Causes of Type 2 Diabetes

By editor | July 24, 2007

The cause of Type 2 diabetes is not as well understood. Two factors appear to be important in Type 2 diabetes. These are insulin resistance and insulin deficiency. There is a debate over which comes first, but the general consensus of the moment is that insulin resistance is the first factor. Type 2 diabetes is also a genetic disease, although the genes are carried on entirely different chromosomes than those for Type 1 diabetes. There are probably multiple genes involved in this disease. For whatever reason, this genetic factor, perhaps interacting with some environmental factors such as obesity, excess caloric intake, deficient caloric expenditure, and aging, may result then in a resistance to insulin. That is, the peripheral cell, a muscle or fat or other cell, does not respond appropriately to the insulin present. The body then begins to produce more insulin in order to try to overcome the insulin resistance. The next part of the sequence may involve two factors. One is that the increasing insulin secretion may ultimately exhaust the beta cells, thus resulting in insulin deficiency. Another factor has been identified recently and toxicity. It turns out that sugar in high amounts can be toxic or poisonous to the cells of the body. In the person with insulin resistance who is running high blood sugars that have been undetected and untreated, or even in the person who know he or she has the disease but does not treat it appropriately, the continuing high levels of sugar have a toxic effect on the insulin, producing cells of the pancreas, thus damaging those cells and reducing insulin secretion. So we then end up with a combination of peripheral resistance to the action of insulin and at the same time insulin deficiency, and those two can then precipitate a severe case of Type 2 diabetes that may in fact require insulin for treatment. There are many steps in the action of insulin at the peripheral cell level, and each of those steps is stimulated by a different enzyme, and each enzyme is controlled by a different gene. Therefore, there are many potential places where the defects can occur, resulting in the same ultimate end: resistance of the peripheral cell to the action of insulin. This is probably the precipitating factor in Type 2 diabetes.

There is an increase in the diabetes for both Type 1 and Type 2 disease but a more pronounced increase in Type 2. The increase is at the rate of about 6 percent per year, which means the number of people with diabetes will double every 15 years. In the United States this increase is occurring predominately in the non,white ethnic populations. The prevalence of diabetes in the Caucasian population is approximately 5 to 6 percent; in the black population it is somewhere between 12 to 15 percent; in the Hispanic population it is around 20 percent; and in the Native American population it frequently exceeds 30 percent. Indeed, there are tribes in which the prevalence may be as high as 65 percent. Likewise, diabetes is increasing in the world, particularly in developing countries. The disease is very rare in third world or undeveloped countries. But as these countries begin to develop and achieve industrial prominence and economic stability there is a mushrooming of the amount of diabetes occurring in these cultures. This was seen in Japan after World War II and most recently in Korea and Taiwan, and it is now occurring in other Southeast Asian countries as the standard of living begins to increase. It is thought that this increase is probably related to increased caloric intake associated with decreased caloric expenditure. The genes for Type 2 diabetes are probably widespread through, out the world in equal amounts for all races and ethnic groups, but the change in life style from manual labor with a low caloric intake to industrial labor with a high caloric intake and reduced caloric expenditure, because of the use of machinery, can then result in a virtual explosion of Type 2 diabetes.

Type 1 diabetes is pervalent in certain geographic areas that are closest to the equator, and as one moves farther north to the arctic circle the prevalence of the disease increases. The highest incidence occurs in the Scandinavian countries; the lowest in the Mediterranean area except for the Island of Sardinia which has an incidence equal to that of Finland. The reasons for these differences are not well understood but it is believed to be due to a change in diet from Brahman cows to English cows a few years ago. It is believed that there may be in English cows used throughout Europe and the Western Hemisphere a protein that may somehow cause the damage to the pancreas and that this protein is lacking in the milk of Brahman cows used in Africa and Asia. Time and research will tell if this is a causative factor in Type 1 diabetes in Europe and North America.


Tagged under:

Share This

Topics: Diabetes |

Comments

You must be logged in to post a comment.