CYP1A2 Genotype and Acute Effects of Caffeine Intake on Growth Hormone and Testosterone Response to Resistance Exercise

Rahimi, Mohammad Rahman; Faraji, Hassan; Khodamoradi, Maryam

doi:10.22059/sshr.2024.382033.1163

CYP1A2 Genotype and Acute Effects of Caffeine Intake on Growth Hormone and Testosterone Response to Resistance Exercise

Document Type : Research Paper

Authors

¹ Department of Exercise Physiology, University of Kurdistan, Sanandaj 66177-15175, Iran. ORCID No: https://orcid.org/0000-0002-4302-1472

² Department of Physical Education and Sports Science, Marivan Branch, Islamic Azad University, Marivan, Iran.

³ Department of Exercise Physiology, University of Kurdistan, 66177-15175 Sanandaj, Iran

10.22059/sshr.2024.382033.1163

Abstract

This study explored the impact of the CYP1A2 rs762551 SNP on how caffeine affects growth hormone (GH) and testosterone (TS) levels in male athletes. Thirty resistance-trained men participated in a randomized, double-blind, placebo-controlled, crossover study. They consumed either caffeine (CAF) or placebo (PL) one hour before performing a resistance exercise (RE) protocol. Participants were categorized as either AA homozygous ("fast" metabolizers) or AC heterozygous ("slow" metabolizers) based on their CYP1A2 genotype.

The results showed significant differences in GH levels across time, with significant time-group and time-genotype-groupinteractions. Specifically, individuals with the AA genotype exhibited higher GH levels following CAF consumption compared toPL, while no significant differences were observed in the AC/CC genotype under both conditions. For testosterone, significant effects of time and time-group interaction were noted, indicating that CAF supplementation post-RE led to increased serum TS levels in AA individuals compared to the PL group. Both CAF and PL groups showed increased serum hormone concentrations post-exercise compared to pre-test levels. the study demonstrated that caffeine consumption significantly increased serum levels of growth hormone and testosterone in individuals with the AA genotype of the CYP1A2 rs762551 SNP. These findings suggest that genetic variations play a role in the hormonal response to caffeine.

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