月经周期不同阶段游离皮质醇昼夜节律的变化

为了研究皮质醇分泌的昼夜节律在月经周期中的变化,实验对15位月经周期正常的育龄期健康妇女,在月经周期的不同阶段分别于24h内每隔两小时采样,检测唾液昼夜游离皮质醇水平。采用非线性回归分析模型分析皮质醇昼夜节律。结果显示,皮质醇昼夜节律在整个月经周期都具有复杂的明显受到亚节律(ultradian)影响的分泌形式;与月经期相比,围排卵期和黄体晚期昼夜节律波峰宽度(peak-width)明显减低(P=0．005与0．031),而昼夜节律波谷(trough)有抬高趋势(P=0．0622与0．066);黄体晚期的亚节律波幅(ultradian amplitude)与月经期相比显著减低(P=0．002)而与围排卵期相比有减低趋势(P=0．05)。这些结果提示月经周期的不同阶段对皮质醇分泌的昼夜节律有影响。

Changes in diurnal rhythms of free cortisol secretion during different phases of menstrual cycle

The effect of the menstrual cycle on the diurnal cortisol rhythm was investigated in 15 normally cyclic healthy women during reproductive life. Salivary cortisol was measured by radioimmunoassay in samples collected every 2 h for 24 h during the four phases of the menstrual cycle: menstrual phase, late follicular/peri-ovulation phase, early to mid luteal phase and late luteal phase, respectively. Distinct diurnal rhythms of free cortisol were found throughout the menstrual cycle by using a nonlinear periodic regression model. The model was characterized by an asymmetrically peaked diurnal cycle and ultradian harmonics. There was a trend to higher troughs and significantly shorter peak-width in phase II and phase IV compared to phase I. The ultradian amplitude in phase IV was significantly lower compared with phase I and showed a trend of decrease compared with phase II. The results suggest that the daily cortisol secretion is modulated by the phase of the menstrual cycle.