School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA.
Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA.
Am J Hum Biol. 2023 Nov;35(11):e23949. doi: 10.1002/ajhb.23949. Epub 2023 Jun 26.
Testosterone plays a role in mediating energetic trade-offs between growth, maintenance, and reproduction. Investments in a high testosterone phenotype trade-off against other functions, particularly survival-enhancing immune function and cellular repair; thus only individuals in good condition can maintain both a high testosterone phenotype and somatic maintenance. While these effects are observed in experimental manipulations, they are difficult to demonstrate in free-living animals, particularly in humans. We hypothesize that individuals with higher testosterone will have higher energetic expenditures than those with lower testosterone.
Total energetic expenditure (TEE) was quantified using doubly labeled water in n = 40 Tsimane forager-horticulturalists (50% male, 18-87 years) and n = 11 Hadza hunter-gatherers (100% male, 18-65 years), two populations living subsistence lifestyles, high levels of physical activity, and high infectious burden. Urinary testosterone, TEE, body composition, and physical activity were measured to assess potential physical and behavioral costs associated with a high testosterone phenotype.
Endogenous male testosterone was significantly associated with energetic expenditure, controlling for fat free mass; a one standard deviation increase in testosterone is associated with the expenditure of an additional 96-240 calories per day.
These results suggest that a high testosterone phenotype, while beneficial for male reproduction, is also energetically expensive and likely only possible to maintain in healthy males in robust condition.
睾丸激素在调节生长、维持和繁殖之间的能量权衡方面发挥作用。高睾丸激素表型的投资与其他功能（特别是增强生存的免疫功能和细胞修复）相权衡；因此，只有身体状况良好的个体才能维持高睾丸激素表型和身体维持。虽然这些影响在实验操作中观察到，但在自由生活的动物中，特别是在人类中，很难证明这一点。我们假设睾丸激素水平较高的个体比睾丸激素水平较低的个体具有更高的能量消耗。
我们使用双标记水在 n = 40 名 Tsimane 觅食者-园艺师（50%男性，18-87 岁）和 n = 11 名哈扎狩猎采集者（100%男性，18-65 岁）中量化了总能量消耗（TEE），这两个群体生活在自给自足的生活方式中，身体活动水平高，感染负担高。测量了尿液中的睾丸激素、TEE、身体成分和身体活动，以评估与高睾丸激素表型相关的潜在身体和行为成本。
内源性男性睾丸激素与能量消耗显著相关，控制体脂量；睾丸激素增加一个标准差与每天额外消耗 96-240 卡路里有关。
这些结果表明，高睾丸激素表型虽然有利于男性生殖，但也需要消耗大量能量，而且只有身体状况良好的健康男性才能维持这种表型。
