First, an acknowledgment: Insomnia bites.
S. Bliss, a reader from Albuquerque, comments that even taking Ativan, he or she awakens at 4:30 a.m., can’t get back to sleep and suffers “a state of sleep deprivation and eventually a kind of walking exhaustion.”
Molly from San Diego bemoans “confusion, anxiety, exhaustion, depression, loss of appetite, frankly a loss of will to go on,” all consequences of her sleeplessness. She memorably adds, “Give me Ambien or give me death.”
Marciacornute reports that she’s turned to vodka (prompting another reader to wonder if Medicare will cover booze).
After several rounds of similar laments here (and not only here; insomnia is prevalent among older adults), I found the results of a study by University of Chicago researchers particularly striking.
What if people who report sleep problems are actually getting enough hours of sleep, overall? What if they’re not getting significantly less sleep than people who don’t complain of insomnia? Maybe there’s something else going on.
It has always been difficult to ascertain how much people sleep; survey questions are unreliable (how can you tell when you’ve dozed off?), and wiring people with electrodes creates such an abnormal situation that the results may bear little resemblance to ordinary nightlife.
Enter the actigraph, a wrist-motion monitor. “The machines have gotten better, smaller, less clunky and more reliable,” said Linda Waite, a sociologist and a co-author of the study.
By having 727 older adults across the United States (average age: almost 72) wear actigraphs for three full days, Dr. Waite and her colleagues could tell when subjects were asleep and when they weren’t. Then they could compare their reported insomnia to their actual sleep patterns.
Overall, in this random sample, taken from an ongoing national study of older adults, people didn’t appear sleep-deprived. They fell asleep at 10:27 p.m. on average, and awakened at 6:22 a.m. After subtracting wakeful periods during the night, they slept an average seven and a quarter hours.
But averages don’t tell us much, so let’s look more closely at their reported insomnia. “What was surprising to us is that there’s very little association between people’s specific sleep problems and what the actigraph shows,” Dr. Waite said.
One question asked how often people felt rested in the morning. The 13 percent who said they rarely or never did got only four minutes less total sleep than the 67 percent who reported feeling rested most of the time. “It’s not enough to make any difference,” Dr. Waite said.
Another question explored problems with falling asleep. Those who said they rarely or never had trouble (42 percent) fell asleep in an average 26.77 minutes. Those who said they had trouble falling asleep most of the time (12 percent) had to wait 30.53 minutes. That nearly four minutes’ difference wasn’t statistically significant.
It gets stranger:
- People who complained of waking up at night most of the time did spend more time awake at night, yet actually got an average 19 minutes more sleep than those who said they rarely or never experienced that problem.
- Those who reported usually waking up too early did, in fact, awaken earlier — but because they also fell sleep earlier, their total sleep time was not significantly different from those rarely troubled by early awakening.
What? I asked Diane Lauderdale, a co-author of the new study and an epidemiologist who has studied sleep for a decade, what might account for such disparities. She listed several possibilities.
Because actigraphs measure length of sleep but not its quality, maybe these older adults weren’t getting enough “deep sleep” or “delta sleep,” the kind that makes teenagers hard to rouse but gets rarer with age.
Maybe those upset about awakening early have undergone a “circadian phase shift,” sleeping earlier in the day to compensate. “It can be annoying to be awake at 4:30 or 5, but there can still be adequate sleep,” Dr. Lauderdale said.
Or maybe the same phenomenon, like waking up at night, makes some sleepers miserable — so they report it as a problem — but hardly bothers others. “That time you’re awake, if you’re full of anxiety, may feel much more important than if you can pass the time calmly,” she said.
(The researchers controlled for certain socio-demographic characteristics. About 4 percent of the sample used prescription sleep medications at least sometimes, but this analysis doesn’t incorporate that data.)
In asking about feeling rested, the researchers may be picking up older people’s views of “their overall vitality, a function of all kinds of mental and physical health,” Dr. Lauderdale said. In general, “these questions, which seem specific, are tapping into some underlying dissatisfaction with sleep” — and perhaps with other elements of their lives.
None of these findings or possible explanations trivialize insomnia: People who complain of it do have more health problems. (But less sleep doesn’t necessarily correlate with higher mortality rates; see this meta-analysis by the Chicago team.)
With actigraph studies, we’ll probably learn more about sleep at all ages, Dr. Lauderdale predicted, “and it will be full of surprises. Things we thought were related to sleep will not be. I think we’ll also discover that things we thought weren’t related to sleep are.”