Protein supplementation increases postexercise plasma myostatin concentration after 8 weeks of resistance training in young physically active subjects

Anabolic myokine responses and muscular performance following 8 weeks of autoregulated compared to linear resistance exercise in recreationally active males

BACKGROUND

To date, no studies, to our knowledge, have compared the efficacy of autoregulated periodized and linear resistance exercises on anabolic myokines and muscular performance among recreationally active individuals. This study aimed to compare the effects of an 8-week autoregulated periodized resistance exercise (APRE) program with a linear resistance exercise (LRE) program on insulin-like growth factor-1 (IGF-1), follistatin (FST), myostatin (MST), body composition, muscular strength, and power in recreationally active males.

METHODS

Thirty males were randomly assigned to either the APRE group (n = 15) or the LRE group (n = 15). Participants completed training three times a week for 8 weeks. The outcome measures included serum IGF-1, FST, MST, muscular strength (isometric knee extension and handgrip), power (vertical jump), lean body mass, and fat mass.

RESULTS

IGF-1 circulating levels increased over time following APRE (34%) and with no significant change following LRE (~-1%). There were no significant differences over time or between groups for FST or MST. Muscular strength (knee extension [21.5 vs. ~16%] and handgrip [right: 31 vs. 25%; left: 31.7 vs. 28.8%]) and power (~ 33 vs. ~26%) significantly increased to a greater extent following APRE compared to LRE. Interestingly, the results revealed that lean body mass increased over time only after APRE (~ 3%), but not LRE.

CONCLUSION

These findings suggest that APRE may be more effective than LRE in increasing muscular strength, power, and lean body mass, as well as circulating IGF-1 levels, in recreationally active males. The observed differences may be attributed to the increased training volume associated with APRE. However, further research is needed to directly assess muscle protein synthesis.

Protein-enriched soup and weekly exercise improve muscle health: A randomized trial in mid-to-old age with inadequate protein intake

BACKGROUND

Prior research has highlighted the synergistic impact of protein supplementation on muscle function post-exercise in adults; however, evidence supporting the combined effects were less robust and inconsistent on those with protein insufficiency. This investigation aims to explore efficacy of protein-enriched soup coupled with exercise on muscle health and metabolism in middle-aged and older adults with suboptimal protein intake.

METHODS

An open-label, 12-week, randomized controlled trial involving participants with insufficient protein intake (<1.0 g/kg/day) was done. The intervention group consumed protein-enriched soup (24-30 g protein daily) and 1-h weekly exercise, while controls received health education. Assessments included laboratory tests, functional assessments, and body composition.

RESULTS

In this trial, 97 out of 100 randomized participants (mean age: 64.65 ± 4.84 years, 81.8% female) completed the study (47 in intervention group and 50 in control group). Compared results of baselines, at 1 and 3 months of intervention, significant improvements in waist circumference (83.48 ± 10.22 vs. 82.5 ± 9.88 vs. 82.37 ± 9.42 cm, P for trend = 0.046), 6-min walking distance (525.65 ± 58.46 vs. 534.47 ± 51.87 vs. 552.02 ± 57.66 m, P for trend = 0.001), five-time sit-to-stand time (7.63 ± 1.63 vs. 6.81 ± 1.8 vs. 6.4 ± 1.42 s, P for trend <0.001), grip strength (26.74 ± 6.54 vs. 27.53 ± 6.99 vs. 28.52 ± 7.09 kg, P for trend <0.001), and MNA score (26.8 ± 2.14 vs. 27.73 ± 1.74 vs. 27.55 ± 1.72, P for trend <0.001) were discerned within the intervention group. The intervention demonstrated a significant reduction in serum triglyceride (105.32 ± 49.84 vs. 101.36 ± 42.58 vs. 93.43 ± 41.49 mg/dL, P for trend = 0.023), increased HDL-C (60.04 ± 16.21 vs. 60 ± 17.37 vs. 62.55 ± 18.27 mg/dL, P for trend = 0.02), and DHEA-S levels (97.11 ± 54.39 vs. 103.39 ± 56.75 vs. 106.83 ± 60.56 μg/dL, P for trend = 0.002). Serum myostatin did not differ in both groups, but serum leptin levels significantly increased (9118.88 ± 5811.68 vs. 11508.97 ± 7151.08 vs. 11220.80 ± 7190.71 pg/mL, P for trend = 0.016) in controls. The intervention group showed greater improvements in 6 min walking distance (β = 0.71, 95% CI: 6.88 to 40.79, P = 0.006), five-time sit-to-stand test (β = -0.87, 95% CI: -1.59 to -0.15, P = 0.017), MNA score (β = 0.96, 95% CI: 0.20 to 1.71, P = 0.013), serum triglycerides (β = -15.01, 95% CI: -27.83 to -2.20, P = 0.022), LDL-C (β = -9.23, 95% CI: -16.98 to -1.47, P = 0.020), and DHEA-S levels (β = 9.98, 95% CI: 0.45 to 19.51, P = 0.04) than controls.

CONCLUSIONS

Protein-enriched soup with weekly exercise over 12 weeks significantly improved physical performance, lipid profile, and DHEA-S levels among middle-aged and older adults with inadequate protein intake, while studies assessing long-term benefits of the intervention are needed.

The Effects of Dietary Supplements, Nutraceutical Agents, and Physical Exercise on Myostatin Levels: Hope or Hype?

Myostatin, a secreted growth factor belonging to the transforming growth factor β (TGF-β) family, performs a role in hindering muscle growth by inhibiting protein kinase B (Akt) phosphorylation and the associated activation of hypertrophy pathways (e.g., IGF-1/PI3K/Akt/mTOR pathway). In addition to pharmacological agents, some supplements and nutraceutical agents have demonstrated modulatory effects on myostatin levels; however, the clinical magnitude must be appraised with skepticism before translating the mechanistic effects into muscle hypertrophy outcomes. Here, we review the effects of dietary supplements, nutraceutical agents, and physical exercise on myostatin levels, addressing the promise and pitfalls of relevant randomized clinical trials (RCTs) to draw clinical conclusions. RCTs involving both clinical and sports populations were considered, along with wasting muscle disorders (e.g., sarcopenia) and resistance training-induced muscle hypertrophy, irrespective of disease status. Animal models were considered only to expand the mechanisms of action, and observational data were consulted to elucidate potential cutoff values. Collectively, the effects of dietary supplements, nutraceutical agents, and physical exercise on myostatin mRNA expression in skeletal muscle and serum myostatin levels are not uniform, and there may be reductions, increases, or neutral effects. Large amounts of research using resistance protocols shows that supplements or functional foods do not clearly outperform placebo for modulating myostatin levels. Thus, despite some biological hope in using supplements or certain functional foods to decrease myostatin levels, caution must be exercised not to propagate the hope of the food supplement market, select health professionals, and laypeople.

Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults

We performed a systematic review, meta-analysis, and meta-regression to determine if increasing daily protein ingestion contributes to gaining lean body mass (LBM), muscle strength, and physical/functional test performance in healthy subjects. A protocol for the present study was registered (PROSPERO, CRD42020159001), and a systematic search of Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Only randomized controlled trials (RCT) where participants increased their daily protein intake and were healthy and non-obese adults were included. Research questions focused on the main effects on the outcomes of interest and subgroup analysis, splitting the studies by participation in a resistance exercise (RE), age (<65 or ≥65 years old), and levels of daily protein ingestion. Three-level random-effects meta-analyses and meta-regressions were conducted on data from 74 RCT. Most of the selected studies tested the effects of additional protein ingestion during RE training. The evidence suggests that increasing daily protein ingestion may enhance gains in LBM in studies enrolling subjects in RE (SMD [standardized mean difference] = 0.22, 95% CI [95% confidence interval] 0.14:0.30, P < 0.01, 62 studies, moderate level of evidence). The effect on LBM was significant in subjects ≥65 years old ingesting 1.2-1.59 g of protein/kg/day and for younger subjects (<65 years old) ingesting ≥1.6 g of protein/kg/day submitted to RE. Lower-body strength gain was slightly higher by additional protein ingestion at ≥1.6 g of protein/kg/day during RE training (SMD = 0.40, 95% CI 0.09:0.35, P < 0.01, 19 studies, low level of evidence). Bench press strength is slightly increased by ingesting more protein in <65 years old subjects during RE training (SMD = 0.18, 95% CI 0.03:0.33, P = 0.01, 32 studies, low level of evidence). The effects of ingesting more protein are unclear when assessing handgrip strength and only marginal for performance in physical function tests. In conclusion, increasing daily protein ingestion results in small additional gains in LBM and lower body muscle strength gains in healthy adults enrolled in resistance exercise training. There is a slight effect on bench press strength and minimal effect performance in physical function tests. The effect on handgrip strength is unclear.

Moderate-Intensity Strength Exercise to Exhaustion Results in More Pronounced Signaling Changes in Skeletal Muscles of Strength-Trained Compared With Untrained Individuals

Lysenko, EA, Popov, DV, Vepkhvadze, TF, Sharova, AP, and Vinogradova, OL. Moderate-intensity strength exercise to exhaustion results in more pronounced signaling changes in skeletal muscles of strength-trained compared with untrained individuals. J Strength Cond Res 34(4): 1103-1112, 2020-The aim of our investigation was to compare the response pattern of signaling proteins and genes regulating protein synthesis and degradation in skeletal muscle after strength exercise sessions performed to volitional fatigue in strength-trained and untrained males. Eight healthy recreationally active males and 8 power-lifting athletes performed 4 sets of unilateral leg presses to exhaustion (65% 1 repetition maximum). Biopsy samples of m. vastus lateralis were obtained before, 1 and 5 hours after cessation of exercise. Phosphorylation of p70S6k, 4EBP1, and ACC increased, whereas phosphorylation of eEF2 and FOXO1 decreased only in the trained group after exercise. Expression of DDIT4, MURF1, and FOXO1 mRNAs increased and expression of MSTN mRNA decreased also only in the trained group after exercise. In conclusion, moderate-intensity strength exercise performed to volitional fatigue changed the phosphorylation status of mTORC1 downstream signaling molecules and markers of ubiquitin-proteasome system activation in trained individuals, suggesting activation of protein synthesis and degradation. In contrast to the trained group, signaling responses in the untrained group were considerably less pronounced. It can be assumed that the slowdown in muscle mass gain as the athletes increase in qualification cannot be associated with a decrease in the sensitivity of systems regulating protein metabolism, but possibly with inadequate intake or assimilation of nutrients necessary for anabolism. Perhaps, the intake of highly digestible protein or protein-carbohydrate dietary supplements could contribute to the increase in muscle mass in strength athletes.

Exercise, Dietary Protein, and Combined Effect on IGF-1

Insulin-like growth factor 1 (IGF-1) is a dichotomous hormone. While beneficial for growth/repair, and regulating muscle hypertrophy, high concentrations of IGF-1 are associated with increased risk of cancer and mortality. Factors thought to mediate IGF-1 include dietary protein and exercise. The purpose of this study was to analyze acute effects of dietary protein and/or exercise on plasma free IGF-1 and the time-course thereof to inform individuals who may benefit from increased IGF-1 (muscle growth/repair) or reduced IGF-1 (risk/diagnosis of cancer). Twenty-four participants (11 females, 24.9±4.6y) completed the three-way crossover study consisting of: (1)a high protein (42g) meal; (2)exercise (20min with four 30sec sprints); and (3)exercise followed by a high protein meal. Blood samples were collected fasted at rest, immediately after rest (or 5min after exercise), and at regular intervals throughout a 5h recovery. An additional fasted venipuncture was performed the morning following each condition (24h after baseline). Free IGF-1 was higher at immediately after exercise in the exercise condition (p=0.04). In the protein condition the 24h IGF-1 was 17.5% higher (p=0.02) than baseline. IGF-1 did not change over time in response to exercise with protein. The data gleaned from this study can enhance the knowledge of the time-course effects from protein and/or exercise on IGF-1. This study can provide a foundation for future research to investigate optimal timing and dosage to enhance muscle protein synthesis for athletes, as well as investigate whether consistent high protein meals may chronically elevate IGF-1 and increase the risk of deleterious health outcomes.

Myostatin as a Biomarker of Muscle Wasting and other Pathologies-State of the Art and Knowledge Gaps

Sarcopenia is a geriatric syndrome with a significant impact on older patients’ quality of life, morbidity and mortality. Despite the new available criteria, its early diagnosis remains difficult, highlighting the necessity of looking for a valid muscle wasting biomarker. Myostatin, a muscle mass negative regulator, is one of the potential candidates. The aim of this work is to point out various factors affecting the potential of myostatin as a biomarker of muscle wasting. Based on the literature review, we can say that recent studies produced conflicting results and revealed a number of potential confounding factors influencing their use in sarcopenia diagnosing. These factors include physiological variables (such as age, sex and physical activity) as well as a variety of disorders (including heart failure, metabolic syndrome, kidney failure and inflammatory diseases) and differences in laboratory measurement methodology. Our conclusion is that although myostatin alone might not prove to be a feasible biomarker, it could become an important part of a recently proposed panel of muscle wasting biomarkers. However, a thorough understanding of the interrelationship of these markers, as well as establishing a valid measurement methodology for myostatin and revising current research data in the light of new criteria of sarcopenia, is needed.

Endocrine Mechanisms Connecting Exercise to Brown Adipose Tissue Metabolism: a Human Perspective

PURPOSE OF REVIEW

To summarize the state-of-the-art regarding the exercise-regulated endocrine signals that might modulate brown adipose tissue (BAT) activity and/or white adipose tissue (WAT) browning, or through which BAT communicates with other tissues, in humans.

RECENT FINDINGS

Exercise induces WAT browning in rodents by means of a variety of physiological mechanism. However, whether exercise induces WAT browning in humans is still unknown. Nonetheless, a number of protein hormones and metabolites, whose signaling can influence thermogenic adipocyte's metabolism, are secreted during and/or after exercise in humans from a variety of tissues and organs, such as the skeletal muscle, the adipose tissue, the liver, the adrenal glands, or the cardiac muscle. Overall, it seems plausible to hypothesize that, in humans, exercise secretes an endocrine cocktail that is likely to induce WAT browning, as it does in rodents. However, even if exercise elicits a pro-browning endocrine response, this might result in a negligible effect if blood flow is restricted in thermogenic adipocyte-rich areas during exercise, which is still to be determined. Future studies are needed to fully characterize the exercise-induced secretion (i.e., to determine the effect of the different exercise frequency, intensity, type, time, and volume) of endocrine signaling molecules that might modulate BAT activity and/or WAT browning or through which BAT communicates with other tissues, during exercise. The exercise effect on BAT metabolism and/or WAT browning could be one of the still unknown mechanisms by which exercise exerts beneficial health effects, and it might be pharmacologically mimicked.

Myostatin as a potential biomarker to monitor sarcopenia in hip fracture patients undergoing a multidisciplinary rehabilitation and nutritional treatment: a preliminary study

Hip fractures are the most common osteoporotic fractures related to disability in older adults, requiring surgery and a subsequent rehabilitation treatment. Sarcopenia is currently considered as a predictive of worse outcome in hip fracture patients and myostatin has been recently proposed a potential biomarker of this condition. Twenty hip fracture patients after total hip replacement (mean aged 75.9 ± 2.4 years) were randomly divided into two groups of ten subjects (groups A and B). Both groups performed a rehabilitation program (5 sessions of 40 min/week for 2 weeks, followed by home-based exercise protocol). Group A received also 2-month amino acid supplementation. Serum myostatin levels significantly decreased after 2 months in both group A (p = 0.01) and group B (p = 0.03) in sarcopenic patients only in group A (p = 0.04). These results suggest that myostatin might be considered a promising biomarker of sarcopenia in hip fracture older adults' patients undergoing rehabilitation and amino acid supplementation.

Circulating Tumor Necrosis Factor Alpha May Modulate the Short-Term Detraining Induced Muscle Mass Loss Following Prolonged Resistance Training

Introduction

Tumor necrosis factor alpha (TNFα) is a pro-inflammatory cytokine that has been shown to modulate muscle mass, and is responsive to exercise training. The effects of resistance training (RT) followed by a short period of detraining on muscle size, architecture and function in combination with circulating TNFα levels have not been previously investigated in a young, healthy population.

Methods

Sixteen participants (8 males and 8 females) were randomly assigned to a training group (TRA; age 20 ± 3 years, mass 76 ± 7 kg), whilst fourteen participants (7 males and 7 females) age 22 ± 2 years, mass 77 ± 6 kg were assigned to a control group (CON). Measures of vastus lateralis (VL) muscle size (normalized physiological cross-sectional area allometrically scaled to body mass; npCSA), architecture (fascicle length; L_F, pennation angle Pθ), strength (knee extensor maximal voluntary contraction; KE MVC), specific force, subcutaneous fat (SF) and circulating TNFα were assessed at baseline (BL), post 8 weeks RT (PT), and at two (DT1) and four (DT2) weeks of detraining.

Results

Pooled BL TNFα was 0.87 ± 0.28 pg/mL with no differences between groups. BL TNFα tended to be correlated with npCSA (p = 0.055) and KEMVC (p = 0.085) but not specific force (p = 0.671) or SF (p = 0.995). There were significant (p < 0.05) increases in npCSA compared to BL and CON in TRA at PT, DT1, and DT2, despite significant (p < 0.05) decreases in npCSA compared to PT at DT1 and DT2. There were significant (p < 0.05) increases in L_F, Pθ and KE MVC at PT but only L_F and torque at DT1. There were no significant (p > 0.05) changes in SF, specific force or TNFα at any time points. There was a significant correlation (p = 0.022, r = 0.57) between the relative changes in TNFα and npCSA at DT2 compared to PT.

Discussion

Neither RT nor a period of short term detraining altered the quality of muscle (i.e., specific force) despite changes in morphology and function. TNFα does not appear to have any impact on RT-induced gains in muscle size or function, however, TNFα may play a role in inflammatory-status mediated muscle mass loss during subsequent detraining in healthy adults.

A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults

OBJECTIVE

We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength.

DATA SOURCES

A systematic search of Medline, Embase, CINAHL and SportDiscus.

ELIGIBILITY CRITERIA

Only randomised controlled trials with RET ≥6 weeks in duration and dietary protein supplementation.

DESIGN

Random-effects meta-analyses and meta-regressions with four a priori determined covariates. Two-phase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM).

RESULTS

Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes (means (95% CI)) in: strength-one-repetition-maximum (2.49 kg (0.64, 4.33)), FFM (0.30 kg (0.09, 0.52)) and muscle size-muscle fibre cross-sectional area (CSA; 310 µm² (51, 570)) and mid-femur CSA (7.2 mm² (0.20, 14.30)) during periods of prolonged RET. The impact of protein supplementation on gains in FFM was reduced with increasing age (-0.01 kg (-0.02,-0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM.

SUMMARY/CONCLUSION

Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.

Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males

Background

Intermittent fasting (IF) is an increasingly popular dietary approach used for weight loss and overall health. While there is an increasing body of evidence demonstrating beneficial effects of IF on blood lipids and other health outcomes in the overweight and obese, limited data are available about the effect of IF in athletes. Thus, the present study sought to investigate the effects of a modified IF protocol (i.e. time-restricted feeding) during resistance training in healthy resistance-trained males.

Methods

Thirty-four resistance-trained males were randomly assigned to time-restricted feeding (TRF) or normal diet group (ND). TRF subjects consumed 100 % of their energy needs in an 8-h period of time each day, with their caloric intake divided into three meals consumed at 1 p.m., 4 p.m., and 8 p.m. The remaining 16 h per 24-h period made up the fasting period. Subjects in the ND group consumed 100 % of their energy needs divided into three meals consumed at 8 a.m., 1 p.m., and 8 p.m. Groups were matched for kilocalories consumed and macronutrient distribution (TRF 2826 ± 412.3 kcal/day, carbohydrates 53.2 ± 1.4 %, fat 24.7 ± 3.1 %, protein 22.1 ± 2.6 %, ND 3007 ± 444.7 kcal/day, carbohydrates 54.7 ± 2.2 %, fat 23.9 ± 3.5 %, protein 21.4 ± 1.8). Subjects were tested before and after 8 weeks of the assigned diet and standardized resistance training program. Fat mass and fat-free mass were assessed by dual-energy x-ray absorptiometry and muscle area of the thigh and arm were measured using an anthropometric system. Total and free testosterone, insulin-like growth factor 1, blood glucose, insulin, adiponectin, leptin, triiodothyronine, thyroid stimulating hormone, interleukin-6, interleukin-1β, tumor necrosis factor α, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. Bench press and leg press maximal strength, resting energy expenditure, and respiratory ratio were also tested.

Results

After 8 weeks, the 2 Way ANOVA (Time * Diet interaction) showed a decrease in fat mass in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area of the arm and thigh, and maximal strength were maintained in both groups. Testosterone and insulin-like growth factor 1 decreased significantly in TRF, with no changes in ND (p = 0.0476; p = 0.0397). Adiponectin increased (p = 0.0000) in TRF while total leptin decreased (p = 0.0001), although not when adjusted for fat mass. Triiodothyronine decreased in TRF, but no significant changes were detected in thyroid-stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, or triglycerides. Resting energy expenditure was unchanged, but a significant decrease in respiratory ratio was observed in the TRF group.

Conclusions

Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males.

Association of serum myokines and aerobic exercise training in patients with spinal cord injury: an observational study

Background

Patients with spinal cord injury (SCI) have a higher prevalence of cardiovascular diseases compared to the healthy population. Aerobic exercise training is one of the recommended treatments. However, literature regarding the effect of aerobic training on patients with SCI is scarce. This study evaluated changes in parameters of exercise physiology and serum myokines immediately after exercise and after a training program among patients with SCI.

Methods

Male patients with SCI and age- and sex-matched healthy individuals were recruited. Cardio-pulmonary exercise testing (CPET) was used to determine oxygen uptake at peak exercise and anaerobic threshold in both groups. The patients with SCI attended aerobic exercise training for 36 sessions within 12–16 weeks. Basic data, hemodynamic and exercise physiology parameters, and serum myokine (myostatin, IGF-1, and follistatin) concentrations were measured pre- and post-exercise in both groups, and were repeated in patients with SCI post-training.

Results

Eleven patients with SCI underwent CPET and 5 completed the training. The 11 patients and 16 healthy adults had no differences in baseline serum myokine concentrations before CPET. Immediately after the CPET, the reference group had an 18 ± 19 % increase in serum IGF-1, while the patients had no observable myokine changes. After aerobic exercise training, the 5 patients had a 48 ± 18 % increase in serum myostatin compared to the pre-training level, although the body weight and exercise physiology parameters remained unchanged.

Conclusions

Acute exercise to exhaustion in CPET results in an immediate increase in serum IGF-1 in healthy individuals while aerobic exercise training results in increased serum myostatin in patients with SCI.

Reduced Resting Metabolic Rate in Adults with Hemiparetic Chronic Stroke

OBJECTIVE

Resting metabolic rate (RMR) is the component of energy expenditure that explains the largest proportion of total daily energy requirements. Since RMR is determined largely by fat-free mass and a low RMR predicts weight gain in healthy adults, identifying the role of muscle atrophy following stroke on RMR may help identify ways to mitigate the development of obesity post-stroke.

METHODS

Thirty-nine stroke survivors with chronic hemiparesis (mean ± SEM: age: 61 ± 1 years, latency from stroke: 107 ± 40 months, BMI: 31 ± 3 kg/m2) underwent DXA scans for measurement of body composition, including total, paretic, and non-paretic leg lean mass and fasted, 30-min indirect calorimetry for measurement of RMR.

RESULT

Predicted RMR was calculated by the Mifflin-St Jeor equation, which considers weight, height, and age for both men and women. RMR was 14% lower than predicted (1438 ± 45 vs. 1669 ± 38 kcals/24 hrs; P<0.01). Total (r=0.73, P<0.01), paretic (r=0.72, P<0.01) and non-paretic (r=0.67, P<0.01) leg lean mass predicted RMR.

CONCLUSION

These data indicate that muscle atrophy post stroke may lead to a reduced RMR. This substantiates the need to attenuate the loss of lean mass after a stroke to prevent declines in RMR and possible weight gain common post-stroke.