The effects of myosteatosis on skeletal muscle function in older adults.

Myosteatosis, or the infiltration of fatty deposits into skeletal muscle, occurs with advancing age and contributes to the health and functional decline of older adults. Myosteatosis and its inflammatory milieu play a larger role in adipose tissue dysfunction, muscle tissue dysfunction, and increased passive muscle stiffness. Combined with the age-related decline of sex hormones and development of anabolic resistance, myosteatosis also contributes to insulin resistance, impaired muscle mechanics, loss of force production from the muscle, and increased risk of chronic disease. Due to its highly inflammatory secretome and the downstream negative effects on muscle metabolism and mechanics, myosteatosis has become an area of interest for aging researchers and clinicians. Thus far, myosteatosis treatments have had limited success, as many lack the potency to completely rescue the metabolic and physical consequences of myosteatosis. Future research is encouraged for the development of reliable assessment methods for myosteatosis, as well as the continued exploration of pharmacological, nutritional, and exercise-related interventions that may lead to the success in attenuating myosteatosis and its clinical consequences within the aging population.

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults.

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals. This study aimed to compare flow mediated dilation (FMD) and vascular augmentation index (AIx75) between young adults with low, moderate, and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise. Forty-three participants (22 men; 21 women) between 18 and 29 years of age completed the study. Participants were classified into low, moderate, and high health-related cardiorespiratory fitness groups according to age- and sex-based relative maximal oxygen consumption (V˙O2 max) percentile rankings. FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70% V˙O2 max. A significant interaction (p â€‹= â€‹0.047; ηp2 â€‹= â€‹0.142) was observed, with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline ([6.7% â€‹± â€‹3.1%] vs. [8.5% â€‹± â€‹2.8%], p â€‹= â€‹0.028; d â€‹= â€‹0.598). We found a significant main effect of group for AIx75 (p â€‹= â€‹0.023; ηp2 â€‹= â€‹0.168), with the high fitness group exhibiting lower AIx75 compared to low fitness group ([-10% â€‹± â€‹10%] vs. [2% â€‹± â€‹10%], respectively, p â€‹= â€‹0.019; g â€‹= â€‹1.07). This was eliminated after covarying for body fat percentage (p â€‹= â€‹0.489). Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness, but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.

Muscle thickness and inflammation during a 50km ultramarathon in recreational runners.

PURPOSE: This study examined changes in circulating levels of inflammatory cytokines [IL-6, sIL-6R, TNF-α, and calprotectin], skeletal muscle morphology, and muscle strength following a 50km race in non-elite athletes. METHODS: Eleven individuals (8 men; 3 women) underwent pre-race assessments of rectus femoris muscle thickness (resting and contracted) using ultrasound, isometric knee extensor torque, and plasma cytokines. Measures were repeated after 10km of running, the 50km finish (post-race), and again 24-hrs post-race. RESULTS: Compared with baseline values, Δ muscle thickness (resting to contracted) increased significantly 24 hrs post-race (11 ± 11% vs. 22 ± 8%; P = 0.01). Knee extensor torque was significantly reduced immediately post-race (151 ± 46 vs. 134 ± 43 Nm; P = 0.047) but remained similar to post-race values at 24 hrs post-race (P = 0.613). Compared with pre-race levels, IL-6 and calprotectin concentrations increased 302% and 50% after 10km, respectively (P<0.017 for both), peaked post-race (2598% vs. pre-race for IL-6 and 68% vs. pre-race for calprotectin; P = 0.018 for both), and returned to pre-race levels at 24-hrs post-race (P>0.05 for both). Creatine kinase levels rose steadily during and after the race, peaking 24-hrs post-race (184 ± 113 U/L pre-race vs. 1508 ± 1815 U/L 24-hrs post-race; P = 0.005). CONCLUSION: This is the first report of delayed increases in Δ muscle thickness at 24 hrs post-50km, which are preceded by reductions in knee extensor torque and elevations in plasma IL-6, and calprotectin. Recreational athletes should consider the acute muscle inflammatory response when determining training and recovery strategies for 50km participation.

Geriatric Vulnerabilities Among Obese Older Adults With and Without Sarcopenia: Findings From a Nationally Representative Cohort Study.

BACKGROUND AND PURPOSE: Sarcopenic obesity is associated with loss of independence among older adults, but the epidemiology of sarcopenic obesity and associated geriatric vulnerabilities are poorly understood. Thus, our objectives were to: (1) estimate the prevalence of older adults with sarcopenic obesity and (2) examine rates of geriatric vulnerabilities among obese older adults, with and without sarcopenia. METHODS: A nationally representative sample of 1600 community-dwelling older adults 65 years and older with obesity and documented measures of muscle function from the National Health and Aging Trends Study (NHATS) was identified as sarcopenic using sex-adjusted grip strength and Short Physical Performance Battery scores. Differences in the prevalence of geriatric vulnerabilities (including pain, depression, disability, and social isolation) were compared between obese older adults with and without sarcopenia. RESULTS AND DISCUSSION: Among obese older adults, 18% (n = 318/1600) were sarcopenic. After adjusting for age and sex, sarcopenic obese older adults had 3.7 times the odds of having 2 or more comorbid conditions (odds ratio [OR] = 3.7; 95% CI 2.2-5.0) and 6.4 times the odds of being frail (OR = 6.4; 95% CI 4.4-9.5) as compared with nonsarcopenic obese older adults. Sarcopenic obese older adults were also more likely to have 1 or more activities of daily living disabilities (OR = 3.7; 95% CI 2.5-5.4), be socially isolated (OR = 2.1; 95% CI 1.3-3.2), and report activity-limiting pain (OR = 2.0; 95% CI 1.5-2.7) as compared with nonsarcopenic obese older adults. These findings, in a nationally representative cohort, suggest obese older adults who are sarcopenic have higher rates of geriatric vulnerabilities that could impact delivery and outcomes of exercise and nutrition interventions. CONCLUSIONS: Concomitant obesity and sarcopenia are associated with higher rates of geriatric vulnerabilities among a nationally representative sample of older adults. More comprehensive interventions, beyond exercise and diet modifications, may be necessary to additionally address these newly identified social and physiological risks.

High-intensity functional exercise does not cause persistent elevations in augmentation index in young men and women.

Elevations in central augmentation index (AIx) are predictive of cardiovascular disease. The objective of this study was to examine AIx immediately and 24 h following an acute bout of high-intensity functional training (HIFT) in apparently healthy young adults. A second aim compared the exercise-induced AIx recovery response between men and women. Thirty-two recreationally active younger adults (n = 16 men) were tested. Baseline central hemodynamic measures were assessed, followed by a single bout of bodyweight HIFT. The HIFT included 4 rounds of burpees, jump squats, split squats, and walking lunges. Assessments were repeated 5, 10, 15, and 24 h post-exercise. AIx was normalized to a heart rate of 75 bpm (AIx75). There was a significant main effect of time on AIx75 across all groups (P < 0.001) with AIx75 increasing at all acute time points compared with baseline and returning to resting values 24 h post-exercise. When examining sex differences after covarying for height and body fat percentage, the authors found no time × sex interaction (P = 0.62), or main effect for sex (P = 0.41), but the significant main effect of time remained (P < 0.001). The AIx75 response to HIFT follows a similar recovery pattern as previously studied modes of exercise with no residual effects 24 h later and no differences between men and women indicating no persistent cardiovascular strain in younger adults participating in this mode of exercise.

Safety of exercise therapy after acute pulmonary embolism.

OBJECTIVE: The role of exercise therapy after acute pulmonary embolism (PE) is unknown. Exercise therapy is safely used after myocardial infarction and chronic obstructive pulmonary disease. The aim of this study was to investigate the safety of exercise therapy after acute PE. METHODS: We implemented a 3-month exercise program after acute PE. Outcomes were death, bleeding, readmissions, recurrent events, changes in peak VO2 and quality of life (QoL). RESULTS: A total of 23 patients were enrolled and received anticoagulation; no adverse events were reported during the exercise period. One death, 1 DVT and 5 readmissions were reported due to non-exercise related reasons. Functional capacity improved as evidenced by an increased peak VO2 at 3 months (+3.9 ± 5.6 mL/kg/min; p = 0.05). Improvement in QoL was observed at 6-months on the functional (+17.0 ± 22.6, p = 0.03) and physical health factor scales (+0.9 ± 4.6, p = 0.03). CONCLUSION: Exercise therapy is feasible and safe in appropriately anticoagulated patients after PE.

Healthy Lifestyle and Cognition: Interaction between Diet and Physical Activity.

PURPOSE OF REVIEW: This review discusses current research on the impact of specific dietary patterns and exercise, both individually and combined, on cognitive function in older adults. RECENT FINDINGS: Observational evidence generally supports a relationship between diet adherence and positive cognitive outcomes related to memory, executive function, and risk for cognitive impairment; however, randomized controlled trials (RCTs) are limited. Exercise research is more extensive, showing improvements in cognitive performance after exercise interventions regardless of baseline cognitive status and noting lower incidences of cognitive impairment in people who engage in regular physical activity. Evidence supports adherence to specific dietary patterns and a combination of aerobic and resistance exercise as an effective approach to mitigate age-associated cognitive decline. Further research on older adults at various stages of cognitive decline, as well as longer-term RCTs, will help determine the best clinical markers of early cognitive dysfunction, and the effectiveness of early lifestyle intervention on cognitive function.