More than 400 million people worldwide have diabetes, most of them type 2 diabetes.
Before developing type 2 diabetes itself, people are often diagnosed with abnormalities in glucose metabolism that are milder than those in diabetes. The term used to indicate such cases is prediabetes. Approximately 5-10% of people with prediabetes develop type 2 diabetes within a year of follow-up.
Insulin resistance in muscle tissue is one of the earliest metabolic abnormalities to be detected in people with type 2 diabetes, and the phenomenon is already seen in prediabetes.
In a joint study, researchers from the University of Helsinki, Helsinki University Hospital and the Minerva Foundation Institute for Medical Research examined the link between skeletal muscle proteome and type 2 diabetes.
The study measured the protein composition of the thigh muscles in men whose glucose tolerance varied from normal to that associated with prediabetes and type 2 diabetes. A total of 148 muscle samples were analyzed.
The results were published in the iScience Journal.
“Our study is the most comprehensive report on human muscle proteomes to date. The results confirm previous observations that uncovered abnormalities in muscle mitochondria associated with type 2 diabetes, ”says lecturer Heikki Koistinen of the University of Helsinki, Helsinki University Hospital and the Minerva Foundation Institute for Medical Research, who led the study.
The protein concentration already decreases in prediabetes
The researchers used mass spectrometry, which allowed them to identify over 2,000 muscle proteins.
According to this, the amount of dozens of proteins in prediabetic study participants had already changed.
The biggest changes were seen in connection with type 2 diabetes, where the amount of more than 400 proteins was mainly decreased. Most of these proteins were linked to mitochondrial energy metabolism.
Indeed, the results underscore the importance of mitochondria as prediabetes progresses towards type 2 diabetes.
“We have found that the content of mitochondrial muscle proteins is already significantly reduced in prediabetes,” says Koistinen.
The researchers also observed abnormalities, both related to prediabetes and type 2 diabetes, in the levels of a number of phosphoproteins that affect metabolism and muscle function.
Regular physical activity as targeted therapy
The researchers believe their new observations have multiple uses, including in finding new drug targets.
“However, there is already an excellent and inexpensive targeted therapy, as regular physical activity increases the number of muscle mitochondria and improves metabolism in many ways,” emphasizes Koistinen.
Physical activity is also key to reducing your risk of developing diabetes.
“You can cut your risk of developing diabetes in half by losing weight, increasing physical activity, and eating a healthy diet,” says Koistinen.
Source of the story:
Materials provided by Helsinki University. Note: The content can be edited in terms of style and length.
