me on insulin, Lantus and Novolog. After my recent visit with the Endo, he stated that I was not a type 2 but a type 1 after the blood work results. My C-peptied was very low. Check out the group about LADA. Plenty of information for people with our condition.

Insulin doesn't make you anything but an insulin user. Most that take insulin are type 1 but there are many type 2 that take insulin, I count myself in the T2 insulin group.

If you are T2 and you start insulin you are still T2. The type designation refers to the cause of your diabetes not the treatment. Type 1 is caused by an autoimmune attack on a persons beta cells which destroys the pancreas's ability to make insulin. Type 2 is a metabolic disease where a body is unable to use efficiently the insulin it makes. As time goes on a T2 pancreas can cease to function enough to cover ones insulin needs and insulin may be needed.

Has anyone had the C peptide test? According to information online, blood can be drawn once, or 24 hour urine collection. The doctor wanted to administer the 3 or 4 hour glucose tolerance test and measure "dynamic" C peptide and insulin response. I don't see the point....I clearly will have abnormal numbers, and would have high blood sugar numbers.

The amount of c-peptide produced is directly related to the amount of insulin you are releasing in response to the foods you eat.

A GGT with matching c-peptide will let your doc see if you elevated BG numbers is related to not making enough insulin, or to being resistant to the insulin produced.

Both causes get you to a high BG, but one indicates likely T1 while the other confirms T2. The treatments are different between the two.

My doctor wanted to me to do the 75 g OGTT back when I was still seeing him. I asked him what the point was? Considering we knew I would fail it, AND I was monitoring with a blood glucose meter at home (and getting abnormal numbers). He ceded the point and we didn't do the test.

C-peptide combined with fasting blood glucose should tell if your insulin production is high or low, though it isn't a very precise test unless one is very high or very low. If c-peptide is high and fasting blood sugar is high it would indicate insulin resistance. If c-peptide is low and blood sugar is high it would tend to indicate relative lack of insulin.

Given your dose of insulin, which seems to be fairly low (does this dose get your blood sugar back to target), it would seem your pancreas is still making some insulin and the injected insulin is 'supportive' therapy.

how was your c peptide determined?