Effects of three doses of 3-indole pyruvic acid on subjective and objective measures of sleep and early morning performance

Abstract

The effects of 3-indole pyruvic acid (IPA) on sleep and morning after performance were investigated in 10 volunteers with previous complaints of mild insomnia. Three doses of IPA (100, 200 and 300 mg) were compared to placebo to assess their effect on sleep, cognitive function and psychomotor performance. The psychometric battery consisted of tests of Critical Flicker Fusion, Choice Reaction Time, Short Term Memory and Compensatory Tracking. The Leeds Sleep Evaluation Questionnaire was also administered shortly after waking the morning following medication. Results show that IPA had no significant effects on any aspect of sleep architecture. However, sleep efficiency was significantly higher on night 1 when subjects had taken 200 or 300 mg IPA compared to those who had received either placebo or 100 mg IPA. No further effects were found on subsequent nights with any of the treatments. There were no morning after effects of IPA on cognitive function or psychomotor performance. The 'first night' effect of sleeping in an unfamiliar environment possibly caused transient insomnia in the subjects and while this effect was not mitigated by placebo or 100 mg IPA, 200 and 300 mg IPA seem to exert sufficient hypnotic effects to overcome the sleep disturbance. These results suggest that the two higher doses of IPA exert a mild hypnotic action, perhaps by relieving the stress experienced in situations that are liable to cause transient insomnia.