Low serum 25-hydroxyvitamin D concentrations in chronic insomnia patients and the association with poor treatment outcome at 2 months

Background: The association between low 25-hydroxyvitamin D [25(OH)D) and sleep disorder has been reported. We investigated whether serum concentrations of 25(OH)D are altered in chronic insomnia patients. The relationship between serum concentrations of 25(OH)D and the treatment outcome in patients at 2 months was also investigated. Methods: In total, 181 chronic insomnia patients were consecutively recruited. All patients received pharmacotherapy for the treatment of chronic insomnia. Serum 25(OH)D concentrations were quantified by a competitive electrochemiluminescence protein binding assay. Treatment outcomes were defined as response versus non-response, according to the change of the Pittsburgh Sleep Quality Index (PSQI). We also recruited 100 healthy subjects as a control group. Results: Fifty-four out of 181 (29.8%) patients met the criteria for non-response. Chronic insomnia patients had significantly lower 25(OH)D concentrations compared with healthy controls (23.01 +/- 9.18 vs 27.17 +/- 6.41 ng/ml, P < 0.001). Non-response patients also had significantly lower 25(OH)D concentrations than those with response. Vitamin D deficiency(25(OH)D concentrations < 20 ng/ml) was independently associated with a higher probability of treatment non-response at 2 months (odds ratio 11.636, 95% confidence interval 3.966-34.142, P < 0.001). Conclusions: Measurement of serum 25(OH)D concentrations are probably useful for judging treatment outcomes of pharmacotherapy in chronic insomnia patients.