A double-blind placebo controlled trial into the impacts of HMB supplementation and exercise on free-living muscle protein synthesis, muscle mass and function, in older adults

Autor: Din, U.S.U., Brook, M.S., Selby, Anna L., Quinlan, Jonathan I., Boereboom, Catherine, Abdullah, H., Franchi, M., Narici, Marco Vincenzo, Phillips, Bethan E., Williams, J.W., Rathmacher, John A., Wilkinson, D.J., Atherton, Philip J., Smith, K.
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Male
RET
Resistance exercise training
MVC
Maximal voluntary contraction
MCME
N –Methoxycarbonyl methyl ester
Skeletal muscle
Gene Expression
1-RM
One repetition maximum
Muscle Development
Article
UT
Untrained leg
HMB
VL
Vastus lateralis
Double-Blind Method
D2O
Deuterium oxide
IRMS
Isotope ratio mass spectrometer
Valerates
GC
Gas chromatography
Humans
Muscle Strength
skin and connective tissue diseases
D2O
Muscle
Skeletal
Exercise
USG
Ultrasonography
RPE- Rating of perceived exertion
PLA- Placebo
Stable isotopes
MPS
Muscle protein synthesis
TC/EA
High temperature conversion elemental analyser
Resistance Training
Middle Aged
HMB-FA
Free Acid β-hydroxy-β-methyl-butyrate
HMB
β-hydroxy-β-methyl-butyrate
DXA
Dual-energy X-ray absorptiometry
2
O
Protein Biosynthesis
Dietary Supplements
human activities
RE
Resistance exercise
APE
Atom percent excess
Zdroj: Clinical Nutrition (Edinburgh, Scotland)
ISSN: 1532-1983
0261-5614
Popis: Summary Age-related sarcopenia and dynapenia are associated with frailty and metabolic diseases. Resistance exercise training (RET) adjuvant to evidence-based nutritional intervention(s) have been shown as mitigating strategies. Given that β-hydroxy-β-methyl-butyrate (HMB) supplementation during RET improves lean body mass in younger humans, and that we have shown that HMB acutely stimulates muscle protein synthesis (MPS) and inhibits breakdown; we hypothesized that chronic supplementation of HMB free acid (HMB-FA) would enhance MPS and muscle mass/function in response to RET in older people. We recruited 16 healthy older men (Placebo (PLA): 68.5 ± 1.0 y, HMB-FA: 67.8 ± 1.15 y) for a randomised double-blind-placebo controlled trial (HMB-FA 3 × 1 g/day vs. PLA) involving a 6-week unilateral progressive RET regime (6 × 8 repetitions, 75% 1-RM, 3 · wk−1). Deuterium oxide (D2O) dosing was performed over the first two weeks (0–2 wk) and last two weeks (4–6 wk) with bilateral vastus lateralis (VL) biopsies at 0–2 and 4–6 wk (each time 75 ± 2 min after a single bout of resistance exercise (RE)) for quantification of early and later MPS responses and post-RE myogenic gene expression. Thigh lean mass (TLM) was measured by DXA, VL thickness and architecture (fibre length and pennation angle) by ultrasound at 0/3/6 wk, and strength by knee extensor 1-RM testing and MVC by isokinetic dynamometry (approx. every 10 days). RET induced strength increases (1-RM) in the exercised leg of both groups (398 ± 22N to 499 ± 30N HMB-FA vs. 396 ± 29N to 510 ± 43N PLA (both P
Databáze: OpenAIRE
Externí odkaz: