The rate and assessment of muscle wasting during critical illness: a systematic review and meta-analysis.

BACKGROUND: Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no synthesis of the data of intensive care unit (ICU) muscle wasting studies, so the true mean rate of muscle loss across all studies is unknown. The aim of this project was therefore to systematically synthetise data on the rate of muscle loss and to identify the methods used to measure muscle size and to synthetise data on the prevalence of ICU-acquired weakness in critically ill patients. METHODS: We conducted a systematic literature search of MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE until January 2022 (International Prospective Register of Systematic Reviews [PROSPERO] registration: CRD420222989540. We included studies with at least 20 adult critically ill patients where the investigators measured a muscle mass-related variable at two time points during the ICU stay. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the Newcastle-Ottawa Scale. RESULTS: Fifty-two studies that included 3251 patients fulfilled the selection criteria. These studies investigated the rate of muscle wasting in 1773 (55%) patients and assessed ICU-acquired muscle weakness in 1478 (45%) patients. The methods used to assess muscle mass were ultrasound in 85% (n = 28/33) of the studies and computed tomography in the rest 15% (n = 5/33). During the first week of critical illness, patients lost every day -1.75% (95% CI -2.05, -1.45) of their rectus femoris thickness or -2.10% (95% CI -3.17, -1.02) of rectus femoris cross-sectional area. The overall prevalence of ICU-acquired weakness was 48% (95% CI 39%, 56%). CONCLUSION: On average, critically ill patients lose nearly 2% of skeletal muscle per day during the first week of ICU admission.

[Relationship between physical activity and muscle mass loss among people aged 60 and above in 15 provinces of China in 2015].

OBJECTIVE: To analyze the relationship between physical activity and muscle mass loss among Chinese elderly aged 60 years and above in 15 provinces. METHODS: Data was collected from 2015 China Nutritional Transition Cohort Study. Information on demographic characteristics and physical activity was investigated by questionnaire. Dietary intake was estimated from three consecutive 24-h recalls for each individual. Appendicular skeletal muscle mass(ASM) was assessed using the bioelectrical impedance analysis(BIA). Skeletal muscle mass(SMI) loss was diagnosed according Asian working group of sarcopenia(AWGS) 2019 recommendation(male: SMI <7.0 kg/m~2, female: <5.7 kg/m~2). A total of 4565 participants aged 60 years and above from 15 provinces in China with complete information were included in the final analysis. Different domains(occupational, domestic, travel and leisure), light physical activity(<3.0 METs), moderate physical activity(3.0-5.9 METs) and vigorous physical activity(≥6.0 METs) of physical activity among elderly adults were evaluated. Logistic multilevel model was used to analyze the relationship between low muscle mass and different intensity of physical activity duration. RESULTS: Among all participants aged 60 years and above in 15 provinces of China in 2015, women's participation rate in domestic physical activity was 91.7%, which was higher than men's rate of 62.3%. However, men's participation rate in occupational, travel and leisure physical activity were higher than those of women. The participation rate, duration of light physical activity and moderate physical activity were higher in women than in men(light physical activity: female duration 11.0 h/week vs. male duration 3.5 h/week; female participation rate 89.9% vs. male participation rate 62.8%; moderate physical activity: female duration 7.0 h/week vs. male duration 4.7 h/week; female participation rate 90.6% vs. male participation rate 75.2%). The median vigorous physical activity was 0 h/week in both male and female group. The prevalence of muscle mass loss was 13.9% among subjects. The median weekly light physical activity and moderate physical activity in muscle mass loss group were 5.8 h and 4.7 h, which were lower than in non-muscle mass loss group(9.3 h and 6.0 h). The OR of muscle mass lass was 0.71(95%CI 0.42-0.98, P<0.05) for the male with 3.5-6.9 hours of moderate physical activity per week, compared to moderate physical activity less than 3.5 h/week. And OR of the female was 0.67(95%CI 0.47-0.95, P<0.05). CONCLUSION: The vast majority of physical activity in China among the elderly is domestic and light physical activity. Light physical activity and moderate physical activity duration increments in female and moderate physical activity duration increments in male were associated with decreased risk of muscle mass loss.

Protein intake and muscle mass maintenance in patients with cancer types with high prevalence of sarcopenia: a systematic review.

RATIONALE: Cancer is associated with muscle wasting. However, optimal protein intake has not been determined, limiting the efficacy of nutritional interventions. This systematic review aims to assess the effect of protein intake on muscle mass of patients with cancer types with high prevalence of sarcopenia during treatment, in longitudinal studies. METHODS: MEDLINE, CINAHL, and Scopus databases were searched following PRISMA guidelines. Longitudinal studies written in English, including adults with high sarcopenia prevalence cancer diagnosis, submitted to (chemo)radiotherapy, with assessment of protein intake and muscle changes during treatment, published until 4 October 2020 were included. Studies including supplementation with substances, such as n-3 fatty acids, specific amino acids, or proteins, were excluded. Study appraisal was independently conducted by two reviewers, and a qualitative research synthesis was performed. RESULTS: Overall, 575 records were identified, of which, eight studies were included (one randomized clinical trial and seven uncontrolled before and after studies). Patients with head and neck (n = 5), lung (n = 2), and esophageal cancer (n = 1) were included, comprising a total of 554 participants. The studies presented heterogeneous methodologies, objectives, and methods to assess body composition. Overall, participant groups with a mean protein intake below 1.2 g/kg presented muscle wasting, with one exception, while those reporting a mean intake above 1.4 g/kg, maintained muscle during treatment. CONCLUSIONS: Our findings show that protein intakes below 1.2 g/kg, even when within the recommendations, have been associated with muscle wasting during treatment. Only intakes above 1.4 g/kg have been associated with muscle maintenance. High-quality research is needed to establish an optimal dose response.

Comparison of postoperative temporalis muscle atrophy between the muscle-preserving pterional approach and the mini-pterional approach in the treatment of unruptured intracranial aneurysms.

This study aimed to compare the muscle-preserving pterional approach (modified classic pterional approach, mCP) and the mini-pterional approach (mPA) with respect to postoperative temporalis muscle atrophy.From November 2013 to April 2020, 78 patients with unruptured intracranial aneurysm of the anterior circulation underwent surgery using mCP or mPA in our institution. Patients' background characteristics, postoperative complications, and temporalis muscle volume (MV) rates (operative side/healthy side) were retrospectively investigated. In 64 patients (n = 31, mCP group; n = 33, mPA group), excluding 14 patients with missing imaging data from 6 to 24 months after surgery, associations between the MV rate and clinical variables were assessed. A multiple regression model was used to examine the association between the MV rate and the surgical method, which is a predictor of postoperative atrophy.The mCP group had a significantly higher mean MV rate than the mPA group (0.955 ± 0.040 and 0.915 ± 0.070, respectively; p = 0.008). Based on the results of the univariate analysis, a multiple regression model was established using sex, age, follow-up period, and the presence of diabetes in addition to the surgical method. Patients who underwent mCP had a higher MV rate than those who underwent mPA (t value = 2.33, p = 0.023).The present result suggested that mCP has a preventive effect on postoperative temporalis muscle atrophy. However, further studies are needed in order to prove that mCP is also effective in terms of postoperative aesthetic and functional outcomes.

Gene-specific facial dysmorphism in Axenfeld-Rieger syndrome caused by FOXC1 and PITX2 variants.

Axenfeld-Rieger syndrome is a genetic condition characterized by ocular and systemic features and is most commonly caused by variants in the FOXC1 or PITX2 genes. Facial dysmorphism is part of the syndrome but the differences between both genes have never been systematically assessed. Here, 11 facial traits commonly reported in Axenfeld-Rieger syndrome were assessed by five clinical geneticists blinded to the molecular diagnosis. Individuals were drawn from the Australian and New Zealand Registry of Advanced Glaucoma in Australia or recruited through the Genetic and Ophthalmology Unit of l'Azienda Socio-Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Italy. Thirty-four individuals from 18 families were included. FOXC1 variants were present in 64.7% of individuals and PITX2 variants in 35.3% of individuals. A thin upper lip (55.9%) and a prominent forehead (41.2%) were common facial features shared between both genes. Hypertelorism/telecanthus (81.8% vs 25.0%, p = 0.002) and low-set ears (31.8% vs 0.0%, p = 0.036) were significantly more prevalent in individuals with FOXC1 variants compared with PITX2 variants. These findings may assist clinicians in reaching correct clinical and molecular diagnoses, and providing appropriate genetic counseling.

Obesity-associated poor muscle quality: prevalence and association with age, sex, and body mass index.

BACKGROUND: Muscle quality (i.e., the expression of muscle function per unit of muscle mass) has been proposed as a clinically-relevant measure to detect individuals at risk of functional incapacity. Individuals with obesity might be at an increased risk of having poor muscle quality. Thus, we aimed to analyze the prevalence of poor muscle quality in obese individuals, to determine associated variables, and to provide normative values for this population. METHODS: 203 individuals with obesity (103 women, age: 18-75 years, body mass index (BMI): 35-64 kg·m- 2) participated in this cross-sectional study. Their muscle strength (handgrip dynamometry), muscle power (sit-to-stand test) and muscle mass (bioelectrical impedance analysis) were measured, and muscle quality (strength/power to muscle mass ratio) was compared with reference values obtained in young healthy individuals. Muscle quality was individually categorized as normal, low or poor based on specific muscle strength and power (i.e., strength and power per unit of muscle mass, respectively). Sex and age-specific normative values of specific muscle strength and power were computed for the whole cohort. RESULTS: Age and being a woman were inversely associated with specific muscle strength, with age being also inversely associated with specific muscle power. A small proportion of participants (6%) presented with an impaired (i.e., low/poor) specific muscle power while most of them (96%) had impaired specific muscle strength. Eventually, 84% of the participants were deemed to have poor muscle quality. Being a woman (odds ratio [OR]: 18.09, 95% confidence intervals [CI]: 4.07-80.38), age (OR: 1.06, 95%CI: 1.03-1.10) and BMI (OR: 1.22, 95%CI: 1.07-1.38) were independently associated with a higher risk of poor muscle quality in adjusted analyses. CONCLUSIONS: These findings show a high prevalence of poor muscle quality among individuals with obesity, with age, sex and BMI being independent predictors.

Estimating the Prevalence of Muscle Wasting, Weakness, and Sarcopenia in Hemodialysis Patients.

OBJECTIVES: Haemodialysis (HD) patients suffer from nutritional problems, which include muscle wasting, weakness, and cachexia, and are associated with poor clinical outcomes. The European Working Group for Sarcopenia in Older People (EWGSOP) and Foundations for the National Institute of Health (FNIH) have developed criteria for the assessment of sarcopenia, including the use of non-invasive techniques such as bioelectrical impedance assessment (BIA), anthropometry, and hand grip strength (HGS) dynamometry. This study investigated the prevalence of muscle wasting, weakness, and sarcopenia using the EWGSOP and FNIH criteria. METHODS: BIA was performed in 24 females (f) and 63 males (m) in the post-dialysis period. Total skeletal muscle mass and appendicular skeletal muscle mass were estimated and index values (i.e., muscle mass divided by height2 [kg/m2]) were calculated (Total Skeletal Muscle Index (TSMI) and Appendicular Skeletal Muscle Index (ASMI)). Mid-arm circumference and triceps skin-fold thickness were measured and mid-upper arm muscle circumference (MUAMC) calculated. HGS was measured using a standard protocol and Jamar dynamometer. Suggested cut-points for low muscle mass and grip strength were utilized using the EWGSOP and FNIH criteria with prevalence estimated, including sarcopenia. RESULTS: The prevalence varied depending on methodology: low TSMI (moderate and severe sarcopenia combined) was 55% for whole group: 21% (f) and 68% (m). Low ASMI was 32% for whole group: 25% (f) and 35% (m). Low MUAMC was 25% for whole group: 0% (f) and 30% (m). ASMI highly correlated with Body Mass Index (r = 0.78, P < .001) and MUAMC (r = 0.68, P < .001). Muscle weakness was high regardless of cut-points used (50-71% (f); 60-79% (m)). CONCLUSIONS: Internationally, this is the first study comparing measures of muscle mass (TSMM and ASMM by BIA and MUAMC) and muscle strength (HGS) using this specific methodology in a hemodialysis population. Future work is required to confirm findings.

Sagittal imbalance, muscle atrophy, and osteoporosis: risk factors for revision posterior lumbar fusion surgery in patients with Parkinson's disease.

OBJECTIVE: The aim of our study was to evaluate features and complications of patients with Parkinson's disease (PD) who underwent posterior lumbar fusion surgery for lumbar degenerative diseases (LDD), as well as the risk factors for revision. METHODS: Between January 2010 and December 2016, 132 patients were retrospectively identified for inclusion. Patients were divided into a 29 revision PD group and a 103 non-revision PD group. Patient factors included bone mineral density (BMD) and severity of PD using the Hoehn and Yahr staging system. Surgical factors included surgical levels and fusion methods. Radiographic measurements included pre-operative spinopelvic parameters, paraspinal muscle atrophy, and fatty infiltration. Logistic regression analysis was used to determine independent predictors for revision posterior lumbar fusion. RESULTS: The average age of the PD patients was 67.96 years, and the follow-up time was 49.01 months. R-PD patients accounted for 21.97% of all PD patients who underwent lumbar fusion surgery. Multivariable analysis indicated that low BMD (p = 0.012), fatty infiltration (p = 0.038), a smaller relative cross-sectional area (rCSA) of the paraspinal muscle (p = 0.008), larger pelvic incidence-lumbar lordosis (PI-LL) (p = 0.01), and sagittal vertical axis (SVA) (p = 0.004) were significant independent risk factors for revision posterior lumbar fusion in PD patients. CONCLUSION: PD patients with low pre-operative BMD, fatty infiltration, a smaller rCSA of the paraspinal muscle, and larger PI-LL and SVA had a higher rate of revision lumbar fusion. Maintaining sagittal balance, functional exercises, and anti-osteoporosis treatment were important in preventing complications in PD patients.

The Molecular Mechanisms and Prevention Principles of Muscle Atrophy in Aging.

Muscle atrophy in aging is characterized by progressive loss of muscle mass and function. Muscle mass is determined by the balance of synthesis and degradation of protein, which are regulated by several signaling pathways such as ubiquitin-proteasome system, autophagy-lysosome systems, oxidative stress, proinflammatory cytokines, hormones, and so on. Sufficient nutrition can enhance protein synthesis, while exercise can improve the quality of life in the elderly. This chapter will discuss the epidemiology, pathogenesis, as well as the current treatment for aging-induced muscular atrophy.

Prevalence and Risk of Protein-Energy Wasting Assessed by Subjective Global Assessment in Older Adults With Advanced Chronic Kidney Disease: Results From the EQUAL Study.

OBJECTIVES: Prevalence and risk factors for protein-energy wasting (PEW) are poorly studied in the nondialysis, older population with advanced chronic kidney disease (CKD). Our aim was to evaluate the prevalence of PEW in advanced stage CKD patients aged greater than 65 years. Furthermore, we aimed to describe risk factors for PEW in the overall study population and among obese individuals. DESIGN: Prospective observational cohort study. METHODS: The EQUAL study, a European Quality Study on treatment in advanced chronic kidney disease, is a multicenter prospective observational cohort study in six European countries. We included patients aged ≥65 years with incident glomerular filtration rate <20mL/min/1.73m2 not on dialysis attending nephrology care. PEW was assessed by 7-point Subjective Global Assessment (7-p SGA). RESULTS: In general, the study cohort (n = 1,334) was overweight (mean body mass index [BMI] 28.4 kg/m2). The majority of the patients had a normal nutritional status (SGA 6-7), 26% had moderate PEW (SGA 3-5), and less than 1% had severe PEW (SGA 1-2). Muscle wasting and loss of fat tissue were the most frequent alterations according to the SGA subscales, especially in those aged >80 years. The prevalence of PEW was higher among women, increased with age, and was higher in those with depression/dementia. PEW was the most common in those with underweight (BMI <22 kg/m2), 55% or normal weight (BMI 22-25 kg/m2), 40%. In obese individuals (BMI >30 kg/m2), 25% were diagnosed with protein wasting. Risk factors for SGA ≤5 in obese people were similar to those for the overall study population. CONCLUSION: This European multicenter study shows that the prevalence of PEW is high in patients with advanced CKD aged >65 years. The risk of PEW increases substantially with age and is commonly characterized by muscle wasting. Our study suggests that focus on nutrition should start early in the follow-up of older adults with CKD.

The prevalence and morphometric analysis of ossified superior transverse scapular ligaments in patients with rotator cuff tears.

BACKGROUND: The prevalence of ossified superior transverse scapular ligaments (OSTSLs) in rotator cuff tears (RCTs) has not yet been determined. The purposes of this study were to evaluate the prevalence of OSTSLs in RCTs and to investigate the correlation between OSTSL morphology and supraspinatus muscle atrophy. METHODS: We analyzed a total of 213 patients with RCTs for whom 3-dimensional (3D) computed tomography (CT) and magnetic resonance imaging were performed prior to arthroscopic procedures. The mean age of the patients was 59.73 ± 8.43 years, and 103 patients were men. OSTSLs were identified based on 3D CT findings. The correlations between OSTSLs and age, sex, and RCT size were analyzed. The horizontal and vertical diameters, area, and circumference of the suprascapular foramen were measured. By use of the occupation ratio calculated from magnetic resonance imaging results, supraspinatus muscle atrophy was evaluated. RESULTS: Of 213 patients with RCTs, 22 (10.3%) had OSTSLs. OSTSLs were found at a rate of 15.5% (16 of 103) in men, higher than that in women (P = .016). The rate of OSTSLs increased with age (P = .003). RCT size was not correlated with the prevalence of OSTSLs. As the horizontal diameter and circumference of the suprascapular foramen increased, muscle atrophy progressed (P = .001 and P = .046, respectively). CONCLUSION: One of ten patients with RCTs had OSTSLs; the rate of OSTSLs was higher among men and increased with age. For patients with RCTs preparing to undergo arthroscopic superior transverse ligament resection, preoperatively identifying OSTSLs through 3D CT would be useful for the resection.

Facial dysmorphism is influenced by ethnic background of the patient and of the evaluator.

The evaluation of facial dysmorphism is a critical step toward reaching a diagnostic. The aim of the present study was to evaluate the ability to interpret facial morphology in African children with intellectual disability (ID). First, 10 experienced clinicians (five from Africa and five from Europe) rated gestalt in 127 African non-Down Syndrome (non-DS) patients using either the score 2 for 'clearly dysmorphic', 0 for 'clearly non dysmorphic' or 1 for 'uncertain'. The inter-rater agreement was determined using kappa coefficient. There was only fair agreement between African and European raters (kappa-coefficient = 0.29). Second, we applied the FDNA Face2Gene solution to assess Down Syndrome (DS) faces. Initially, Face2Gene showed a better recognition rate for DS in Caucasian (80%) compared to African (36.8%). We trained the Face2Gene with a set of African DS and non-DS photographs. Interestingly, the recognition in African increased to 94.7%. Thus, training improved the sensitivity of Face2Gene. Our data suggest that human based evaluation is influenced by ethnic background of the evaluator. In addition, computer based evaluation indicates that the ethnic of the patient also influences the evaluation and that training may increase the detection specificity for a particular ethnic.

Effect of surgery-induced acute muscle wasting on postoperative outcomes and quality of life.

BACKGROUND: Gastrectomy results in a significant loss of body composition in the long term, but the acute skeletal muscle wasting after gastrectomy has been rarely investigated. Moreover, the association between postoperative muscle wasting and quality of life (QOL) has never been reported. In the present study, we aimed to investigate the risk factors for acute muscle wasting after gastric cancer surgery and its effect on QOL and short-term postoperative outcomes. METHODS: We conducted a prospective study of patients who underwent curative gastrectomy for gastric cancer between June 2015 and December 2015. Skeletal muscle mass was measured by computed tomography within 1 month before and 1 week after surgery. QOL was assessed 1, 3, and 6 months postoperatively. Univariate and multivariate analyses were performed to identify the risk factors for clinically relevant muscle wasting (muscle wasting ≥10%). RESULTS: A total of 110 patients were included, in which 35 patients had muscle wasting ≥10% within 1 week after surgery. Age ≥65 years and diabetes were independent risk factors for muscle wasting ≥10%. Patients with muscle wasting ≥10% had a poorer QOL in terms of fatigue and physical functioning at 1 and 3 months postoperatively, as well as a higher incidence of postoperative complications, a higher incidence of handgrip strength reduction ≥10%, longer hospital stays, and higher costs. CONCLUSIONS: Age ≥65 years and diabetes were independently associated with clinically relevant muscle wasting within 1 week after gastric cancer surgery. Clinically relevant muscle wasting was associated with a poorer QOL and short-term outcomes after surgery.

Minipterional Craniotomy for Treatment of Unruptured Middle Cerebral Artery Aneurysms. A Single-Center Comparative Analysis with Standard Pterional Approach as Regard to Safety and Efficacy of Aneurysm Clipping and the Advantages of Reconstruction.

Pterional craniotomy (PT) has long been the standard approach for the treatment of middle cerebral artery (MCA) aneurysms, even though it may cause temporalis muscle atrophy, facial nerve injury, and masticatory difficulties. Minipterional craniotomy (MPT) is an alternative approach that may provide the same surgical corridor, limiting the risk of postoperative esthetic and functional complications. From January 2011 to December 2014 we consecutively performed 68 craniotomies for surgical treatment of unruptured MCA aneuryms: 37 were standard PT and 31 were MPT. There were no significant differences in mean age, sex, and aneurysm topography between the two groups. The mean skin incision length was 14 cm in the PT group and 6 cm in the MPT group. According to the Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS), there were no significant differences in clinical outcome at discharge or follow-up between the two groups. Also, the rates of complete aneurysm exclusion were comparable. However, the number of patients complaining of masticatory disorders was higher among those treated with PT. Finally, the number of complications observed in the PT group was higher than that in the MPT group, but only the differences in mean hospitalization length and necessity for a dural patch for reconstruction were statistically significant. In conclusion, the MPT approach is a safe and effective alternative to the standard PT for the treatment of unruptured MCA aneurysms.

Does early exercise attenuate muscle atrophy or bone loss after spinal cord injury?

OBJECTIVES: To systematically identify and assess the evidence on the efficacy of exercise initiated early after traumatic spinal cord injury (SCI). METHODS: A comprehensive search (Any-2014) of eleven databases identified studies evaluating exercise interventions initiated within 12 weeks after SCI on muscle and bone loss in paralyzed limbs and comparing with standard care or immobilization. Two reviewers assessed methodological quality. One reviewer extracted data and critiqued results according to the Spinal Cord Injury Rehabilitation Evidence body of evidence framework. RESULTS: A total of 2811 titles were screened. Eleven studies were included: five randomized controlled trials, four cohort studies and two within-subject control studies. All provided level II evidence with a moderate risk of bias. Two studies found significant positive effects of high-load FES-resisted stance on physiological measures of muscle. Three reported positive effects of 3 months of Functional Electrical Stimulation (FES) on muscle size. Two studies found positive effects of 6-month body-weight supported treadmill training or FES on trabecular bone using pQCT. CONCLUSION: We found consistent evidence of positive effects of early exercise on muscle, possibly related to load intensity of the protocol. However, the heterogeneity of interventions and outcomes makes this determination speculative. Evidence for the effectiveness of early exercise on bone is scant and confined to measures of trabecular bone mineral density via pQCT. Transparent reporting of methods and variability of data, combined with standardization of valid and sensitive measures of muscle atrophy and bone loss, could facilitate future meta-analysis on this topic.

A Comparison of Methods for the Estimation of Body Composition in Highly Trained Wheelchair Games Players.

The purpose of this study was to assess the agreement in body composition measurements of wheelchair athletes using skinfolds, bio-impedance analysis (BIA) and air displacement plethysmography (ADP) relative to dual-energy X-ray absorptiometry (DXA). A secondary objective was to develop new skinfold prediction equations to estimate %fat for this sample. 30 wheelchair games players were recruited and the body composition outcomes of BIA, ADP, and skinfolds were compared to the DXA outcomes by a paired-samples t-test (systematic bias), intraclass correlation (ICC, relative agreement) and Bland-Altman plots (absolute agreement). Regression models to predict the %fat as measured by DXA by the sum of skinfolds or BIA were calculated. Results showed that the predictions of %fat when using BIA, ADP or skinfolds systematically underestimated the %fat mass as measured by the DXA. All ICC values, except for the measurement of fat (kg) by ADP (ICC=0.702), were below 0.7. New prediction models found the ∑7 skinfolds and calf circumference as the best model to predict %fat (R(2)=0.84). In conclusion, BIA, ADP and existing skinfolds equations should be used with caution when estimating %fat of wheelchair athletes with substantial body asymmetry, lower body muscular atrophy and upper body muscular development.

Creatinine clearance, walking speed, and muscle atrophy: a cohort study.

BACKGROUND: Chronic kidney disease is associated with malnutrition and inflammation. These processes may lead to loss of skeletal muscle and reduced physical performance. Associations of kidney function with muscle composition and longitudinal measures of physical performance are unknown. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We evaluated 826 community-dwelling older adults enrolled in the Invecchiare in Chianti (InCHIANTI) Study who were free of baseline stroke or activities of daily living disability. PREDICTOR: Baseline creatinine clearance (Clcr) based on 24-hour urine collection. OUTCOMES: Cross-sectional and longitudinal trajectories of physical performance measured by 7-m usual gait speed, 400-m fast gait speed, and knee extension strength using isometric dynamometry. Calf muscle composition assessed by quantitative computed tomography. RESULTS: Mean age of participants was 74 ± 7 (SD) years, with 183 having Clcr < 60 mL/min/1.73 m(2). After adjustment, each 10-mL/min/1.73 m(2) decrement in Clcr was associated with 0.01 (95% CI, 0.004-0.017) m/s slower 7-m usual walking speed and 0.008 (95% CI, 0.002-0.014) m/s slower 400-m walking speed. Each 10-mL/min/1.73 m(2) decrement in Clcr was associated with 28 (95% CI, 0.8-55) mm(2) lower muscle area and 0.15 (95% CI, 0.04-0.26) mg/cm(3) lower muscle density. After adjustment, lower Clcr was associated with slower mean 7-m (P=0.005) and 400-m (P=0.02) walk and knee extension strength (P=0.001) during the course of follow-up. During a mean follow-up of 7.1 ± 2.5 years, each 10-mL/min/1.73 m(2) lower baseline Clcr was associated with 0.024 (95% CI, 0.01-0.037) kg/y greater decline in knee strength. LIMITATIONS: Single baseline measurement of Clcr and 3-year interval between follow-up visits may lead to nondifferential misclassification and attenuation of estimates. CONCLUSIONS: Among older adults, lower Clcr is associated with muscle atrophy, reduced walking speed, and more rapid declines in lower-extremity strength over time.

Pattern difference of dissociated hand muscle atrophy in amyotrophic lateral sclerosis and variants.

INTRODUCTION: Split hand is considered to be a specific feature of amyotrophic lateral sclerosis (ALS). METHODS: We evaluated the pattern difference of intrinsic hand muscles of upper limb-onset ALS (UL-ALS), upper limb-onset progressive muscular atrophy (UL-PMA), brachial amyotrophic diplegia (BAD), and Hirayama disease (HD) by measuring objective electrophysiological markers. RESULTS: The abductor digiti minimi (ADM)/abductor pollicis brevis (APB) compound muscle action potential (CMAP) amplitude ratio was significantly higher in UL-ALS than other variants, but a considerable proportion of UL-ALS cases had an amplitude ratio in the range of other variants. Absent APB CMAP and abnormally high ADM/APB CMAP amplitude ratio (≥4) occurred only with UL-ALS. Conversely, an absent ADM CMAP was identified only in UL-PMA and BAD. CONCLUSIONS: The absolute ADM/APB CMAP amplitude ratio was not specific for ALS; however, several findings from simple electrophysiological measurements may help predict prognosis in patients with motor neuron diseases and may be early diagnostic markers for ALS.

Relation of serum 25-hydroxyvitamin D status with skeletal muscle mass by sex and age group among Korean adults.

The objective of this study was to examine whether high serum 25-hydroxyvitamin D (25(OH)D) concentration was associated with high skeletal muscle mass, taking into account the effects of sex and age among the participants of the Korea National Health and Nutrition Examination Survey (KNHANES) aged 40 years or older. This was a cross-sectional study using data from the 2009 to 2010 KNHANES; a total of 8406 subjects (3671 men and 4735 women) were included. The appendicular skeletal muscle mass index (ASMMI, kg/m2) was estimated to measure the skeletal muscle mass. Hypovitaminosis was classified when the level of serum 25(OH)D was <20 ng/ml. The general linear model adjusted for confounding factors was used to determine differences in means of ASMMI by 25(OH)D status. The mean values of ASMMI were higher for men when compared with women. Women had a greater proportion of hypovitaminosis (71·1%) compared with men (53·2%). After adjusting for multiple factors, men were seen to have significant differences in ASMMI based on 25(OH)D status regardless of age, showing a lower mean value of ASSMI in those with hypovitaminosis. However, there was no difference in ASMMI by 25(OH)D status among women in both younger and older age groups. In conclusion, we found that there might be a positive relationship between 25(OH)D and skeletal muscle mass in men, indicating that interventions to improve 25(OH)D levels that are aimed at increasing muscle mass could be beneficial for men with more rapid decreased rate of skeletal muscle mass.

Prevalence and pattern of gluteus medius and minimus tendon pathology and muscle atrophy in older individuals using MRI.

PURPOSE: To evaluate gluteus medius and minimus tendon pathology and muscle atrophy in older individuals using MRI. METHODS: A retrospective MRI study of 185 individuals was performed. The inclusion criterion was age ≥50. Exclusion criteria were hip surgery, fracture, infection, tumor, or inadequate image quality. Greater trochanteric bursitis was graded none, mild, moderate, or severe. Gluteus medius, gluteus minimus, and iliopsoas tendinopathy was graded normal, tendinosis, low-grade partial tear, high-grade partial tear, or full thickness tear. Gluteus medius, gluteus minimus, tensor fascia lata, and iliopsoas muscle atrophy was scored using a standard scale. Insertion site of tendinopathy and location of muscle atrophy were assessed. Descriptive and statistical analysis was performed. RESULTS: There was increasing greater trochanteric bursitis and gluteus medius and minimus tendinopathy and atrophy with advancing age with moderate to strong positive associations (p < 0.0001) for age and tendinopathy, age and atrophy, bursitis and tendinopathy, and tendinopathy and atrophy for the gluteus medius and minimus. There is a weak positive association (p < 0.0001) for age and tensor fascia lata atrophy, and no statistically significant association between age and tendinopathy or between age and atrophy for the iliopsoas. Fisher's exact tests were statistically significant (p < 0.0001) for insertion site of tendon pathology and location of muscle atrophy for the gluteus medius. CONCLUSIONS: Gluteus medius and minimus tendon pathology and muscle atrophy increase with advancing age with progression of tendinosis to low-grade tendon tears to high-grade tendon tears. There is an associated progression in atrophy of these muscles, which may be important in fall-related hip fractures.