BMI May Be a Bigger Risk Factor for Type 2 Diabetes Than Genetics

  • Researchers say body mass index (BMI) may be a higher risk factor for type 2 diabetes than genetics.
  • Other experts say genetics is actually the number one factor for developing diabetes, but they note that lowering BMI can help delay or even prevent the onset of the disease.
  • They say you can lower your risk for type 2 diabetes by having your blood sugar screened every 3 years after age 45 as well as exercising regularly, eating a healthy diet, and not smoking.

Weight is a risk factor for type 2 diabetes.

So are genetics and aging.

Of those risk factors, the only one you have any control over is weight.

Managing your weight may prevent type 2 diabetes, delay onset, or even reverse it in some cases, according to new research presented at the European Society of Cardiology Congress 2020.

The study involved more than 445,000 people in the United Kingdom.

Participants were divided into groups according to genetic risk and body mass index (BMI). Average age was about 57 years. Researchers followed participants to an average age of 65 years.

During that time, more than 31,000 people developed type 2 diabetes.

The group with the highest BMI was found to have the greatest risk over other groups, independent of genetic risk.

The researchers suggest that BMI has a more powerful impact on diabetes risk than genetics.

They also theorize there’s a certain BMI threshold where blood sugar levels become abnormal. This, researchers say, may differ from person to person.

The broader picture

Dr. Kathleen Wyne, an endocrinologist at The Ohio State University Wexner Medical Center, specializes in treating people with diabetes.

We need to look at this data carefully, Wyne advised Healthline.

“Review of data from the U.K. shows that while there is diabetes in the 45- to 55-year-old age group, it really starts to take off in this older group, around the age they studied,” she explained.

Wyne contrasts that with the United States, where as early as 2000, data showed the average age at diagnosis is the early 40s.

“The other problem with this analysis is that they took a very heterogenous disease and tried to create groups based on BMI and clusters from the genes they included in the analysis,” she said.

Wyne notes that a single gene doesn’t cause type 2 diabetes. Multiple genes with partial or complete defects are likely to cause it.

“What would be interesting is to compare the gene profiles in the most lean and most obese of the people who did develop diabetes. Or take the five subtypes of diabetes… then ask where these people fit into those phenotypic groups and look at their gene cluster. I doubt the obese people would all sort into the same one of the five groups, thereby proving that obesity does not identify a homogeneous risk group,” Wyne said.

According to Wyne, the single biggest factor is genetics.

“However, you have control over when you get the diabetes. This is related to the combination of weight and activity level. At the same weight, the more active person is more insulin sensitive and less likely to progress to diabetes. If you keep your weight down, then you can possibly put off your diabetes until you are in your 70s,” Wyne said.

Multifactorial disease

Dr. Emory Hsu is an endocrinologist with Santa Clara Valley Medical Center in San Jose, California.

Hsu emphasizes the new research is specific to type 2 diabetes, the most common form, as opposed to type 1 or rare forms of diabetes.

“In general, type 2 diabetes is the result of insulin resistance. The body’s blood sugars are too high despite your body making enough insulin, a hormone made in the pancreas that allows sugar to be utilized by your cells,” he told Healthline.

“The frustrating thing about type 2 diabetes is that there is no one definitive cause and no one magic bullet. It’s what we call multifactorial, meaning many things may increase or decrease your risk. It would be hard to say there is one single biggest factor. This research identifies that obesity is a large contributor,” Hsu said.

But it’s a bit more complicated than that.

Not all people with obesity develop diabetes, and some people with a moderate weight do.

“There are many more nuances to obesity, such as the distribution of fat and whether it is more central or peripheral (often different between women and men), and ethnic differences that we don’t completely understand. For example, the risk of diabetes starts at a lower BMI for South Asians and East Asians compared to Caucasians or Africans,” Hsu said.

Dr. Alexander Li is the deputy chief medical officer for L.A. Care Health Plan in Los Angeles, California.

“In terms of primary causes of diabetes, we’re shifting from a genetic component to more social or maybe environmental changes,” Li told Healthline.

He cites factors such as food availability, increasingly sedentary lifestyle, and longer life expectancy.

Early diagnosis

Li says everyone should have their blood sugar checked on a regular basis.

“There’s a general desire in the health community to test early and to detect early enough,” he said. “Part of the new framework adapted 8 to 10 years ago is to look for people with prediabetes and recognize there might be a progression of those at risk for diabetes. So, if blood sugar is elevated, but not high enough to be diabetes, you’re at least giving people a chance to take a more active role in their health.”

Absent risk factors, the American Diabetes Association recommends that people start screening at age 45 and then every 3 years if results are normal.

“However, adults with risk factors should be screened earlier, and a very large percentage of the country is considered at higher risk,” Hsu said.

“Unfortunately, most of the time there are no obvious clinical signs for diabetes, so the diagnosis may be missed for a long time if someone doesn’t go for a checkup. Rarely, someone with a very high sugar level may present with frequent thirst, frequent urination, and/or blurry vision,” he added.

Lowering risk and managing diabetes

Diabetes increases the risk of heart disease and stroke.

It’s also the seventh-leading cause of death in the United States.

Despite that reality, Li wants people to know that diabetes isn’t a death sentence.

“Many people are able to get it under control. However, if one doesn’t control it, one can easily go blind, have increased risk of heart attack and stroke, as well as losing limbs or nerve sensations,” Li said.

“We try to paint a broad picture that you have ability to turn this around. Increasing physical activity and lowering calorie intake seems to be effective enough in the prediabetic phase. It’s also possible after a diabetes diagnosis, but basically, one has to work harder,” he added.

“Many times, antidiabetic medication is needed to control blood sugar. Some may need insulin for a period of time. Some can potentially get off insulin again and let the body’s natural insulin production help modulate one’s blood sugar. Others may become insulin dependent. It depends on one’s own innate ability to produce insulin and the response to natural insulin still available in the body,” Li explained.

Dramatic changes are usually not sustainable, he cautions.

“When you go slow and steady in changing your behavior, you can adapt to a better lifestyle,” Li said.

Hsu advises first checking with your doctor to make sure the changes you want to make are safe, as well as these tips:

  • If you’re sedentary, any additional activity is good.
  • Aim for at least 30 minutes of moderate-intensity exercise a day.
  • If you smoke, quit. Quitting can be very difficult, so seek support.
  • Have no more than one alcoholic beverage a day.
  • Replace processed foods, red meats, and simple carbohydrates with whole grains, nuts, beans, and fresh fruits and vegetables.
  • Stop drinking sugary drinks like sodas.
  • Follow up with your doctor regularly.

“There are other ‘hot topic’ areas of research, such as gut microbiota, artificial sweeteners, environmental pollutants, and endocrine disruptors, etc.,” Hsu said.

The bottom line, though, is still eating less, choosing more fresh foods over processed, and exercising, he says.

“These are the foundations of a healthier and happier life,” Hsu said.

Wyne says many people with diabetes are actually doing better through the COVID-19 pandemic. They have more time to focus on healthy eating and taking daily walks.

There’s a flip side to that.

Wyne suspects there may be an increase in type 2 diabetes diagnoses during the next year. That’s because the pandemic has pushed some people into a more sedentary lifestyle.

If you do develop type 2 diabetes, Wyne doesn’t want you to think it’s your own fault.

“It is clearly inherited. But, as mentioned earlier, you have control over when you get it. Hopefully you can put it off until you are in your 70s, or maybe even 80s or 90s, by staying active and eating healthy,” she said.


Source: Read Full Article