The causal role of accelerometer-derived sleep traits on glycated haemoglobin: a Mendelian randomization study

Abstract

AbstractSelf-reported (SR) shorter/longer sleep duration, insomnia, and evening preference are associated with hyperglycaemia in observational analyses, with similar results observed in small studies using accelerometer-derived (AcD) sleep traits. Mendelian randomization (MR) studies support an effect of SR insomnia, but not other sleep traits, on glycated haemoglobin (HbA1c). We used MR to explore effects of AcD sleep traits (duration, mid-point least active 5-hours, mid-point most active 10-hours, sleep fragmentation, and efficiency) on HbA1c in European adults from the UK Biobank (UKB) (n = 73,797) and the MAGIC consortium (n = 149,054). Main and sensitivity MR analyses showed no causal effect of any AcD sleep trait on HbA1c. Similar MR results for SR sleep traits in the UKB sub-sample with AcD measures suggested our results were not explained by selection bias. Genetic correlation analyses suggested complex relationships between SR and AcD traits indicating that they may reflect different types of exposure.