Age difference in heart rate changes associated with micro-arousals in humans.
OBJECTIVE
Heart rate (HR) is known to change in association to micro-arousals (MA) during sleep. The aim of the present study was to evaluate the effect of age on HR variations associated with MA.


METHODS
Thirty-two healthy subjects underwent one night of polysomnographic recording. They were divided into two groups of 16 subjects according to age i.e. young (20-35 years) and middle-aged (50-65 years). The R-R intervals were calculated for 11 heart beats (10 intervals) before and 15 heart beats after the onset of MA.


RESULTS
HR changes associated with MA were characterized by a tachycardia followed by a bradycardia in both young- and middle-aged subjects. However, middle-aged subjects showed a significant reduction in the amplitude of both tachycardia and bradycardia as compared to young subjects.


CONCLUSIONS
This study revealed an age-related reduction in the amplitude of the HR changes associated with MA. These results may reflect a decline in parasympathetic functions and a higher risk of cardiovascular diseases with advancing age.
Gosselin
N
N
Centre d'étude du sommeil et des rythmes biologiques, Hôpital du Sacré-Coeur de Montréal, 5400 boul. Gouin Ouest, Quebec, Montreal, Canada.
Michaud
M
M
Carrier
J
J
Lavigne
G
G
Montplaisir
J
J
D000328:Adult; D000367:Age Factors; D000368:Aged; D001143:Arousal / Q000502:physiology*; D004562:Electrocardiography; D004569:Electroencephalography; D004585:Electrooculography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012016:Reference Values; D012890:Sleep / Q000502:physiology*