Scientists have long known that there’s a link between obesity and diabetes. In fact, the term “diabesity” was coined to describe the situation. Some 80% of people with Type 2 diabetes mellitus (T2DM) are obese, and recent research has demonstrated evidence that obesity also affects Type 1 diabetes. To answer the question of how the two are linked, let’s start with the basics:
Over 30 million people in the United States have diabetes. But what is it?
Cells called beta Langerhans islet cells (beta cells for short) produce insulin, and insulin helps your body move glucose from your blood into the cells where it’s used for energy. When these cells either cease to produce insulin or don’t produce enough insulin, your blood glucose levels rise. That’s the problem with diabetes and it’s life-threatening.
There are two types of diabetes:
Type 1 diabetes is a genetic condition that involves your immune system attacking the beta cells that make insulin. Although it can appear at any age, it’s usually diagnosed in children, and people with this type of diabetes must take insulin daily to survive.
This is where your body either doesn’t make or use insulin well because the beta cells have been damaged and receptor cells have become resistant to the effects of insulin. It can occur at any age, but it’s most commonly diagnosed in individuals in middle age or older. This is also the most common form of diabetes.
Obesity is an excess of body fat. It’s measured by an indicator called body mass index (BMI), a measurement based on a person’s weight and height. Individuals with a BMI of 25-29.9 are considered overweight, and individuals with a BMI of 30 or higher are considered obese. According to the Centers for Disease Control and Prevention (CDC), almost 40% of adults in the US are considered obese.
Researchers have long seen the evidence for a link in the statistics of obese diabetics, but discovering why was more complicated.
Unlike with Type 2 diabetes, the majority of people with Type 1 diabetes aren’t obese. But, there’s an association between obesity and the onset of Type 1 diabetes. Weight gain lowers the age at which a diagnosis is made. This is called “the accelerator hypothesis.” It states that weight gain speeds up the onset of diabetes in people who are already genetically predisposed to the condition.
The diagnosis is accelerated in obese patients because of something called insulin resistance. Insulin resistance causes your cells to resist the effects of insulin. That means it takes more insulin to produce the same effect.
Overeating stresses a structure inside the cell called the endoplasmic reticulum. It sends out an alarm signaling the cell to dampen the insulin receptors on the outside of the cell. This is how the insulin transports glucose to the cell — it attaches to these insulin receptors. If they aren’t receiving, the insulin can’t attach, and the glucose can’t be transferred. Over time, this causes dysfunction in the beta cells of the pancreas.
Insulin resistance also plays a major role in Type 2 diabetes. There are normal cycles of insulin sensitivity during a healthy individual’s life, but intermittent periods of insulin resistance resolve because of a continuous feedback between the beta cells and insulin sensitive tissues.
Adipose tissue (i.e., fat tissue) produces what are called non-esterified fatty acids (NEFA). These play a role in insulin release. In an obese individual, however, there’s constant exposure to NEFAs, and that eventually impairs beta cell function and the feedback mechanism that regulates blood glucose levels. The deregulation of blood glucose levels leads to the development of Type 2 diabetes mellitus.
Dr. John Monroe, MD at Healthy Life Family Medicine in Bingham Farms, Michigan, is a specialist in internal medicine and, specifically, diabetes. If you’ve been diagnosed with diabetes or have symptoms, such as fatigue, vision complications, frequent urination, and/or excess thirst and hunger, Dr. Monre can help with a diagnosis and a treatment plan that’s right for you.
Call our office today or book an appointment online to find out what kind of treatment is right for you.