Cognitive effects of a 30-min aerobic exercise bout on adults with overweight/obesity and type 2 diabetes

Glucose tolerance status associates with improvements in cognitive function following high-intensity exercise in adults with obesity

PURPOSE

Obesity, insulin resistance (IR), and proinflammatory cytokines associate with cognitive decline. Numerous studies document cognitive benefits of acute exercise bouts in lean individuals. However, how co-morbidities such as obesity and IR influence cognitive changes induced by acute exercise is unclear. We examined the effects of acute high-intensity aerobic exercise on cognitive function in age-matched and BMI-matched obese adults with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) and in lean, NGT adults.

METHODS

49 adults (15 Lean, 18 Obese-NGT, 16 Obese-IGT) performed one session of high-intensity interval exercise (four cycles of 4-min at 75% Wmax with 3-min rest). Cognitive function testing and blood sampling were performed pre- and post-exercise.

RESULTS

Following exercise, measurements of executive function and working memory were improved in Lean and Obese-NGT (p < 0.05), but not Obese-IGT. Changes in cognitive function following exercise negatively correlated with 2-hr glucose during an OGTT after controlling for body weight and body composition (rp = -0.40, p = 0.007). Serum levels of inflammatory cytokines IL-6 and CRP remained increased 60-minutes post-exercise in Obese-IGT, but not in Lean or Obese-NGT, which positively associated with 2-hr glucose during an OGTT (p < 0.01) and negatively with changes in cognitive function following exercise (p < 0.01). Greater insulin levels in Obese-IGT post-exercise also negatively correlated with changes in cognitive function following exercise (p < 0.01).

CONCLUSION

Improvements in cognition following acute high-intensity exercise positively associate with glucose tolerance, independent of body weight and body composition. Further, poorer changes in cognitive performance following exercise associate with persistent peripheral inflammation.

Acute effects of different exercise forms on executive function and the mechanism of cerebral hemodynamics in hospitalized T2DM patients: a within-subject study

Objective

This study aimed to investigate the acute effects of aerobic exercise (AE), resistance exercise (RE), and integrated concurrent exercise (ICE; i.e., AE plus RE) on executive function among hospitalized type 2 diabetes mellitus (T2DM) inpatients, and the mechanism of cerebral hemodynamics.

Methods

A within-subject design was applied in 30 hospitalized patients with T2DM aged between 45 and 70 years in the Jiangsu Geriatric Hospital, China. The participants were asked to take AE, RE, and ICE for 3 days at 48-h intervals. Three executive function (EF) tests, namely, Stroop, More-odd shifting, and 2-back tests, were applied at baseline and after each exercise. The functional near-infrared spectroscopy brain function imaging system was used to collect cerebral hemodynamic data. The one-way repeated measurement ANOVA was used to explore training effects on each test indicator.

Results

Compared with the baseline data, the EF indicators have been improved after both ICE and RE (p < 0.05). Compared with the AE group, the ICE and RE groups have demonstrated significant improvements in inhibition (ICE: MD = - 162.92 ms; RE: MD = -106.86 ms) and conversion functions (ICE: MD = -111.79 ms; RE: MD = -86.95 ms). Based on the cerebral hemodynamic data, the beta values of brain activation in executive function related brain regions increased after three kinds of exercise, the EF improvements after the ICE showed synchronous activation of blood flow in the dorsolateral prefrontal cortex (DLPFC), the frontal polar (FPA) and orbitofrontal cortex (OFC), the improvement of inhibitory function after RE displayed synchronous activation of DLPFC and FPA, and AE mainly activates DLPFC. The HbO₂ concentration in the pars triangularis Broca's area increased significantly after AE, but the EF did not improve significantly.

Conclusion

The ICE is preferred for the improvements of executive function in T2DM patients, while AE is more conducive to the improvements of refresh function. Moreover, a synergistic mechanism exists between cognitive function and blood flow activation in specific brain regions.

Acute bouts of aerobic and resistance exercise similarly alter inhibitory control and response time while inversely modifying plasma BDNF concentrations in middle-aged and older adults with type 2 diabetes

Impairments in several domains of cognitive functions are observed in people with Type 2 Diabetes Mellitus (T2DM), often accompanied by low Brain-derived neurotrophic factor (BDNF) concentrations. Although aerobic and resistance exercise enhances cognitive functions and raises BDNF concentrations in several populations, it remained uncertain in T2DM subjects. This study compared the effects of a single bout of aerobic (AER, 40 min of treadmill walk at 90-95% of the maximum walk speed) or resistance (RES, 3 × 10 repetitions in eight exercises at 70% of 10-RM) exercise on specific cognitive domain performance and plasma BDNF concentrations of physically active T2DM subjects. Eleven T2DM subjects (9 women/2 men; 63 ± 7 years) performed two counterbalanced trials on non-consecutive days. Stroop Color and Word (SCW) task [assessing the attention (congruent condition) and inhibitory control (incongruent condition)], Visual response time (assessing the response time), and blood collection (for plasma BDNF concentrations) were performed pre and post-exercise sessions. With distinct magnitude, both AER and RES improved the incongruent-SCW (d = - 0.26 vs. - 0.43 in AER and RES, respectively; p < 0.05), RT_(best) (d = - 0.31 vs. - 0.52, p < 0.05), and RT_(1-5) (d = - 0.64 vs. - 0.21, p < 0.05). The congruent-SCW and RT_(6-10) were not statistically different. Plasma BDNF concentrations were elevated 11% in AER (d = 0.30) but decreased by 15% in RES (d = - 0.43). A single session of aerobic or resistance exercise similarly improved the inhibitory control and response time of physically active T2DM subjects. Nevertheless, aerobic and resistance exercise sessions induced an opposite clinical effect in plasma BDNF concentrations.

Effects of Acute Aerobic Exercise Combined with Resistance Exercise on Neurocognitive Performance in Obese Women

To the best of the author’s knowledge, there have been no previous studies conducted on the effects of a combination of acute aerobic and resistance exercise on deficit of inhibitory control in obese individuals. The aim of this study was, thus, to examine the effect of a single bout of such an exercise mode on behavioral and cognitive electrophysiological performance involving cognitive interference inhibition in obese women. After the estimated VO₂max and percentage fat (measured with dual-energy X-ray absorptiometry (Hologic, Bedford, MA, USA) were assessed, 32 sedentary obese female adults were randomly assigned to an exercise group (EG) and a control group (CG), with their behavioral performance being recorded with concomitant electrophysiological signals when performing a Stroop task. Then, the EG engaged in 30 min of moderate-intensity aerobic exercise combined with resistance exercise, and the CG rested for a similar duration of time without engaging in any type of exercise. After the interventions, the neurocognitive performance was measured again in the two groups. The results revealed that although acute exercise did not enhance the behavioral indices (e.g., accuracy rates (ARs) and reaction times (RTs)), cognitive electrophysiological signals were improved (e.g., shorter N2 and P3 latencies, smaller N2 amplitudes, and greater P3 amplitudes) in the Stroop task after the exercise intervention in the EG. The findings indicated that a combination of acute moderate-intensity aerobic and resistance exercise may improve the neurophysiological inhibitory control performance of obese women.

MKP-5 Relieves Lipotoxicity-Induced Islet β-Cell Dysfunction and Apoptosis via Regulation of Autophagy

Mitogen-activated protein kinase phosphatase-5 (MKP-5) is a regulator of extracellular signaling that is known to regulate lipid metabolism. In this study, we found that obesity caused by a high-fat diet (HFD) decreased the expression of MKP-5 in the pancreas and primary islet cells derived from mice. Then, we further investigated the role of MKP-5 in the protection of islet cells from lipotoxicity by modulating MKP-5 expression. As a critical inducer of lipotoxicity, palmitic acid (PA) was used to treat islet β-cells. We found that MKP-5 overexpression restored PA-mediated autophagy inhibition in Rin-m5f cells and protected these cells from PA-induced apoptosis and dysfunction. Consistently, a lack of MKP-5 aggravated the adverse effects of lipotoxicity. Islet cells from HFD-fed mice were infected using recombinant adenovirus expressing MKP-5 (Ad-MKP-5), and we found that Ad-MKP-5 was able to alleviate HFD-induced apoptotic protein activation and relieve the HFD-mediated inhibition of functional proteins. Notably, HFD-mediated impairments in autophagic flux were restored by Ad-MKP-5 transduction. Furthermore, the autophagy inhibitor 3-methyladenine (3-MA) was used to treat Rin-m5f cells, confirming that the MKP-5 overexpression suppressed apoptosis, dysfunction, inflammatory response, and oxidative stress induced by PA via improving autophagic signaling. Lastly, employing c-Jun amino-terminal kinas (JNK), P38, or extracellular-regulated kinase (ERK) inhibitors, we established that the JNK and P38 MAPK pathways were involved in the MKP-5-mediated apoptosis, dysfunction, and autophagic inhibition observed in islet β cells in response to lipotoxicity.

Influence of Slow-Paced Breathing on Inhibition After Physical Exertion

This research aims to investigate whether slow-paced breathing (SPB) improves adaptation to psychological stress, and specifically inhibition, when it is performed before or after physical exertion (PE). According to the resonance model, SPB is expected to increase cardiac vagal activity (CVA). Further, according to the neurovisceral integration model, CVA is positively linked to executive cognitive performance, and would thus play a role in the adaptation to psychological stress. We hypothesized that SPB, in comparison to a control condition, will induce a better adaptation to psychological stress, measured via better inhibitory performance. Two within-subject experiments were conducted with athletes: in the first experiment (N = 60) SPB (or control – neutral TV documentary) was realized before PE (“relax before PE”), and in the second experiment (N = 60) SPB (or the watching TV control) was realized after PE (“relax after PE”). PE consisted of 5 min Burpees, a physical exercise involving the whole body. In both experiments the adaptation to psychological stress was investigated with a Stroop task, a measure of inhibition, which followed PE. Perceived stress increased during PE (partial η² = 0.63) and during the Stroop task (partial η² = 0.08), and decreased during relaxation (partial η² = 0.15), however, no effect of condition was found. At the physiological level PE significantly increased HR, RF, and decreased CVA [operationalized in this research via the root mean square of successive differences (RMSSD)] in both experiments. Further, the number of errors in the incongruent category (Stroop interference accuracy) was found to be lower in the SPB condition in comparison to the control condition, however, these results were not mediated by RMSSD. Additionally, the Stroop interference [reaction times (RTs)] was found to be lower overall in “relax before PE,” however, no effect was found regarding SPB and Stroop interference (RTs). Overall, our results suggest that SPB realized before or after PE has a positive effect regarding adaptation to psychological stress and specifically inhibition, however, the underlying mechanisms require further investigation.

Cognitive effects of a 30-min aerobic exercise bout on adults with overweight/obesity and type 2 diabetes

BACKGROUND

Several studies document reliable brain health benefits of acute exercise bouts. However, no prior studies have explored such effects among those living with co-morbid overweight/obesity and type 2 diabetes (T2DM), both of which are conditions associated with cognitive performance decrements.

PURPOSE

To examine the impact of a 30-min bout of moderate-intensity aerobic exercise on executive function among adults with overweight/obesity and T2DM, employing a widely used experimental paradigm.

METHODS

Thirty adults with overweight/obesity and T2DM were randomly assigned to moderate (30% maximal heart rate reserve) and minimal (r.p.m. 30-50; work load 5) intensity aerobic exercise. Pre-exercise to post-exercise changes in Stroop interference and Go/No-Go scores were compared across conditions.

RESULTS

Primary analyses revealed no overall effect of exercise condition on changes in Stroop or Go/No-Go performance. Post-hoc moderation analyses indicated that Stroop interference scores were reduced, following moderate exercise among female participants and among those who were more physically active.

CONCLUSION

The current study revealed no reliable benefit of acute aerobic exercise for overweight and obese individuals living with T2DM overall. There may be limited benefits for women and more and active subgroups, but the precise nature of such benefits remains unclear.