Decreased Nocturnal Heart Rate Variability and Potentially Related Brain Regions In Arteriosclerotic Cerebral Small Vessel Disease

Background: To assess heart rate variability(HRV) among patients with arteriosclerotic cerebral small vessel disease (CSVD) by comparing with control subjects, and to determine whether HRV parameters were related to structural alterations in brain regions involved in autonomic regulation among CSVD patients. Methods: We consecutively recruited subjects aged between 50 and 80 years who visited the Sleep Center of Huashan Hospital from September 1, 2018 to August 31, 2019. Brain magnetic resonance imaging(MRI) was scanned before enrollment. 63 patients were assigned to the arteriosclerotic CSVD group and 46 to the control group. Polysomnography and synchronous analyses of HRV were performed. Multivariable binary logistic regression was used to identify the relationship between HRV parameters and CSVD. A number of 24 CSVD patients and 21 control participants further underwent three-dimensional brain volume scan, and the voxel based morphometry (VBM) analysis was used to identify gray matter atrophy. Results: Lower standard deviation of normal-to-normal intervals(SDNN, OR=0.943, 95% CI 0.903 to 0.985, P=0.009) and higher ratio of low to high frequency power (LF/HF, OR=4.372, 95% CI 1.033 to 18.508, P=0.045) during the sleep period were associated with CSVD, independent of traditional cerebrovascular risk factors and sleep disordered breathing. Based on VBM results, SDNN during the awake time (b=0.544, 95% CI 0.211 to 0.877, P=0.001) and the sleep period(b=0.532, 95% CI 0.202 to 0.862, P=0.001) were both positively related with gray matter thickness within the right inferior frontal gyrus only among CSVD patients. Conclusions: Decreased nocturnal HRV may be associated with arteriosclerotic CSVD independent of traditional cerebrovascular risk factors and sleep disordered breathing. The structural atrophy of some brain regions associated with cardiac autonomic regulation sheds light on the potential relationship. Trial registration Trial registration number: ChiCTR1800017902.Date of registration: 2018-08-20