Potential Mechanisms for How Long-Term Physical Activity May Reduce Insulin Resistance

Intra-Individual Variations in How Insulin Sensitivity Responds to Long-Term Exercise: Predictions by Machine Learning Based on Large-Scale Serum Proteomics

Physical activity is effective for preventing and treating type 2 diabetes, but some individuals do not achieve metabolic benefits from exercise ("non-responders"). We investigated non-responders in terms of insulin sensitivity changes following a 12-week supervised strength and endurance exercise program. We used a hyperinsulinaemic euglycaemic clamp to measure insulin sensitivity among 26 men aged 40-65, categorizing them into non-responders or responders based on their insulin sensitivity change scores. The exercise regimen included VO2max, muscle strength, whole-body MRI scans, muscle and fat biopsies, and serum samples. mRNA sequencing was performed on biopsies and Olink proteomics on serum samples. Non-responders showed more visceral and intramuscular fat and signs of dyslipidaemia and low-grade inflammation at baseline and did not improve in insulin sensitivity following exercise, although they showed gains in VO2max and muscle strength. Impaired IL6-JAK-STAT3 signalling in non-responders was suggested by serum proteomics analysis, and a baseline serum proteomic machine learning (ML) algorithm predicted insulin sensitivity responses with high accuracy, validated across two independent exercise cohorts. The ML model identified 30 serum proteins that could forecast exercise-induced insulin sensitivity changes.

Positive Effects of Physical Activity on Insulin Signaling

Physical activity is integral to metabolic health, particularly in addressing insulin resistance and related disorders such as type 2 diabetes mellitus (T2DM). Studies consistently demonstrate a strong association between physical activity levels and insulin sensitivity. Regular exercise interventions were shown to significantly improve glycemic control, highlighting exercise as a recommended therapeutic strategy for reducing insulin resistance. Physical inactivity is closely linked to islet cell insufficiency, exacerbating insulin resistance through various pathways including ER stress, mitochondrial dysfunction, oxidative stress, and inflammation. Conversely, physical training and exercise preserve and restore islet function, enhancing peripheral insulin sensitivity. Exercise interventions stimulate β-cell proliferation through increased circulating levels of growth factors, further emphasizing its role in maintaining pancreatic health and glucose metabolism. Furthermore, sedentary lifestyles contribute to elevated oxidative stress levels and ceramide production, impairing insulin signaling and glucose metabolism. Regular exercise induces anti-inflammatory responses, enhances antioxidant defenses, and promotes mitochondrial function, thereby improving insulin sensitivity and metabolic efficiency. Encouraging individuals to adopt active lifestyles and engage in regular exercise is crucial for preventing and managing insulin resistance and related metabolic disorders, ultimately promoting overall health and well-being.

Exploratory integrated analysis of circulating exosomal miRNA and tissue mRNA related to long-term physical activity for more than 25 years: a bioinformatics study

Physical activity exerts various positive effects on both physical and mental health. Although the comprehensive expression profiles of each microRNA (miRNA) or messenger RNA (mRNA) related to physical activity have already been reported, the association between miRNA and mRNA remains unclear. Here, the integrated study was conducted to comprehensively explore the potential miRNA-mRNA relationships related to long-term physical activity over 25 years. Genome-wide public deposited mRNA expression data of adipose tissue (GSE20536) from six same-sex twin pairs (no information regarding gender) and of skeletal muscle tissue (GSE20319) from ten same-sex twin pairs (four female twin pairs) were used, and differentially expressed mRNAs (DEMs) related to discordant leisure-time physical activity for 30 years were identified using GEO2R. Overlapped mRNAs between DEMs and predicted possible target mRNAs, based on a previous study and TargetScan tool, were then identified and used as long-term physical activity-related mRNAs targeted by miRNAs. In adipose tissue, 36 mRNAs and 42 mRNAs were identified as upregulated or downregulated DEMs, respectively. Based on the results of the overlapped analysis between DEMs and predicted possible target mRNAs targeted by miRNAs, 15 upregulated mRNAs, including NDRG4, FAM13A, ST3GAL6, and AFF1, and 10 downregulated mRNAs, including RPL14, LBP, and GLRX, were identified. In muscle tissue, three downregulated mRNAs overlapped with the predicted target mRNAs targeted by miRNAs. Fifteen upregulated mRNAs in adipose tissue showed a tendency to enrich in "Cardiovascular" in GAD_DISEASE_CLASS category. Potential miRNA-mRNA relationships related to long-term physical activity over 25 years were identified through bioinformatics analysis.

The Effects of Exercise Habit on Albuminuria and Metabolic Indices in Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Study

Background and Objectives: Diabetes mellitus (DM) can cause macrovascular and microvascular complications, potentially resulting in further life-threatening complications. In general, the global prevalence of type 2 DM is increasing. To date, the care of DM comprises three aspects: diet, medication and exercise; among them, exercise is the most economical. Albuminuria is associated with renal injury and the progress of chronic kidney disease (CKD). The effects of habitual exercise in patients with new onset of diabetic kidney disease (DKD) have not been generally recognized. Our aim was to conduct an observational study regarding the effects of regular exercise on proteinuria and associated metabolic indices in patients with newly diagnosed type 2 DM. To investigate the effects of an exercise habit on albuminuria and the metabolic indices including renal function, blood glucose, and plasma lipids among patients with newly diagnosed type 2 DM. Materials and Methods: A cross-sectional study was conducted on newly diagnosed DM patients in two teaching hospitals in Taiwan from 1 June to 31 December 2020. The DM patients participated in the Diabetes Shared Care Network. According to the DM care mode, the patients’ blood biochemical results were analysed. Based on exercise duration, the patients were divided into two groups, i.e., the exercise group (≥150 min per week) and the non-exercise group (<150 min per week). Clinical demographic features and laboratory examination including blood and urine biochemistries were determined. Results: A total of 229 patients including 99 males (43.2%) and 130 females (56.8%) participated in the study. The proportion of DM patients with normoalbuminuria was higher (p < 0.05) in the exercise group (69.8%) than in the non-exercise group (53.7%), and the proportion of DM patients with micro or macroalbuminuria was lower in the exercise group (30.2%) than in the non-exercise group (46.3%). Levels of glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), triglycerides (TG) and high-density lipoprotein (HDL) were significantly different in both groups. Compared with the non-exercise group, lower HbA1c (6.89 ± 0.69 vs. 7.16 ± 1.05%) (p < 0.05), lower FPG (121.9 ± 25.7 vs. 140.5 ± 42.4 mg/dL) (p < 0.05), lower TG (115.6 ± 53.6 vs. 150.2 ± 15.4 mg/dL) (p < 0.05), and higher HDL (50.3 ± 11.4 vs. 44.1 ± 9.26 mg/dL) (p < 0.05) levels were noted in the exercise group. Conclusions: Regular exercise remains imperative and may bear an impact on albuminuria, blood glucose, and plasma lipids among type 2 DM patients. Therefore, medical staff and healthcare providers should encourage patients to maintain an exercise duration ≥150 min per week for preventing and controlling DM progression.