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Study · Measured the body's own peptide · 2019

1 result

Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men.

Gharahdaghi N, Rudrappa S, Brook MS, Idris I, Crossland H, Hamrock C, Abdul Aziz MH, Kadi F, Tarum J, Greenhaff PL, Constantin-Teodosiu D, Cegielski J and 5 more

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Phillips BE, Wilkinson DJ, Szewczyk NJ, Smith K, Atherton PJ

Journal of cachexia, sarcopenia and muscle30 Sept 2019Cited by 67 (Europe PMC)

PMID31568675 (opens in a new tab)PMCIDPMC6903447 (opens in a new tab)DOI10.1002/jcsm.12472 (opens in a new tab)PepBankPUB-31568675
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Summary

BackgroundThe andropause is associated with declines in serum testosterone (T), loss of muscle mass (sarcopenia), and frailty. Two major interventions purported to offset sarcopenia are anabolic steroid therapies and resistance exercise training (RET). Nonetheless, the efficacy and physiological and molecular impacts of T therapy adjuvant to short-term RET remain poorly defined.MethodsEighteen non-hypogonadal healthy older men, 65-75 years, were assigned in a random double-blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole-body RET (three sets of 8-10 repetitions at 80% one-repetition maximum). Subjects underwent dual-energy X-ray absorptiometry, ultrasound of vastus lateralis (VL) muscle architecture, and knee extensor isometric muscle force tests; VL muscle biopsies were taken to quantify myogenic/anabolic gene expression, anabolic signalling, muscle protein synthesis (D2 O), and breakdown (extrapolated).ResultsTestosterone adjuvant to RET augmented total fat-free mass (P=0.007), legs fat-free mass (P=0.02), and appendicular fat-free mass (P=0.001) gains while decreasing total fat mass (P=0.02). Augmentations in VL muscle thickness, fascicle length, and quadriceps cross-section area with RET occured to a greater extent in T (P -1 vs. P: 1.34 ± 0.13%·day-1 , P=0.0009) and absolute breakdown rates (T: 140.2 ± 15.8 g·day-1 vs. P: 90.2 ± 11.7 g·day-1 , P=0.02) were elevated with T therapy, which led to higher net turnover and protein accretion in the T group (T: 8.3 ± 1.4 g·day-1 vs. P: 1.9 ± 1.2 g·day-1 , P=0.004). Increases in ribosomal biogenesis (RNA:DNA ratio); mRNA expression relating to T metabolism (androgen receptor: 1.4-fold; Srd5a1: 1.6-fold; AKR1C3: 2.1-fold; and HSD17β3: two-fold); insulin-like growth factor (IGF)-1 signalling [IGF-1Ea (3.5-fold) and IGF-1Ec (three-fold)] and myogenic regulatory factors; and the activity of anabolic signalling (e.g. mTOR, AKT, and RPS6; P < 0.05) were all up-regulated with T therapy. Only T up-regulated mitochondrial citrate synthase activity (P=0.03) and transcription factor A (1.41 ± 0.2-fold, P=0.0002), in addition to peroxisome proliferator-activated receptor-γ co-activator 1-α mRNA (1.19 ± 0.21-fold, P=0.037).ConclusionsAdministration of T adjuvant to RET enhanced skeletal muscle mass and performance, while up-regulating myogenic gene programming, myocellular translational efficiency and capacity, collectively resulting in higher protein turnover, and net protein accretion. T coupled with RET is an effective short-term intervention to improve muscle mass/function in older non-hypogonadal men.
CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study1

No result from this study comes from a test of the peptide.

Natural levels measured1

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 01HumanEndogenous levelRandomized controlled trialMechanism

    In healthy older men doing resistance training, testosterone therapy increased muscle IGF-1Ec mRNA about three-fold versus placebo.

    In plain wordsIn healthy older men, testosterone with exercise raised the body's own IGF-1Ec gene activity in muscle compared with placebo.

    Peptide
    MGF / PEG-MGF
    Outcome
    IncreaseMuscle IGF-1Ec mRNA expression
    Study

    n = 18

    Comparator
    Placebo (saline)
    Outcome group
    Endogenous peptide levels · Musculoskeletal

    Source sentences

    Summary
    Increases in ribosomal biogenesis (RNA:DNA ratio); mRNA expression relating to T metabolism (androgen receptor: 1.4-fold; Srd5a1: 1.6-fold; AKR1C3: 2.1-fold; and HSD17β3: two-fold); insulin-like growth factor (IGF)-1 signalling [IGF-1Ea (3.5-fold) and IGF-1Ec (three-fold)]
    1 context sentence
    Summary · context
    Eighteen non-hypogonadal healthy older men, 65-75 years, were assigned in a random double-blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole-body RET (three sets of 8-10 repetitions at 80% one-repetition maximum).

    This result measures the body's own MGF / PEG-MGF. Nobody was given the peptide. It is not evidence about taking it.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 21:44 UTC

    Study results updated

  2. Version 1

    13 Oct 2026, 16:31 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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