A combination of factors causes diabetes. These factors are not completely understood and the multiple types of the disease, each with varying risk factors, further cloud the understanding. The most common types are Type 1 and Type 2; approximately 97% of diabetes cases in the United States are one of these two types. A combination of genetic and environmental factors contributes to both types.
Of those, Type 2 is far and away the most common, about 90% of cases.
A major factor in Type 2 is thought to be obesity. Obesity itself results from both lifestyle choices and genetic factors, so it is a good model for a cause of diabetes. Some individuals naturally shed weight more easily or put on pounds more quickly than others do, but lifestyle choices obviously play a distinct role in obesity.
Besides obesity, there are many additional factors.
Gestational diabetes (diabetes that occurs during pregnancy) can add to your future risk of Type 2 diabetes, even though the condition disappears after delivery. Approximately 40 % of women who experience gestational diabetes will develop Type 2 diabetes. Usually this happens 5-10 years after they give birth. Large babies indicate a greater risk of diabetes for the mother.
An intolerance of glucose is another factor influenced by genetics. It is logical that glucose intolerance is a contributing factor to Type 2, because this form of diabetes stems from an insufficient use of insulin, rather than a lack of insulin (like Type 1). It is strange that glucose intolerance exists, because glucose in the body’s major energy source. Abnormal genes can make strange situations.
Though the reasons are not completely clear, ethnicity is a risk factor for Type 2 diabetes. Regardless of lifestyle factors, Africans, Latin Americans, Aboriginals, and some Asian groups are at higher risk. According to a one Canadian study, the incidence in these groups may be twice the incidence rate in Caucasians. Strangely, Caucasians are at the highest risk for Type 1 diabetes.
Hypertension (high blood pressure) is yet another risk factor. Blood pressure is influenced by genetic factors as well as exercise and diet. The correlation between high blood pressure and the development of diabetes is strong. High cholesterol levels also increase the risk. More than 40% of diabetics have high blood cholesterol levels.
The largest genetic risk factor is likely a family history of diabetes.
An individual with a parent or sibling who has Type 1 diabetes has him or herself a risk 10-20 times higher than average. For a newborn baby with a parent who has Type 1 diabetes the odds are 1 in 25, or 4% if the mother gives birth before age 25. Over age 25, the risk is 1%, about the same as the general population. The odds rise again to about 10% if either parent contracted diabetes before age 11.
Scientists are actively researching the genetic factors of diabetes. Modern genetic treatments offer hope of lowering the odds; a hope previous generations did not have.