In T2 diabetes by Jeff Cyr
1-Insulin release is delayed and reduced. Loss of beta-cell mass. Loss of glucose sensitivity and loss of insulin release.
2-Glucagon release from alpha-cell is not properly suppressed. Glucagon raises blood sugar. Higher signal of glucagon tells the liver to release stored glucose, even if blood glucose is above normal.
3-What I just stated, leads to constant hyperglycemia-elevated blood sugars.
4-We have the incretin effect, the gut hormones GIP, GLP-1, and GLP-2. These gut hormones are responsible for 50-70% of the insulin release from pancreatic beta-cells after the nutrients from the food you eat enters into the small intestines. GLP-1 also suppresses the release of glucagon from the alpha-cells. GLP-1 is also heavily involved in slowed gastric emptying and proper satiety signaling the the brain. Peptide YY is also co-secreted alongside GLP-1, PYY is also involved with proper satiety signaling in the post meal phase. These gut hormones, the incretin effect is greatly impaired in T2 diabetes.
Here are 3 links to reference papers on the impaired incretin effect in T2 diabetes.
🔺" In patients with type 2 diabetes, however, the incretin effect is lost or greatly impaired. It is hypothesized that this loss explains an important part of the impaired insulin secretion in patients. Further analysis of the incretin effects in patients has revealed that the secretion of GIP is near normal, whereas the secretion of GLP-1 is decreased. On the other hand, the insulintropic effect of GLP-1 is preserved, whereas the effect of GIP is greatly reduced, mainly because of a complete loss of the normal GIP-induced potentiation of second-phase insulin secretion. "
https://www.physiology.org/doi/full/10.1152/ajpendo.00545.2003 .🔺
🔺"There is no doubt that the incretin hormones play a major role in healthy subjects, and it can be concluded that the incretin effect plays a major role for normal glucose tolerance. In people with type 2 diabetes, this ability is dramatically reduced."
http://care.diabetesjournals.org/content/34/Supplement_2/S251 .🔺
🔺" In type 2 diabetes, the incretin effect has been shown to be markedly reduced (3). This incretin defect is accompanied by a reduced GLP-1 response to a mixed meal (4,5), a decreased insulinotropic potency of GLP-1 (6), and an almost complete loss of late-phase insulin secretion in response to GIP (7). In addition, we have recently shown that the suppression of glucagon secretion is impaired during oral glucose tolerance tests (OGTTs) ."
http://diabetes.diabetesjournals.org/content/56/8/1951.long .🔺
5- Just this little bit of information tells me that a T2 diabetic cannot, and should not eat any refined carbohydrate. They can handle some low carb fibrous veggies. Some low-glycemic berries.
6- The American diabetes Association still advocates for a very high carbohydrate diet for diabetics, T2 diabetes.
