Senile insomnia? No, you're all right!
According to the results of a study conducted by scientists at the University of Surrey (UK) under the leadership of Professor Derk-Jan Dijk, the results of which were published in the journal Sleep on February 1 in the article "Age-Related Reduction in Daytime Sleep Propensity and Nocturnal Slow Wave Sleep", healthy elderly people who do not suffer from disorders sleep, need less deep sleep and feel less sleepy in the daytime than healthy young people. It turned out that the total duration of a person's night sleep per day progressively decreases with age, even while maintaining an eight-hour "bedtime" period.
Moreover, artificial disruption of periods of slow sleep for two nights caused similar reactions in all age groups. This was manifested in an increase in the need for night sleep and an increase in periods of deep sleep during the night of restorative sleep. According to the authors, this indicates that the decrease in daytime sleepiness with age-associated changes in sleep patterns cannot be explained by immunity to regime variations. Apparently, the process of normal aging is accompanied by a decrease in the duration and depth of sleep necessary to ensure daytime wakefulness.
In total, 110 healthy people who had no complaints of sleep disorders participated in the study: 44 young (20-30 years old), 35 middle-aged (40-55 years old) and 31 elderly (66-83 years old). After the first eight-hour sleep quality test, the participants were randomly divided into two groups. The slow sleep of the participants of one group for two nights was disturbed with the help of sound signals. The third night was given over to restorative sleep. The sleep of the control group was not disturbed during all three nights.
The quality of night sleep was assessed using the polysomnography method, and the need for sleep was assessed using the Multiple Sleep Latency Test (MSLT) and the Karolinska Sleepiness Scale (Karolinska Sleepiness Scale).
As a result, it turned out that at night, elderly people sleep on average about 20 minutes less than middle-aged people, who, in turn, sleep 23 minutes less than young people. The number of awakenings and the duration of periods of wakefulness after the first falling asleep increase significantly with age, while the duration of deep slow sleep decreases. Despite this, during the day, old people show less objective and subjective need for sleep than younger people. When participants were asked to go to bed during the day, take a comfortable position and try to fall asleep, young people fell asleep for an average of 8.7 minutes, while middle–aged people needed 11.7 minutes to do this, and the elderly - 14.2 minutes.
The authors note that the reasons for the age-related decrease in the need for slow sleep have yet to be clarified. Possible factors include changes in the hormonal background and features of the functioning of the brain in old age. They also add that the study did not evaluate sleepiness in the evening hours, when older people may feel more sleepy than young people.
The authors believe that the data they obtained should be taken into account in the treatment of insomnia in the elderly, which in some cases may be imaginary: complaints of insomnia may be caused by the fact that the elderly do not realize that they slept well, focusing only on the shortened sleep time.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru According to ScienceDaily: Healthy Adults May Need Less Sleep as They Age.
03.02.2010