Detection of nighttime melatonin level in Chinese Original Quiet Sitting.

Abstract

Some research has shown that melatonin levels increase after meditation practices, but other research has shown that they do not. In our previous functional magnetic resonance imaging study, we found positive activation of the pineal body during Chinese Original Quiet Sitting (COQS). To find other supporting evidence for pineal activation, the aim of this study was to evaluate the effect of COQS on nighttime melatonin levels. Twenty subjects (11 women and 9 men, aged 29-64 years) who had regularly practiced daily meditation for 5-24 years participated in this study. All subjects served alternately as participants in the mediation and control groups. COQS was adopted in this study. Tests were performed during two nighttime sessions. Saliva was sampled at 0, 10, 20, 30, 45, 60 and 90 minutes after COQS and tested for level of melatonin. Time period effect analysis and mixed effect model analysis were preceded by paired t test analysis. In the meditation group (n = 20), the mean level of melatonin was significantly higher than the baseline level at various times post-meditation (p < 0.001). Within the control group (n = 20), the mean level of melatonin at various times was not significantly different compared with baseline (p>0.05). These results suggested that the melatonin level was statistically elevated in the meditation group and almost unchanged in the control group after nighttime meditation. The urine serotonin levels detected by measuring 5-hydroxy-indole-3-acetic acid levels were also studied, but no detectable difference between the groups was found. Our results support the hypothesis that meditation might elevate the nighttime salivary melatonin levels. It suggests that COQS can be used as a psychophysiological stimulus to increase endogenous secretion of melatonin, which in turn, might contribute to an improved sense of well-being.