Greater upper limb muscle mass associated with reduced cardiovascular mortality compared with other muscle groups in diabetics

OBJECTIVES

Although muscle mass and its distribution have been shown to affect prognosis, the association between regional muscle mass and cardiovascular mortality risk in diabetic patients remains unclear.

METHODS

This prospective cohort study analyzed data from 2166 individuals with diabetes who participated in the National Health and Nutrition Survey conducted in the United States between 2003 to 2006 and 2011 to 2018, linked to the National Death Index. Weighted Kaplan-Meier analysis and multivariable Cox proportional hazards models were used to explore the association between different regional lean mass and cardiovascular mortality.

RESULTS

The weighted Kaplan-Meier analysis revealed statistically significant differences in survival probabilities across lean upper limbs, lean lower limbs, lean gynoid, and lean trunk mass levels in diabetic participants (P < 0.05). In the multivariate adjusted Cox proportional hazards models, higher levels of upper limb lean mass were found to be associated with decreased cardiovascular mortality (hazard ratio, 0.589; 95% confidence interval, 0.332-0.976; P = 0.041). Notably, this correlation was more significant in men (hazard ratio, 0.378; 95% confidence interval, 0.171-0.834; P = 0.016), which was indicated by the results of the Cox regression and nonlinear regression analysis.

CONCLUSIONS

Higher upper limb lean mass is associated with lower cardiovascular mortality compared with other regional lean mass in patients with diabetes, especially for men. Further research is needed to elucidate the mechanisms involved in muscle metabolic differentiation.

Adiponectin-to-leptin ratio and incident chronic kidney disease: Sex and body composition-dependent association

BACKGROUND

The association between the adiponectin-to-leptin ratio (A/L ratio) and the risk of incident chronic kidney disease (CKD) is poorly understood. This study aimed to investigate the association between A/L ratio and the risk of incident CKD and to examine whether such a relationship varied according to sex and body composition.

METHODS

In this prospective community-based cohort, participants with normal kidney function were analysed (N = 5192). The association between the A/L ratio at baseline and the risk of incident CKD, defined as two or more occasions with an estimated glomerular filtration rate of <60 mL/min/m2 or proteinuria of ≥1+ on a dipstick test during the follow-up period, was evaluated using multivariable Cox proportional hazards analyses. Subgroup analyses were conducted based on sex, body mass index (BMI) and the presence of sarcopenia.

RESULTS

The participants' mean age was 57.2 ± 8.3 years, and 53.2% were women. The A/L ratio was higher in men compared with women (1.5 [0.8-3.2] and 0.5 [0.3-0.9] μg/ng, P < 0.001). During a median follow-up of 9.8 [9.5-10.0] years, 417 incident CKD events occurred (8.7 per 1000 person-years). Men in the highest quartile of A/L ratio had a lower risk of incident CKD (adjusted hazard ratio [aHR], 0.57; 95% confidence interval [CI], 0.33-0.99) than those in the lowest quartile. Additionally, a 1.0 increase in A/L ratio was associated with a 12% decreased risk of incident CKD in men (aHR, 0.88; 95% CI, 0.80-0.97). However, no significant association was observed in women. In subgroup analysis stratified by BMI and the presence of sarcopenia, the association between a high A/L ratio and a reduced risk of incident CKD was consistent in men with a BMI < 23.0 kg/m2 and those with sarcopenia. However, no significant association was observed between men with a BMI ≥ 23.0 kg/m2 and those without sarcopenia.

CONCLUSIONS

A high A/L ratio is an independent marker of a reduced risk of incident CKD in men, especially in those with a BMI < 23.0 kg/m2 and sarcopenia.

Evaluation of muscle mass and intramuscular fatty infiltration in dogs with hypercortisolism and their association with prognosis

BACKGROUND

Muscle atrophy and intramuscular fatty infiltration, as well as their association with prognosis, have not been quantified in dogs with spontaneous hypercortisolism (HC).

OBJECTIVE

To quantitatively evaluate muscle atrophy and IM fatty infiltration in dogs with HC and determine their prognostic impact.

ANIMALS

Fifty-three dogs with HC and 66 control dogs without HC.

METHODS

Retrospective cohort study. Medical records and computed tomography images obtained between 2014 and 2021 were evaluated. Kaplan-Meier curves and log-rank tests were used to analyze the effect of muscle atrophy and IM fatty infiltration on the prognosis of dogs with HC.

RESULTS

Dogs with HC showed lower visually measured cross-sectional area (VCSA) and cross-sectional area based on attenuation (HCSA) than control dogs (median [interquartile range {IQR}]: 50.3 mm2/mm [36.2-67.8] vs 66.7 mm2/mm [48.0-85.9]; P < .001; 30.4 mm2/mm [13.7-57.2] vs 54.8 mm2/mm [39.7-71.5]; P < .001, respectively). Dogs with HC had lower epaxial muscle attenuation (L3HU) than control dogs (median [IQR]: 21.2 Hounsfield [HU] [12.4-28.2] vs 33.2 HU [22.6-43.6]; P < .001). Dogs with HC with lower HCSA or L3HU had shorter survival (median [IQR]: 670 days [222-673] vs 949 days [788-1074], P < .01; 523 days [132-670] vs 949 days [756-1074], P < .01, respectively) but not lower VCSA (median [IQR]: 673 days [132-788] vs 949 days [523 to not applicable]; P = .30).

CONCLUSION AND CLINICAL IMPORTANCE

Hypercortisolism in dogs causes muscle atrophy and IM fatty infiltration and is associated with poor prognosis.

Sarcopenia as a robust predictor of readmission within six months among individuals experiencing acute stroke

Objective

Sarcopenia negatively affects the short-term prognosis of hospitalized older adults. However, no evidence currently supports a direct relationship between sarcopenia and readmission among individuals who have experienced an acute stroke. Therefore, we investigated whether sarcopenia is associated with readmission after discharge.

Methods

This retrospective cohort study included patients who had experienced acute stroke. Sarcopenia was defined as the coexistence of low skeletal muscle mass index (SMI) and grip strength. We applied the log-rank test and Cox proportional hazards regression analysis to analyze whether sarcopenia, low SMI, and low grip strength were associated with readmission within 6 months.

Results

Among 228 included patients (mean age, 72.8 years; 146 males), the prevalence of sarcopenia was 24.6% (n=56; male, 17.8%; female, 36.6%). Cox proportional hazards regression analysis using the propensity score as a covariate revealed that sarcopenia (hazard ratio [HR] 7.21 [95% confidence interval (CI) 1.45-35.8]; p=0.016) and low skeletal muscle mass (HR 7.40 [95% CI 1.14-48.1; p=0.036), but not low grip strength (HR 1.42 [95% CI 0.281-7.21]; p=0.670), were significantly associated with readmission for stroke within 6 months.

Conclusions

Sarcopenia was negatively associated with readmission within 6 months of stroke onset in patients in Japan who had experienced an acute stroke. These findings suggest that the identification of sarcopenia may facilitate prognostic prediction from the acute stage and intervention(s) to prevent rehospitalization.

Effect of Sarcopenia on 10-Year Risk of Atherosclerotic Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus

Objective

To investigate the impact of sarcopenia on the 10-year risk of atherosclerotic cardiovascular disease (ASCVD) among individuals with type 2 diabetes mellitus (T2DM).

Methods

This study included the clinical, laboratory, and body composition data of 1491 patients with T2DM who were admitted to the Department of Endocrinology and Metabolism at Tianjin Union Medical Center from July 2018 to July 2023. The China-PAR model was utilized to evaluate cardiovascular disease risk. Associations between ASCVD risk and various clinical parameters were analyzed, and the relationship between body composition parameters and ASCVD risk was assessed using logistic regression.

Results

The analysis revealed that T2DM patients with sarcopenia had a higher 10-year ASCVD risk compared to those without sarcopenia, with reduced muscle mass independently predicting an increased risk of cardiovascular disease. This association was significant among female T2DM patients, while male T2DM patients with sarcopenia showed a marginally higher median ASCVD risk compared to their non-sarcopenic counterparts. ASCVD risk inversely correlated with body muscle parameters and positively correlated with fat content parameters. Specifically, height- and weight-adjusted fat mass (FM, FM%, FMI) were identified as risk factors for ASCVD. Conversely, muscle parameters adjusted for weight and fat (ASM%, SMM%, FFM%, ASM/FM, SMM/FM, FMM/FM) were protective against ASCVD risk. These findings highlight the critical role of sarcopenia in influencing cardiovascular disease risk among Chinese patients with T2DM, as predicted by the China-PAR model.

Conclusion

This study highlights the importance of sarcopenia in T2DM patients, not only as an indicator of ASCVD risk, but possibly as an independent risk factor in this demographics.

Dietary Inflammatory Index and Dietary Diversity Score Associated with Sarcopenia and Its Components: Findings from a Nationwide Cross-Sectional Study

Little is known about the independent and joint effects of the energy-adjusted dietary inflammatory index (E-DII) and dietary diversity score (DDS) on sarcopenia and its components (low muscle mass, low muscle strength, and low physical performance). A total of 155,669 UK Biobank participants with ≥1 (maximum 5) 24 h dietary assessments were included in this cross-sectional analysis. We used logistic regression models to investigate the associations of E-DII and DDS with sarcopenia and its three components. We further examined the joint effects of E-DII and DDS on sarcopenia and its components using additive and multiplicative interaction analyses. We observed that lower E-DII and higher DDS were associated with lower odds of sarcopenia and its components. There were significant joint associations of E-DII and DDS with sarcopenia and low physical performance (p-interaction < 0.05) on the multiplicative interactive scale. Our study suggests that lower dietary inflammatory potential and higher dietary diversity might be important protective factors against sarcopenia and its components. More cases of sarcopenia and low physical performance might be preventable by adherence to a more anti-inflammatory diet combined with a higher dietary diversity.

Explanatory sequential mixed-methods approach to understand how registered dietitians implemented computed tomography skeletal muscle assessments in clinical practice

BACKGROUND

There is a need to adopt valid techniques to assess skeletal muscle (SM) in clinical practice. SM can be precisely quantified from computed tomography (CT) images. This study describes how registered dietitians (RDs), trained to quantify SM from CT images, implemented this technique in clinical practice.

METHODS

This was an explanatory sequential mixed-methods design with a quantitative and a qualitative phase. RDs collected data describing how they implemented CT SM assessments in clinical practice, followed by a focus group exploring barriers and enablers to using CT SM assessments.

RESULTS

RDs (N = 4) completed 96 CT SM assessments, with most (94%, N = 90/96) taking <15 min to complete. RDs identified reduced muscle mass in 63% (N = 45/72) of men and 71% (N = 17/24) of women. RDs used results of CT SM assessments to increase protein composition of the diet/nutrition support, advocate for initiation or longer duration of nutrition support, coordinate nutrition care, and provide nutrition education to patients and other health service providers. The main barriers to implementing CT SM assessments in clinical practice related to cumbersome health system processes (ie, CT image acquisition) and challenges integrating CT image analysis software into the health system computing environment.

CONCLUSION

Preliminary results suggest RDs found CT SM assessments positively contributed to their nutrition care practice, particularly in completing nutrition assessments and in planning, advocating for, and implementing nutrition interventions. Use of CT SM assessments in clinical practice requires innovative IT solutions and strategies to support skill development and use in clinical nutrition care.

Absence of association between low calf circumference, adjusted or not for adiposity, and ICU mortality in critically ill adults: A secondary analysis of a cohort study

BACKGROUND

Despite its correlation with skeletal muscle mass and its predictive value for adverse outcomes in clinical settings, calf circumference is a metric underexplored in intensive care. We aimed to determine whether adjusting low calf circumference for adiposity provides prognostic value superior to its unadjusted measurement for intensive care unit (ICU) mortality and other clinical outcomes in critically ill patients.

METHODS

In a secondary analysis of a cohort study across five ICUs, we assessed critically ill patients within 24 h of ICU admission. We adjusted calf circumference for body mass index (BMI) (25-29.9, 30-39.9, and ≥40) by subtracting 3, 7, or 12 cm from it, respectively. Values ≤34 cm for men and ≤33 cm for women identified low calf circumference.

RESULTS

We analyzed 325 patients. In the primary risk-adjusted analysis, the ICU death risk was similar between the low and preserved calf circumference (BMI-adjusted) groups (hazard ratio, 0.90; 95% CI, 0.47-1.73). Low calf circumference (unadjusted) increased the odds of ICU readmission 2.91 times (95% CI, 1.40-6.05). Every 1-cm increase in calf circumference as a continuous variable reduced ICU readmission odds by 12%. Calf circumference showed no significant association with other clinical outcomes.

CONCLUSION

BMI-adjusted calf circumference did not exhibit independent associations with ICU and in-hospital death, nor with ICU and in-hospital length of stay, compared with its unadjusted measurement. However, low calf circumference (unadjusted and BMI-adjusted) was independently associated with ICU readmission, mainly when analyzed as a continuous variable.

Association between protein intake and muscle wasting in critically ill children: A prospective cohort study

BACKGROUND

Survival from pediatric critical illness in high-income countries is high, and the focus now must be on optimizing the recovery of survivors. Muscle mass wasting during critical illness is problematic, so identifying factors that may reduce this is important. Therefore, the aim of this study was to examine the relationship between quadricep muscle mass wasting (assessed by ultrasound), with protein and energy intake during and after pediatric critical illness.

METHODS

A prospective cohort study in a mixed cardiac and general pediatric intensive care unit in England, United Kingdom. Serial ultrasound measurements were undertaken at day 1, 3, 5, 7, and 10.

RESULTS

Thirty-four children (median age 6.65 [0.47-57.5] months) were included, and all showed a reduction in quadricep muscle thickness during critical care admission, with a mean muscle wasting of 7.75%. The 11 children followed-up had all recovered their baseline muscle thickness by 3 months after intensive care discharge. This muscle mass wasting was not related to protein (P = 0.53, ρ = 0.019) (95% CI: -0.011 to 0.049) or energy intake (P = 0.138, ρ = 0.375 95% CI: -0.144 to 0.732) by 72 h after admission, nor with severity of illness, highest C-reactive protein, or exposure to intravenous steroids. Children exposed to neuromuscular blocking drugs exhibited 7.2% (95% CI: -0.13% to 14.54%) worse muscle mass wasting, but this was not statistically significant (P = 0.063).

CONCLUSION

Our study did not find any association between protein or energy intake at 72 h and quadricep muscle mass wasting.

Gromwell (Lithospermum erythrorhizon) Attenuates High-Fat-Induced Skeletal Muscle Wasting by Increasing Protein Synthesis and Mitochondrial Biogenesis

Gromwell (Lithospermum erythrorhizon, LE) can mitigate obesity-induced skeletal muscle atrophy in C2C12 myotubes and high-fat diet (HFD)-induced obese mice. The purpose of this study was to investigate the anti-skeletal muscle atrophy effects of LE and the underlying molecular mechanism. C2C12 myotubes were pretreated with LE or shikonin, and active component of LE, for 24 h and then treated with 500 μM palmitic acid (PA) for an additional 24 h. Additionally, mice were fed a HFD for 8 weeks to induced obesity, and then fed either the same diet or a version containing 0.25% LE for 10 weeks. LE attenuated PA-induced myotubes atrophy in differentiated C2C12 myotubes. The supplementation of LE to obese mice significantly increased skeletal muscle weight, lean body mass, muscle strength, and exercise performance compared with those in the HFD group. LE supplementation not only suppressed obesity-induced skeletal muscle lipid accumulation, but also downregulated TNF-α and atrophic genes. LE increased protein synthesis in the skeletal muscle via the mTOR pathway. We observed LE induced increase of mitochondrial biogenesis and upregulation of oxidative phosphorylation related genes in the skeletal muscles. Furthermore, LE increased the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha and the phosphorylation of adenosine monophosphate-activated protein kinase. Collectively, LE may be useful in ameliorating the detrimental effects of obesity-induced skeletal muscle atrophy through the increase of protein synthesis and mitochondrial biogenesis of skeletal muscle.

Supplementation with Lactiplantibacillus brevis GKEX Combined with Resistance Exercise Training Improves Muscle Mass, Strength Performance, and Body Fat Condition in Healthy Humans

In addition to maintaining good exercise and dietary habits, recent studies have shown that probiotics may have potential benefits for muscle mass and strength. It is worth noting that the effects may vary depending on the specific strains used. To date, no studies have analyzed the effects of Lactiplantibacillus brevis in this context. Here, we combine the L. brevis strain GKEX with resistance training to further understand its effects on muscle mass, thickness, performance, and fat loss. In a six-week intervention for a double-blind randomized trial, 52 healthy subjects were divided into two groups (10 male and 16 female participants in each group): a placebo group (two capsules/day, containing 0 CFU of GKEX per capsule) and a GKEX group (two capsules/day, containing 1 × 1010 CFU of GKEX per capsule). Before the intervention, no differences were observed between the two groups in any of the tests (body composition, muscle thickness, exercise performance, and blood parameters). However, supplementation with GKEX significantly improved muscle mass and thickness, as well as grip strength, muscle strength, and explosive performance, when compared to the associated parameters before the intervention. Additionally, GKEX supplementation promoted a reduction in the body fat percentage (p < 0.05). Through analysis of the change amount, we observed that GKEX supplementation yielded significantly improved benefits when compared to the placebo group (p < 0.05). In summary, our findings support the notion that a six-week resistance exercise training program combined with L. brevis GKEX supplementation has superior additive effects that enhance muscle mass and strength performance, while also reducing body fat percentage. This intervention can promote muscle gain and fat loss.

[Sarcopenia: is a clinical diagnosis possible?]

Introducción: La sarcopenia aumenta el riesgo de caídas y fracturas, además de relacionarse con diversas enfermedades y aumento de la mortalidad. Distintos grupos de investigación proponen diferentes definiciones para el diagnóstico de sarcopenia, que incluyen la medición de la masa muscular por DEXA y la valoración de la fuerza de prensión palmar a través de un dinamómetro de mano. Sin embargo, estos 2 instrumentos no están habitualmente disponibles en los consultorios médicos. Objetivos: Determinar la utilidad diagnóstica de 2 pruebas de rendimiento físico: velocidad de marcha e incorporarse de una silla, como herramientas para la detección de pacientes con probable sarcopenia. Metodología: Se incluyeron 706 mujeres, entre 50 y 85 años, a las que se realizó las pruebas funcionales y DXA (n=376) para medir la masa muscular. Resultados: El 26,1% registró una velocidad de marcha disminuida mientras que el 55,3% presentó alteración en la realización de la prueba de incorporarse de una silla. La prevalencia de sarcopenia varió desde un 4,5% hasta un 35% según los criterios utilizados. Ambas pruebas presentaron un alto valor predictivo negativo (>70%) para el diagnóstico de sarcopenia, mientras que la prueba de incorporarse de una silla mostró además, una alta sensibilidad (> 66%) para dicho diagnóstico. Conclusión: La implementación en el consultorio de estas pruebas sencillas y sin costo, simplificaría la detección de pacientes con probable sarcopenia.

Comparative Efficacy of Different Protein Supplements on Muscle Mass, Strength, and Physical Indices of Sarcopenia among Community-Dwelling, Hospitalized or Institutionalized Older Adults Undergoing Resistance Training: A Network Meta-Analysis of Randomized Controlled Trials

Aging-related sarcopenia exerts harmful impacts on muscle mass, strength, and physical mobility. Protein supplementation has been demonstrated to augment efficacy of resistance training (RT) in elderly. This study compared the relative effects of different protein supplements on muscle mass, strength, and mobility outcomes in middle-aged and older individuals undergoing RT. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) examining the efficacy of protein supplement plus RT in untrained community-dwelling adults, hospitalized, or institutionalized residents who suffered acute or chronic health conditions. Network meta-analysis (NMA) was performed using a frequentist method for all analyses. Treatment effects for main outcomes were expressed as standard mean difference (SMD) with 95% confidence interval (CI). We used the surface-under-the cumulative-ranking (SUCRA) scores to rank probabilities of effect estimation among all identified treatments. Meta-regression analyses were performed to identify any relevant moderator of the treatment efficacy and results were expressed as β with 95% credible interval (CrI). We finally included 78 RCTs (5272 participants) for analyses. Among the six protein sources identified in this NMA, namely whey, milk, casein, meat, soy, and peanut, whey supplement yielded the most effective treatments augmenting efficacy of RT on muscle mass (SMD = 1.29, 95% CI: 0.96, 1.62; SUCRA = 0.86), handgrip strength (SMD = 1.46, 95% CI: 0.92, 2.00; SUCRA = 0.85), and walking speed (SMD = 0.73, 95% CI: 0.39, 1.07; SUCRA = 0.84). Participant's health condition, sex, and supplementation dose were significant factors moderating the treatment efficacy on muscle mass (β = 0.74; 95% CrI: 0.22, 1.25), handgrip strength (β = -1.72; 95% CrI: -2.68, -0.77), and leg strength (β = 0.76; 95% CrI: 0.06, 1.47), respectively. Our findings suggest whey protein yields the optimal supplements to counter sarcopenia in older individuals undergoing RT.

Change Over Time in Pre-End-Stage Renal Disease 24-Hour Urine Creatinine as Muscle Mass Surrogate and Post-End-Stage Renal Disease Mortality

OBJECTIVE

Loss of muscle mass and sarcopenia are common in chronic kidney disease (CKD) and end-stage renal disease (ESRD), and sarcopenia can worsen insidiously in patients with advancing CKD. The temporal dynamics of sarcopenia in patients with progressive loss of kidney function, and its association with future outcomes, is unclear.

METHODS

In a contemporary national cohort of incident ESRD US veterans, we selected 661 patients who had at least 2 24-hour urine creatinine (24hrUC) measurements, a surrogate of muscle mass, performed during the 3-year prelude period prior to ESRD transition. We estimated 24hrUC slopes in mixed effects models. To assess the temporal dynamics of pre-ESRD changes in 24hrUC and its association with changing eGFR, we separately fitted in mixed effects models a penalized spline regression of 24hrUC on time and on eGFR. We examined the association of 24hrUC slopes with postdialysis all-cause mortality using Cox models adjusted for confounders.

RESULTS

The mean slope of 24hrUC versus time was -78 mg/year (95% confidence interval: -102 to -54), with a steeper decline noted in the last year prior to ESRD. More severe decreases in 24hrUC were associated with higher all-cause mortality: a 100 mg/year decrease in 24hrUC was associated with a multivariable adjusted death hazard ratio of 1.41 (95% confidence interval: 1.00-1.98, P = .05).

CONCLUSION

Patients with advanced CKD lose a substantial proportion of their muscle mass each year during pre-ESRD prelude. Loss of muscle mass accelerates near ESRD transition, and more loss of muscle mass is associated with higher mortality after ESRD transition.

Physical condition and perceived fatigue in post-covid patients: An observational descriptive study

BACKGROUND

Patients with severe coronavirus disease 2019 (COVID-19) often require hospital admission and experience sequelae such as chronic fatigue or low muscle mass.

OBJECTIVE

To analyze the functional capacity of a cohort of patients with severe acute respiratory syndrome coronavirus 2 who required hospitalization.

DESIGN AND SETTING

An observational descriptive study was conducted on post-COVID-19 patients referred to the Rehabilitation Department of Gregorio Marañón Hospital (Madrid, SPAIN).

METHODS

Cardiorespiratory fitness, muscle strength, body composition, and perception of fatigue and dyspnea were analyzed. Furthermore, the existing correlations between clinical variables and physical conditions were analyzed.

RESULTS

Forty-two patients who required hospital admission (80 ± 22.45 days) or intensive care unit (ICU) admission (58 ± 10.52 days) were analyzed. They presented with decreased strength, respiratory capacity, and moderate-to-severe perceived fatigue. Additionally, an inverse correlation was found between right-handgrip strength and days in the ICU, as well as the 6-minute walk test for women. Similarly, strength and fitness were negatively associated with perceived fatigue.

CONCLUSIONS

Post-COVID-19 patients showed low muscle function and low levels of physical fitness associated with high perceived fatigue.

Agreement and diagnostic differences among three definitions of sarcopenia in patients with chronic hepatitis C

BACKGROUND

There is neither a gold standard definition nor a universal consensus to diagnose sarcopenia in patients with chronic hepatitis C. Thus, we aimed to compare the prevalence of sarcopenia and the agreement and discrepancies between European Working Group on Sarcopenia in Older People (EWGSOP1), EWGSOP2, and Foundation for the National Institutes of Health Biomarkers Consortium Sarcopenia Project (FNIH) definitions in chronic hepatitis C.

METHODS

Dual-energy x-ray absorptiometry was used to assess muscle mass by quantifying appendicular lean mass (ALM) adjusted for squared height (ALM/ht2 ) or for body mass index (ALMBMI ). Muscle function was evaluated by handgrip strength. Subjective Global Assessment was used to assess the nutrition status.

RESULTS

This cross-sectional study included 103 outpatients (mean age, 50.6 ± 11.3 years; 33.0% with compensated cirrhosis). Sarcopenia prevalence was 8.7%, 9.7%, and 9.7%, according to EWGSOP1, EWGSOP2, and FNIH definitions, respectively. There was neither a sex- nor a liver disease severity-specific difference in the prevalence of sarcopenia between the criteria applied. Sixteen (15.5%) patients fulfilled at least one of these criteria, and 3 out of 16 (18.8%) simultaneously had sarcopenia by consensus of the three criteria. Sarcopenic obesity was identified in 9 out of 16 (56.3%) patients, and 6 out of 9 (66.7%) of these only met FNIH consensus.

CONCLUSIONS

In patients without cirrhosis or with compensated cirrhosis, and with chronic hepatitis C, the agreement between EWGSOP1 and EWGSOP2 classifications was substantial for sarcopenia diagnosis. Concerning EWGSOP and FNIH criteria, a fair agreement and limited overlap were found in these patients.

Prevalence of low calf circumference in hospitalized patients classified by raw or body mass index-adjusted values

BACKGROUND

Adiposity can influence the estimation of muscle mass using calf circumference (CC) and underestimate the frequency of low CC. An adjustment for CC using body mass index (BMI) was proposed to reduce this effect. We aimed to compare the low CC frequency in hospitalized patients when considering raw and BMI-adjusted values and explore data by sex, age, and race (white and non-white).

METHODS

Secondary analysis from two cohort studies conducted with adult hospitalized patients using BMI and CC data collected in the first 72 h after hospital admission. We classified low CC by two approaches: (1) raw CC; (2) BMI-adjusted CC for patients with BMI ≥ 25. Cutoff values for low CC were ≤34 cm (men) and ≤33 cm (women).

RESULTS

Among 1272 patients (54.1 ± 15.3 years old; 51.7% women; 82.1% White race), low CC frequency was 30.6% and low BMI-adjusted CC was 68.9%. For all elevated BMI categories, the low CC frequency was higher when considering BMI-adjusted values (P < 0.001). Low CC was more frequent (P < 0.001) in older adults (38.7% by raw; 79.1% by BMI-adjusted value) than in younger adults (27.6% by raw; 65.2% by BMI-adjusted value) and it was not associated with race. Low CC by raw values was more frequent in men than in women (35.0% versus 26.4%; P = 0.001), but did not differ between sexes when classified by BMI-adjusted values (70.7% versus 67.1%; P = 0.184).

CONCLUSION

Low CC BMI adjusted was 2.2 times more frequent in comparison with raw CC values, and it was identified in >60% of patients with BMI ≥ 25.

The metabolic load-capacity model and cardiometabolic health in children and youth with obesity

BACKGROUND

The metabolic load-capacity index (LCI), which represents the ratio of adipose to skeletal muscle tissue-containing compartments, is potentially associated with cardiometabolic diseases.

OBJECTIVES

To examine the associations between the LCI and cardiometabolic risk factors in children and youth with obesity.

METHODS

This is a cross-sectional study including 10-18 years-old participants with a BMI of ≥95th . LCI by air-displacement plethysmography (ADP) was calculated as fat mass divided by fat-free mass, and LCI by ultrasound (US) as subcutaneous adipose tissue divided by skeletal muscle thickness. Sex-specific medians stratified participants into high versus low LCI. Single (inflammation, insulin resistance, dyslipidemia and hypertension) and clustered cardiometabolic risk factors were evaluated. Linear and logistic regression models tested the associations between these variables, adjusted for sexual maturation.

RESULTS

Thirty-nine participants (43.6% males; 59% mid-late puberty) aged 12.5 (IQR: 11.1-13.5) years were included. LCI by ADP was positively associated with markers of inflammation and dyslipidemia; having a higher LCI predicted dyslipidemia in logistic regression. Similarly, LCI by US was positively associated with markers of dyslipidemia and blood pressure. In mid-late pubertal participants, LCI by US was positively associated with markers of insulin resistance and inflammation.

CONCLUSIONS

Participants with unfavourable cardiometabolic profile had higher LCI, suggesting its potential use for predicting and monitoring cardiometabolic health in clinical settings.

Potential protective effects of increased serum uric acid concentration in sarcopenia: A meta-analysis and systematic review

BACKGROUND

Previous studies on the association between serum uric acid (UA) levels and sarcopenia have yielded contradictory results. This meta-analysis and literature review assessed the association between serum UA levels and sarcopenia. Moreover, we conducted a comparative analysis of the differences in serum UA concentrations between individuals with and without sarcopenia.

METHODS

A systematic search was conducted across various medical databases, namely PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, and Wanfang (from the start to August 20, 2023). This search focused on published studies that investigated the relationship between serum UA levels and sarcopenia. The relationship between serum UA concentration and the occurrence of sarcopenia was analyzed, and the differences in serum UA concentrations between individuals with sarcopenia and control groups were reviewed. Statistical analysis was performed using STATA 11.0 and R 4.1.3.

RESULTS

Sixteen studies were considered for our analysis. The results indicated a significant association between low serum UA concentration and a higher sarcopenia risk, particularly among male patients (adjusted odds ratio = 0.65, 95% confidence interval [CI] = 0.49, 0.87, P = .004, I2 = 0%). Individuals with sarcopenia exhibited decreased serum UA concentrations compared with those of the control group (mmol/L: weighted mean difference = -28.25, 95% CI = -40.45, -16.05, P < .001; mg/dL: weighted mean difference = -0.82, 95% CI = -1.05, -0.58, P < .001). Additionally, serum UA concentration was positively correlated with skeletal muscle mass index and handgrip strength (skeletal muscle index: correlation coefficient = 0.17, 95% CI = 0.11, 0.22, P < .001; handgrip strength: common odds ratios = 0.10, 95% CI = 0.06, 0.14, P < .001).

CONCLUSION

Individuals with sarcopenia have relatively low serum UA concentrations. A notable correlation between serum UA concentration and sarcopenia was observed. Hence, monitoring UA levels could aid in the early detection and treatment of sarcopenia, enabling timely intervention to preserve muscle mass and strength.

The Improvement in Exercise Performance during Reduced Muscle Mass Exercise is Associated with an Increase in Femoral Blood Flow in Older and Younger Endurance-Trained Athletes

This study investigated whether the improved performance observed with maximal self-paced single-leg (SL), compared with double-leg (DL) cycling, is associated with enhanced femoral blood flow and/or altered tissue oxygenation. The hyperaemic response to exercise was assessed in younger and older athletes. Power output was measured in 12 older (65 ± 4 y) and 12 younger (35 ± 5 y) endurance-trained individuals performing 2 x 3 min maximal self-paced exercise using SL and DL cycling. Blood flow (BF) in the femoral artery was assessed using Doppler ultrasound and muscle oxygenation was measured using near-infrared spectroscopy on the vastus lateralis. SL cycling elicited a greater power output (295 ± 83 vs 265 ± 70 W, P < 0.001) and peak femoral BF (1749.1 ± 533.3 vs 1329.7 ± 391.7 ml/min, P < 0.001) compared with DL cycling. Older individuals had a lower peak BF in response to exercise (1355.4 ± 385.8 vs 1765.2 ± 559.6 ml/min, P = 0.019) compared with younger individuals. Peak BF in response to exercise was correlated with power output during SL (r = 0.655, P = 0.002) and DL (r = 0.666, P = 0.001) cycling. The greater exercise performance during SL compared with DL cycling may be partly explained by a greater hyperaemic response when reducing active muscle mass. Despite regular endurance training, older athletes had a lower femoral BF in response to maximal self-paced exercise compared with younger athletes.

The effect of protein or amino acid provision on immobilization-induced muscle atrophy in healthy adults: A systematic review and meta-analysis

Bed rest and limb immobilization are models of muscle disuse associated with skeletal muscle atrophy and reduced strength. The purpose of this systematic review was to examine the impact of protein or amino acid provision before and/or during a period of muscle disuse on muscle atrophy (primary outcome), strength and muscle protein synthesis (secondary outcomes) following a disuse period. We performed a systematic review of Embase, MEDLINE, Web of Science, PubMed and Clinical Trials in December 2022. Eligible studies were randomized controlled trials that combined a dietary protein or amino acid intervention versus control during an experimental model of disuse (bed rest or unilateral limb immobilization) in healthy individuals aged ≥18 years. Nine articles from eight independent trials were identified and rated for risk of bias by two authors. A meta-analysis of muscle mass data revealed no effect (standardized mean difference: 0.2; 95% confidence interval: -0.18 to 0.57, P = 0.31) of protein/amino acid intervention in preventing disuse-induced muscle atrophy. Although the meta-analysis was not conducted on strength or muscle protein synthesis data, there was insufficient evidence in the reviewed articles to support the use of protein/amino acid provision in mitigating the disuse-induced decline in either outcome measurement. Additional high-quality studies, including the reporting of randomization procedures and blinding procedures and the provision of statistical analysis plans, might be required to determine whether protein or amino acid provision serves as an effective strategy to attenuate muscle atrophy during periods of disuse.

Association between nutrition intake and muscle mass in adult inpatients receiving nutrition support: A prospective cohort study

OBJECTIVE

The present study aimed to evaluate the association between muscle mass variation, estimated by different equations, during hospitalization with the energy and protein intake and clinical and nutrition outcomes of patients using nutrition support.

METHODS

A prospective observational study with patients older than 18 years in use of enteral and/or parenteral nutrition therapy and monitored by the Nutritional Therapy Committee between December 14, 2021, and December 14, 2022. Data were collected from the electronic records and were applied in 11 equations to estimate the four different portions of muscle mass of patients receiving nutrition support at the beginning and the end of hospitalization.

RESULTS

A total of 261 patients were evaluated, with a median age of 61.0 (49.0-69.75) years, and 106 were women (40.6%). According to the nutrition diagnosis, several participants had severe malnutrition (39.5%). The most muscle mass estimation equations indicated a reduction of muscle mass during hospitalization. All patients presented negative energy and protein balances during hospitalization, but greater protein intake increased the lean soft tissue. Also, the greater the number of infections, metabolic complications, and scheduled diet interruption, the greater was the chance of losing muscle mass.

CONCLUSION

There can be an association between the variation in muscle mass and energy and protein intake during hospitalization of patients using nutrition support. In addition, variation in muscle mass was associated with complications from nutrition support. The results emphasize the importance of anthropometric measurements to estimate muscle mass when other methods are not available.

Exploring the Dynamic Relationship between the Gut Microbiome and Body Composition across the Human Lifespan: A Systematic Review

This systematic review aimed to identify different gut microbiome profiles across the human lifespan and to correlate such profiles with the body composition. PubMed, Scopus, and Cochrane were searched from inception to March 2022. Sixty studies were included in this systematic review. Overall, the gut microbiome composition in overweight participants exhibited decreased α-diversity, decreased levels of the phylum Bacteroidetes and its taxa, and increased levels of the phylum Firmicutes, its taxa, and the Firmicutes/Bacteroidetes ratio, in comparison to normal-weight participants. Other body composition parameters showed similar correlations. Fat mass and waist circumference were found to correlate positively with the Firmicutes taxa and negatively with the Bacteroidetes taxa. In contrast, lean body mass and muscle mass demonstrated a positive correlation with the Bacteroidetes taxa. Notably, these correlations were more pronounced in athletes than in obese and normal-weight individuals. The composition of the gut microbiome is evidently different in overweight individuals or athletes of all age groups, with the former tending towards decreased Bacteroidetes taxa and increased Firmicutes taxa, while a reversed relationship is observed concerning athletes. Further studies are needed to explore the dynamic relationship between energy intake, body composition, and the gut microbiome across the human lifespan.

Correlates of Skeletal Muscle Mass and Differences Between Novel Subtypes in Recent-Onset Diabetes

CONTEXT

Low skeletal muscle mass (SMM) is associated with long-standing diabetes but little is known about SMM in newly diagnosed diabetes.

OBJECTIVE

We aimed to identify correlates of SMM in recent-onset diabetes and to compare SMM between novel diabetes subtypes.

METHODS

SMM was normalized to body mass index (SMM/BMI) in 842 participants with known diabetes duration of less than 1 year from the German Diabetes Study (GDS). Cross-sectional associations between clinical variables, 79 biomarkers of inflammation, and SMM/BMI were assessed, and differences in SMM/BMI between novel diabetes subtypes were analyzed with different degrees of adjustment for confounders.

RESULTS

Male sex and physical activity were positively associated with SMM/BMI, whereas associations of age, BMI, glycated hemoglobin A1c, homeostatic model assessment for β-cell function, and estimated glomerular filtration rate with SMM/BMI were inverse (all P < .05; model r2 = 0.82). Twenty-three biomarkers of inflammation showed correlations with SMM/BMI after adjustment for sex and multiple testing (all P < .0006), but BMI largely explained these correlations. In a sex-adjusted analysis, individuals with severe autoimmune diabetes had a higher SMM/BMI whereas individuals with severe insulin-resistant diabetes and mild obesity-related diabetes had a lower SMM/BMI than all other subtypes combined. However, differences were attenuated after adjustment for the clustering variables.

CONCLUSION

SMM/BMI differs between diabetes subtypes and may contribute to subtype differences in disease progression. Of note, clinical variables rather than biomarkers of inflammation explain most of the variation in SMM/BMI.

Muscle Quality in Relation to Prediabetes Phenotypes: A Population-Based Study With Mediation Analysis

CONTEXT

Prediabetes is associated with an increased risk of physical disability, yet no studies have assessed the extent to which muscle quality, a measure reflecting muscle functionality, was altered in prediabetes and its specific phenotype.

OBJECTIVE

We evaluated their associations in a general US population with mediation analysis.

METHODS

This was a cross-sectional study based on the National Health and Nutrition Examination Survey 2011-2014. Participants with prediabetes were stratified as having an isolated defect (impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or impaired hemoglobin A1c [IA1c]), 2 defects (IFG + IGT, IFG + IA1c, or IGT + IA1c), or all defects (IFG + IGT + IA1c). Muscle quality was calculated as dominant grip strength divided by dominant arm muscle mass measured by dual-energy X-ray absorptiometry.

RESULTS

We included 2351 participants (938 with prediabetes and 1413 with normoglycemia). Despite higher grip strength and larger arm muscle mass, arm muscle quality was lower in prediabetes and all prediabetes phenotypes (except for IGT) than normoglycemia (all P < .04), and was unrelated to prediabetes awareness. Arm muscle quality was decreased and the odds of low arm muscle quality was increased in prediabetes with increasing numbers of glucometabolic defects (both P < .001), with insulin resistance being the predominant mediator. HbA1c-defined prediabetes (IA1c) had lower arm muscle quality and higher odds of low arm muscle quality than blood glucose-defined prediabetes (IFG, IGT, or IFG + IGT).

CONCLUSION

Muscle quality was impaired in prediabetes and its specific phenotype. Relative to blood glucose, elevated HbA1c might be a better predictor of reduced muscle quality.

Comparison of the cachexia index based on hand-grip strength (H-CXI) with the original CXI for the prediction of cancer cachexia and prognosis in patients who underwent radical colectomy for colorectal cancer

Background and aims

The cachexia index (CXI) is a novel biomarker for estimating cancer cachexia. The cachexia index based on hand-grip strength (H-CXI) has been recently developed as a simple proxy for CXI. The present study aims to compare both the H-CXI and CXI for the prediction of cancer cachexia and postoperative outcomes in patients who underwent radical colectomy for colorectal cancer.

Methods

Patients who underwent radical operations for colorectal cancer were included in this study. Cancer cachexia was diagnosed according to the international consensus outlined by Fearon et al. The cachexia index (CXI) was calculated as [skeletal muscle index (SMI) × serum albumin/neutrophil-to-lymphocyte ratio (NLR)]. The H-CXI was calculated as [hand-grip strength (HGS)/height2 × serum albumin/NLR]. The SMI was measured based on the preoperative CT images at the third lumbar vertebra (L3) level. HGS was measured before surgery.

Results

From July 2014 to May 2021, a total of 1,411 patients were included in the present study, of whom 361 (25.6%) were identified as having cancer cachexia. Patients with cachexia had a lower CXI (p < 0.001) and lower H-CXI (p < 0.001) than those without cachexia. A low CXI but not low H-CXI independently predicted cancer cachexia in the multivariate analysis (OR 1.448, p = 0.024). Both a low CXI (HR 1.476, p < 0.001 for OS; HR 1.611, p < 0.001 for DFS) and low H-CXI (HR 1.369, p = 0.007 for OS; HR 1.642, p < 0.001 for DFS) were independent predictors for overall survival (OS) and disease-free survival (DFS) after adjusting for the same covariates. A low H-CXI but not low CXI was an independent risk factor for postoperative complications (OR 1.337, p = 0.044). No significant association was found between cancer cachexia and postoperative complications.

Conclusion

The CXI and H-CXI exhibited better prognostic value than cancer cachexia for the prediction of postoperative outcomes in patients who underwent radical colectomy for colorectal cancer. The H-CXI was a superior index over the CXI in predicting short-term clinical outcomes, whereas the CXI demonstrated a closer correlation with Fearon's criteria for cancer cachexia. Ideal tools for the assessment of cancer cachexia should incorporate not only weight loss but also muscle mass, physical function, and inflammatory state.

The Effect of Web-Based Culinary Medicine to Enhance Protein Intake on Muscle Quality in Older Adults: Randomized Controlled Trial

BACKGROUND

The most common age-related musculoskeletal disorder is sarcopenia. Sarcopenia is the progressive and generalized loss of muscle mass, strength, and function. The causes of sarcopenia can include insufficient nutritional status, which may be due to protein-energy malnutrition, anorexia, limited food access and eating ability, or malabsorption. In the United States, 15.51% of older adults have been diagnosed with sarcopenia. Culinary medicine (CM) is a novel evidence-based medical field that combines the science of medicine with food and cooking to prevent and treat potential chronic diseases. CM helps individuals learn and practice culinary skills while tasting new recipes. Therefore, this program could successfully reduce barriers to protein intake, enabling older adults to enhance their diet and muscle quality.

OBJECTIVE

This study aimed to examine how a web-based CM intervention, emphasizing convenient ways to increase lean red meat intake, could improve protein intake with the promotion of physical activity to see how this intervention could affect older adults' muscle strength and mass.

METHODS

A 16-week, single-center, parallel-group, randomized controlled trial was conducted to compare a web-based CM intervention group (CMG) with a control group (CG) while monitoring each group's muscle strength, muscle mass, and physical activity for muscle quality. The CMG received weekly web-based cooking demonstrations and biweekly nutrition education videos about enhancing protein intake, whereas the CG just received the recipe handout. Anthropometrics, muscle mass, muscle strength, dietary habits, physical activity, and cooking effectiveness were established at baseline and measured after the intervention. The final number of participants for the data analysis was 24 in the CMG and 23 in the CG.

RESULTS

No between-group difference in muscle mass (P=.88) and strength (dominant P=.92 and nondominant P=.72) change from the prestudy visit was detected. No statistically significant difference in protein intake was seen between the groups (P=.50). A nonsignificant time-by-intervention interaction was observed for daily protein intake (P=.08). However, a statistically significant time effect was observed (P≤.001). Post hoc testing showed that daily protein intake was significantly higher at weeks 1 to 16 versus week 0 (P<.05). At week 16, the intake was 16.9 (95% CI 5.77-27.97) g higher than that at the prestudy visit.

CONCLUSIONS

This study did not affect protein intake and muscle quality. Insufficient consistent protein intake, low physical activity, intervention adherence, and questionnaire accuracy could explain the results. These studies could include an interdisciplinary staff, different recruitment strategies, and different muscle mass measurements. Future research is needed to determine if this intervention is sustainable in the long term and should incorporate a follow-up to determine program efficacy on several long-term behavioral and health outcomes, including if the participants can sustain their heightened protein intake and how their cooking skills have changed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05593978; https://clinicaltrials.gov/ct2/show/NCT05593978.

Resistance exercise snacks improve muscle mass in female university employees: a prospective, controlled, intervention pilot-study

Background

Although resistance training (RT) is essential to preserve musculoskeletal fitness and maintain a healthy, independent life into old age, few women perform RT. We investigated whether resistance exercise snacking (RES) could be an efficient training approach for the workplace health promotion (WHP) to minimize barriers for participation and facilitate RT in women in order to improve musculoskeletal fitness.

Methods

This pilot-study followed a prospective, controlled intervention design. Female employees with sedentary occupations doing RT on less than 2 days/week before study participation were included. Participants self-selected for either intervention (IG) or control group (CG). While the IG [N = 15, mean age 42.1 (SD = 11.1) years] did 10 min of RES on working days for 12 weeks, the CG [N = 15, mean age 49.9 (SD = 9.7) years] was instructed to maintain their habitual physical activity. Primary endpoint was change in muscle mass. Secondary endpoint was change in maximum isometric strength. Balance, cardiovascular fitness, perceived health, and general life satisfaction was assessed for exploratory purpose. Measurements were taken before and after the intervention.

Results

12 participants of IG and 14 of CG completed the study. Muscle mass improved significantly more in the IG [+0.42 (SD = 0.54) kg] compared to the CG [-0.16 (SD = 0.51) kg] (p = 0.01, ƞ2p = 0.24). Strength did not change significantly between groups. Nevertheless, there was a trend for greater improvements in the IG compared to the CG for trunk extension, trunk flexion, and upper body push but not upper body pull. Regarding exploratory endpoints, no significant between-group changes were found. Despite their poor fitness, both groups perceived their health as good and had high life satisfaction before and after the intervention.

Conclusion

RES could be an effective approach for the WHP to promote RT in inactive women with sedentary occupations and improve their muscle mass.

Probiotics supplementation or probiotic-fortified products on sarcopenic indices in older adults: systematic review and meta-analysis from recent randomized controlled trials

Introduction: A noteworthy correlation was seen between changes in the gut microbiome and sarcopenia in older adults. Along with increasing research on probiotic supplementation for various medical problems, we aimed to obtain evidence and summarize the effect of probiotic supplementation on sarcopenic indices among older adults. Methods: We utilized PubMed, EBSCO, and Proquest, in addition to manual search using synonyms and variation for 'probiotic,' 'sarcopenia,' and 'older adults.' Randomized controlled trials investigated the utilization of probiotics or probiotic-containing products in older adults with sarcopenic indices including muscle mass and strength. The random-effects model was applied to the meta-analysis process. Results: Seven studies were obtained with 733 pooled older adults. Probiotic supplementation resulted in a significant increase of muscle mass with adjusted SMD (Standardized Mean Difference) of 0.962 (95% CI: 0.288 to 1.635, p = 0.049) using till and trim analysis and muscle strength with SMD of 1.037 (95% CI: 0.077 to 1.996, p = 0.03). However, both outcomes were associated with significantly high heterogeneity (I2 = 89.5% and I2 = 89.9%, respectively). Conclusion: When opposed to a placebo, the probiotic treatment improved the amount of muscle and its endurance based on recent evidence, however, further studies should be done with larger samples and targeted populations.

In people with type 2 diabetes, sarcopenia is associated with the incidence of cardiovascular disease: A prospective cohort study from the UK Biobank

AIM

To investigate the association of sarcopenia with cardiovascular disease (CVD) incidence in people with type 2 diabetes.

MATERIALS AND METHODS

A prospective cohort study with 11 974 White European UK Biobank participants with type 2 diabetes, aged 40-70 years, included. Sarcopenia was defined based on the European Working Group on Sarcopenia in Older People as either non-sarcopenic or sarcopenic. Outcomes included CVD, stroke, heart failure (HF) and myocardial infarction (MI). The association between sarcopenia and the incidence of outcomes was investigated using Cox proportional hazard models adjusted for sociodemographic and lifestyle factors. The rate advancement period was used to estimate the time period by which CVD is advanced because of sarcopenia.

RESULTS

Over a median follow-up of 10.7 years, 1957 participants developed CVDs: 373 had a stroke, 307 had an MI and 742 developed HF. Compared with non-sarcopenia, those with sarcopenia had higher risks of CVD (HR 1.89 [95% CI 1.61; 2.21]), HF (HR 2.59 [95% CI 2.12; 3.18]), stroke (HR 1.90 [95% CI 1.38; 2.63]), and MI (HR 1.56 [95% CI 1.04; 2.33]) after adjustment for all covariates. Those with sarcopenia had CVD incidence rates equivalent to those without sarcopenia who were 14.5 years older. Similar results were found for stroke, HF and MI.

CONCLUSIONS

In people with type 2 diabetes, sarcopenia increased the risk of developing CVD, which might occur earlier than in those without sarcopenia. Therefore, sarcopenia screening and prevention in patients with type 2 diabetes may be useful to prevent the complications of CVD.

Diagnostic Criteria and Measurement Techniques of Sarcopenia: A Critical Evaluation of the Up-to-Date Evidence

Sarcopenia, a geriatric syndrome characterized by progressive skeletal muscle mass and function decline, poses a significant health risk among the elderly, contributing to frailty, falls, hospitalization, loss of independence and mortality. The prevalence of sarcopenia varies significantly based on various factors, such as living status, demographics, measurement techniques and diagnostic criteria. Although the overall prevalence is reported at 10% in individuals aged 60 and above, disparities exist across settings, with higher rates in nursing homes and hospitals. Additionally, the differences in prevalence between Asian and non-Asian countries highlight the impact of cultural and ethnic factors, and variations in diagnostic criteria, cut-off values and assessment methods contribute to the observed heterogeneity in reported rates. This review outlines diverse diagnostic criteria and several measurement techniques supporting decision making in clinical practice. Moreover, it facilitates the selection of appropriate tools to assess sarcopenia, emphasizing its multifactorial nature. Various scientific groups, including the European Working Group of Sarcopenia in Older People (EWGSOP), the International Working Group on Sarcopenia (IWGS), the Asian Working Group on Sarcopenia (AWGS), the American Foundation for the National Institutes of Health (FNIH) and the Sarcopenia Definition and Outcomes Consortium (SDOC), have published consensus papers outlining diverse definitions of sarcopenia. The choice of diagnostic criteria should be aligned with the specific objectives of the study or clinical practice, considering the characteristics of the study population and available resources.

Higher resistance training volume offsets muscle hypertrophy nonresponsiveness in older individuals

The magnitude of muscle hypertrophy in response to resistance training (RT) is highly variable between individuals (response heterogeneity). Manipulations in RT variables may modulate RT-related response heterogeneity; yet, this remains to be determined. Using a within-subject unilateral design, we aimed to investigate the effects of RT volume manipulation on whole muscle hypertrophy [quadriceps muscle cross-sectional area (qCSA)] among nonresponders and responders to a low RT dose (single-set). We also investigated the effects of RT volume manipulation on muscle strength in these responsiveness groups. Eighty-five older individuals [41M/44F, age = 68 ± 4 yr; body mass index (BMI) = 26.4 ± 3.7 kg/m2] had one leg randomly allocated to a single (1)-set and the contralateral leg allocated to four sets of unilateral knee-extension RT at 8-15 repetition maximum (RM) for 10-wk 2 days/wk. Pre- and postintervention, participants underwent magnetic resonance imaging (MRI) and unilateral knee-extension 1-RM strength testing. MRI typical error (2× TE = 3.27%) was used to classify individuals according to responsiveness patterns. n = 51 were classified as nonresponders (≤2× TE) and n = 34 as responders (>2× TE) based on pre- to postintervention change qCSA following the single-set RT protocol. Nonresponders to single-set training showed a dose response, with significant time × set interactions for qCSA and 1-RM strength, indicating greater gains in response to the higher volume prescription (time × set: P < 0.05 for both outcomes). Responders improved qCSA (time: P < 0.001), with a tendency toward higher benefit from the four sets RT protocol (time × set: P = 0.08); on the other hand, 1-RM increased similarly irrespectively of RT volume prescription (time × set: P > 0.05). Our findings support the use of higher RT volume to mitigate nonresponsiveness among older adults.NEW & NOTEWORTHY Using a within-subject unilateral design, we demonstrated that increasing resistance training (RT) volume may be a simple, effective strategy to improve muscle hypertrophy and strength gains among older adults who do not respond to low-volume RT. In addition, it could most likely be used to further improve hypertrophic outcomes in responders.

Calf circumference predicts sarcopenia in maintenance hemodialysis

BACKGROUND

Early recognition of sarcopenia in hemodialysis (HD) patients will be of great importance in preventing adverse outcomes and improving the quality of life in these patients. The main goal of this study was to evaluate the diagnostic accuracy of calf circumference (CC) measurement in detecting sarcopenia among CKD patients undergoing maintenance HD.

METHODS

This cross-sectional study included 52 patients (53 ± 17 years) who were currently in a maintenance HD. Muscle strength was evaluated using handgrip strength, and smooth muscle mass index (SMI) was assessed through bioelectrical impedance analysis, and CC was measured at the widest part of the calf with the foot pressed against a hard surface.

RESULTS

Out of the total patient population, sarcopenia was identified in 32.7% (n = 17). The two groups were comparable in terms of age, weight, and height, but the median body mass index of sarcopenic group was statistically lower than nonsarcopenic group (21.6 kg/m2 [18.9-24.6] vs 24.7 kg/m2 [21.4-27.3]. The sarcopenic group had a substantially smaller CC than the nonsarcopenic group (30.0 cm [26.5-32.0] vs 31.5 cm [30.3-34.8], P = 0.013; respectively). In the regression analysis, CC was found to be independently associated with post-HD SMI (P < 0.001; odds ratio, 1.938; and 95% CI, 1.020-2.856). CC was positively but weakly correlated with handgrip strength, however strong and significant correlation was found between CC and SMI (r = 0.277, P = 0.047 and r = 0.733, P < 0.001; respectively). A CC of 31 cm or less predicted confirmed sarcopenia in HD patients (area under the curve = 0.709, P = 0.006, specificity = 0.556, sensitivity = 0.765).

CONCLUSIONS

Low muscle mass and potentially low muscle strength in HD patients can be accurately identified through the use of CC measurements. Specifically, a CC measurement below 31 cm has found to be a useful indicator to identify individuals on maintenance HD.

Determination of Body Composition in Community-Dwelling Older Adults With and Without Sarcopenia Using Data From Practical Measures

Adequate body composition is essential for health, function, and independence in older adults. However, standard body composition assessments require complex and costly modalities, limiting their use for early detection of body composition changes and periodic follow-up. This study explored the ability of three practical measures-handgrip strength, five times sit-to-stand test, and upper limb loading during seated push-up test (ULL-SPUT)-to determine body composition in 109 older adults with and without sarcopenia. Participants (average age 76 years) were cross-sectionally measured for outcomes of the study. The ULL-SPUT and handgrip strength, but not the five times sit-to-stand test, significantly correlated with body composition (rs, r = .297-.827, p < .01). The ULL-SPUT, in combination with demographic data, could determine body composition up to 82%. Therefore, the ULL-SPUT may be a practical preliminary measure to identify older adults for whom standard body composition assessments and follow-up would prove timely and beneficial.

Effectiveness of exercise interventions on muscle mass among older adults with sarcopenic obesity: A scoping review

A disease known as sarcopenic obesity is characterized by decreased lean body mass in conjunction with excessive amounts of adipose tissue. Skeletal muscle mass, also known as SMM, is responsible for the largest share of fat-free mass in the body and plays an extremely vital role in the maintaining of metabolic health. Physical activity and exercise boosts the physiological health and overall quality of life of senior citizens. The objective of the study is to investigate the effectiveness of varied exercise interventions among the geriatric people with sarcopenic obesity. During the time period (2016-2023), a scoping review was undertaken using PubMed, orthopedic journals, and the Google Scholar database, and six literature evidences relating to the topic were discovered and subsequently analyzed. The study includes six randomized control trial publications that investigated the effectiveness and impact of exercise therapies on sarcopenic obesity. According to the pre and post-test values found in the reviewed articles, we discovered that resistance exercise is more effective than aerobic or combination exercise therapies. In conclusion, according to this scoping analysis, resistance training is more effective than other types of exercise in improving muscle mass in older people with sarcopenic obesity.

Genome-wide association study of growth traits and validation of key mutations (MSTN c.C861T) associated with the muscle mass of meat pigeons

Selective breeding of meat pigeons is primarily based on growth traits, especially muscle mass (MM). Identification of functional genes and molecular markers of growth and slaughter traits through a genome-wide association study (GWAS) will help to elucidate the underlying molecular mechanisms and provide a theoretical basis for the selective breeding of meat pigeons. The phenotypic data of body weight (BW) and body size (BS) of 556 meat pigeons at 52 and 80 weeks of age were collected. In total, 160 434 high-quality single nucleotide polymorphism sites were obtained by restriction site-associated DNA sequencing. The GWAS analysis revealed that MSTN, IGF2BP3 and NCAPG/LCORL were important candidate genes affecting the growth traits of meat pigeons. IGF2BP3 and NCAPG/LCORL were highly correlated to BW and BS, which are related to overall growth and development, while MSTN was associated with pectoral thickness and BW. Phenotypic association validation with the use of two meat pigeon populations found that the MSTN mutation c.C861T determines the MM. These results provide new insights into the genetic mechanisms underlying phenotypic variations of growth traits and MM in commercial meat pigeons. The identified markers and genes provide a theoretical basis for the selective breeding of meat pigeons.

Preoperative Body Composition Correlates with Postoperative Muscle Volume and Degeneration after Total Hip Arthroplasty

Impaired muscle recovery after total hip arthroplasty (THA) may affect gait and activities of daily living. Bioelectrical impedance analysis (BIA) can assess body composition and muscle volume, and computed tomography (CT) can assess muscle volume and the fatty degeneration of muscle. This study aimed to explore the effectiveness of BIA, and the correlation between preoperative body composition and postoperative muscle volume and degeneration after THA using BIA and CT. Thirty-eight patients who underwent THA and had BIA and CT performed pre- and postoperatively were retrospectively assessed. The BIA-derived measurements of preoperative body composition (fat mass index, fat-free mass index, and phase angle) were correlated with the CT-derived measurements (pre- and postoperative muscle volume and gluteus maximus and quadriceps Hounsfield Units of the affected hip). The preoperative fat mass index negatively correlated with the postoperative muscle volume of the gluteus maximus (p = 0.02) and quadriceps (p < 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.03). The preoperative fat-free mass index positively correlated with the postoperative muscle volume of the quadriceps (p = 0.02). The preoperative phase angle positively correlated with the postoperative muscle volume of the quadriceps (p = 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.001). In patients who underwent THA, preoperative body composition correlated with postoperative muscle volume and the fatty degeneration of the affected lower limb. Preoperative body composition may help predict postoperative muscle volume and fatty degeneration and thus, postoperative recovery.

Ultrasound Muscle Evaluation for Predicting the Prognosis of Patients with Head and Neck Cancer: A Large-Scale and Multicenter Prospective Study

Head and neck cancer (HNC) is a prevalent and aggressive form of cancer with high mortality rates and significant implications for nutritional status. Accurate assessment of malnutrition in patients with HNC is crucial for optimizing treatment outcomes and improving survival rates. This study aimed to evaluate the use of ultrasound techniques for predicting nutritional status, malnutrition, and cancer outcomes in patients with HNC. A total of 494 patients with HNC were included in this cross-sectional observational study. Various tools and body composition measurements, including muscle mass and adipose tissue ultrasound evaluations, were implemented. Using regression models, we mainly found that high levels of RF-CSA (rectus femoris cross-sectional area) were associated with a decreased risk of malnutrition (as defined with GLIM criteria (OR = 0.81, 95% CI: 0.68-0.98); as defined with PG-SGA (OR = 0.78, 95% CI: 0.62-0.98)) and sarcopenia (OR = 0.64, 95% CI: 0.49-0.82) after being adjusted for age, sex, and BMI. To predict the importance of muscle mass ultrasound variables on the risk of mortality, a nomogram, a random forest, and decision tree models were conducted. RF-CSA was the most important variable under the random forest model. The obtained C-index for the nomogram was 0.704, and the Brier score was 16.8. With an RF-CSA < 2.7 (AUC of 0.653 (0.59-0.77)) as a split, the decision tree model classified up to 68% of patients as possessing a high probability of survival. According to the cut-off value of 2.7 cm2, patients with a low RF-CSA value lower than 2.7 cm2 had worse survival rates (p < 0.001). The findings of this study highlight the importance of implementing ultrasound tools, for accurate diagnoses and monitoring of malnutrition in patients with HNC. Adipose tissue ultrasound measurements were only weakly associated with malnutrition and not with sarcopenia, indicating that muscle mass is a more important indicator of overall health and nutritional status. These results have the potential to improve survival rates and quality of life by enabling early intervention and personalized nutritional management.

A sex-specific association of leukocyte telomere length with thigh muscle mass

OBJECTIVES

Telomeres are DNA-protein complexes at the ends of linear chromosomes that protect against DNA degradation. Telomeres shorten during normal cell divisions and therefore, telomere length is an indicator of mitotic-cell age. In humans, telomere shortening is a potential biomarker for disease risk, progression and premature death. Physical activity has been associated with longer leukocyte telomere length (LTL) in some studies. In the current study the relationship between LTL, thigh muscle mass and adipose tissue distribution was explored.

METHODS

We performed anthropometric measurements and magnetic resonance imaging (MRI) measurements of the thigh in 149 healthy subjects (77 male, 72 female). LTL was measured using qPCR. Additionally, the subjects answered a questionnaire concerning their training behaviour.

RESULTS

In male subjects, LTL was significantly associated with thigh muscle mass, independent of age and body mass index (p=0.006). In addition, a slight association of LTL with weekly endurance units in the male group was found. These relations could not be observed in females.

CONCLUSIONS

In conclusion, we observed a sex-specific association of LTL and thigh muscle mass in healthy males. The reason of this sex-specific association is currently unclear, but could be related to different training effects and/or hormonal pathways in men and women.

Differences in Functional Capacity between Oncologic and Non-Oncologic Populations: Reference Values

This study is focused on the fact that in the context of increasing global aging and cancer diagnoses, additional challenges arise in clinical care. Adequate functionality and body composition are key to coping with antineoplastic treatment, which can lead to better treatment tolerance, survival, and quality of life. This is a cross-sectional comparative study focused on the assessment and comparison of body composition and functionality between cancer patients and a reference population, with the aim of establishing meaningful baseline values. Techniques such as manual dynamometry, the Five-Times Sit-to-Stand test, and bioimpedance were used to collect data from 374 oncologic patients and 1244 reference individuals. The results reveal significant disparities in functionality and body composition among participants, and provide age group-specific adjusted baseline values for those diagnosed with cancer. These findings may have crucial clinical implications for applying particular cut-off points designed for this population group, which makes the assessment process faster and more accurate, enhances the capacity of medical personnel to act quickly, and improves the management of frailty in cancer patients.

Exploring the Impact of Protein Supplement Source on Body Composition in Women Practicing Anaerobic Resistance Exercise: A Pilot Study

Supplements based on protein hydrolysates have been used as an effective source to access amino acids with greater bioavailability, promoting absorption to improve body composition. Five groups of young women were randomly selected. They followed a personalized eating plan that included different protein supplements (meat, vegan, branched-chain amino acids [BCAAs], whey, and control group), combined with an exercise plan, for eight weeks, aiming to assess their consumption effects combined with resistance exercise on body composition. Bioelectrical impedance before and after the treatment was conducted. The results showed that the supplementation with BCAAs presented a significant decrease (p < 0.05) on the BMI in this group (initial BMI = 19.7 kg/m2; final BMI = 19.4 kg/m2). When comparing the final measures among the groups, the BCAAs and vegan supplements caused a significant decrease in body weight (50.24 kg and 51.34 kg, respectively). The BMI of the group supplemented with meat proteins was statistically higher (22.06 kg/m2) than that the group supplemented with BCAAs (19.4 kg/m2) (p < 0.05). No significant changes were observed in the type of protein consumed to produce muscle mass in the participants after eight weeks of study under a controlled diet and anaerobic resistance exercise. Participants exhibited energy deficiencies, but their macronutrient distribution appeared normal. Following an 8-week intervention, meat and BCAAs reduced weight and BMI, although no statistical differences were observed. It is recommended to extend the treatment for a more comprehensive understanding.

Nutrition and Lifestyle-Related Factors as Predictors of Muscle Atrophy in Hematological Cancer Patients

BACKGROUND

Cancer and side effects from cytostatic treatment commonly affect nutritional status manifested as a decrease in muscle mass. We aimed to investigate the impact of nutrition and lifestyle-related factors on muscle mass in patients with hematological cancer.

METHODS

Dietary intake, food preferences, quality of life (QoL), and physical activity level (PAL) were monitored during 1-2 cytostatic treatment series. Body composition was estimated using bioelectrical impedance analysis (BIA).

RESULTS

61 patients were included. Weight loss and loss of muscle mass were detected in 64% and 59% of the patients, respectively. Muscle mass was significantly positively correlated to increasing PAL (p = 0.003), while negatively correlated to increasing age (p = 0.03), physical QoL (p = 0.007), functional QoL (p = 0.05), self-perceived health (p = 0.004), and self-perceived QoL (p = 0.007). Weight was significantly positively correlated to increased intake of soft drinks (p = 0.02) as well as the favoring of bitter grain and cereal products (p = 0.03), while negatively correlated to increasing age (p = 0.03) and increasing meat intake (p = 0.009) Conclusions: Several nutritional and lifestyle-related factors affected change in body composition. The clinical significance of these changes should be investigated in controlled, interventional studies.

Longitudinal Changes in the Body Composition of Non-Institutionalized Spanish Older Adults after 8 Years of Follow-Up: The Effects of Sex, Age, and Organized Physical Activity

Aging leads to physiological changes affecting body composition, mediated by lifestyle. However, the effectiveness of organized physical activities (OPAs) in attenuating or delaying these age-related transformations remains an area of limited understanding. The primary objectives of this study were threefold: (I) to comprehensively assess the evolution of body composition in a cohort of Spanish older adults over an 8-year period; (II) to compare this evolution in the different age groups; and (III) to investigate the influence of active engagement in OPAs on these age-related changes. From a sample of 3136 Spanish older adults recruited in 2008, 651 agreed to participate in the 8-year follow-up. Anthropometric and bioelectrical impedance data were included for 507 females (70.3 ± 4.4 years) and 144 males (77.8 ± 4.5 years). Age groups were categorized as follows: youngest (65-69 years), mid (70-74 years), and oldest (≥75 years). The engagement in OPA was recorded before and after the follow-up. A repeated measures ANOVA was performed to evaluate the 8-year changes. Males increased in hip (98.1 ± 9.3 vs. 101.5 ± 10.2 cm) and waist circumferences (101.2 ± 6.6 vs. 103.2 ± 6.1 cm), specifically in the youngest group (p < 0.05). Females decreased in weight (67.6 ± 10.0 vs. 66.6 ± 10.5 kg) and fat mass percentage (39.3 ± 5 vs. 38.8 ± 5.4%) and increased in hip circumference (104.4 ± 9.0 vs. 106.5 ± 9.7 cm); these effects were the most remarkable in the oldest group (all p < 0.05). OPA engagement seemed to slow down fat-free mass loses in males, but not in females (grouped by time, p < 0.05). Body composition changes caused by aging seem to happen earlier in males than in females. Moreover, participating in OPAs does not prevent fat-free mass due to aging.

Effect of breakfast protein intake on muscle mass and strength in adults: a scoping review

BACKGROUND

The distribution of protein intake throughout the day is frequently skewed, with breakfast having the lowest protein intake across all age groups. There is no review that addresses the association between breakfast protein intake and muscle mass and strength.

OBJECTIVE

This scoping review aims to summarize the literature on the relationship between protein intake during breakfast and muscle mass and strength in adults.

METHODS

This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Two independent reviewers screened and appraised the articles identified from 3 electronic databases (Medline, Web of Science, and Scopus) that focused on protein intake per meal and its impact on muscle-related outcomes.

RESULTS

A total of 14 763 articles were retrieved from 3 databases, and after the screening process, 15 articles were included for analysis. Approximately 58.8% of findings from 11 studies examining the association between high protein intake during breakfast and muscle mass indicated an increase in muscle mass among participants. Half of 6 studies (50.0%) exploring the relationship between high protein intake at breakfast and muscle strength demonstrated an increase in muscle strength. Consuming high amounts of protein at breakfast or more protein in the morning than in the evening was associated with an increase in the skeletal muscle index and lean body mass.

CONCLUSION

Protein consumption at breakfast revealed potential benefits in increasing muscle mass across 5 studies involving an elderly population and 2 studies encompassing middle-aged women and young men in our review. However, the relationship between protein intake at breakfast and muscle strength remains unclear. Further high-quality randomized controlled trials are required to examine whether adults can preserve skeletal muscle health outcomes by consuming higher amounts of protein at breakfast.

Decreased Neuromuscular Function and Muscle Quality along with Increased Systemic Inflammation and Muscle Proteolysis Occurring in the Presence of Decreased Estradiol and Protein Intake in Early to Intermediate Post-Menopausal Women

Menopause causes a reduction in estradiol (E2) and may be associated with neuromuscular degeneration. Compared to pre-menopausal (PRE-M) women, this study sought to determine dietary protein intake and whether lower levels of circulating E2 in post-menopausal women (POST-M) were occurring alongside increased levels of biomarkers of axonal and neuromuscular junction degeneration (NMJ), inflammation, muscle protein degradation, and reduced indices of muscle quality and performance. Employing a cross-sectional design, PRE-M (n = 6) and POST-M (n = 6) dietary analysis data were collected and participants then donated a blood and urine sample followed by assessments for body composition, motor unit activation, and muscle performance. Independent group t-tests were performed to determine differences between groups (p ≤ 0.05). In POST-M women, E2, motor unit activity, muscle quality, and muscle performance were significantly less than those for PRE-M women; however, the levels of c-terminal fragment of agrin, tumor necrosis factor-α, and urinary titin were significantly greater (p < 0.05). POST-M women were also shown to be ingesting fewer total calories and less protein than PRE-M (p < 0.05). Reduced E2 and dietary protein intake in POST-M women occurs in conjunction with increased levels of biomarkers of NMJ degradation, inflammation, and muscle proteolysis, which may be associated with reduced motor unit activation and muscle quality.

Sweat Rate, Sweat Sodium Losses, and Body Composition in Professional Male Soccer Players in Southwest Colombia

Background and Objective: Dehydration and hyperhydration impact athletes' performance. Exploring the fluid balance concerning body composition might help estimate individual hydration requirements. This area of research, particularly regarding sodium losses, has been relatively understudied. We evaluated the sweat rate (SR), sweat sodium losses, and their relationship with body composition in professional soccer players in Cali, Colombia. Materials and Methods: Thirty-two male players, aged 24.3 (±5.2) years, from the Colombian main soccer league, underwent high-intensity training at 32 °C (with a relative humidity of 79%). The outcome variables included SR, calculated using weight loss and fluid intake; forearm sweat sodium concentration (FSCC), measured through the direct ion-selective electrode method; and estimated the predicted whole sweat sodium loss (PWSSL) in mmol. Predictor variables (body mass, fat, and muscle masses) were estimated using the Deborah Kerr anthropometry method. The association between predictors and outcomes was assessed using linear regression. Results: The mean FSCC, PWSSL, and SR were 26.7 ± 11.3 mmol/L, 43 ± 15.9 mmol/L, and 1.7 ± 0.5 L/h, respectively. Body mass positively predicted FSCC in unadjusted and age/fat-mass-adjusted models [Beta 1.28, 95% confidence interval (CI) 0.39-2.18, p = 0.006], and continued related to FSCC after adjustment for muscle mass with marginal significance [Beta 0.85, 95% CI -0.02 to 1.73, p = 0.056]. Muscle mass was associated with the PWSSL in unadjusted and age/fat-mass-adjusted models [Beta 2.42, 95% CI 0.58-4.26, p = 0.012] and sustained an association with marginal statistical significance after adjustment for body mass [Beta 1.86, 95% CI -0.35 to 4.09, p = 0.097]. Conclusions: Under hot tropical weather conditions, FSCC was relatively low among the players. Body mass was better associated with the FSSC, and muscle mass better related to the PWSSL. Body and muscle masses could be regarded as potential factors to be explored in the estimation of individual sodium needs. However, further studies are required to validate and contrast our findings.

The Vicious Cycle of Type 2 Diabetes Mellitus and Skeletal Muscle Atrophy: Clinical, Biochemical, and Nutritional Bases

Today, type 2 diabetes mellitus (T2DM) and skeletal muscle atrophy (SMA) have become increasingly common occurrences. Whether the onset of T2DM increases the risk of SMA or vice versa has long been under investigation. Both conditions are associated with negative changes in skeletal muscle health, which can, in turn, lead to impaired physical function, a lowered quality of life, and an increased risk of mortality. Poor nutrition can exacerbate both T2DM and SMA. T2DM and SMA are linked by a vicious cycle of events that reinforce and worsen each other. Muscle insulin resistance appears to be the pathophysiological link between T2DM and SMA. To explore this association, our review (i) compiles evidence on the clinical association between T2DM and SMA, (ii) reviews mechanisms underlying biochemical changes in the muscles of people with or at risk of T2DM and SMA, and (iii) examines how nutritional therapy and increased physical activity as muscle-targeted treatments benefit this population. Based on the evidence, we conclude that effective treatment of patients with T2DM-SMA depends on the restoration and maintenance of muscle mass. We thus propose that regular intake of key functional nutrients, along with guidance for physical activity, can help maintain euglycemia and improve muscle status in all patients with T2DM and SMA.

Physiological and molecular predictors of cycling sprint performance

The study aimed to identify novel muscle phenotypic factors that could determine sprint performance using linear regression models including the lean mass of the lower extremities (LLM), myosin heavy chain composition (MHC), and proteins and enzymes implicated in glycolytic and aerobic energy generation (citrate synthase, OXPHOS proteins), oxygen transport and diffusion (myoglobin), ROS sensing (Nrf2/Keap1), antioxidant enzymes, and proteins implicated in calcium handling. For this purpose, body composition (dual-energy X-ray absorptiometry) and sprint performance (isokinetic 30-s Wingate test: peak and mean power output, Wpeak and Wmean ) were measured in young physically active adults (51 males and 10 females), from which a resting muscle biopsy was obtained from the musculus vastus lateralis. Although females had a higher percentage of MHC I, SERCA2, pSer16 /Thr17 -phospholamban, and Calsequestrin 2 protein expressions (all p < 0.05), and 18.4% lower phosphofructokinase 1 protein expression than males (p < 0.05), both sexes had similar sprint performance when it was normalized to body weight or LLM. Multiple regression analysis showed that Wpeak could be predicted from LLM, SDHB, Keap1, and MHC II % (R 2  = 0.62, p < 0.001), each variable contributing to explain 46.4%, 6.3%, 4.4%, and 4.3% of the variance in Wpeak , respectively. LLM and MHC II % explained 67.5% and 2.1% of the variance in Wmean , respectively (R 2  = 0.70, p < 0.001). The present investigation shows that SDHB and Keap1, in addition to MHC II %, are relevant determinants of peak power output during sprinting.

The Association of Isocaloric Substitution of Dietary Protein in Middle Age with Muscle Mass and Strength in Old Age: The Hordaland Health Study

Background

Age-associated loss of muscle mass and strength is an important predictor of disability in older persons. Although several mechanisms contribute to the decline in muscle mass and function seen with aging, the process is thought to be accelerated by an inadequate protein intake. However, the optimal amount and source of protein and the role of dietary protein intake over the life course remain uncertain.

Objectives

In a sample of community-dwelling adults in Western Norway, the current study examined both cross-sectional and longitudinal associations over 20 y of dietary protein intake with appendicular skeletal muscle mass (ASMM) and muscle strength measured by handgrip strength (HGS) in older age.

Methods

Dietary intake was assessed using food frequency questionnaires (FFQs) in middle age (46-49 y) and older age (67-70 y) within the community-based Hordaland Health Study.

Results

Adjusted, multivariate linear regression analyses revealed a negative cross-sectional association between the substitution of total protein (TP) and animal protein (AP), with fat and carbohydrates, on ASMM in women but not in men. No longitudinal associations were found between substitution of dietary protein intake and ASMM in either sex in adjusted models. Similarly, no cross-sectional or longitudinal associations were evident between substitution of dietary protein intake and HGS in either sex in adjusted models.

Conclusion

The findings in the current study highlight the need to clarify the role of dietary protein intake in the maintenance of muscle mass and muscle strength in healthy older adults.