The Response of Mitochondrial Respiration and Quantity in Skeletal Muscle and Adipose Tissue to Exercise in Humans with Prediabetes

Prolonged Endurance Exercise Increases Macrophage Content and Mitochondrial Respiration in Adipose Tissue in Trained Men

BACKGROUND

The aim of this study was to investigate the effect of prolonged endurance exercise on adipose tissue inflammation markers and mitochondrial respiration in younger and older men.

METHODS

"Young" (aged 30 years, n = 7) and "old" (aged 65 years, n = 7) trained men were exposed to an exercise intervention of 15 consecutive days biking 7 to 9 hours/day at 63% and 65% of maximal heart rate (young and old, respectively), going from Copenhagen, Denmark to Palermo, Italy. Adipose tissue was sampled from both the gluteal and abdominal depot before and after the intervention. Mitochondrial respiration was measured by high-resolution respirometry, and adipose inflammation was assessed by immunohistochemical staining of paraffin embedded sections.

RESULTS

An increased number of CD163+ macrophages was observed in both the gluteal and abdominal depot (P < .01). In addition, an increased mitochondrial respiration was observed in the abdominal adipose tissue from men in the young group with complex I (CIp) stimulated respiration, complex I + II (CI+IIp) stimulated respiration and the capacity of the electron transport system (ETS) (P < .05), and in the older group an increase in CIp and CI+IIp stimulated respiration (P < .05) was found.

CONCLUSION

Overall, we found a positive effect of prolonged endurance exercise on adipose tissue inflammation markers and mitochondrial respiration in both young and old trained men, and no sign of attenuated function in adipose tissue with age.

Exercise in the Prevention and Treatment of Type 2 Diabetes

Type 2 diabetes is a systemic, multifactorial disease that is a leading cause of morbidity and mortality globally. Despite a rise in the number of available medications and treatments available for management, exercise remains a first-line prevention and intervention strategy due to established safety, efficacy, and tolerability in the general population. Herein we review the predisposing risk factors for, prevention, pathophysiology, and treatment of type 2 diabetes. We emphasize key cellular and molecular adaptive processes that provide insight into our evolving understanding of how, when, and what types of exercise may improve glycemic control. © 2023 American Physiological Society. Compr Physiol 13:1-27, 2023.

The effect of tai chi intervention on NLRP3 and its related antiviral inflammatory factors in the serum of patients with pre-diabetes

Background

NLRP3 inflammasome and its related antiviral inflammatory factors have been implicated in the pathogenesis of type 2 diabetes mellitus (T2DM) and insulin resistance, but its contribution to pre-diabetes remains poorly understood.

Objective

To investigate the effects and the potential mechanism of Tai Chi intervention on NLRP3 inflammasome and its related inflammatory factors in the serum of middle-aged and older people with pre-diabetes mellitus (PDM).

Methods

40 pre-diabetic subjects were divided into a pre-diabetic control group (PDM-C group, N=20) and a Tai Chi group (PDM-TC group, N=20) by random number table. 10 normoglycemic subjects (NG) were selected as controls. We measured clinical metabolic parameters and collected blood samples before and after the 12 weeks of Tai Chi intervention. Antiviral inflammatory factors in serum were detected by enzyme-linked immunosorbent assay.

Results

The blood glucose, insulin resistance, and inflammation in PDM groups were higher than those in the NG group (P<0.05 and P<0.01, respectively). The results also suggested that 12 weeks of Tai Chi intervention could reduce body weight, blood pressure, blood glucose, insulin resistance, blood lipid, and the expressions of serum inflammatory factors in the pre-diabetic population.

Conclusion

Tai Chi intervention may improve blood glucose, lipid levels, and insulin resistance in middle-aged and elderly pre-diabetic patients by reducing the level of NLRP3 inflammasome and its related inflammatory factors.

Impairment of Mitochondrial Respiration in Metabolic Diseases: An Overview

Mitochondrial dysfunction has emerged as a central pathomechanism in the setting of obesity and diabetes mellitus, linking these intertwined pathologies that share insulin resistance as a common denominator. High-resolution respirometry (HRR) is a state-of-the-art research method currently used to study mitochondrial respiration and its impairment in health and disease. Tissue samples, cells or isolated mitochondria are exposed to various substrate-uncoupler-inhibitor-titration protocols, which allows the measurement and calculation of several parameters of mitochondrial respiration. In this review, we discuss the alterations of mitochondrial bioenergetics in the main dysfunctional organs that contribute to the development of the obese and diabetic phenotypes in both animal models and human subjects. Herein we review data regarding the impairment of oxidative phosphorylation as integrated mitochondrial function assessed by means of HRR. We acknowledge the critical role of this method in determining the alterations in oxidative phosphorylation occurring in the early stages of metabolic pathologies. We conclude that there is a mutual two-way relationship between mitochondrial dysfunction and insulin insensitivity that characterizes these diseases.