Premium
Age‐related changes in autonomic control during sleep: symbolic and complexity analyses of heart rate variability
Author(s) -
Tobaldini Eleonora,
Viola Antoine,
Chellappa Sara,
Porta Alberto,
Casali Karina R,
Montano Nicola
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.625.19
Subject(s) - heart rate variability , sample entropy , polysomnography , medicine , heart rate , psychology , sleep stages , cardiology , audiology , endocrinology , blood pressure , cognitive psychology , pattern recognition (psychology) , apnea
Scanty data are available on the differences in neural control of circulation during sleep between young (Y) and older (O) subjects. The aim of our study was to assess the age‐related changes of heart rate variability during sleep using symbolic analysis (SA) and entropy indexes, Shannon entropy (SE) and Conditional Entropy (CE). A polysomnography was performed in 12 Y and 12 O healthy volunteers; time series of RR intervals were constructed for each sleep stage (Wake, W; slow wave sleep, SWS; and REM) and analyzed using SA, SE and CE. SA is based on the conversion of time series into symbols, the construction of patterns and the identification of four families: 0V (no variation), marker of sympathetic modulation, 1V, 2LV and 2UV (two unlike variations), marker of parasympathetic modulation. SE and CE measure the amount of information carried by the new sample when the previous are known. A decrease of entropy indexes is marker of aging and disease. In the O, REM was characterized by a decrease of SE, CE and 2UV% and an increase of 0V%, with respect to SWS and W. Compared to Y, the O showed in all stages a reduction of SE, CE and 2UV% and an increase of 0V%, and these differences were more evident during REM sleep. In conclusion, REM is characterized by a decrease of complexity and a predominance of sympathetic modulation in older subjects and it may represent a state of increased risk for cardiovascular events during aging.