What Are the Causes and Risk Factors of Type 2 Diabetes?

Whether you are living with type 2 diabetes or curious about your blood sugar, it’s important to know whether you’re at risk and, if so, what you can do to prevent type 2 diabetes.

What Causes Type 2 Diabetes?

When you have type 2 diabetes, glucose doesn’t move into the cells effectively; this is called insulin resistance. Instead, insulin builds up in the bloodstream, causing high blood sugar. In turn, your pancreas tries to make even more insulin, and it might not be able to make enough.

This condition can occur because of lifestyle factors or be inherited. “Type 2 diabetes has a strong genetic component,” says Leann Olansky, MD, a board-certified endocrinologist at Cleveland Clinic in Ohio. “But if you choose a healthy lifestyle, you may be able to avoid diabetes or put it way off.”

You can still be diagnosed with diabetes without the genetic component, says Los Angeles–based John P. Martin, MD, the codirector for diabetes management for the Southern California region of Kaiser Permanente. “It’s not like not having the genetic tendency is going to protect you,” he says. “You can still get it if your diet, your weight management, and your self-care aren’t where they need to be.”

What Are the Risk Factors for Type 2 Diabetes?

• Overweight or Obesity Being overweight can lead to insulin resistance, which can lead to type 2 diabetes. It’s not just excess weight; where you carry it matters. Extra fat in the belly area, called visceral fat, is linked to insulin resistance and type 2 diabetes. One reason is that visceral fat secretes retinol-binding protein 4, which increases insulin resistance.

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• Activity Level Being physically active less than three times a week increases your risk.

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   This is because activity can help your body use glucose as energy.
• Cholesterol Levels Low levels of HDL (“good”) cholesterol are linked to insulin resistance and may contribute to an increased risk of type 2 diabetes. Levels less than 40 milligrams per deciliter (mg/dL) in a man and less than 50 mg/dL in a woman are considered low, Dr. Olansky says.
• High Levels of Triglycerides As with low HDL cholesterol, high triglycerides, which are a kind of fat found in your blood, may indicate insulin resistance and be linked to an elevated type 2 diabetes risk. Levels of less than 150 mg/dL are considered normal, though according to Dr. Martin, high levels don’t necessarily mean you have type 2 diabetes.

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   “Anything above that probably shows some risk,” Olansky says.
• Smoking “Smoking is another thing that can increase insulin resistance and can increase the likelihood that you’ll manifest diabetes,” Olansky says.
• Family History “If you have family members with type 2 diabetes, then you probably have the genetic risk,” Olansky says. “And if you’ve got them on both your mother’s and your father’s side, you have an even higher likelihood because you’re going to get a combination of both of those.”
• Race and Ethnicity Type 2 diabetes is more common among Black, Hispanic, and Asian people, as well as among American Indians and Pacific Islanders.
• Age Risk increases with age, particularly after age 35.
• Health History If you’ve had gestational diabetes or had a baby who weighed more than 9 pounds at birth, you are at increased risk. Having metabolic dysfunction-associated steatotic liver disease, formerly known as nonalcoholic fatty liver disease, or polyendocrine metabolic ovarian syndrome can also increase your risk.

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• Socioeconomic Factors Your environment can play a role in many elements of your health, some of which may add to the aforementioned risks, Martin says. “You can’t control the socioeconomic stressors you have in your life that might limit your ability to buy healthy foods and buy them cheaply,” he says. “There are not always resources to overcome those socioeconomic health barriers.”

How Can I Help Prevent Type 2 Diabetes?

• Maintaining a Healthy Weight “The most important thing is weight management,” Martin says. Losing 7 to 10 percent of your body weight when you have prediabetes, for example, can strongly reduce your type 2 diabetes risk.
• Exercising Regularly Aim for 2.5 hours of moderate exercise per week. This exercise does not have to be over the top; try walking for 30 minutes five days a week. “Brisk walking is adequate — you don’t have to be a marathon runner,” Olansky says. Talk to your doctor and care team about the exercise plan that might be best for your situation, especially if you already take insulin.

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• Eat a Healthy, Balanced Diet Although there is no one diabetes diet, it’s often wise to home in fruits, nonstarchy vegetables, lean proteins, lean dairy products, and whole grains.

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  “You want to limit the amount of saturated fat and carbohydrates, particularly simple sugars,” Olansky says. Simple sugars, such as glucose and fructose, can be dangerous because they can lead to blood sugar spikes and increased insulin secretion.

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Martin says it’s also important to stay in contact with your physician if you’re at risk and to educate yourself about diabetes.

“The more you know, the more power you have so you can take control of your life,” he says. “The reality is that you can have a strong genetic component, but mitigating lifestyle risk factors, such as obesity, poor diet, and lack of exercise, can help prevent the transition into a diabetes diagnosis. It’s not easy. It’s a lot of work. It’s not always going to go perfectly, and there will be times when you may fall off in terms of self-care. But the important thing is that you get back on.”

You can join the conversation in the forums on Everyday Health’s network site Diabetes Daily.