Purpose: An increased blood pressure variability (BPV) has been reported to be associated with older age and cognitive dysfunction; however, associations between increased BPV and rapid eye movement sleep behaviour disorder (RBD) has not been thoroughly investigated in patients without clinical Lewy body diseases.
Materials and methods: In frailty outpatient clinic, we evaluated ambulatory BP, RBD screening questionnaire (RBDSQ), and beat-to-beat heart rate variability during positional change from sitting to standing in 112 elderly hypertensive patients.
Results: The mean age was 81.2 ± 6.3 years (68% male). There were 15 patients who had probable RBD (RBDSQ scores ≥ 5). Patients with RBD had a greater body mass index, coefficient of variation (CV) in 24-h diastolic BP (23.5 ± 6.1 versus 18.7 ± 5.8, p = 0.005), awake diastolic BP (23.0 ± 7.7 versus 18.6 ± 6.2, p = 0.017), and nocturnal systolic BP (14.9 ± 5.5 versus 12.0 ± 4.4, p = 0.025) compared with those without RBD, while systolic BP, diastolic BP, and cognitive function did not differ significantly between patients with and without RBD. Patients with RBD exhibited larger orthostatic BP fall compared with patients without RBD (-4.9 ± 11.0 versus 7.5 ± 11.8, p = 0.009) and lower CV of R-R intervals while standing (1.3 ± 0.6 versus 2.4 ± 1.5, p = 0.039). Multiple regression analysis revealed that patients with RBD had significantly greater CV of nocturnal systolic BP independent of age, sex, BMI, history of diabetes and dyslipidaemia, and use of antihypertensive drugs (p = 0.008).
Conclusion: An increased BPV in ambulatory BP, associated with autonomic dysfunction, can be observed in patients with probable RBD even in elderly patients without clinical presentation of Lewy body diseases.
Keywords: Blood pressure variability; autonomic dysfunction; elderly; rapid eye movement sleep behaviour disorder.