Clinical Interventions in Aging (May 2023)
An Exploratory Study of Sleep-Wake Differences of Autonomic Activity in Patients with Mild Cognitive Impairment: The Role of Melatonin as a Modulating Factor
Abstract
Carolina Abulafia,1,2 María F Vidal,3 Natividad Olivar,4 Andrea Odzak,5 Ignacio Brusco,4– 6 Salvador M Guinjoan,7 Daniel P Cardinali,8 Daniel E Vigo1,9 1Laboratory of Chronophysiology, Institute for Biomedical Research (BIOMED), Pontifical Catholic University of Argentina (UCA) and CONICET, Buenos Aires, Argentina; 2Facultad de Psicología, Universidad de Buenos Aires, Buenos Aires, Argentina; 3Servicio de Psiquiatría, Departamento de Neurología, Fleni, Buenos Aires, Argentina; 4Hospital de Clínicas “José de San Martín”, Universidad de Buenos Aires, Buenos Aires, Argentina; 5Servicio de Clínica Médica, Hospital Argerich, Buenos Aires, Argentina; 6CONICET, Buenos Aires, Argentina; 7Laureate Institute for Brain Research, Tulsa, OK, USA; 8Facultad de Ciencias Médicas, Universidad Católica Argentina, Buenos Aires, Argentina; 9Faculty of Psychology and Educational Sciences, Katholieke Universiteit Leuven, Leuven, BelgiumCorrespondence: Daniel E Vigo, Instituto de Investigaciones Biomédicas, Pontificia Universidad Católica Argentina, Alicia Moreau de Justo 1500, 4° piso, Buenos Aires, C1107AAZ, Argentina, Tel +54 0810-2200-822 ext 1152, Email [email protected]; [email protected]: The objective of the present study was to assess sleep-wake differences of autonomic activity in patients with mild cognitive impairment (MCI) compared to control subjects. As a post-hoc objective, we sought to evaluate the mediating effect of melatonin on this association.Patients and Methods: A total of 22 MCI patients (13 under melatonin treatment) and 12 control subjects were included in this study. Sleep-wake periods were identified by actigraphy and 24hr-heart rate variability measures were obtained to study sleep-wake autonomic activity.Results: MCI patients did not show any significant differences in sleep-wake autonomic activity when compared to control subjects. Post-hoc analyses revealed that MCI patients not taking melatonin displayed lower parasympathetic sleep-wake amplitude than controls not taking melatonin (RMSSD − 7 ± 1 vs 4 ± 4, p = 0.004). In addition, we observed that melatonin treatment was associated with greater parasympathetic activity during sleep (VLF 15.5 ± 0.1 vs 15.1 ± 0.1, p = 0.010) and in sleep-wake differences in MCI patients (VLF 0.5 ± 0.1 vs 0.2 ± 0.0, p = 0.004).Conclusion: These preliminary findings hint at a possible sleep-related parasympathetic vulnerability in patients at prodromal stages of dementia as well as a potential protective effect of exogenous melatonin in this population.Keywords: heart rate variability, actigraphy, circadian rhythms, wavelets
