Andrew Lim

Dr. Lim’s research program aims to elucidate the brain mechanisms underlying the bi-directional links between sleep, circadian/seasonal rhythms, and Alzheimer’s Disease (AD), and translate these to treatments to prevent AD and AD-related disability.  To achieve his, his research program combines wearable sensors, artificial intelligence, neuroimaging, and advanced genomics to observational studies and clinical trials of 100's to 1000's of participants in Canada, the US, and worldwide.  Key discoveries over the past 3 years include 1) in older adults, sleep fragmentation (repeated awakenings from sleep) is associated greater a) neuroinflammation, b) dysfunction of the brain's support cells, and c) dysfunction of the brain's pericytes - the cells that regulate the small blood vessels of the brain, as revealed by brain gene expression.  2) treatment of sleep apnea, a key cause of sleep fragmentation, can prevent accumulating damage to the channels used to clear brain toxins, as revealed by MRI 3) disruption of these channels is in turn associated with greater sleep need and 4) irregularity of sleep/wake patterns is also associated with damage to the small vessels of the brain.

Going forward,  he is pursuing studies in 3 main areas: 1) AI and wearable technologies - Dr. Lim and his team have developed new deep learning models to enable automated characterization of sleep and sleep disorders from novel wearable technologies, and have deployed these sensors and algorithms in cohorts of patients across Canada and in the US including the Canadian Longitudinal Study of Aging, Rush Memory and Aging Project, and Canadian Consortium on Neurodegeneration in Aging CTU Cohort 2) Mechanisms linking sleep and dementia - Dr. Lim leads several studies using MR brain imaging and gene expression analysis of human brain tissue to understand the molecular and cellular changes linking sleep to dementia 3) Clinical trials of sleep interventions - Dr. Lim is leading trials of insomnia treatment, and sleep apnea treatment, to delay or prevent dementia including the sleep component of the 500-person SYNERGIC2 trial, and the multinational Brain Changes in Sleep Apnea trial.

In support of these studies, Dr. Lim is PI or co-PI on 3 grants from the CIHR and 2 from the NIH through 2027.