Why Thin People Get Type 2 Diabetes
While it’s true that being overweight is a primary risk factor for type 2 diabetes, it’s also true that slender individuals can develop diabetes.
Thin people seem to burn the calories they consume and don’t appear to have fatty muscles that interfere with glucose delivery. However, because there are genetic and other risk factors associated with type 2 onset, even rail-thin people can have high blood sugar.
Genes vs Lifestyle
A study published in 2014 compared lifestyle interventions to genetic testing for the prevention of type 2 diabetes. Though it was already known that both genetic and lifestyle factors influence diabetes onset, the researchers wondered if lifestyle factors - such as lack of exercise, or poor diet - raised a person’s genetic diabetes risk.
The investigation revealed obesity increased the risk for type 2 diabetes whatever the person’s underlying genetic risk level. Further, it showed that for those who are younger and leaner, genes are more influential than lifestyle factors in the development of diabetes.
Muscle and Fat
Another issue that may put people of normal weight at risk for diabetes is their fitness level. Not all thin individuals exercise regularly, or even eat well.
A sedentary lifestyle, combined with a diet high in processed foods could theoretically make someone thin on the outside, but fat on the inside. Although their actual weight is in the normal range, the ratio between their muscle and fat cells might be skewed enough to instigate insulin resistance.
Lean, but otherwise healthy children of type 2 diabetics might also inherit a genetic defect that disrupts their mitochondria's function. People with this defect burn glucose and fatty acids inefficiently, leading to an accumulation of muscle fat that disrupts insulin signaling.
Other Factors
Other factors relevant for type 2 diabetes in slender people are similar to the factors relevant for overweight individuals:
- NAFLD. Non-alcoholic fatty liver disease (NAFLD) affects up to 30 percent of the population in industrialized countries. Studies suggest NAFLD could be a primary factor for insulin resistance and type 2 diabetes in lean individuals.
- Genetics can predispose people to NAFLD, and diet plays a role. For instance, foods made with processed commercial oils and high-fructose corn syrup are known to promote NAFLD.
- Inflammation. Inflammation, which can occur in people of any weight, frequently precedes the onset of diabetes. Even low-grade inflammation contributes to decreased insulin signaling, leading to insulin resistance in fat, liver, and muscle cells.
- Autoimmunity. One in four lean individuals with type 2 diabetes produces antibodies to an enzyme called GAD (glutamic acid decarboxylase-65). GAD is the same pancreatic enzyme that is attacked in type 1 diabetes, an autoimmune disease.
- This suggests some thin people diagnosed with type 2 diabetes may actually have late developing type 1 diabetes, sometimes called type 1.5 diabetes.
- Stress. Chronic stress, typically brought on by chronic worry, causes the body to release a steady stream of the hormone cortisol—and cortisol raises our blood sugar. Anyone, at any weight, can suffer from chronic stress, even if they exercise, and eat well.
It’s likely that a substantial number of people with undiagnosed type 2 diabetes have a slender build. Should they assume that only heavy individuals get diabetes they might walk around for years with high blood sugar, and slowly accrue the retinal, nerve, blood vessel, and kidney damage associated with the condition.
So, our best bet, whatever the bathroom scale might say, is to cultivate healthy lifestyle habits, and have our fasting glucose level checked regularly.
Sources: Diabetic Connect, Web MD, Chris Kresser
Photo: Pexels