Animal studies show that vigorous workouts, including weight training can help people living with diabetes control their blood sugar better
Research conducted at the University of Campinas (UNICAMP) in São Paulo State, Brazil, shows that vigorous physical exercise such as strength and weight training can help people living with diabetes. It can reduce accumulated liver fat and improve blood sugar control in obese and diabetic individuals in a short time span, even before significant weight loss occurs.
In experiments with mice, researchers at UNICAMP’s Molecular Biology of Exercise Laboratory (LaBMEx) found that two weeks of such exercise was sufficient to modify gene expression in liver tissue in ways that “burned” more stored lipids and contributed to the treatment of nonalcoholic fatty liver disease. Cellular insulin signaling in tissue improved, and hepatic synthesis of glucose decreased.
The results of the study, which was supported by São Paulo Research Foundation – FAPESP, are published in the Journal of Endocrinology.
Moura explained that excess fat in the liver causes local inflammation, which makes liver cells less sensitive to the action of insulin. This condition can progress to cirrhosis and eventually to liver failure
“Everyone knows physical exercise helps control disease. Our research focuses on how and why this is so, on the mechanisms involved. If we can discover a key protein whose levels rise or fall with training, we’ll have taken a step toward the development of drugs that mimic some of the benefits of physical exercise,” said Leandro Pereira de Moura, a professor at UNICAMP’s School of Applied Sciences and the principal investigator of the study.
Moura explained that excess fat in the liver causes local inflammation, which makes liver cells less sensitive to the action of insulin. This condition can progress to cirrhosis and eventually to liver failure.
“In obese individuals at cardiometabolic risk, reducing liver fat is vital to help control diabetes,” Moura told. “The liver should produce glucose only under fasting conditions, but if insulin signaling in tissue is impaired, the liver releases glucose into the blood stream even after ingestion of carbohydrate, when insulin levels are high, and this raises the level of blood sugar.”
Gluconeogenesis
In fasting conditions, the liver is the main organ responsible for maintaining adequate blood sugar levels. In the context of diabetes, control of gluconeogenesis (endogenous glucose production) is absent as a result of insulin resistance, and the individual can become hyperglycemic.
To evaluate the effect of strength exercise on the control of hepatic gluconeogenesis, the researchers tested the animals for tolerance of pyruvate, the main substrate used by the liver to produce glucose.
“The test consisted basically of administering pyruvate to the mice and measuring the amount of glucose produced by the liver,” Moura explained. “We found that the trained mice produced less glucose than the sedentary obese mice even though they received the same amount of substrate. This showed that the trained animal’s liver underwent metabolic alterations that made it more sensitive to insulin.”
