***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Cancer cachexia syndrome contributes to wasting and weight loss leading to inefficacy of anticancer therapy . In this study , the anticatabolic agent beta-hydroxy-beta-methylbutyrate ( HMB ) was supplemented to adult Walker 256 tumor-bearing rats during 8 weeks aim ing to determine if tumor burden could be reduced . Male Wistar rats were r and omly assigned to nontumor and tumor-bearing groups and fed regular chow or regular chow plus HMB supplemented ( 76 mg/kg body weight ) . Beta-hydroxy-beta-methylbutyrate supplementation induced a lower tumor weight and tumor cell proliferation ex vivo , totally prevented glycemia reduction , as well as blunted the increase in the serum lactate concentrations and also preserved glycogen stores in tumor-bearing rats . Reduction in tumor cell proliferation ex vivo was accompanied by increased nuclear factor-kappaB inhibitor-alpha content by more than 100 % . In contrast , nuclear factor-kappaB p65 subunit content was suppressed by 17 % with HMB supplementation . In conclusion , HMB supplementation , at a similar dose used in humans to increase muscle mass , caused antitumor and anticachectic effects , with tumor-cell nuclear factor-kappaB pathway participation , which might be a potential nutritional strategy in cancer therapy Studies in young adults have demonstrated that beta-hydroxy-beta-methylbutyrate ( HMB ) can increase gains in strength and fat-free mass during a progressive resistance-training program . The purpose of this study was to determine whether HMB would similarly benefit 70-y-old adults undergoing a 5 d/wk exercise program . Thirty-one men ( n = 15 ) and women ( n = 16 ) ( 70 + /- 1 y ) were r and omly assigned in a double-blind study to receive either capsules containing a placebo or Ca-HMB ( 3 g/d ) for the 8-wk study . Skin fold estimations of body composition as well as computerized tomography ( CT ) and dual X-ray absorptiometry ( DXA ) scans were measured before the study and immediately after the 8-wk training program . HMB supplementation tended to increase fat-free mass gain ( HMB , 0.8 + /- 0.4 kg ; placebo , -0.2 + /- 0.3 kg ; treatment x time , P = 0.08 ) . Furthermore , HMB supplementation increased the percentage of body fat loss ( skin fold : HMB , -0.66 + /- 0.23 % ; placebo , -0.03 + /- 0.21 % ; P = 0.05 ) compared with the placebo group . CT scans also indicated a greater decrease in the percentage of body fat with HMB supplementation ( P < 0.05 ) . In conclusion , changes in body composition can be accomplished in 70-y-old adults participating in a strength training program , as previously demonstrated in young adults , when HMB is supplemented daily BACKGROUND & AIMS Rheumatoid arthritis ( RA ) is complicated by cytokine-driven alterations in protein and energy metabolism and consequent muscle wasting ( cachexia ) . The aim of this r and omised controlled trial was to investigate the efficacy of a mixture of beta-hydroxy-beta-methylbutyrate , glutamine and arginine ( HMB/GLN/ARG ) as nutritional treatment for rheumatoid cachexia . METHODS Forty RA patients supplemented their diet with either HMB/GLN/ARG or a nitrogen ( 7.19 g/day ) and calorie ( 180 kcal/day ) balanced mixture of alanine , glutamic acid , glycine , and serine ( placebo ) for 12 weeks . Body composition and other outcomes were assessed at baseline and follow-up , and analysed by mixed ANOVA . RESULTS Dietary supplementation with HMB/GLN/ARG was not superior to placebo in the treatment of rheumatoid cachexia ( groupxtime interactions P>0.05 for all outcomes ) . Both amino acid mixtures significantly increased ( main effect of time ) fat-free mass ( 727+/-1186 g , P<0.01 ) , total body protein ( 719+/-1703 g , P=0.02 ) , arms ( 112+/-183 g , P<0.01 ) and legs ( 283+/-534 g , P<0.01 ) lean mass , and some measures of physical function . No significant adverse event occurred during the study , but patients in the HMB/GLN/ARG group reported fewer gastrointestinal complaints compared to placebo . CONCLUSIONS Dietary supplementation with HMB/GLN/ARG is better tolerated but not more effective in reversing cachexia in RA patients compared to the mixture of other non-essential amino acids used as placebo . Further controlled studies are necessary to confirm the beneficial anabolic and functional effects of increased nitrogen intake in this population This study assesses the effects of daily beta-hydroxy beta-methylbutyrate ( HMB ) supplementation on muscular strength ( bench press , squats , and power cleans ) and body composition ( body weight and body fat ) among collegiate football players undergoing a strenuous exercise program . Subjects were collegiate football players ( n = 35 ) training under the supervision of certified strength coaches averaging 20 hours of weekly exercise . In the first supplementation period , 16 of the 35 subjects were supplemented with 3 g of HMB per day for 4 weeks ; the other 19 received a placebo followed by a 1-week washout period and then a second supplementation period in a r and omized double-blind crossover , placebo design . There were no significant changes ( p > 0.05 ) in muscular strength , including bench press , squats , and power cleans , among the subjects . There were also no significant changes ( p > 0.05 ) in body composition , including body fat and body weight . Very little clinical evidence exists for supplementing HMB in athletic population β-hydroxy-β-methylbutyrate ( HMB ) , a leucine metabolite , improves muscle mass and function . This study aim ed at evaluating the effects of HMB administration in an experimental in vivo model of cancer cachexia ( CC ) . Wistar rats were r and omized to receive st and ard or 4 % HMB-enriched chow .  Rats from both groups were r and omized to receive an i.p . inoculum of AH-130 cells ( TB ) . All rats were weighed and sacrificed at day 24 . Liver , heart and muscles were dissected and weighed . The protein levels of p-p70S6k , p-eIf2α , p-mTOR and p-4-EB-P1 were evaluated by Western blotting on gastrocnemius muscle ( GSN ) . As expected , the growth of the AH-130 ascites hepatoma induced significant carcass weight and GSN muscle loss . HMB treatment significantly increased GSN and heart weight in controls ( p=0.002 and p<0.001 , respectively ) . In HMB-treated  TB , body weight was not lost but significantly ( p=0.003 ) increased , and GSN loss was significantly ( p=0.04 ) attenuated with respect to TB . Phosphorylated eIF2α markedly decreased in TB-rats vs. C. Feeding the HMB-enriched diet result ed in decreased p-eIF2α levels in control animals , while no changes could be observed in the TB group . Phosphorylated p70S6 K and phosphorylated mTOR were markedly increased by HMB treatment in controls and further increased in TB . Phosphorylated 4-EB-P1 was markedly increased in TB but substantially unaffected by HMB treatment . Administration of HMB  attenuates body weight and muscle loss  in experimental CC . Increased phosphorylation of key anabolic molecules suggests that these actions are mediated by improved protein anabolism in muscle Objective To examine the effect of arginine , & bgr;-hydroxy-&bgr;-methylbutyrate ( HMB ) , and glutamine supplementation on wound collagen accumulation in a double-blind , r and omized study . Summary Background Data Control of wound collagen synthesis has been an elusive goal for clinicians and scientists alike . In many clinical instances , it is desired to increase collagen deposition as a means of enhancing wound strength and integrity . Arginine , a semiessential amino acid , has been shown to increase wound collagen accumulation in rodents and humans . HMB , a metabolite of leucine , regulates muscle proteolysis in animals and humans and increases collagen deposition in rodents . Methods Thirty-five healthy , nonsmoking human volunteers 70 years or older were enrolled and underwent subcutaneous implantation of two small , sterile polytetrafluoroethylene ( PTFE ) tubes into the deltoid region under strict aseptic techniques . The tubes were 1 mm in diameter and 6 cm in length with pore size of 90 to 120 & mgr;m to allow optimal ingrowth of fibroblasts and the deposition of matrix . Eighteen volunteers ( mean age 75.4 years ; 2 men , 16 women ) were r and omized to receive daily supplementation of 14 g arginine , 3 g HMB , and 14 g glutamine ( total nitrogen 3.59 g ) in two divided doses . The control group ( n = 17 ; mean age 75.3 years ; 6 men , 11 women ) received an isonitrogenous , isocaloric supplementation of nonessential amino acids . Catheters were removed at 7 and 14 days postimplantation and analyzed for hydroxyproline ( OHP , nmol/cm catheter , an index of collagen accumulation ) and & agr;-amino nitrogen ( & agr;-AN , mmol/cm , an index of total protein deposition ) . Results Supplements were well tolerated , without any reported side effects . Supplementation with the specialized amino acid mixture led to a significant rise in plasma arginine and ornithine levels . The specialized amino acid supplement led to a significant increase in collagen deposition ( as reflected by OHP content ) in the PTFE tubes without an effect on total protein accumulation . Conclusions Collagen synthesis is significantly enhanced in healthy elderly volunteers by the oral administration of a mixture of arginine , HMB , and glutamine . This provides a safe nutritional means for increasing wound repair in patients This study examined the effects of supplemental beta-hydroxy-beta-methylbutyrate ( HMB ) on  muscle damage as a result of intense endurance exercise . Subjects ( n = 13 ) were paired according to their 2-mile run times and past running experience . Each pair was r and omly assigned a treatment of either HMB ( 3 g/day ) or a placebo . After 6 wk of daily training and supplementation , all subjects participated in a prolonged run ( 20-km course ) . Creatine phosphokinase and lactate dehydrogenase ( LDH ) activities were measured before and after a prolonged run to assess muscle damage . The placebo-supplemented group exhibited a significantly greater ( treatment main effect , P = 0.05 ) increase in creatine phosphokinase activity after a prolonged run than did the HMB-supplemented group . In addition , LDH activity was significantly lower ( treatment main effect , P = 0.003 ) with HMB supplementation compared with the placebo-supplemented group . In conclusion , supplementation with 3.0 g of HMB results in a decreased creatine phosphokinase and LDH response after a prolonged run . These findings support the hypothesis that HMB supplementation helps prevent exercise-induced muscle damage The use of ergogenic nutritional supplements is becoming inseparable from competitive sports . β-Hydroxy-β-Methylbutyric acid ( HMB ) has recently been suggested to promote fat-free mass ( FFM ) and strength gains during resistance training in adults . In this prospect i ve r and omized , double-blind , placebo-controlled study , we studied the effect of HMB ( 3 g/day ) supplementation on body composition , muscle strength , anaerobic and aerobic capacity , anabolic/catabolic hormones and inflammatory mediators in elite , national team level adolescent volleyball players ( 13.5–18 years , 14 males , 14 females , Tanner stage 4–5 ) during the first 7 weeks of the training season .  HMB led to a significant greater increase in FFM by skinfold thickness ( 56.4 ± 10.2 to 56.3 ± 8.6 vs. 59.3 ± 11.3 to 61.6 ± 11.3 kg in the control and HMB group , respectively , p < 0.001 ) . HMB led to a significant greater increase in both dominant and non-dominant knee flexion isokinetic force/FFM , measured at fast ( 180 ° /sec ) and slow ( 60 ° /sec ) angle speeds , but had no significant effect on knee extension and elbow flexion and extension . HMB led to a significant greater increase in peak and mean anaerobic power determined by the Wingate anaerobic test ( peak power : 15.5 ± 1.6 to 16.2 ± 1.2 vs. 15.4 ± 1.6 to 17.2 ± 1.2 watts/FFM , mean power : 10.6 ± 0.9 to 10.8 ± 1.1 
    Output:
    
Most of the selected studies showed the effectiveness of HMB  in preventing exercise-related muscle damage in healthy trained and untrained individuals as well as muscle loss during chronic diseases .