Older people may need less sleep, study finds

Along with all the other changes that come with age, healthy older people also lose some capacity for sleep, according to a new report published online on July 24th in Current Biology, a Cell Press publication. When asked to stay in bed for 16 hours in the dark each day for several days, younger people get an average of 9 hours of shuteye compared to 7.5 for older people, the researchers report.

" The most parsimonious explanation for our results is that older people need less sleep," said Elizabeth Klerman of Brigham and Women's Hospital & Harvard Medical School. "It's also possible that they sleep less even when given the opportunity for more sleep because of age-related changes in the ability to fall asleep and remain asleep," she added, noting that the new results apply only to healthy individuals taking no medication and having no medical conditions or sleep disorders.

The study also found that most healthy people, and young people in particular, don't get as much sleep as they need.

The idea that sleep changes markedly across the life span isn't new. In fact, insomnia is a common complaint among older people. But whether age-related changes in sleep were due to changes in social factors, circadian rhythms, or shifts in an internal "set point" for sleep need or the ability to sleep had remained unresolved.

In the new study, Klerman and her colleague Derk-Jan Dijk, of the University of Surrey in the UK, set out to compare the capacity for sleep in young people (between the ages of 18 and 32) compared to older people (age 60 to 72) under conditions that controlled for circadian rhythms by allowing the chance to sleep during both the night and the day and by controlling individual choices in sleep opportunities.

" While humans can sometimes override the homeostatic set point and not sleep when tired, there is no evidence that they can sleep when they are not tired," Klerman explained.

Given the same amount of time in bed, older people take longer to fall asleep and sleep for less time than younger people do, they found. When required to remain in bed for 16 hours a day, older people slept 1.5 hours less on average than younger people, they showed. That age-related decline in sleep included an even split between rapid eye movement (REM) sleep, which is associated with dreaming, and non-REM sleep, they found.

Most younger subjects slept for many more hours during the study than their usual self-selected sleep times. Given the evidence that insufficient sleep is associated with increased risk of accidents, errors, and metabolic changes similar to diabetes, Klerman emphasized that younger people should sleep more.

The findings may also influence treatment for insomnia in older people, Klerman said.

" If older people believe that they need more sleep than they can achieve even when they spend extra time in bed, then they may complain of insomnia: being awake when wanting to be asleep. They may start using medications needlessly. If they are tired during the day, they should consider evaluation for a sleep disorder that may be interfering with their ability to obtain good sleep at night."

Source: Cell Press

Related stories:

Pill that boosts productivity gaining favor, raising concerns among medical ethicists
In a place like Silicon Valley, where career prospects often hinge on a person's intelligence and ability to work hellishly long hours, "brain doping" probably was inevitable.
Loneliness undermines health as well as mental well-being
Feeling connected to others is vital to a person's mental well-being, as well as physical health, research at the University of Chicago shows.
What a sleep study can reveal about fibromyalgia
Research engineers and sleep medicine specialists from two Michigan universities have joined technical and clinical hands to put innovative quantitative analysis, signal-processing technology and computer algorithms to work in the sleep lab. One of their recent findings is that a new approach to analyzing sleep fragmentation appears to distinguish fibromyalgia patients from healthy controls.
Gustav becomes 'dangerous' as it bears down on Cuba
Hurricane Gustav swelled into a "dangerous" category three hurricane Saturday as it bore down on Cuba after ripping through the Cayman Islands, Dominican Republic, Haiti and Jamaica, killing 85 people.
Research examines variations of rare lung disease
Lymphangioleiomyomatosis, or LAM, is a rare but serious lung disease that may cause severe respiratory symptoms in patients. The often-fatal disease has no cure.
How does bluetongue virus survive through the winter?
In 2006, Bluetongue virus – which infects livestock – reached Northern Europe for the first time. Some people thought that the outbreak would be limited to that particular year, as winter was expected to kill off the midges that host and spread the disease, bringing the threat of infection to an end. In actuality, the disease escalated in the following year, spreading to the UK. So, how did the virus survive the winter?
Kids with pets grow up to be snorers
A predisposition to adult snoring can be established very early in life. Research published today in BioMed Central's open access journal Respiratory Research describes possible childhood risk factors, including exposure to animals, early respiratory or ear infections and growing up in a large family.
Insomnia: Changing your bedtime habits could help relieve insomnia
Many people sleep better when they are on holiday and wish that they could sleep as well all the time. But according to the German Institute for Quality and Efficiency in Health Care (IQWiG), it is not only being free of daily worries that can make a difference to sleep. Good bedtime habits can help people to sleep well all year round. Medication provides short-term relief at best.

News discussion:

Medicine & Health news