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Study 23 of 26MK-677 (Ibutamoren) literatureMedicine and science in sports and exercise · Observational2023

When Size Goes Inside: Visceromegaly in Bodybuilders Is Not Attributed to High-Protein Intake but More Likely Associated with the Use of Appearance- and Performance-Enhancing Drugs.

Visceral organ enlargement in bodybuilders is likely due to APED use rather than high-protein diets, as shown by significant differences in organ volumes.

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this study against the rest of the mk-677 (ibutamoren) corpus
1
Preclinical
20
Observational · this one
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Open-label
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Randomised
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Reviews

Summary and findings

This study measured visceral organ volumes in male bodybuilders using appearance- and performance-enhancing drugs (APED) compared to natural bodybuilders and recreationally active males. The habitual protein intake was significantly higher in bodybuilders, with BB-NAT at 2.5 g/kg body mass/d and BB-USE at 2.9 g/kg body mass/d. The findings suggest that visceromegaly is more likely associated with APED use rather than high-protein intake.

How much of this paper we could read: full text read (0.80). We had a clear abstract, so the summary below closely tracks the paper. What this means →
Total lean BM: BB-USE 87.8 ± 8.0 kg, BB-NAT 72.7 ± 6.4 kg, CON 62.8 ± 4.8 kg, P < 0.001.n=452023

Abstract

The authors’ words, as Medicine and science in sports and exercise supplied them

<h4>Background</h4>Bodybuilders use progressive resistance exercise training and high-protein-intake diets to develop muscular physiques. Some also use appearance- and performance-enhancing drugs (APED) to further enhance their physique. It has been speculated that a high-protein intake and APED use may induce visceral organ hypertrophy. Therefore, the primary objective of this study was to assess visceral organ volumes in natural and APED-using male bodybuilders and to compare these with recreationally active males (CON).<h4>Methods</h4>Magnetic resonance imaging (MRI) was applied to assess skeletal muscle and visceral organ volume in 15 CON (age: 29 ± 6 y), 15 competitive male natural bodybuilders (BB-NAT; age: 30 ± 5 y), and 15 competitive male APED-using bodybuilders (BB-USE; age: 31 ± 4 y). In addition, dual-energy X-ray absorptiometry (DXA) was performed to assess total body lean mass. All participants reported their habitual food intake (via 7-d food diary) and, if applicable, their use of APED.<h4>Results</h4>Habitual protein intake was much higher in the bodybuilders (BB-NAT: 2.5 ± 0.6 g/kg body mass (BM)/d; BB-USE: 2.9 ± 0.4 g/kg BM/d) compared with CON (1.4 ± 0.3 g/kg BM/d; P < 0.001), with no differences between both bodybuilder groups ( P = 0.109). Total lean BM was significantly different across all groups and was greater in BB-USE (87.8 ± 8.0 kg) versus BB-NAT (72.7 ± 6.4 kg) versus CON (62.8 ± 4.8 kg; P < 0.001). Muscle volumes were also different between groups, with average thigh muscle volumes of 7.1 ± 1.0, 5.8 ± 0.7, and 4.5 ± 0.4 L in BB-USE, BB-NAT, and CON, respectively ( P < 0.001). All visceral organ volumes were greater in BB-USE compared with BB-NAT and CON ( P < 0.05), with no differences between BB-NAT and CON ( P > 0.05). Heart volume averaged 1.20 ± 0.15, 0.89 ± 0.14, and 0.83 ± 0.15 L in BB-USE, BB-NAT, and CON, respectively. Liver volume averaged 2.57 ± 0.39, 1.82 ± 0.20, and 1.79 ± 0.21 L, respectively.<h4>Conclusions</h4>Despite higher habitual protein intake and greater lean BM, natural bodybuilders do not show greater visceral organ volumes compared to age-matched controls. Bodybuilders using APED show substantially greater lean mass, muscle mass, as well as greater visceral organ volumes, compared with natural bodybuilders or age-matched controls. We conclude that visceromegaly in bodybuilders cannot be attributed to a high-protein intake but is secondary to the use of APED.

Background

This paper addresses the relationship between high-protein diets, APED use, and visceral organ hypertrophy in bodybuilders. Prior research has suggested that both dietary intake and APED could influence organ size, but this study aims to clarify the specific contributions of each. Understanding these factors is important for assessing health risks associated with bodybuilding practices.

Methods

The study utilized magnetic resonance imaging (MRI) to assess visceral organ and skeletal muscle volumes in three groups: 15 recreationally active males (CON), 15 natural bodybuilders (BB-NAT), and 15 APED-using bodybuilders (BB-USE). Participants' habitual food intake was recorded through a 7-day food diary. The study compared visceral organ volumes and lean body mass across these groups.

Results

The primary endpoint showed that total lean body mass was significantly different across groups, with BB-USE at 87.8 ± 8.0 kg, BB-NAT at 72.7 ± 6.4 kg, and CON at 62.8 ± 4.8 kg (P < 0.001). Additionally, all visceral organ volumes were greater in BB-USE compared to BB-NAT and CON (P < 0.05).

Interpretation

These findings indicate that while high protein intake is associated with bodybuilders, it does not correlate with increased visceral organ volume, which is more closely linked to APED use. The effect sizes observed, while statistically significant, may not be clinically meaningful without further longitudinal studies to assess health implications. Limitations such as the small sample size and lack of long-term follow-up may confound the conclusions drawn.

Key findings

  • Habitual protein intake: BB-NAT 2.5 ± 0.6 g/kg BM/d, BB-USE 2.9 ± 0.4 g/kg BM/d, CON 1.4 ± 0.3 g/kg BM/d, P < 0.001.
  • Total lean BM: BB-USE 87.8 ± 8.0 kg, BB-NAT 72.7 ± 6.4 kg, CON 62.8 ± 4.8 kg, P < 0.001.
  • Average thigh muscle volumes: BB-USE 7.1 ± 1.0 L, BB-NAT 5.8 ± 0.7 L, CON 4.5 ± 0.4 L, P < 0.001.
  • Heart volume: BB-USE 1.20 ± 0.15 L, BB-NAT 0.89 ± 0.14 L, CON 0.83 ± 0.15 L.
  • Liver volume: BB-USE 2.57 ± 0.39 L, BB-NAT 1.82 ± 0.20 L, CON 1.79 ± 0.21 L.
  • All visceral organ volumes greater in BB-USE compared to BB-NAT and CON (P < 0.05).

Limitations

  • small sample size of 15 participants per group
  • does not account for long-term effects of APED use
  • cross-sectional design limits causal inferences
  • self-reported dietary intake may introduce bias

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