Shimian granules improve sleep, mood and performance of shift nurses in association changes in melatonin and cytokine biomarkers: a randomized, double-blind, placebo-controlled pilot study

ABSTRACT

Shift nurses are prone to sleep problems and impaired nighttime alertness, with risk for reduced health status plus decreased performance, handling errors, and workplace accidents. Attention to and improvements in the situation of shift nurses are urgent. Shimian granules (SMG), an improved formula of Jieyuanshen with liver qingre and yangxin tranquilizing effects, for more than a decade has been used in China as a herbal treatment of sleep disorders in clinical practice. However, clinical data on SMG have rarely been reported. This double-blinded, randomized, placebo-controlled, pilot clinical trial (ChiCTR-IOR-17013031) aimed to explore whether Shimian granules (SMG) improves sleep and affective state in shift nurses and in association with changes in concentrations of salivary cytokines. Fifty-three rotating-shift female nurses with a Pittsburgh Sleep Quality Index (PSQI) score ≥8 were orally treated with 10.0 g SMG or placebo 2 times daily (30 min after breakfast and 30 min before bed) for 1 month. The Insomnia Severity Index (ISI), a psychomotor vigilance task, Hospital Anxiety and Depression Scale (HADS-A/HADS-D), and levels of four salivary cytokines were evaluated by single time-of-day sampling at baseline and after 1 month of treatment. Significantly lower ISI, HADS, HADS-A, and HADS-D scores, but higher 1/mean reaction time (1/mRT) score, were found in shift nurses treated with SMG than in those who received placebo, and these effects were associated with changes in salivary melatonin, TNF, IL-1β, and IL-6 levels. These latter findings suggest melatonin, TNF, and IL-6 levels may be suitable biomarkers of ISI score in shift nurses, whereas TNF level may be a suitable biomarker of 1/mRT score and IL-6 level a suitable biomarker of HADS score in response to SMG treatment. The results of this pilot study suggest SMG can effectively improve sleep, alertness, plus anxiety and depression symptoms in shift nurses in association with changes in salivary cytokine levels. The results of this study provide an experimental basis for the evaluation of traditional Chinese medicines for the treatment of insomnia and underlying mechanisms of their actions that require detailed future exploration.

KEYWORDS:

• Shift work
• nurses
• sleep disorders
• Shimian granule
• salivary cytokines
• melatonin
• TNF
• IL-6

Declaration of interest statement

The authors report no conflict of interest.

Additional information

Funding

This study is supported by the Youth Science and Technology Innovation Personnel Training Project of Shaanxi Province (No. 2017KJXX-84), and Special Support Scheme for Shaanxi Province.