Regular exercise reduces the risk of type 2 diabetes. A study by the German Centre for Diabetes Research (DZD) looked at the role played by the skeletal musculature and the subcutaneous adipose tissue in the health-promoting effects of exercise.
The findings, published in the International Journal of Obesity, show that the subcutaneous adipose tissue also plays a crucial role in the prevention of metabolic diseases, despite it reacting in a very different way to exercise than muscle tissue.
Adjustment at the Molecular Level
“We showed that physical activity leads to molecular level changes in the subcutaneous adipose tissue associated with lipid storage, lipogenesis, and the circadian rhythm. These could combat the progression of metabolic syndrome to type 2 diabetes,” explains DZD researcher Dr. Simon Dreher from Tübingen University Hospital.
“Among other things, regular exercise leads to restoration of a healthy cellular circadian rhythm in obese people,” says Dr Dreher.
The study involved eight women and six men with a predominantly sedentary lifestyle who were either overweight or obese. They completed 8 weeks of supervised endurance training consisting of one hour of training three times per week – 30 minutes cycling and 30 minutes on the treadmill. Samples of subcutaneous adipose tissue and skeletal musculature were taken before and after training for transcriptome analysis.
Exercise Modifies Gene Expression in Fatty Tissue
It was observed that, following the first exercise session, 37 transcripts in the subcutaneous adipose tissue showed acute downregulation or increased regulation. Transcripts of genes associated with lipid metabolism and circadian rhythm were particularly affected.
In contrast, in the muscular tissue, regulation modifications were observed in 394 transcripts after the first exercise session. “There was almost no overlap between fat and muscle tissue, which highlights how differently fat and muscle tissue react to exercise,” says Prof. Cora Weigert, the lead author of the study. “These adjustments in the transcriptome also appear to be long-term as they could also be observed after the 8-week training program”.
An increase in mitochondrial respiration, as observed in the skeletal muscles during physical activity, was not evident in the subcutaneous adipose tissue. Also, no browning of the adipose tissue was observed in the probands.
The changes to the circadian rhythm and lipid metabolism caused by exercise may lead to a healthier metabolism and reduced risk of type 2 diabetes. According to the researchers, understanding how physical activity protects against type 2 diabetes at the molecular level will help create improved diabetes prevention strategies.
Dreher SI, Irmler M, Pivovarova-Ramich O, Kessler K, Jürchott K, Sticht C, Fritsche L, Schneeweiss P, Machann J, Pfeiffer AFH, Hrabě de Angelis M, Beckers J, Birkenfeld AL, Peter A, Niess AM, Weigert C, Moller A. Acute and long-term exercise adaptation of adipose tissue and skeletal muscle in humans: a matched transcriptomics approach after 8-week training-intervention. International Journal of Obesity 2023;47: 313-324; https://doi.org/10.1038/s41366-023-01271-y