2023 Rainmaker start up- Does exposure to artificial light alter circadian rhythm and glucose control in Australian adults? A pilot study

Despite the evidence that circadian disruption can cause diverse metabolic disorders and light is the primary cue for circadian disruption, there remains a paucity of high-quality evidence that has examined actual light exposure (including artificial light) in Australians and whether light exposure is associated with circadian disruption, glucose control, sleep health, and activity. This has left the scientific community and health professionals without well-founded knowledge to design, develop and test any novel interventions and to examine their translational feasibility in humans.
The investigators aim to submit a national research grant application with the hypothesis that the longer photoperiod is perturbing human lifestyle, disrupting the circadian rhythm, and leading to reduced glucose control. Reduced glucose control is cause for the development of future type 2 diabetes. To create pilot data for a national funding scheme application, this project will examine photoperiod (duration of light exposure per day), glycosylated haemoglobin (marker of glucose control), sleep quality, and actigraphy (activity) in non-shift worker volunteers. This project will create pilot data for preliminary findings, power calculations, and feasibility of the study. The larger study to be submitted to a national funding scheme will measure light exposure in the day (duration, 24-hour spectrum, 24-hour intensity, melanopic, photopic, infrared), melatonin in saliva (6 time points of the day), clock genes expression in saliva sample (6 time points of the day), sleep quality and sleep parameters, actigraphy (activity), 24-hour skin temperature, meal period, glycosylated haemoglobin, fasting glucose, and metabolic health parameters in a larger number of participants (the actual number of participants will be decided after power calculation based on this pilot study).