Rest: It's required

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Rest: It's required

Adequate sleep is as crucial to a healthy life as diet and exercise,

researchers are finding.

By Brink, Times Staff Writer

October 9, 2006

http://www.latimes.com/features/health/la-he-

sleep9oct09,1,6864206.story?coll=la-headlines-health

THE alarm clock in Thom Stys' bedroom goes off at 4 a.m. every

weekday, a scant four to five hours after his head hits the pillow.

By 5 a.m., he's left his Chino Hills home for the freeway, and before

the sun is up, he's at his desk in Long Beach, making a round of

phone calls to clients in Europe. " If I left later, it would take me

an hour and a half to get to work, " says the 57-year-old vice

president of an aerospace forging company. " I simply can't afford to

spend time caught up in freeway traffic. "

Most working blokes know that the more they work, the less they

sleep. What they may not know is that the more time they spend in

their cars, the less they sleep. Drive time — not television viewing,

computer addiction or exercise — is second only to hours on the job

as a reason people don't get the shut-eye they need.

" The most deadly combination, " says F. Dinges, chief of the

division of sleep and chronobiology at the University of Pennsylvania

School of Medicine, " would be long commute time, long work hours and

living in a place where you have to get in the car and drive to get

anything. "

Sound like home?

The combination is deadly because a good night's sleep now appears to

be every bit as important to good health and long life as a

nutritious diet and regular exercise.

" Sleep is in the top three, " says Dinges. " And I think it's No. 1.

Sleep is a biological imperative and not getting enough has health-

related costs. "

In April, the Institute of Medicine issued a report confirming links

between sleep deprivation and an increased risk of hypertension,

diabetes, obesity, depression, heart attack and stroke.

Some scientists are exploring possible connections between inadequate

sleep and a decline in immune function.

The Archives of Internal Medicine devoted its Sept. 18 issue to the

relationship between sleep and health. An editorial called for

assessment of sleep habits as a standard part of all medical checkups.

That's because short sleep can hasten the arrival of the inevitable

long sleep. The largest study of sleep duration and mortality was

published in February 2002 in the Archives of General Psychiatry. The

Cancer Prevention Study II of the American Cancer Society followed

more than a million participants for six years. The best survival was

found among those who slept about seven hours a night, the worst

among those who slept less than 4.5 hours. Too much sleep — nine

hours or more — also was associated with a higher risk of mortality.

In the last decade, researchers have begun studying sleep based on

today's reality: a country open for business virtually 24/7, and a

populace increasingly unwilling or unable to call it a day. Sleep

needs vary slightly, but the vast majority of people, experts agree,

need just about eight hours of sleep each night to fully recover from

16 hours of being awake.

Yet Americans are racking up sleep debt like a college kid with a

credit card. About 40% of Americans say they get fewer than seven

hours of sleep on weekdays, and most — 71% — get fewer than eight

hours of sleep, according to a 2005 survey by the National Sleep

Foundation. Even on weekends, they sleep about 7.4 hours — better,

but not enough to pay back the week's loss. Every hour they fall

behind is considered an hour of sleep debt, and Americans accumulate

about two full weeks of personal sleep debt a year.

Sleep researchers have a name for the way the vast majority of people

in this country sleep: volitional chronic sleep deprivation, and it

is a lifestyle disorder.

Without enough sleep, the cost in reduced memory, focus,

concentration and reaction time is well established. Incidents in the

lore of sleep research include the Exxon Valdez oil spill and the

Chernobyl nuclear power plant disaster. In each, key decisions were

made by people who were sleep deprived.

But it's only in the last half a dozen years that studies have begun

to link chronic partial sleep deprivation to serious physical health

consequences.

Command center signals

Sleep is essential to the workings of every organ. And it seems that

the connection between sleep and health starts at the brain's central

command post, the hypothalamus. There, sleep or lack of it can work

to activate, or inhibit, hormone production. There, too, is where the

body gets the signal to go to bed, to wake up and to adjust

temperature, blood pressure, digestive secretions and immune activity.

Inadequate sleep works on hormone production in other areas as well.

Without enough sleep, the central nervous system becomes more active,

inhibiting the pancreas from producing adequate insulin, the hormone

the body needs to digest glucose.

A groundbreaking study in 1999, led by Eve Van Cauter, a professor of

medicine at the University of Chicago, showed that just six days of

sleep restricted to four hours pushed 11 healthy young male

volunteers into a pre-diabetic state. Those jaw-dropping results

expanded the field of sleep research, and convinced scientists that

chronic, partial sleep deprivation damaged the body, not just the

mind.

The young men in the same study also had reduced levels of the stress

hormone cortisol, which normally surges just before waking from a

good night's sleep, energizing people for the day's demands. The

study participants had the low morning levels of cortisol typical of

their grandparents.

And these volunteers also showed that, with chronic inadequate sleep,

young people might be accelerating the beer-belly, pear-bottom

problems typically linked to middle age. They were producing lower

levels of growth hormone after less than a week of four hours of

sleep. Growth hormone is largely secreted during the night's first

round of deep sleep. As adults age, they naturally spend less time in

deep sleep, getting less of the hormone that, in addition to driving

childhood growth, plays a role in controlling the body's proportions

of fat and muscle.

The University of Chicago study's findings were the first solid

evidence that chronic partial sleep deprivation could have physical

health consequences. Since then, researchers have begun to look

harder and deeper at the links between sleep and illness. A study

published in the Dec. 7, 2004, ls of Internal Medicine found that

when 12 healthy, young men were restricted to four hours of sleep for

just two nights, normal levels of leptin, a hormone that signals

satiety, dropped, while levels of ghrelin, a hormone that prompts

appetite, increased.

When the men awoke, following the sleep-deprived state, their hunger

and appetite increased — especially for calorie-dense, high

carbohydrate foods. " Chronic short sleep is the royal road to

diabetes and obesity, " says Karine Spiegel, a sleep researcher from

Brussels and author of the study. She spoke of her work last June at

the annual meeting of the Associated Professional Sleep Societies.

It appears, some researchers believe, that the links between sleep

deprivation and obesity are two interacting epidemics. " A few years

ago, I would look at obese people and see weakness of character, "

says Fred Turek, a sleep researcher at Northwestern University and

director of the Center of Sleep & Circadian Biology. " Now I believe

that if you interfere with sleep, you're interfering with weight. If

you interfere with weight, you're interfering with sleep. "

The Nurses' Health Study, an epidemiologic study begun in 1976

monitoring the health of more than 100,000 nurses, put poundage to

sleep loss. In a study reported in the Aug. 16, 2006, issue of the

American Journal of Epidemiology, researchers found that after 12 to

16 years, women who slept, on average, less than five hours per night

were 5 1/2 pounds heavier than those who slept an average of seven

hours nightly.

The resting heart

The brain controls a lot, but the ever-beating heart needs sleep too.

During the night, the heart gets a break. Most people experience a

20% to 30% reduction in blood pressure, and a 10% to 20% drop in

heart rate when they're asleep, according to 24-hour blood pressure

studies of more than 5,000 people by Dr. White at the

University of Connecticut Health Center.

Sleep is so important for the heart that, in a study published in the

Aug. 2 issue of the journal Sleep, researcher Dr. J. Gottlieb

of Boston University School of Medicine suggested that a good night's

sleep should be tested as a nonpharmacologic treatment in managing

high blood pressure. He questioned more than 5,000 men and women ages

40 to 100 on their sleep habits and found that people sleeping less

than six hours had as much as a 66% greater prevalence of

hypertension.

" Sleep is good for your heart, " says Dr. Virend Somers, a

cardiologist and sleep researcher at the Mayo Clinic. " I think

physicians should always address the question of sleep with their

patients. That's particularly true if they have cardiovascular

diseases that are not responding well to treatment. "

Those most at risk for heart disease because of sleep problems are

people with apnea, a disorder in which airways are obstructed and the

person wakes up, sometimes hundreds of times a night, snoring and

gasping for air. The sleeper, often unaware of waking, breathes

harder and faster during the episodes, and blood pressure and heart

rate surge. Sleep apnea puts people at higher risk of heart attack

and stroke, in part because their cardiovascular system doesn't get

its nightly dose of an easier workload.

A good night's sleep also can stave off short-term illness such as

colds and flu, as well as hasten the benefits of a flu shot.

In a study reported in the Sept. 25, 2002, Journal of the American

Medical Assn., 25 healthy young men, who normally slept 7.5 to 8.5

hours each night, received flu shots. Eleven of the men were

vaccinated on the fourth of five days in which their sleep was

restricted to four hours, while the others got their usual nights'

sleep. Ten days later, blood tests showed that those who got the

shots while sleep deprived had less than half the protective benefits

as those who slept normally.

The immune response to the vaccine of sleep-deprived volunteers

didn't catch up with that of the well-rested subjects for more than

three weeks.

Even some cancers might be rooted in sleep deprivation — or, more

precisely, to too many hours exposed to artificial light, according

to G. s, cancer researcher at the University of

Connecticut Health Center. His work is based on the theory that the

increase in breast cancer in the industrialized world is linked to

the disruption of hormone cycles.

Light, he says, suppresses production of the hormone melatonin, which

allows levels of estrogen to rise. And, when lights are on long after

dark, it confuses women's circadian clocks, the roughly 24-hour

internal rhythm that keeps hormones and organs on their daily

schedule. " Cells don't know when not to divide, " he says.

His theory was bolstered by a 1991 Centers for Disease Control and

Prevention report showing that blind women are about half as likely

as sighted women to get breast cancer. An Oct. 15, 2005, study in

Cancer Research looked at sleep patterns of more than 12,000 women.

Although researchers found no statistically significant increase in

cancer risk among short sleepers, says s, an author of the

study, the risk estimates were consistently lower in long sleepers.

" We don't know why breast cancer is increasing in industrialized

societies, " he says. Until more is known, he advises women to get

adequate sleep — and to do it in a very dark room.

It's essential

Adequate sleep may be essential for good health but it's every bit as

hard to pull off as eating a healthy, well-balanced diet or finding

an hour a day to exercise.

" The most common sleep disorder is insufficient sleep, " says Dr.

Dennis Nicholson, director of the Pomona Valley Hospital Medical

Center's Sleep Disorders Center. " People come in and say they're

sleepy. It's because they're not getting enough sleep. " The

connection seems like a no-brainer, but many people don't see it, he

says. They want a sleep study and a pill.

Just as Americans can lay part of the blame for their eating patterns

on the food processing industry, and part of the blame for their

sedentary lifestyle on unwalkable suburbs and sprawling cities, part

of the blame for not quite enough sleep lies with congested highways

and homes located far from work.

The University of Pennsylvania's Dinges studied numbers from the U.S.

Department of Labor's American Time Use Survey, conducted in 2003, to

find what Americans were doing instead of sleeping. He thought that,

after time spent working, the next biggest temptation would come from

television, computers and entertainment. Not so. " Here's the big

surprise. The more time you spend in the car, for any reason, the

less you sleep, " Dinges said.

Someone who spends a total of 40 minutes in the car each day — that's

a round-trip commute plus all daily car errands — gets a good seven

to eight hours of sleep. He reported those unpublished findings at

the June meeting of Associated Professional Sleep Societies. And he

found that for each eight minutes in the car beyond that, sleep time

drops by about 15 minutes.

So if a long commute, traffic congestion or a lot of short trips to

pick up kids or take dogs to the vet adds just 15 minutes of travel

time to that 40 minutes, it means half an hour less sleep. Commuters

in the counties of Los Angeles, Ventura, Orange, Riverside and San

Bernardino are chalking up hundreds of millions of miles each day on

freeways and highways that cover 7,200 miles. It's safe to assume

there are a lot of sleep-deprived drivers on the road.

One of them is costume designer Deena Appell, 43, of West Los

Angeles. Her day can start with the alarm going off at 4:30 a.m. and

take her from one end of the county to the other in a never-ending

quest for the perfect shirt, skirt or accessory for characters in a

TV series or film. For months at a time, including work on weekends,

she might drop into bed around 11 p.m., only to be startled awake 5

1/2 hours later to start all over again.

Appell knows her schedule takes a mental toll. " You really do feel a

diminished capacity, like your brain has literally been suctioned out

of your head, " she says. " And it's not just at night. You're

mesmerized by the traffic. I've nodded off at lights, and suddenly

you're rolling into the car in front of you. It's not a bad accident.

You're just dazed. "

The National Highway Traffic Safety Administration estimates that

100,000 accidents and 1,500 traffic fatalities annually are caused by

drowsy driving, far more than those attributed to cellphone

use. " Those are the people who are driving next to you and me, " says

Nicholson.

Sleeplessness in America is a safety issue and a health

problem. " Sleep is as important as breathing, drinking and eating, "

says Dr. Meir Kryger, a sleep scientist at the University of

Manitoba. " Animals who are deprived of sleep die, but they don't die

because their memory is poor. They die a metabolic death: Their fur

falls out, they lose weight. Things that happen are over and above

just the brain being sleepy. It's critical to health, but it takes

longer to notice. "

So far, Thom Stys hasn't noticed any health consequences. As he wraps

up his work day, the European clients he called in the morning are

long asleep. He ends his day with a round of phone calls to his Asian

clients, who are just getting to their offices. Then he's back on the

highway to Chino Hills, to dinner, family and a bit of work before

falling instantly asleep around midnight.

At 4 a.m., his alarm goes off.