The causes of diabetes are complex and only partly understood. Why any particular person gets diabetes isn't completely known. Complicating the situation is the fact that there are different types of the disease, though Type 1 and Type 2 are the most common. Each results from a combination of environmental and genetic influences.

Genetic Risk Factors for Diabetes

Each type of diabetes has its own risk factors. As mentioned above, Type 1 and Type 2 diabetes are the most common, encompassing about 97% or more of cases. Of those, Type 2 is far and away the most common, it accounts for about 90% of cases. in the U.S. 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.

A history of diabetes during pregnancy contributes to part of the total risk. Just shy of 40% of women who develop diabetes during pregnancy (a type known as gestational diabetes) will later develop Type 2 diabetes. That typically occurs within 5-10 years after giving birth. Those who give birth to larger babies have a greater 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.

Ethnicity plays a role in whether or not an individual will develop Type 2 diabetes, though the reasons are not fully understood. Even after adjusting for lifestyle, Aboriginals, Africans, Latin Americans and some Asian groups are at higher risk. The profile varies between 1.5-2 times the incidence among Caucasians, according to one broad Canadian study.

Oddly, though, the risk of Type 1 diabetes is much higher among Caucasians than any other race. 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. But simple family medical circumstance is probably the largest genetic risk factor. 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.

The genetic risk factors of contracting diabetes are still an active area of research. Fortunately, while in generations past there was nothing one could do to influence them, modern genetic treatments hold out promise of altering even these odds.

Environmental and Lifestyle Risk Factors for Diabetes

Fortunately for those who are at risk, many factors are lifestyle choices and therefore can be altered. Even after contracting the disease, much of the management of the disease involves controllable issues. Obesity is widely recognized as one of the leading risk factors for developing Type 2 diabetes.

While there is a genetic influence - some shed or gain weight and body fat more easily than others - it is subject to influence by choices. A high BMI (Body Mass Index) is an adjustable number with the proper diet and exercise. A BMI of higher than 27 correlates with increased risk of Type 2 diabetes. The number should not be taken as a sole determinant, however, since its diagnostic value is less for those who are very muscular or are pregnant. But a high BMI is an indicator of obesity and should be checked.

Beyond simply being overweight, where the majority of excess body fat resides plays a role in the odds of contracting Type 2 diabetes. Those who tend to store body fat around the waist are at higher risk. While that in itself is largely a genetic issue - some individuals are naturally pear-shaped, others are not - the results can be influenced by diet and exercise.

Claims of supplements that target fat at the waistline are yet to be proven. Similarly, assertions that it's possible to selectively remove waistline body fat through specific exercises are ill-founded. But an overall weight-reducing diet and general exercise program will help reduce large fat deposits, including those of the waistline.

More generally, a sedentary lifestyle increases the odds of contracting Type 2 diabetes. Partly that's the result of adopting a mindset that brings with it a number of less than ideal choices. But in particular, the lack of exercise is a direct cause of higher body fat percentage as well as a number of follow on effects.

Exercise certainly burns calories. But even the resting state burns about 70 calories per hour just to power metabolic processes. But regular movement helps stimulate the lymph system, strengthen and loosen muscles, oxygenate tissues and brings with it many other positive benefits. Exercise helps control blood pressure, a factor in contracting diabetes. It helps regulate glucose levels, which have a major role in the disease since excess glucose in the blood is a defining attribute of diabetes. It alters cholesterol levels, another risk factor for contracting the condition.

Though the risk of contracting diabetes is present for anyone, it's good to know you can drive it to much lower odds by adopting healthy choices.