Objective

The hypothalamic-pituitary-gonadal (HPG) and -adrenal (HPA) axes are traditional viewed as mutually inhibitory systems. However, several diurnal studies have reported positive within-person testosterone and cortisol relationships, as evidence of facilitative processes, but with some constraints (e.g., low-frequency sampling, use of static longitudinal models). Continuous-time (CT) models can help illuminate testosterone-cortisol “coupling” by testing for bidirectional, cross-lagged effects.

Methods

This study investigated diurnal testosterone and cortisol coupling in healthy males (n = 30) using high-frequency sampling protocols. Participants self-collected saliva at work or home using one of three sampling formats; every 10 mins for 9 h, 15 mins for 8 h, and 30 mins for 10 h. After detrending, daily within-person fluctuations in testosterone and cortisol concentration were modeled in a CT framework.

Results

Autoregressive effects for each hormone indicated moderate stability over a shorter period (~6 mins), as a mean-reverting process, and higher stability over longer time periods. Cross-lagged effects were also demonstrated, with testosterone showing a positive relationship to cortisol (.12 within-person standardized effect) and cortisol to testosterone (.08). Both linkages followed a non-linear trajectory, rising in strength from a zero-time lag to peak with a lag of ~8 mins before dissipation beyond this period.

Conclusion

We verified reports of positive within-person coupling between testosterone and cortisol across the day in healthy men. Added novelty comes from bidirectional and time-lagged associations on hormonal pulses, although the effect sizes were small. Hence, we offer a more nuanced understanding of HPG and HPA crosstalk within a CT framework.

中文翻译：

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健康男性睾丸激素和皮质醇之间的日内人际耦合：使用连续时间模型的正向和双向时间滞后关联的证据

客观的

下丘脑-垂体-性腺（HPG）和-肾上腺（HPA）轴传统上被视为相互抑制的系统。但是，一些日间研究报告了人体内睾丸激素和皮质醇的正相关性，这是促进过程的证据，但存在一些限制（例如，低频采样，使用静态纵向模型）。连续时间（CT）模型可以通过测试双向交叉滞后效应来帮助阐明睾丸激素-皮质醇的“偶联”。

方法

这项研究 使用高频采样方案调查了健康男性（n = 30）的昼夜睾丸激素和皮质醇耦合。参与者使用以下三种采样方式之一在工作或家庭中自行收集唾液；每10分钟9小时，15分钟8小时和30分钟10小时。消除趋势后，在CT框架中模拟人体内睾丸激素和皮质醇浓度的每日波动。

结果

每种激素的自回归作用表明在较短的时间内（〜6分钟）有中等程度的稳定性（作为均值回复过程），在较长的时间段内具有较高的稳定性。交叉滞后效应也得到了证实，其中睾丸激素与皮质醇呈正相关（0.12人内标准化作用），而皮质醇与睾丸激素呈正相关（0.08）。两种连接都遵循非线性轨迹，强度从零时间滞后上升到峰值，滞后约8分钟，然后才耗散超过此时间段。

结论

我们验证了健康男性全天睾丸激素和皮质醇之间人内偶联阳性的报道。尽管效应量很小，但更多的新颖性来自激素脉冲的双向和时间滞后关联。因此，我们在CT框架内提供了对HPG和HPA串扰的更细微的了解。