The Effectiveness of Low-Level LED Light Therapy for Sleep Problems, Psychological Symptoms, and Heart Rate Variability in Shift-Work Nurses: A Randomized Controlled Trial.

Shift-work schedules can cause sleep and psychological problems among nurses, negatively affecting their health and quality of life. This trial examined the effects of low-energy light therapy on sleep, psychological symptoms, and heart rate variability among shift-work nurses. This randomized controlled trial was conducted from July 2021 to June 2022. The inclusion criteria were nurses with self-reported insomnia who worked in shifts in the last 6 months in a medical center in northern Taiwan. Block randomization was used to assign the study participants to two groups: experimental ( = 32) and control ( = 32). A portable Meridian Aura Cap equipped with a low-level light-emitting diode was used to provide red and near-infrared light (660 and 850 nm) for 30 min, three times a week for 4 weeks; the control group did not receive any intervention. The Depression Anxiety Stress Scale-21 and Insomnia Severity Index were used to measure psychological symptoms and sleep problems, respectively. Heart rate variability was measured by the ANSWatch. No significant differences were reported in preintervention scores. After the 4-week intervention, the intervention group scored significantly lower in insomnia (4.3 vs. 12.6, respectively; < 0.001), depression (2.5 vs. 7.9, < 0.001), anxiety (3.1 vs. 9.2, < 0.001), and stress (5.6 vs. 12, < 0.001) than those in the controls. No significant differences were observed in heart rate variability between the two groups. Low-level light-emitting diode light therapy improved sleep quality in shift-work nurses with insomnia and alleviated depression, anxiety, and stress symptoms; however, it did not improve heart rate variability, possibly because of the short intervention duration and the ongoing shift-work schedule. Employers could consider providing phototherapy for shift nurses to improve their health. ClinicalTrials.gov identifier: NCT05146596.