Project description:IntroductionType 2 diabetes mellitus (T2DM) is associated with a reduction in muscle quality. However, there is inadequate empirical evidence to determine whether changes in muscle quality following exercise are associated with improvement in cardiorespiratory fitness (CRF) in individuals with T2DM. The objective of this study was to investigate the association between change in muscle quality following a 9-month intervention of aerobic training (AT), resistance training (RT) or a combination of both (ATRT) and cardiorespiratory fitness (CRF) in individuals with T2DM.Material and methodsA total of 196 participants were randomly assigned to a control, AT, RT, or combined ATRT for a 9-months intervention. The exposure variable was change in muscle quality [(Post: leg muscle strength/leg muscle mass)-[(Pre: leg muscle strength/leg muscle mass)]. Dependent variables were change in CRF measures including absolute and relative VO2peak, and treadmill time to exhaustion (TTE) and estimated metabolic equivalent task (METs).ResultsContinuous change in muscle quality was independently associated with change in absolute (β = 0.015; p = 0.019) and relative (β = 0.200; p = 0.005) VO2peak, and TTE (β = 0.170; p = 0.043), but not with estimated METs (p > 0.05). A significant trend was observed across tertiles of change in muscle quality for changes in absolute (β = 0.050; p = 0.005) and relative (β = 0.624; p = 0.002) VO2peak following 9 months of exercise training. No such association was observed for change in TTE and estimated METs (p > 0.05).DiscussionThe results from this ancillary study suggest that change in muscle quality following exercise training is associated with a greater improvement in CRF in individuals with T2DM. Given the effect RT has on increasing muscle quality, especially as part of a recommended training program (ATRT), individuals with T2DM should incorporate RT into their AT regimens to optimize CRF improvement.Trial registrationClinicaltrials.gov NCT00458133.
Project description:Low cardiorespiratory fitness (CRF) is an independent risk factor for cardiovascular disease (CVD), especially in individuals with type 2 diabetes. Age-predicted, sex-stratified, and maximal MET cut points have been developed to determine the risk of CVD events and mortality in low CRF categories. We examined the proportion of Health Benefits of Aerobic and Resistance Training in Individuals With Type 2 Diabetes (HART-D) participants above these cut points before and after 9 months of aerobic training (AT), resistance training (RT), or a combination of both (ATRT).Participants from the HART-D study (n=196) who were randomly assigned to exercise training (AT, RT, or ATRT) or to a nonexercise control group between April 2007 and August 2009 were used in this ancillary study. Cut points were previously established for age-predicted METs (>100% and >85%, mean and increased CVD risk, respectively), age- and sex-stratified METs (Aerobic Center Longitudinal Study), and clinically discernible METs (men>8.0, women>6.5).Baseline prevalence of participants above these cut points was similar for all intervention groups (P>0.50) and ranged from 11.9% (>100% age predicted) to 55.1% (>85% age predicted). Baseline prevalence and age-, sex-, and race/ethnic group-adjusted percentage of participants above each cut point increased significantly after AT and ATRT (P<0.05 for all).Structured exercise training, especially the AT component, was associated with a greater number of participants moving above established cut points indicative of low CRF. These results have public health and clinical implications for the growing number of patients with type 2 diabetes at high risk for CVD.
Project description:High intensity interval training (HIIT) improves metabolism, but maybe with differences in sustainability between prediabetes and type 2 diabetes (T2D). We hypothesized that HIIT-induced changes are maintained after 4-week detraining in humans with (20 T2D) and without T2D (12 insulin-sensitive, IS-NDM; 10 insulin-resistant, IR-NDM). To explore the change in protein cargo of small extracellular vesicles (SEV), we measured the proteome of SEVs from serum of T2D, IR-NMD and IR-NDM individuals.
Project description:PurposeTo assess the effects of exercise training parameters on cardiorespiratory fitness of individuals with type 2 diabetes mellitus (T2DM).MethodsThis systematic review was registered on PROSPERO (CRD42020210470). Searches were performed on PubMed, PEDro EMBASE, MEDLINE (Ovid), LILACS, PsycINFO, SCIELO, CINAHL, and Cochrane Library. The primary outcome was cardiorespiratory fitness, defined as maximal oxygen uptake (VO2max) during a maximal or submaximal exercise test. Two independent reviewers extracted data and assessed the risk of bias. Data were pooled using a random effects model and expressed as mean difference (MD) and 95% confidence interval (95%CI). Heterogeneity (I2) was assessed using Cochran's Q test. The risk of bias and quality of evidence was assessed using the Cochrane risk of bias tool and GRADE.ResultsTwenty-two studies comparing exercise and control groups were included. The risk of bias indicated some concerns in most studies, and the quality of evidence was rated very low. Interventions with moderate (MD = 1.91, 95%CI = .58 to 3.34) and progressive exercise intensity (MD = 2.70, 95%CI = 2.43 to 2.96) and volume (MD = 1.72, 95%CI = .59 to 2.85) showed greater improvements in VO2max.ConclusionsProtocols that progressively increased exercise training parameters improved the cardiorespiratory fitness response. Progressive exercise might be more suitable for individuals with T2DM. Our conclusion may be limited due to the very low quality of evidence.Supplementary informationThe online version contains supplementary material available at 10.1007/s40200-023-01205-5.
Project description:AimGut leakage has been shown to associate with low-grade inflammation and lower cardiorespiratory fitness in diabetic subjects. We aimed to investigate whether gut leakage markers related to cardiorespiratory fitness in patients with both coronary artery disease and type 2 diabetes, and whether these were affected by long-term exercise training.MethodsPatients with angiographically verified coronary artery disease and type 2 diabetes mellitus (n = 137) were randomized to either 12 months exercise intervention or conventional follow-up. A cardiopulmonary exercise test and fasting blood samples were obtained before and after intervention to assess VO2peak and the biomarkers soluble CD14, lipopolysaccharide-binding protein and intestinal fatty-acid binding protein as markers of gut leakage.Results114 patients completed the intervention satisfactory. VO2peak correlated inversely to sCD14 (r = - 0.248, p = 0.004) at baseline. Dividing sCD14 into quartiles (Q), VO2peak was significantly higher in Q1 vs. Q2-4 (p = 0.001), and patients in Q2-4 (sCD14 > 1300 ng/mL) had an OR of 2.9 (95% CI 1.2-7.0) of having VO2peak below median (< 23.8 ml/kg/min) at baseline. There were no statistically significant differences in changes in gut leakage markers between the two randomized groups (all p > 0.05) after 12 months.ConclusionsCardiorespiratory fitness related inversely to sCD14, suggesting physical capacity to be associated with gut leakage in patients with CAD and T2DM. Long-term exercise training did not affect circulating gut leakage markers in our population. Trial registration NCT01232608, Registered 02 November 2010-Retrospectively registered at https://clinicaltrials.gov/ct2/show/NCT01232608?term=NCT01232608&draw=2&rank=1.
Project description:BackgroundThe purpose of this study was to reveal any association between cardiorespiratory fitness level and excess post-exercise oxygen consumption (EPOC) using three cycling protocols with varying degrees of exercise intensity, i.e., sprint interval training (SIT), high-intensity interval aerobic training (HIAT), and continuous aerobic training (CAT).FindingsTen healthy men, aged 20 to 31 years, attended a cross-over experiment and completed three exercise sessions: SIT consisting of 7 sets of 30-s cycling at 120% VO2max with a 15-s rest between sets; HIAT consisting of 3 sets of 3-min cycling at 80~90% VO2max with a 2-min active rest at 50% VO2max between sets; and CAT consisting of 40 min of cycling at 60~65% VO2max. During each session, resting VO2, exercise VO2, and a 180-min post-exercise VO2 were measured. The net exercise VO2 during the SIT, HIAT, and CAT averaged 14.7 ± 1.5, 31.8 ± 4.1, and 71.1 ± 10.0 L, and the EPOCs averaged 6.8 ± 4.0, 4.5 ± 3.3, and 2.9 ± 2.8 L, respectively. The EPOC with SIT was greater than with CAT (P < 0.01) and HIAT (P = 0.12). Correlation coefficients obtained between subjects' VO2max and the ratio of EPOC to net exercise VO2 for SIT, HIAT, and CAT were -0.61 (P = 0.06), -0.79 (P < 0.01), and -0.42 (P = 0.23), respectively.ConclusionsOur data suggest that cardiorespiratory fitness level correlates negatively with the magnitude of EPOC, especially when performing aerobic-type interval training.
Project description:Background Substantial heterogeneity exists in the cardiorespiratory fitness (CRF) change in response to exercise training, and its long-term prognostic implication is not well understood. We evaluated the association between the short-term supervised training-related changes in CRF and CRF levels 10 years later. Methods and Results STRRIDE (Studies of a Targeted Risk Reduction Intervention Through Defined Exercise) trial participants who were originally randomized to exercise training for 8 months and participated in the 10-year follow-up visit were included. CRF levels were measured at baseline, after training (8 months), and at 10-year follow-up as peak oxygen uptake (vo2, mL/kg per min) using the maximal treadmill test. Participants were stratified into low, moderate, and high CRF response groups according to the training regimen-specific tertiles of CRF change. The study included 80 participants (age: 52 years; 35% female). At 10-year follow-up, the high-response CRF group had the least decline in CRF compared with the moderate- and low-response CRF groups (-0.35 versus -2.20 and -4.25 mL/kg per minute, respectively; P=0.02). This result was largely related to the differential age-related changes in peak oxygen pulse across the 3 groups (0.58, -0.23, and -0.86 mL/beat, respectively; P=0.03) with no difference in the peak heart rate change. In adjusted linear regression analysis, high response was significantly associated with greater CRF at follow-up independent of other baseline characteristics (high versus low [reference] CRF response: standard β=0.25; P=0.004). Conclusions Greater CRF improvement in response to short-term training is associated with higher CRF levels 10 years later. Lack of CRF improvements in response to short-term training may identify individuals at risk for exaggerated CRF decline with aging.
Project description:BackgroundPeople with type 2 diabetes mellitus (T2D) have preclinical cardiac and vascular dysfunction associated with low cardiorespiratory fitness (CRF). This is especially concerning because CRF is a powerful predictor of cardiovascular mortality, a primary issue in T2D management. Glucagon-like pepetide-1 (GLP-1) augments cardiovascular function and our previous data in rodents demonstrate that potentiating the GLP-1 signal with a dipeptidyl peptidase-4 (DPP4) inhibitor augments CRF. Lacking are pharmacological treatments which can target T2D-specific physiological barriers to exercise to potentially permit adaptations necessary to improve CRF and thereby health outcomes in people with T2D. We therefore hypothesized that administration of a DPP4-inhibitor (sitagliptin) would improve CRF in adults with T2D.Methods and resultsThirty-eight participants (64 ± 1 years; mean ± SE) with T2D were randomized in a double-blinded study to receive 100 mg/day sitagliptin, 2 mg/day glimepiride, or placebo for 3 months after baseline measurements. Fasting glucose decreased with both glimepiride and sitagliptin compared with placebo (P = 0.002). CRF did not change in any group (Placebo: Pre: 15.4 ± 0.9 vs. Post: 16.1 ± 1.1 ml/kg/min vs. Glimepiride: 18.5 ± 1.0 vs. 17.7 ± 1.2 ml/kg/min vs. Sitagliptin: 19.1 ± 1.2 vs. 18.3 ± 1.1 ml/kg/min; P = 0.3). Sitagliptin improved measures of cardiac diastolic function, however, measures of vascular function did not change with any treatment.ConclusionsThree months of sitagliptin improved diastolic cardiac function, however, CRF did not change. These data suggest that targeting the physiological contributors to CRF with sitagliptin alone is not an adequate strategy to improve CRF in people with T2D.Clinical trials registrationwww.clinicaltrials.gov NCT01951339.
Project description:Higher cardiorespiratory fitness is associated with lower risk of type 2 diabetes. However, the causality of this relationship and the biological mechanisms that underlie it are unclear. Here, we examine genetic determinants of cardiorespiratory fitness in 450k European-ancestry individuals in UK Biobank, by leveraging the genetic overlap between fitness measured by an exercise test and resting heart rate. We identified 160 fitness-associated loci which we validated in an independent cohort, the Fenland study. Gene-based analyses prioritised candidate genes, such as CACNA1C, SCN10A, MYH11 and MYH6, that are enriched in biological processes related to cardiac muscle development and muscle contractility. In a Mendelian Randomisation framework, we demonstrate that higher genetically predicted fitness is causally associated with lower risk of type 2 diabetes independent of adiposity. Integration with proteomic data identified N-terminal pro B-type natriuretic peptide, hepatocyte growth factor-like protein and sex hormone-binding globulin as potential mediators of this relationship. Collectively, our findings provide insights into the biological mechanisms underpinning cardiorespiratory fitness and highlight the importance of improving fitness for diabetes prevention.
Project description:OBJECTIVE:To examine cardiorespiratory fitness in individuals with traumatic brain injury (TBI), before and following participation in a supervised 12-week aerobic exercise training program. METHODS:Ten subjects with nonpenetrating TBI (TBI severity: mild, 50%; moderate, 40%; severe, 10%; time since injury [mean ± SD]: 6.6 ± 6.8 years) performed exercise training on a treadmill 3 times a week for 30 minutes at vigorous intensity (70%-80% of heart rate reserve). All subjects completed a cardiopulmonary exercise test, with pulmonary gas exchange measured and a questionnaire related to fatigue (Fatigue Severity Scale) at baseline and following exercise training. RESULTS:After training, increases (P < .01) in peak oxygen consumption ((Equation is included in full-text article.); +3.1 ± 2.4 mL/min/kg), time to volitional fatigue (+1.4 ± 0.8 minutes), and peak work rate (+59 ± 43 W) were observed. At the anaerobic threshold, (Equation is included in full-text article.)(+3.6 ± 2.1 mL/kg/min), treadmill time (+1.8 ± 1.1 minutes), and work rate (+37 ± 39 W) were higher (P < .01) following exercise training. Subjects also reported significantly lower (P < .05) Fatigue Severity Scale composite scores (-0.9 ± 1.3) following exercise training. CONCLUSION:These findings suggest that individuals with TBI may benefit from participation in vigorous aerobic exercise training with improved cardiorespiratory fitness and diminished fatigue.