0014 A New Home Dim Light Melatonin Onset Kit with iPhone App

Abstract Introduction The dim light melatonin onset (DLMO) remains the gold standard circadian phase marker in humans. We previously developed a proof-of-concept home DLMO kit and demonstrated that valid DLMOs could be collected at home, with objective markers of light exposure and sample timing. Nonetheless, the proof-of-concept kit uses costly external technologies such as photosensors (to monitor light exposure) and MEMS TrackCaps (to monitor sample timing). Here we present a new home DLMO kit which includes a novel iPhone app that improves upon the original proof-of-concept kit. Methods The new home DLMO kit includes a novel iPhone app that: (1) streamlines the home DLMO collection procedure, (2) maintains the objective assessment of light exposure and sample timing with internal app features, (3) provides real-time feedback on errors in light exposure and sample timing to both participants and an externally located researcher, and (4) provides cost savings over the original proof-of-concept kit. Programming capability includes options to (1) sample saliva at half-hourly or hourly intervals, (2) end sampling at participants’ habitual bedtime or up to 3 hours past habitual bedtime, and (3) set a light intensity threshold of choice to alert the research participant and externally located researcher in real-time that melatonin levels may be suppressed. At the conclusion of the home DLMO collection, the app emails a report of light levels and sample timing to the researcher. Saliva samples can then be sent to a qualified laboratory for assay processing. Results The new home DLMO kit has been extensively tested, including by external circadian research groups who report the new kit to be an improvement on the previous proof-of-concept kit, and that the new kit can be implemented into research protocols. Flow diagrams of the back-end programming capability available to researchers and the front-end step-by-step display screens guiding research participants will be reviewed. Home DLMO profiles collected with the new home DLMO kit will also be reviewed. Conclusion A new home DLMO kit with a novel iPhone app is now available to better support the collection of DLMOs at home and facilitate research examining circadian timing in human populations. Support (if any)