Heart rate variability and its influencing factors in patients with dementia with Lewy bodies and patients with Parkinson disease dementia

Abstract

Objective To compare the difference in heart rate variability(HRV)between patients with dementia with Lewy bodies(DLB)and those with Parkinson disease dementia(PDD)and to identify the influencing factors. Methods We retrospectively enrolled 30 patients with DLB(DLB group)and 41 patients with PDD(PDD group)at the outpatient and inpatient services of our hospital from January 2010 to December 2017 in this study, and further recruited 119 normal elderly individuals to serve as the control group.HRV was recorded with 24 h dynamic electrocardiogram and compared between the DLB group and the PDD group.Time domain measures including standard deviation of all normal to normal(NN)intervals(SDNN)and square root of the mean squared differences of successive NN intervals(rMSSD)and frequency domain measures including total power(TP), low frequency(LF), and high frequency(HF)were analyzed with a customized program.The levodopa equivalent dose(LED), mini-mental state examination(MMSE), Montreal Cognitive Assessment(MoCA), Hoehn-Yahr stage(H-Y stage)and the unified Parkinson's disease rating scale Ⅲ(UPDRS Ⅲ), and the Alzheimer's disease Cooperative Study-Activities of Daily Living scale(ADCS-ADL)were assessed in DLB and PDD patients to investigate the influencing factors. Results SDNN, TP, and LF in the DLB group and the PDD group were significantly lower than in the control group(F=14.154, 4.742, 4.897, P 0.05). The DLB group and the PDD group did not differ in HF from the control group(P>0.05). There was no significant difference in any HRV indexes between DLB and PDD patients(P>0.05). Correlation analysis showed no correlation of HRV with cognitive level(MMSE, MoCA), motor disturbance degree(UPDRS Ⅲ, H-Yahr stage), daily living ability(ADCS-ADL), or dosage of anti-PD drugs(each P>0.05). Conclusions DLB and PDD patients present similar impairments in autonomic nervous system function, which are not associated with disease severity. Key words: Dementia; Lewy bodies; Parkinson disease; Heart rate variability