Effect of exercise on myosteatosis in adults: a systematic review and meta-analysis

Efficacy of high-intensity interval training versus continuous training on serum myonectin and lipid outcomes in adults with metabolic syndrome: A post-hoc analysis of a clinical trial

BACKGROUND

Myonectin is a myokine with potential effects on the lipid metabolism; however, its regulation by exercise in humans remains unclear. We aimed to compare the efficacy of high-intensity interval training low-volume (HIIT) versus moderate-intensity continuous training (MICT) on serum myonectin, serum lipids, appendicular fat and lean mass, and intramuscular lipids in humans.

METHODS

Secondary analysis of a controlled, randomized, clinical trial in adults of both sexes with metabolic syndrome, who underwent a supervised, three-times/week, 12-week treadmill program. HIIT (n = 29) consisted of six intervals with one-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak) for a total of 22 min. MICT (n = 31) trained at 60% of VO2peak for 36 min. Serum myonectin was measured using a human enzyme-linked immunosorbent assay. Lipid profile was determined by enzymatic methods and free fatty acids (FFA) were measured by gas chromatography. Fat and lean mass were assessed by dual-energy X-ray absorptiometry. Intramuscular lipids were measured through proton magnetic resonance spectroscopy.

RESULTS

Subjects had a mean age of 50.8±6.0 years and body mass index of 30.6±4.0 kg/m2. Compared to MICT, HIIT was not superior at increasing serum myonectin (p = 0.661) or linoleic acid (p = 0.263), reducing palmitic (p = 0.286) or stearic acid (p = 0.350), or improving lipid profile (all p>0.05), appendicular fat mass index -AFMI- (p = 0.713) or appendicular lean mass percentage -ALM- (p = 0.810). Compared to baseline, only HIIT significantly increased myonectin (p = 0.042), with a large effect size, although both interventions reduced AFMI and increased ALM with a large effect size. Lipid profile, FFA and intramuscular lipids did not change in any intervention group (p>0.05).

CONCLUSIONS

Compared to MICT, HIIT low volume did not demonstrate superiority in improving serum lipids. The fact that both training types reduced AFMI without paralleled significant changes in serum myonectin suggests that this myokine may have a minor effect on short-middle-term exercise-induced fat mobilization.

Myosteatosis in multiple myeloma: a key determinant of survival beyond sarcopenia

OBJECTIVE

Fatty infiltration of skeletal muscle (Myosteatosis) is associated with increased frailty, decreased muscle and mobility function, which seems fairly prevalent in multiple myeloma (MM) patients. This study aimed to determine the prognostic value of myosteatosis assessed by CT for progression-free survival (PFS) and overall survival (OS).

MATERIALS AND METHODS

This IRB-approved cohort study included patients with newly diagnosed MM who were treated at a single university hospital and received CT at baseline. Geriatric assessment was performed via International Myeloma Working Group frailty score and Revised Myeloma Comorbidity Index. Myosteatosis was determined through measurement of paravertebral muscle radiodensity. Statistical analyses included uni- and multivariable Cox proportional hazard models and the Kaplan-Meier-method.

RESULTS

A total of 226 newly diagnosed MM patients (median age: 65 years [range: 29-89], 63% males, mean BMI: 25 [14-42]) were analyzed. The prevalence of myosteatosis was 51%. Muscle radiodensity was significantly decreased in individuals with International Staging System stage III vs. I (p < 0.001), indicating higher fatty muscle infiltration in patients with advanced disease. Both PFS and OS were significantly decreased in patients with myosteatosis (PFS: median 32.0 months (95% CI 20.5.5-42.2) vs. 66.4 months without myosteatosis (95% CI 42.5-not reached), p < .001); OS: median 58.6 (95% CI 51.3-90.2) vs. not reached, p < .001). Myosteatosis remained an independent predictor of OS in multivariable analyses (HR: 1.98; 95%-CI: 1.20-3.27).

CONCLUSION

Myosteatosis seems fairly prevalent in patients with newly diagnosed MM and associated with impaired overall survival. Prospective clinical trials are required to better understand the role of myosteatosis in MM patients.

Low muscle quality on a procedural computed tomography scan assessed with deep learning as a practical useful predictor of mortality in patients with severe aortic valve stenosis

BACKGROUND & AIMS

Accurate diagnosis of sarcopenia requires evaluation of muscle quality, which refers to the amount of fat infiltration in muscle tissue. In this study, we aim to investigate whether we can independently predict mortality risk in transcatheter aortic valve implantation (TAVI) patients, using automatic deep learning algorithms to assess muscle quality on procedural computed tomography (CT) scans.

METHODS

This study included 1199 patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) between January 2010 and January 2020. A procedural CT scan was performed as part of the preprocedural-TAVI evaluation, and the scans were analyzed using deep-learning-based software to automatically determine skeletal muscle density (SMD) and intermuscular adipose tissue (IMAT). The association of SMD and IMAT with all-cause mortality was analyzed using a Cox regression model, adjusted for other known mortality predictors, including muscle mass.

RESULTS

The mean age of the participants was 80 ± 7 years, 53% were female. The median observation time was 1084 days, and the overall mortality rate was 39%. We found that the lowest tertile of muscle quality, as determined by SMD, was associated with an increased risk of mortality (HR 1.40 [95%CI: 1.15-1.70], p < 0.01). Similarly, low muscle quality as defined by high IMAT in the lowest tertile was also associated with increased mortality risk (HR 1.24 [95%CI: 1.01-1.52], p = 0.04).

CONCLUSIONS

Our findings suggest that deep learning-assessed low muscle quality, as indicated by fat infiltration in muscle tissue, is a practical, useful and independent predictor of mortality after TAVI.

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.

One-leg standing time is a simple measure for loss of skeletal muscle mass and fat deposition in muscle: the J-SHIPP study

BACKGROUNDS

One-leg standing time (OLST) has been frequently used physical performance measure; however, what muscular characteristics OLST represents remains uncertain.

AIM

This cross-sectional study aimed to investigate the association between OLST and muscle characteristics to clarify the possibility of using OLST as a physical performance measure.

METHODS

Study participants comprised 1144 older adults aged 65 years or older. Computed tomography images provided mid-thigh skeletal muscle cross-sectional area and mean attenuation value. OLST was measured for a maximum of 60 s. Static postural instability was assessed using a posturography.

RESULTS

A frequency of OLST < 20 s was increased by quartiles of muscle cross-sectional area (Q1: 33.6, Q2: 12.8, Q3: 13.6, Q4: 11.9%, P < 0.001) and mean attenuation value (Q1: 32.3, Q2: 21.7, Q3: 14.3, Q4: 7.7%, P < 0.001). Results of the multinomial regression analysis indicated that muscle cross-sectional area and mean attenuation value were independently associated with an OLST of less than 20 s. The crude odds ratio of OLST less than 20 s for the lowest quartiles of both cross-sectional area and mean attenuation value was 4.19 (95% CI: 3.01 - 5.84). The cross-sectional area of muscles with greater fat deposition was inversely associated with OLST, while that with smaller fat deposition showed a positive association with OLST, indicating why mean attenuation value and cross-sectional area were independently associated with OLST. No clear relationship was observed with static postural instability.

CONCLUSION

OLST was a simply measurable quantifiable physical measure representing the loss of muscle mass and quality in older adults.

Ectopic lipid deposition in muscle and liver, quantified by proton magnetic resonance spectroscopy

Advances in the development of noninvasive imaging techniques have spurred investigations into ectopic lipid deposition in the liver and muscle and its implications in the development of metabolic diseases such as type 2 diabetes. Computed tomography and ultrasound have been applied in the past, though magnetic resonance-based methods are currently considered the gold standard as they allow more accurate quantitative detection of ectopic lipid stores. This review focuses on methodological considerations of magnetic resonance-based methods to image hepatic and muscle fat fractions, and it emphasizes anatomical and morphological aspects and how these may influence data acquisition, analysis, and interpretation.

Myosteatosis as a prognostic factor of Mycobacterium avium complex pulmonary disease

Quantitative body composition affects the prognosis of patients with Mycobacterium avium complex pulmonary disease (MAC-PD). However, whether the qualitative body composition obtained indirectly through computed tomography (CT) affects their prognosis is debatable. We retrospectively analyzed patients with MAC-PD who underwent non-contrast CT at MAC-PD diagnosis. The cross-sectional area of the erector spinae muscle (ESM area), the Hounsfield unit of the erector spinae muscle (ESM HU), and the cross-sectional area of subcutaneous fat (SQF area) were measured at the level of the first lumbar vertebra. Myosteatosis were defined below the median value of ESM HU for each sex. Of 377 patients, 45 (11.9%) died during the follow-up. Patients who died were older and had a lower ratio of females (33.3%). In body compositions, SQF area and ESM HU were lower in the patients who died. In multivariable analysis, a low ESM HU was associated with increased mortality (ESM HU adjusted hazard ratio [aHR] 0.95, 95% confidence interval [CI] 0.93-0.97) through body composition. SQF area revealed protective effects in MAC-PD patients with body mass index ≥ 18.5 kg/m2 (aHR 0.98, 95% CI 0.95-1.00). In conclusion, the decrease in ESM HU, which indirectly reflects myosteatosis, is associated with mortality in patients with MAC-PD.

Centile reference curves of the ultrasound-based characteristics of the rectus femoris muscle composition in children at 4-11 years old

Quantitative diagnostic ultrasound has been proposed as a way to characterize muscle structure, but there is a lack of normative data for children. This study aims to establish age-specific normal ranges for echo-intensity (EI), cross-sectional area (CSA), muscular thickness (MT), and subcutaneous adipose thickness (SAT) values of the rectus femoris muscle in typically developing children. The study recruited 497 children (288 boys and 209 girls) aged 4-10.9 years (mean age 7.39 years), and muscle parameters were measured using 2D B-mode ultrasound. Percentile values and reference curves were calculated using the Lambda, Mu, and Sigma method (LMS). The results showed small variation between measurements for boys compared to girls, with the most significant difference in EI, CSA, and MT values. EI decreased with age, with the most pronounced curve in boys. SAT increased in both sexes, with a slightly higher increase in girls after the age of 9.0 years. This study provides the first age-specific reference norms for the rectus femoris muscle architecture in children, and further research is needed to validate these curves and determine their clinical utility.

Skeletal muscle mass in patients with end-stage liver disease: Not only muscle size but especially muscle quality matters in relation to physical fitness

BACKGROUND

Physical fitness is an important modifiable factor related to quality of life. Sarcopenia and myosteatosis are associated with morbidity and mortality in patients with end-stage liver disease (ESLD). However, their relationship with physical fitness has not been established yet. Therefore, the main purpose of this study was to investigate the association between both low skeletal muscle index (SMI) and myosteatosis with physical fitness in patients with ESLD.

METHODS

In this retrospective cross-sectional cohort study, a cohort of patients with ESLD who were evaluated for liver transplantation (LT) was included. Physical fitness was reflected by cardiorespiratory fitness (CRF) and skeletal muscle strength, as measured by the 6-min walking distance (6MWD) and handgrip strength (HGS), respectively. Both were included in routine LT evaluation. Skeletal Muscle Index (SMI) and Muscle Radiation Attenuation (MRA) were evaluated based on the routine abdominal computed tomography. Linear and logistic regression analyses were performed.

RESULTS

Out of the 130 patients 94 (72%) were male, mean age was 56 ± 11 years. Myosteatosis was significantly associated with low 6MWD as percentage of predicted (β = -12.815 (CI -24.608 to -1.022, p-value 0.034)) as well as with low absolute 6MWD (<250 m) (OR 3.405 (CI 1.134-10.220, p-value 0.029)). No association was found between SMI and/or myosteatosis with HGS, or between SMI and 6MWD.

CONCLUSION

In contrast to SMI, myosteatosis is associated with low CRF. Neither low SMI nor myosteatosis was associated with skeletal muscle strength. Therefore physical exercise training might be especially beneficial for LT candidates with myosteatosis.

Effect of High-Intensity Interval Training on Fatty Infiltration After Delayed Rotator Cuff Repair in a Mouse Model

Background

Fatty infiltration (FI) of the rotator cuff muscles is correlated with shoulder function and retear rates after rotator cuff repair. High-intensity interval training (HIIT) induces beige adipose tissue to express more uncoupling protein 1 (UCP1) to consume lipids. The beta-3 adrenergic receptor (β3AR) is located on adipocyte membrane and induces thermogenesis.

Purpose

To test the role of HIIT in improving muscle quality and contractility in a delayed rotator cuff repair mouse model via β3AR.

Study Design

Controlled laboratory study.

Methods

Three-month-old C57BL/6J mice underwent a unilateral supraspinatus (SS) tendon transection with a 6-week delayed tendon repair. Mice ran on a treadmill with the HIIT program for 6 weeks after tendon transection or after delayed repair. To study the role of β3AR, SR59230A, a selective β3AR antagonist, was administered to mice 10 minutes before each exercise through intraperitoneal injection. The SS, interscapular brown adipose tissue (iBAT), and subcutaneous inguinal white adipose tissue (ingWAT) were harvested at the end of the 12th week after tendon transection and were analyzed by histology and Western blotting. Tests were performed to assess muscle contractility of the SS.

Results

Histologic analysis of SS showed that HIIT prevented and reversed muscle atrophy and FI. The contractile tests showed higher contractility of the SS in the HIIT groups than in the no-exercise group. In the HIIT groups, SS, iBAT, and ingWAT all showed increased expression of tyrosine hydroxylase, UCP1, and upregulated β3AR thermogenesis pathway. However, SR59230A inhibited HIIT, suggesting that the effect of HIIT depends on β3AR.

Conclusion

HIIT improved SS quality and function after delayed rotator cuff repair through a β3AR-dependent mechanism.

Clinical Relevance

HIIT may serve as a new rehabilitation method for patients with rotator cuff muscle atrophy and FI after rotator cuff repair to improve postoperative clinical outcomes.

Supervised resistance exercise for women with ovarian cancer who have completed first-line treatment: a pragmatic study

OBJECTIVES

In ovarian cancer (OC), suboptimal muscle morphology (i.e., low muscle mass and density) is associated with poor clinical outcomes, yet little is known about the effect of interventions aimed at improving these measures. We investigated the effect of resistance exercise after first-line treatment on muscle mass and density, muscle strength and physical function, health-related quality of life (QoL), and pelvic-floor function in advanced-stage OC survivors.

METHODS

Fifteen OC survivors participated in supervised resistance exercise twice weekly for 12 weeks (in-clinic or by telehealth). Assessments included muscle mass and density (dual-energy X-ray absorptiometry, peripheral quantitative computed tomography), muscle strength (1-repetition maximum [1RM] chest press, 5RM leg press, handgrip strength), physical function (400-m walk, timed up-and-go [TUG]), QoL (QLQ-C30 questionnaire), and self-reported pelvic floor function (Australian Pelvic Floor Questionnaire).

RESULTS

The median age was 64 (range 33-72) years, 10 women underwent neoadjuvant chemotherapy and five underwent adjuvant chemotherapy. All participants completed the intervention (median attendance = 92%; range 79-100%). Post-intervention improvements were observed for whole-body lean mass (1.0 ± 1.4 kg, p = 0.015), appendicular lean mass (0.6 ± 0.9 kg, p = 0.013), muscle density (p = 0.011), upper and lower body strength (p ≤ 0.001), 400-m walk (p = 0.001), TUG (p = 0.005), and social and cognitive QoL domains (p = 0.002 and 0.007), with no change to pelvic floor symptoms (p > 0.05).

CONCLUSION

In this study, supervised resistance exercise effectively improved muscle mass and density, muscle strength, and physical functioning without deleterious effects on the pelvic floor. Considering the prognostic value of these outcomes, larger studies are needed to confirm the benefits of resistance exercise in OC supportive care.

Muscle fat infiltration in chronic kidney disease: a marker related to muscle quality, muscle strength and sarcopenia

Muscle fat infiltration (MFI) also known as myosteatosis refers to any deposit of lipids found in the skeletal muscle. MFI is preferably assessed by image-based methods like computed tomography (CT), magnetic resonance image (MRI) and ultrasound, normally from muscle groups located in the legs, arms and in the trunk. MFI is understood as a marker of muscle quality, where a muscle with higher fat deposition has lower contraction power and capacity to produce force per unit of muscle mass. This concept supports the hypothesis that a decrease in muscle strength is not always explained by a decrease in muscle mass, but also by other factors, including lipid deposition in the muscle. In the general population, MFI is associated with older age, physical inactivity and with insulin resistance and inflammation. In chronic kidney disease (CKD), MFI has been associated with a decrease in muscle strength and impaired muscle quality as well as with metabolic abnormalities, cardiovascular disease and increased mortality. Interventions aimed at reducing MFI in CKD are incipient, but it seems that guided exercise can ameliorate muscle quality in patients on hemodialysis. The aim of this narrative review about MFI in CKD is to draw attention to a still not often addressed complication in CKD. We conclude that more studies are warranted to investigate mechanisms and factors promoting MFI in CKD. Thus, clinical trials aimed at understanding the type, frequency and intensity of exercise that can diminish MFI and improve the clinical condition of the patients are needed.

Associations of myosteatosis with disc degeneration: A 3T magnetic resonance imaging study in individuals with impaired glycaemia

BACKGROUND

Intervertebral disc degeneration (IVDD) may be linked to dysregulations of skeletal muscle glucose metabolism and fatty alterations of muscle composition (Myosteatosis). Our aim was to evaluate the different associations of magnetic resonance imaging (MRI)-based paravertebral myosteatosis with lumbar disc degeneration in individuals with impaired glucose metabolism and normoglycaemic controls.

METHODS

In total, 304 individuals (mean age: 56.3 ± 9.1 years, 53.6% male sex, mean body mass index [BMI]: 27.6 ± 4.7 kg/m² ) from a population-based cohort study who underwent 3-Tesla whole-body chemical-shift-encoded (six echo times) and T2-weighted single-shot-fast-spin-echo MRI were included. Lumbar disc degeneration was assessed at motion segments L1 to L5, categorized according to the Pfirrmann score and defined as Pfirrmann grade > 2 and/or disc bulging/herniation on at least one segment. Fat content of the autochthonous back muscles and the quadratus lumborum muscle was quantified as proton density fat fraction (PDFF_muscle ). Logistic regression models adjusted for age, sex, BMI and regular physical activity were calculated to evaluate the association between PDFF_muscle and outcome IVDD.

RESULTS

The overall prevalence of IVDD was 79.6%. There was no significant difference in the prevalence or severity distribution of IVDD between participants with or without impaired glucose metabolism (77.7% vs. 80.7%, P = 0.63 and P = 0.71, respectively). PDFF_muscle was significantly and positively associated with an increased risk for the presence of IVDD in participants with impaired glycaemia when adjusted for age, sex and BMI (PDFF_{autochthonous back muscles} : odds ratio [OR] 2.16, 95% confidence interval [CI] [1.09, 4.3], P = 0.03; PDFF_{quadratus lumborum} : OR 2.01, 95% CI [1.04, 3.85], P = 0.04). After further adjustment for regular physical activity, the results attenuated, albeit approaching statistical significance (PDFF_{autochthonous back muscles} : OR 1.97, 95% CI [0.97, 3.99], P = 0.06; PDFF_{quadratus lumborum} : OR 1.86, 95% CI [0.92, 3.76], P = 0.09). No significant associations were shown in healthy controls (PDFF_{autochthonous back muscles} : OR 0.62, 95% CI [0.34, 1.14], P = 0.13; PDFF_{quadratus lumborum} : OR 1.06, 95% CI [0.6, 1.89], P = 0.83).

CONCLUSIONS

Paravertebral myosteatosis is positively associated with intervertebral disc disease in individuals with impaired glucose metabolism, independent of age, sex and BMI. Regular physical activity may confound these associations. Longitudinal studies will help to better understand the pathophysiological role of skeletal muscle in those with concomitant disturbed glucose haemostasis and intervertebral disc disease, as well as possible underlying causal relationships.

Fat infiltration and muscle hydration improve after high-intensity resistance training in women with sarcopenia. A randomized clinical trial

BACKGROUND

Resistance training is recommended for preventing sarcopenia, but the benefits for the quality and quantity of muscle mass are uncertain.

OBJECTIVE

To assess the effects of high-intensity resistance training (HIRT) on clinical and magnetic resonance imaging (MRI) parameters in women with sarcopenia.

METHODS

A researcher-blinded randomized clinical trial was conducted. Community-dwelling older women with sarcopenia were randomized to six months of HIRT or a control group (CG). Body composition was assessed with bioimpedance equipment, and participants underwent strength and functional performance tests (short physical performance battery [SPPB] and gait speed). MRI scans of the thigh were taken to quantify muscle mass and quality.

RESULTS

Thirty-eight women completed the study (20 in the HIRT group). Sarcopenia remitted in 50 % of the HIRT group. HIRT elicited a significant group × time interaction effect for muscle mass (p = 0.027; Ƞ² = 0.129), muscle mass index (p = 0.023; Ƞ² = 0.135), fat mass (p = 0.048; Ƞ² = 0.103) and all strength variables (p < 0.05; Ƞ² > 0.120). Moreover, the HIRT group obtained higher scores on the SPPB (mean difference [MD] 1.2; p = 0.005) and the 5 times sit-to-stand test (MD = 0.7; p = 0.009). Regarding MRI parameters, infiltrated microscopic fat decreased significantly (HIRT: MD = -0.01; p < 0.05), while hydration (T2) decreased in the CG (MD = 3.6 ms; p = 0.053) at six months. There were significant between-group differences at six months for water diffusion (HIRT: 1.09 × 10^-3 mm²/s vs CG: 1.26 × 10^-3 mm²/s) and total muscular volume (HIRT: 832.4 L vs CG: 649.2 L).

CONCLUSIONS

HIRT led to the remission of sarcopenia in half of the older women, as seen in muscle mass, strength, and functional performance and MRI biomarkers, with significant increases in muscle quality. REGISTERED IN CLINICALTRIALS.GOV: NCT03834558.

RESTORATIVE EFFECT OF JOGGING ON LOWER LIMB MUSCLES

ABSTRACT Introduction: Jogging can be a great way to improve physical condition, boosting mind and body. Its method of movement is simple, and there are no sporting limitations as to age, gender, or training place. Jogging is believed to help repair muscle and joint injuries in the lower limbs. Objective: To explore the effects of running on recovering lower limb muscles. Methods: We surveyed 60 undergraduate students who took a 400-meter test at the same site. According to the test results, they were divided into low, medium, and high fitness levels. A questionnaire survey was also used with 20 undergraduate students from the Physical Education Department. Four groups of volunteers did some jogging exercises. Physiological, biochemical, and muscle strength measurements were performed after jogging. The data were statistically treated. Results: The magnitude of change in the sagittal angle of the knee and ankle joint did not increase significantly with increasing jogging rate. The changes in the sagittal angles of the hip, knee, and ankle joints were the same for the volunteers with different jogging rates. After 60 minutes of exercise, the low-fitness group showed faster breathing, an elevated heart rate, and a higher rate of lactate and creatinine in the blood. After 120 minutes of exercise training, all sedentary volunteers showed an increase in lactate, creatinine, respiratory rate, and heart rate (P<0.05). The test performance started to decrease at 400 meters. Conclusion: The maximal activation of different parts of the locomotor system changed under different rates of movement. Brief, controlled jogging may be beneficial to lower limb muscles. Still, long-term jogging may cause even more damage to the body and deleterious changes to rehabilitation in blood and biochemical parameters. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Reduced muscle strength in patients with long-COVID-19 syndrome is mediated by limb muscle mass

Understanding the impact of COVID-19 on muscle strength may help to elucidate the organ systems that contribute to acute and chronic COVID-19 sequelae. We questioned whether patients with postdischarge symptoms after COVID-19 had compromised muscle strength compared with a control group, and if this potential relationship was mediated by the lower appendicular lean mass index (ALMI). A total of 99 patients with long-COVID-19 and 97 control participants were screened. Maximal grip strength was assessed with a TKK 5101 digital dynamometer, and leg extension 1RM was measured using EGYM Smart Strength machines. Body composition (fat mass percentage, lean mass, visceral fat, and appendicular lean mass index) was determined using a whole body dual-energy X-ray densitometer. Results showed that grip strength and leg extension strength were significantly higher in controls than in COVID-19 survivors (mean [SD], 32.82 [10.01] vs. 26.94 [10.33] kg; difference, 5.87 kg; P < 0.001) and (mean [SD], 93.98 [33.73] vs. 71.59 [33.70] kg; difference, 22.38 kg; P < 0.001), respectively). The relationship between long-COVID syndrome and grip/leg strength levels was partly mediated by ALMI, which explained 52% of the association for grip strength and 39% for leg extension. Our findings provide novel insights into the mechanisms underlying the relationship between long-COVID syndrome and grip/leg strength levels, supporting the negative effects of long-COVID syndrome on muscle function.NEW & NOTEWORTHY The causes of post-COVID-19 syndrome are uncertain. Limb muscle wasting common to patients with COVID-19 limits daily activities and exercise. In this cross-sectional study, we found that patients with long-COVID-19 syndrome had significantly lower absolute and relative muscle strength measurements than control participants. Interestingly, we identified that these relationships were mostly mediated by limb muscle mass. Our data thus suggest that the evident reduced upper and lower muscle mass is a putative cause of-or contributor to-the functional limitation of patients with long-COVID-19 syndrome.

Determinants of muscle density and clinical outcomes: Findings from the Hertfordshire Cohort Study

PURPOSE

The age-related loss of skeletal muscle mass and strength is associated with adverse health outcomes. However, to date, peripheral quantitative computed tomography (pQCT)-derived muscle density has been little studied. We used a well characterised cohort of older adults to identify lifestyle and anthropometric determinants of pQCT-derived muscle density measured 11 years later, and to report relationships between pQCT-derived muscle density with history of falls and prevalent fractures.

METHODS

A lifestyle questionnaire was administered to 197 men and 178 women, aged 59-70 at baseline. After a median of 11.5 (IQR 10.9, 12.3) years, pQCT (Stratec XCT2000) of the radius and tibia was performed to measure forearm muscle density (FMD) and calf muscle density (CMD). Presence of falls and fractures since the age of 45 were determined through participant recall; vertebral fractures were also ascertained through vertebral fracture assessment using iDXA. Total hip BMD (TH aBMD) was assessed using DXA. Baseline characteristics in relation to muscle density at follow-up were examined using linear regression; associations between muscle density and prior falls and fractures were investigated using logistic regression. All analyses were adjusted for sex and age.

RESULTS

Mean (SD) age at muscle density measurement was 76.3 (2.6) years. Mean (SD) FMD was 79.9 (3.1) and 77.2 (3.2) among males and females, respectively; CMD was 80.7 (2.6) and 78.5 (2.6) among males and females, respectively. Significant sex-differences in muscle density were observed at each site (p < 0.001). Female sex, lower weight, and lower body mass index were associated (p < 0.05) with both lower FMD and CMD. Additional correlates of lower CMD included older age and shorter stature. Lifestyle measures were not associated with muscle density in this cohort. Lower FMD was related to increased risk of previous fracture (odds ratio (95 % CI) per SD lower FMD: 1.42 (1.07, 1.89), p = 0.015) but not after adjustment for TH aBMD (p > 0.08). No significant relationships were seen between muscle density and falls.

CONCLUSION

Female sex, older age, and lower BMI were associated with subsequent lower muscle density in older community-dwelling adults. Lower FMD was related to increased risk of previous fracture. Changes in muscle density over time might precede adverse outcomes such as falls and fractures and may be a long-term predictor of frailty. It could be also suggested that muscle density could be a more clinically meaningful surrogate of functional decline and disability than muscle size or mass, but more studies are needed to support this notion.

Effect of a Multicomponent Intervention on Hepatic Steatosis Is Partially Mediated by the Reduction of Intermuscular Abdominal Adipose Tissue in Children With Overweight or Obesity: The EFIGRO Project

OBJECTIVE

In adults, there is evidence that improvement of metabolic-associated fatty liver disease (MAFLD) depends on the reduction of myosteatosis. In children, in whom the prevalence of MAFLD is alarming, this muscle-liver crosstalk has not been tested. Therefore, we aimed to explore whether the effects of a multicomponent intervention on hepatic fat is mediated by changes in intermuscular abdominal adipose tissue (IMAAT) in children with overweight/obesity.

RESEARCH DESIGN AND METHODS

A total of 116 children with overweight/obesity were allocated to a 22-week family-based lifestyle and psychoeducational intervention (control group, n = 57) or the same intervention plus supervised exercise (exercise group, n = 59). Hepatic fat percentage and IMAAT were acquired by MRI at baseline and at the end of the intervention.

RESULTS

Changes in IMAAT explained 20.7% of the improvements in hepatic steatosis (P < 0.05). Only children who meaningfully reduced their IMAAT (i.e., responders) had improved hepatic steatosis at the end of the intervention (within-group analysis: responders -20% [P = 0.005] vs. nonresponders -1.5% [P = 0.803]). Between-group analysis showed greater reductions in favor of IMAAT responders compared with nonresponders (18.3% vs. 0.6%, P = 0.018), regardless of overall abdominal fat loss.

CONCLUSIONS

The reduction of IMAAT plays a relevant role in the improvement of hepatic steatosis after a multicomponent intervention in children with overweight/obesity. Indeed, only children who achieved a meaningful reduction in IMAAT at the end of the intervention had a reduced percentage of hepatic fat independent of abdominal fat loss. Our findings suggest that abdominal muscle fat infiltration could be a therapeutic target for the treatment of MAFLD in childhood.

Prognostic value of myosteatosis and sarcopenia for elderly patients with colorectal cancer: A large-scale double-center study

BACKGROUND

Myosteatosis and sarcopenia are forms of muscle depletion that impair the normal physiological function of elderly patients, resulting in a worse prognosis. This study aimed to evaluate the prognostic value of sarcopenia and myosteatosis on postoperative outcomes in elderly patients with colorectal cancer.

METHODS

From February 2015 to March 2021, a total of 921 elderly patients who underwent curative surgeries for colorectal cancer at 2 centers were enrolled and grouped by the presence of either myosteatosis or sarcopenia. Clinicopathological characteristics and postoperative outcomes were compared between the 2 groups. The independent risk factors for complications and overall survival were evaluated.

RESULTS

Patients with myosteatosis had higher incidences of total and surgical complications, longer surgical duration, lower numbers of lymph nodes harvested, and longer postoperative hospital stays. Patients with sarcopenia had higher incidences of total complications, medical complications, and shorter surgical durations. Both conditions had adverse effects on overall survival and disease-free survival. Overweight status (P = .004), hypoalbuminemia (P < .001), myosteatosis, (P = .029) and sarcopenia (P = .017) were independent risk factors for total complications. Hypoalbuminemia (P = .035), myosteatosis (P = .003), sarcopenia (P = .027), and tumor-nodes-metastasis stage (≥Ⅲ; P < .001) were independent negative prognostic factors for overall survival.

CONCLUSION

Myosteatosis and sarcopenia have different characteristics and are associated with poor prognoses in elderly patients with colorectal cancer. Myosteatosis occurs more frequently. Early diagnosis and intervention for myosteatosis should be included in preoperative management, which may improve prognosis in elderly patients.

Influence of cross-sectional area and fat infiltration of paraspinal muscles on analgesic efficacy of epidural steroid injection in elderly patients

BACKGROUND

An assessment of paraspinal muscle degeneration based on magnetic resonance imaging has been used to investigate both sarcopenia and myosteatosis. The morphologic changes in cross-sectional area and fat infiltration of the paraspinal muscles can affect pain outcomes after epidural steroid injection.

METHODS

Patients ≥65 years of age who underwent fluoroscopy-guided lumbar epidural steroid injections were enrolled. Good analgesia was defined as ≥50% reduction in pain score at 4 weeks after injection. Cross-sectional area and grade of fat infiltration of the paraspinal muscles on magnetic resonance images at the level of L3-L4 disc were measured. Patient demographics, pain-related factors, clinical factors, and paraspinal muscle measurements were compared between good and poor analgesia groups. The factors associated with pain outcomes after injection were identified using multivariate analysis.

RESULTS

A total of 245 patients consisting of 149 and 96 patients in the good and poor analgesia groups, respectively, fully satisfied the study criteria for analysis. Patients of older age, opioid use, and high-grade foraminal stenosis were frequently observed in the poor analgesia group. The grade of fat infiltration of the paraspinal muscles was significantly higher in the poor analgesia group (Grade 2, 20.8% vs. 42.7%, p < 0.001), and this result was predominantly observed in female patients. However, there was no difference in the muscle cross-sectional area between the two groups (18.29 ± 3.16 vs. 18.59 ± 3.03 cm² /m² , p = 0.460). The percentage of patients with good analgesia decreased as the grade of fat infiltration increased (Grade 0 = 75.0%, Grade 1 = 65.8%, Grade 2 = 43.0%, p < 0.001). Multivariate logistic regression analysis revealed that preinjection opioid use [adjusted odds ratio (aOR) = 1.926, 95% confidence interval (CI) = 1.084-3.422, p = 0.025], moderate to severe foraminal stenosis (aOR = 2.859, 95% CI = 1.371-5.965, p = 0.005), and high-grade fat infiltration of the paraspinal muscles (aOR = 4.258, 95% CI = 1.805-10.043, p = 0.001) were significantly associated with poor analgesia after injection.

CONCLUSION

High fat infiltration of the paraspinal muscles at the mid-lumbar region appeared to be an independent factor associated with poor analgesia after epidural steroid injection in elderly patients with symptomatic degenerative lumbar spinal disease receiving conservative care. However, the cross-sectional area of the paraspinal muscles was not associated with pain relief after injection.

Tailoring prehabilitation to address the multifactorial nature of functional capacity for surgery

Mounting evidence suggests that recovery begins before the surgical incision. The pre-surgery phase of recovery - the preparation for optimal surgical recovery - can be reinforced with prehabilitation. Prehabilitation is the approach of enhancing the functional capacity of the individual to enable them to withstand a stressful event. With this narrative review, we apply the Wilson & Cleary conceptual model of patient outcomes to specify the complex and integrative relationship of health factors that limit functional capacity before surgery. To have the greatest impact on patient outcomes, prehabilitation programs require individualized and coordinated care from medical, nutritional, psychosocial, and exercise services. This article is protected by copyright. All rights reserved.

Sarcopenia Related to Human Immunodeficiency Virus: Protective Effects of Exercise

We discuss recent evidence supporting the hypothesis that sarcopenia is an emerging health concern among people with human immunodeficiency virus (HIV) because of increasing life expectancy and HIV- and treatment-related comorbidities. We also hypothesize that combined exercise at higher intensity has a key role in managing sarcopenia in this population because it directly (increases muscle strength and stimulates hypertrophy) and indirectly (prevents mitochondrial dysfunction, oxidative stress, and persistent inflammation) counteracts sarcopenia hallmarks.

Aerobic fitness and muscle density play a vital role in postoperative complications in colorectal cancer surgery

Background and Objectives

To assess the association of preoperative aerobic fitness and body composition variables with a patient's resilience to the development and impact of postoperative complications after elective colorectal cancer (CRC) surgery.

Methods

Preoperative aerobic fitness was assessed by steep ramp test performance. Preoperative body composition was assessed by muscle mass and density determined from preoperative computed tomography scan analysis at the L3‐level. Complication development and severity was graded according to Clavien‐Dindo. Complication impact was assessed by the time to recovery of physical functioning after complications. Multivariable logistic regression analyses adjusted for age, sex, comorbidities and tumour location was performed.

Results

Of 238 included patients, 96 (40.3%) developed postoperative complications. Better preoperative aerobic fitness decreased the likelihood to develop complications, independent of muscle mass (odds ratio [OR]: 0.55, 95% confidence interval [CI]: 0.35−0.85) or muscle density (OR: 0.57, 95% CI: 0.36−0.89). A prolonged time to recovery following complications was associated with lower preoperative muscle density (OR: 4.14, 95% CI: 1.28−13.41), independent of aerobic fitness.

Conclusions

Lower aerobic fitness increases the risk of complication development, while low muscle density seems associated with a prolonged recovery from complications. Aerobic fitness and muscle density could be valuable additives to preoperative risk assessment.

Associations between physical fitness components with muscle ultrasound parameters in prepuberal children

BACKGROUND/OBJECTIVES

Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. This technique is related to several physical performance parameters and body composition components in adults; however, this relationship remains unexplored in early aged. We aimed to evaluate the association between physical fitness components with muscle ultrasound parameters in prepuberal children.

METHODS

A sample of 282 prepuberal children aged 5-9 years (144 boys) participated in the study. A trained sonographer obtained six B-mode images from femoral rectus for muscle thickness, subcutaneous adipose tissue (SAT) and area of the muscle of interest, were captured, and muscle ultrasound parameters (echo-intensity: EI _uncorrected, EI _{correct equations}) and intramuscular adipose tissue (IMAT) were extracted. Lean muscle tissue has low EI, whereas intramuscular fat and connective tissue have high EI. Physical fitness components (cardiorespiratory fitness, upper and lower muscle strength, speed-agility, and overall fitness levels) were also evaluated. Children were categorized as fit or unfit for each specific fitness test.

RESULTS

After adjustment for sex and age, higher physical fitness components and overall fitness (z-score) levels were negatively associated with EI, IMAT, and SAT (cardiorespiratory fitness β range = -0.264 to -0.298; upper-muscular strength β range = -0.389 to -0.457; and lower-muscular strength β range = -0.202 to -0.279; and speed-agility β range = -0.257 to -0.302). Children categorized as fit according to four physical fitness components had lower EI _uncorrected, EI _{correct equation 1-2}, IMAT, and SAT than unfit children for each respective tests (all Ps < 0.001).

CONCLUSION

Physical fitness components are inversely associated with EI, IMAT, SAT after adjusting for potential confounders, including sex and age, in prepuberal children. The present study strengthens the idea that muscle and adiposity parameters is affected by physical fitness even from early childhood.

Quality Matters as Much as Quantity of Skeletal Muscle: Clinical Implications of Myosteatosis in Cardiometabolic Health

Although age-related changes in skeletal muscles are closely associated with decreases in muscle strength and functional decline, their associations with cardiometabolic diseases in the literature are inconsistent. Such inconsistency could be explained by the fact that muscle quality-which is closely associated with fatty infiltration of the muscle (i.e., myosteatosis)-is as important as muscle quantity in cardiometabolic health. However, muscle quality has been less explored compared with muscle mass. Moreover, the standard definition of myosteatosis and its assessment methods have not been established yet. Recently, some techniques using single axial computed tomography (CT) images have been introduced and utilized in many studies, as the mass and quality of abdominal muscles could be measured opportunistically on abdominal CT scans obtained during routine clinical care. Yet, the mechanisms by which myosteatosis affect metabolic and cardiovascular health remain largely unknown. In this review, we explore the recent advances in the assessment of myosteatosis and its changes associated with aging. We also review the recent literature on the clinical implication of myosteatosis by focusing on metabolic and cardiovascular diseases. Finally, we discuss the challenges and unanswered questions that need addressing to set myosteatosis as a therapeutic target for the prevention or treatment of cardiometabolic diseases.

Exercise effects on muscle quality in older adults: a systematic review and meta-analysis

To systematically review and analyse the effects of exercise on morphological and neuromuscular muscle quality (MQ) outcomes in older adults and assess a range of possible moderators that may affect the impact of exercise on MQ outcomes. Using PRISMA guidelines, randomised controlled trials were searched in CINAHL, EMBASE, LILACS, PubMed, SciELO, Web of Science, MedNar, OpenGrey and OpenThesis databases. Eligible trials examined the effects of exercise interventions on morphological and neuromuscular MQ in older adults (≥ 60 years). Twenty-one trials (n = 973 participants) were included. Exercise significantly improved morphological MQ (effect size (ES) = 0.32, 95% CI 0.13–0.51, P < 0.001) with significant results maintained for studies assessing muscle density and intermuscular adipose tissue (ES = 0.45–0.52, P < 0.05). For neuromuscular MQ, exercise provided significant positive effects (ES = 0.49, 95% CI 0.29–0.69, P < 0.001) but only maintained for physically healthy participants (ES = 0.43, P < 0.001), resistance exercise interventions (ES = 0.64, P < 0.001), or studies assessing 1-RM or knee extensor isokinetic muscle strength relative to leg lean mass (ES = 0.48–0.62, P = 0.001). Associations between exercise duration and changes in MQ measures were not observed (P > 0.05). Supervised exercise interventions significantly improved different measures of MQ regardless of exercise duration, although these effects were small-to-moderate and not supported across all population-, exercise-, and methods-related features.

A Retrospective Cohort Study of Myosteatosis and Quality of Life in Head and Neck Cancer Patients

Simple Summary

Quality of life (QOL) is an important patient reported outcome that effects both care and life outside of treatment. There is a shortage of nontaxing ways to determine which patients may need enhanced care over the course of their therapy and beyond to help avoid long-term declines in QOL. Therefore, we investigated whether myosteatosis as determined through existing diagnostic imaging could be used to predict QOL trajectories. In this study, patients with pretreatment myosteatosis were more likely to have lower physical and global QOL scores than patients with normal muscle density. In conclusion, myosteatosis may be a way of determining patients in need of extra assistance over the course of treatment and afterwards.

Abstract

Head and neck cancer (HNC) treatment-related morbidity can be detrimental to quality of life (QOL). Myosteatosis is associated with poor QOL in multiple cancers. If predictive of poor QOL trajectories, myosteatosis would be a tool for clinicians to determine which patients may require additional support during treatment. The purpose of this study was to determine if pretreatment myosteatosis is associated with a poor QOL trajectory following treatment completion. Methods: In a retrospective cohort design, myosteatosis was determined from pretreatment CT scans. Both physical and global QOL score was assessed through patient interview on follow-up appointment. Demographic, cancer-specific, and social covariates were collected, reported, and considered as potential confounders. Results: The population of 163 patients was mostly male (82.2%) and white (91.4%) with oropharyngeal cancer (55.8%). Males with myosteatosis had a physical QOL score 46.84 points lower at one-year following treatment completion (p = 0.01) than those with normal muscle density (p = 0.01). Males with myosteatosis averaged 57.57 points lower at one-year post-treatment (p = 0.01) in global QOL scores. Conclusions: Over one year following completion of treatment, patients with myosteatosis reported worse physical and global QOL scores than patients with normal muscle density.

Walking Exercise Therapy Effects on Lower Extremity Skeletal Muscle in Peripheral Artery Disease

Walking exercise is the most effective noninvasive therapy that improves walking ability in peripheral artery disease (PAD). Biologic mechanisms by which exercise improves walking in PAD are unclear. This review summarizes evidence regarding effects of walking exercise on lower extremity skeletal muscle in PAD. In older people without PAD, aerobic exercise improves mitochondrial activity, muscle mass, capillary density, and insulin sensitivity in skeletal muscle. However, walking exercise increases lower extremity ischemia in people with PAD, and therefore, mechanisms by which this exercise improves walking may differ between people with and without PAD. Compared with people without PAD, gastrocnemius muscle in people with PAD has greater mitochondrial impairment, increased reactive oxygen species, and increased fibrosis. In multiple small trials, walking exercise therapy did not consistently improve mitochondrial activity in people with PAD. In one 12-week randomized trial of people with PAD randomized to supervised exercise or control, supervised treadmill exercise increased treadmill walking time from 9.3 to 15.1 minutes, but simultaneously increased the proportion of angular muscle fibers, consistent with muscle denervation (from 7.6% to 15.6%), while angular myofibers did not change in the control group (from 9.1% to 9.1%). These findings suggest an adaptive response to exercise in PAD that includes denervation and reinnervation, an adaptive process observed in skeletal muscle of people without PAD during aging. Small studies have not shown significant effects of exercise on increased capillary density in lower extremity skeletal muscle of participants with PAD, and there are no data showing that exercise improves microcirculatory delivery of oxygen and nutrients in patients with PAD. However, the effects of supervised exercise on increased plasma nitrite abundance after a treadmill walking test in people with PAD may be associated with improved lower extremity skeletal muscle perfusion and may contribute to improved walking performance in response to exercise in people with PAD. Randomized trials with serial, comprehensive measures of muscle biology, and physiology are needed to clarify mechanisms by which walking exercise interventions improve mobility in PAD.

Sarcopenic Obesity in Africa: A Call for Diagnostic Methods and Appropriate Interventions

This perspective aims to highlight the lack of current knowledge on sarcopenic obesity in Africa and to call for diagnostic methods and appropriate interventions. Sarcopenic obesity has been defined as obesity that occurs in combination with low muscle mass and function, which is typically evident in older adults. However, there has been no clear consensus on population-specific diagnostic criterion, which includes both gold-standard measures that can be used in a more advanced health care system, and surrogate measures that can be used in low-income settings with limited resources and funding. Importantly, low and middle-income countries (LMICs) across Africa are in an ongoing state of economic and social transition, which has contributed to an increase in the aging population, alongside the added burden of poverty, obesity, and associated co-morbidities. It is anticipated that alongside the increased prevalence of obesity, these countries will further experience an increase in age-related musculoskeletal diseases such as sarcopenia. The developmental origins of health and disease (DOHaD) approach will allow clinicians and researchers to consider developmental trajectories, and the influence of the environment, for targeting high-risk individuals and communities for treatment and/or prevention-based interventions that are implemented throughout all stages of the life course. Once a valid and reliable diagnostic criterion is developed, we can firstly assess the prevalence and burden of sarcopenic obesity in LMICs in Africa, and secondly, develop appropriate and sustainable interventions that target improved dietary and physical activity behaviors throughout the life course.