Correlation study of basic Chinese medicine syndromes and neurotransmitter levels in patients with primary insomnia

To investigate the correlation between basic Chinese medicine (CM) syndromes (deficiency and excess syndromes) and intracranial neurotransmitter levels in primary insomnia (PI), to provide objective indicators and syndrome-based medical evidence for the differentiation of PI.

A total of 158 patients with PI were recruited for CM syndrome differentiation. Another 30 healthy people without sleep disorders were selected as control group. An encephalofluctuograph analyzer was used to test the levels of intracranial neurotransmitters, including γ- aminobutyric acid (GABA), glutamate (Glu), 5-hydroxytryptamine (5-HT), dopamine (DA), etc., and their relevance were analyzed.

The neurotransmitter levels in the basic-deficiency group were lower than those in the healthy-control group, while the basic-excess group had higher levels than the healthy-control and basic-deficiency groups. Among the neurotransmitters, the 5-HT level was higher in the basic-excess group than in the basic-deficiency group (24.20±4.07 vs. 21.13±3.23; P<0.05); for the intermingled deficiency-excess group, the level of GABA was higher than that in the basic-deficiency group (9.48±3.07 vs. 7.23±3.67; P<0.05), Glu level was higher than that in the healthy-control group (7.53±4.10 vs. 5.83±0.99, P<0.05), and 5-HT and DA levels were lower than those in the healthy-control group (19.80±5.68 vs. 22.63±3.31, 5.27±3.79 vs. 6.83±1.58, respectively; P<0.05).

There was a correlation between the basic syndromes and intracranial neurotransmitter levels in patients with PI, which could objectively reflect the CM differentiation in PI. This information could be important for improving CM diagnosis and treatment in PI.