handdator

Visa fullständig version : HMB vid hälsa och sjukdom; en genomgång.


tjing
2013-11-26, 18:24
Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trials.

Abstract

Beta-hydroxy-beta-methylbutyrate (HMB), a metabolite of the branched-chain amino acid leucine, is extensively used by athletes and bodybuilders in order to increase strength, muscle mass and exercise performance.

We performed a systematic review of the clinical literature on the effectiveness of HMB supplementation in healthy and pathological conditions (i.e. training programs, aging, acute and chronic diseases, and after bariatric surgery). We reviewed all clinical trials indexed in Medline that tested HMB supplementation as well as all the experimental data regarding HMB intracellular mechanisms of action. Search terms included: randomized controlled trials, controlled clinical trials, single- and double-blind method, HMB, proteolytic pathways, muscle atrophy, cachexia, and training.

We found out 13 studies testing HMB in healthy young trained subjects, 11 in healthy young untrained subjects, 9 in patients affected by chronic diseases (i.e. cancer, HIV, chronic obstructive pulmonary disease), and 6 in elderly subjects. The indexed studies support that HMB is effective in preventing exercise-related muscle damage in healthy trained and untrained individuals as well as muscle loss during chronic diseases.

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. The usual dose of 3 g/day may be routinely recommended to maintain or improve muscle mass and function in health and disease.

The safety profile of HMB is unequivocal. Further, well-designed clinical studies are needed to confirm effectiveness and mode of action of HMB, particularly in pathological conditions.

Amino Acids. 2013 Dec;45(6):1273-92.

http://www.ncbi.nlm.nih.gov/pubmed/24057808

hurril
2013-11-26, 18:30
Har man kontrollerat för skillnad i HMB-variant? (Alltså bundet som salt eller i fri form.)


TL;DR.

tjing
2013-11-26, 18:44
Det omnämns:

"...All studies employed capsule, drink or powder form of CaHMB salt (Table 1). Two studies used HMB free acid form, which produced a different plasma kinetic profile (Fuller et al. 2011a, b; Wilson et al. 2013)"

Den fria formen verkar intressant baserat på studierna som nämns ovan, då den både ökar mängden HMB i blodet och också får bort det snabbare.

Free acid gel form of β-hydroxy-β-methylbutyrate (HMB) improves HMB clearance from plasma in human subjects compared with the calcium HMB salt.

"...Free acid gel resulted in quicker and greater plasma concentrations (+185%) and improved clearance (+25%) of HMB from plasma. In conclusion, HMB free acid gel could improve HMB availability and efficacy to tissues in health and disease."

http://www.ncbi.nlm.nih.gov/pubmed/21134325

Vidare från artikeln:

"...Further studies are necessary to indicate the optimal dosage in consideration of the different damage and catabolic stimuli, the optimal duration of supplementation and the best form of supplementation, i.e. gel, powder, capsule or drink, taking into account the HMB intestinal rates of HMB absorption, metabolism, plasma kinetics and interactions with other supplements.

The effects obtained with short-lasting HMB supplementation appear trivial in comparison with long-lasting HMB supplementation; a long-lasting HMB supplementation is able to counteract muscle loss in cachectic conditions as well as to prevent muscle damage and support muscular strength in trained and untrained individuals engaging in resistance-exercise training (Wilson et al. 2008)."

En annan ny studie (som jag tror jag länkat tidigare på forumet) på fri-form HMB:

β-Hydroxy-β-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained men.

"...In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session."

http://www.ncbi.nlm.nih.gov/pubmed/23286834

Fredriiik
2013-11-28, 22:45
att den som är inte är bunden till kalcium är "effektivare" såg vi ju på videoföreläsningen för ett tag sen och att den får effekt mycket snabbare.
Dock är frågan vart jag kan hitta denna fria form? Bara hittat bundet till Ca..