Type 2 is due to the body cells being resistant to the patients own insulin resulting in overproduction of insulin by the pancreas. This HIGH insulin level is needed to make the cell accept glucose. Type 1 is not genetic. Type 2 is genetically transmitted. If one parent has Type 2, 25% of the children will get it. If both parents have Type 2, 100% of the children will get it.
Type 2 diabetes is heavily influenced by heritage and lifestyle. Patients produce insulin but their weight and other factors interfere with its action causing their blood glucose to drift into high ranges. Diet and oral medications usually control their diabetes, but insulin may be needed as well. In their case, treatment with insulin is an option not a necessity.
Type 2 diabetes is due to insulin resistance and eventual beta cell failure. These people have high insulin levels on presentation and are generally obese. Their tissues are insensitive to their insulin and the beta cells must produce insulin at a high rate to prevent the development of diabetes. They are mostly obese, may have high blood pressure, high waist to hip ratio, elevated triglycerides, low HDL and urine protein. Prior to the development of diabetes in theses people their fasting sugars may be between 100 and 125; normal fasting is below 100. Two hours after eating their sugars may range from above 140 to 199. Diabetes is diagnosed when fasting sugar is 126 or over or the two hour after eating sugar aboive 200.
As the diabetes in type 2 disease progresses the beta cell stops producing insulin and these people require insulin for treatment. Prior to that time oral agents are used to treat as well as lifestyle changes which includes low carb, low-fat diets for weight loss and exercise to at least 150 minutes a week. In pre-diabetes, these lifestyle changes may delay the onset of diabetes and the eventual development of the many complications of the disease.
It is very important to treat both type 1 and 2 early in the disease to reduce the rate of complications. As part of treatment program attention is paid not only to the blood sugar but to treatment of high blood pressure, cholesterol, overweight or obesity and to cessation of smoking.
Dr. Marina Strizhevsky
Type 2 diabetes is a different disease. It begins with the bodies resistance to insulin and an increase not a decrease in blood insulin levels. Later the pancreas may wear down from the need for hyper secretion of insulin & go into failure. The patient may then need insulin to control blood glucose but is not dependent upon it to live. This disease occurs mostly in adults but there is an increasing incidence in children with the epidemic of obesity (which causes insulin resistance) in children. I have treated a 4 yr. old child with Type 2 diabetes. The genetic background which interacts with environmental factors to cause these two diseases are different as are the environmental factors. Type 2 diabetes is usually associated with obesity while people with Type 1 are usually slender & have lost wt. prior to diagnosis. There is overlap in these 2 diseases, however, with some children with Type 1 getting overwt. & developing simultaneous Type 2 -- what is now called Double diabetes. Type 2 patients can also lose all their insulin producing ability & be dependent on insulin for life. It is like 2 roads that may eventually come together to produce the same symptoms, but how you got there was different.
TYPE 1: Insulin deficiency or absence. This is typically due to antibodies against the insulin making cells of the pancreas. Many doctors (Endocrinologists) will test for these antibodies against the beta cell of the pancreas (IA-2 antibody) or an enzyme in the pancreas (GAD65). The face of type 1 diabetes is typically children and adolescents. However, many adults can develop type 1 diabetes. We sometimes call this "Latent autoimmune diabetes of adulthood" or LADA. Because the problem in this type of diabetes is an inability to make insulin, the therapy is to give insulin.
TYPE 2: These people often make insulin, however, their body is RESISTANT to using the insulin. Namely, fat tissue (adipose tissue) does not like to use insulin. I often think of sugar/glucose/carbohydrate as a "lock" and insulin a "key". A patient with type 2 diabetes has tissue cells "doors" that do not like the locks and keys. We call this INSULIN RESISTANCE. We can beat the insulin resistance by weight loss (decreasing fat tissue) or by providing more 'locks' and 'keys' to open the door of the cells. In this, the cells will store the glucose/sugar or use it as energy. Many medicines are designed to provide more insulin (keys). Some are aimed at reducing fat tissue (doors). Some are targeted to reduce glucose (locks) in the bloodstream by urinating it out.
This is such an important question, and often many people are incorrectly diagnosed. Subsequently they're put on the wrong treatment.