Obstructive sleep apnea and the risk of Alzheimer's disease and Parkinson disease: A Mendelian randomization study OSA, Alzheimer's disease and Parkinson disease

Abstract

BackgroundPrevious studies reported that obstructive sleep apnea (OSA) was associated with neurodegenerative diseases. However, whether these associations are causal are still unsettled. In our study, we investigated the causal effects of genetically-predicted OSA on Alzheimer's disease (AD) and Parkinson disease (PD). MethodsWe implemented two-sample Mendelian randomization to judge causation using summary statistics from three independent and large genome-wide association studies on OSA (cases n = 16,761, controls n = 201,194), AD (cases n = 71,880, controls n = 383,378) and PD (cases n = 33,774, controls n = 449,056). Four single nucleotide polymorphisms (SNPs) with genome-wide significance associated with OSA served as instrumental variables. We prioritized the inverse variance weighted method when generating unconfounded estimates. Besides, MR-Egger regression, weighted mode, and weighted median methods were adopted as a supplement to the inverse variance weighted method. ResultsWe found no evidence supporting significant causal relationships between OSA and AD or PD among European population. The risk ratio of AD was 0.99 (95% confidence interval (CI) [0.92,1.08]) and that of PD was 0.82 (95%CI [0.47, 1.40]). Results from alternative approaches were generally consistent with that of the inverse variance weighted method. ConclusionThe present study found no evidence for causal associations between OSA and the risk of AD or PD in individuals of European ancestry.