Heredity and Diabetes
The factors causing diabetes are extremely complex and poorly understood. The multiple types of the disease confuse the matter further, since each type has it own risk factors. The majority of cases in the United States are Type 1 or Type 2 diabetes. Each form is a result on numerous hereditary and environmental influences.
Type 2 diabetes is the most common type.
Obesity is thought to be a major contributor to Type 2 diabetes. Being overweight is a good prototype for a cause since it is itself a combination of genetic background and lifestyle choices. Though the diet opted for and the amount of exercise one chooses to undertake are lifestyle choices, it’s still true that some individuals gain or shed weight more easily than others.
But there are many other factors, as well.
While diabetes that develops during pregnancy (gestational diabetes), ceases after delivery, it is a risk factor for developing Type 2 diabetes later in life. Nearly 40 % of women who have gestational diabetes will develop Type 2 diabetes, usually within ten years of the pregnancy in which the gestational diabetes occurred. Giving birth to a larger baby is another sign of high risk.
Glucose intolerance is another genetically influenced factor. Since Type 2 diabetes results not from underproduction of insulin (as in Type 1) but from inadequate use of it, it shouldn’t be surprising that glucose intolerance is a contributing circumstance. That glucose intolerance should exist is puzzling enough, since it’s a major source of the body’s energy. But genetic anomalies produce some unusual situations.
Another risk factor of Type 2 diabetes is ethnicity. The reasons for this are not understood. Some Asians, as well as Africans, Latin Americans, and Aboriginals are at higher risk. One Canadian study found that these groups have from a risk level of 1.5 to 2 times higher than Caucasians. However, Caucasians are at greater risk for developing Type 1 diabetes than other groups are.
Having high blood pressure raises the odds, too. That again is partly a lifestyle (chiefly, diet and exercise) choice but it has a strong genetic aspect as well. There’s a strong correlation between those with high blood pressure and those who will develop diabetes. Similarly, high cholesterol levels increase the risk. Over 40% of those with diabetes have higher than average levels of cholesterol in the blood.
While all of these factors have a genetic component having a family member with the disease likely represents the highest hereditary risk factor.
Someone with a sibling or a parent with Type 1 diabetes has as a 10-20 times higher risk than the average person of developing the disease. Babies of mothers under the age of 25 have a 1 in 25 chance of developing diabetes if one of their parents has the condition. Babies born to mother older than 25, have about a 1% chance of developing diabetes if one of the parents has it; this is about the same risk as the general population. If the parents were younger than age 11 when they developed the diabetes, their baby’s chance of getting diabetes rises to 10%.
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.