Human health is affected by an internal body clock known as a circadian rhythm. These cycles are influenced by light exposure, and when disrupted, circadian rhythms create irregular sleep and wakefulness patterns which can influence a large number of chronic health conditions especially in those who work night or early morning shifts.

When Dr. Greg Clare, College of Human Sciences assistant professor in design, housing and merchandising, proposed his study, Comparing the Effects of Caregiver Work Lighting Exposure and Physical Activity on Circadian Rhythms at Large, Older Adult Congregate Living Facilities, the Center for Family Resilience awarded him its first ever pilot grant.

Clare examined how light affects sleep patterns within a built environment, specifically in the case of this project, the sleep patterns of caregivers within continuing care retirement centers. To determine the effect of shift work on healthy healthcare workers, subjects wore actigraphy devices on their wrists from 1-3 weeks.  These actigraphy devices used for the study were Philips actigraph spectrum watches, which measure light across the spectrum. They represent a cost-effective, rapidly evolving method of collecting sleep data natural environments. The watches provided details, which could be formatted into a clinician’s report for participants, such as the time which the subjects went to bed, the overall length of the sleep period, and interruptions in sleep, such as tossing and turning.

Clare’s findings supported the conclusion that there were differences between night shift workers and day shift workers. While day shift workers slept for a longer duration, within the natural light/dark cycles of a circadian rhythm, the night shift workers slept for a shorter duration, but experienced deeper sleep with fewer interruptions.

“Findings from this pilot study offer promising directions for future externally funded research into the effects of workplace lighting on human health,” Clare said. 

“Dr. Clare’s project supports the goals of the Center for Family Resilience,” Dr. Michael Merten, CFR director said. “Caregivers and other night shift workers must adapt daily to high stress work environments by balancing long shifts or night shifts which may impact their circadian rhythms negatively, affecting their health and family life.” 

Clare hopes to use the information from this project as preliminary data in a project being proposed to the National Institute of Health Exploratory/Developmental Research Grant program.  He plans to use LED lights designed for use on space stations where astronauts must depend on artificial lighting to regulate the cycles of their circadian rhythms. The study will utilize these lights to determine the effect of red-spectrum light upon workers in corrections facilities, nurses’ stations, and other internal built environments.

The Oklahoma State University Center for Family Resilience (CFR) is an initiative of Oklahoma State University’s College of Human Sciences, Cooperative Extension Service, and OSU-Tulsa. The CFR was established to ensure every family is equipped to support its members in achieving their full personal and social potential. The CFR’s mission is to enable and sustain family resilience locally, regionally and nationally through community engagement, research, and education.