Sleep Better — Get Smart about Your Smartphone

By Dr. David O. Volpi, M.D.

Smartphones, iPads, and other personal electronic devices are great ways to communicate and entertain ourselves, but they may also be negatively impacting the quality and quantity of our sleep.

As personal electronic devices have become more ubiquitous, the bright-light emitting screens that allow the use of mobile devices in dimly lit rooms have become a more common reason for sleep disruption, whether users realize it or not.

Why is that? Melatonin is a hormone produced by the pineal gland at night and when it is dark. It is a “timer” that tells the body that it is nighttime, and time to go to sleep. Exposure to light at night, such as that in the brightly-lit screens of many personal mobile devices, can interfere with melatonin, the hormone that helps control our sleep and wake cycles.

But rest easier: New research from the Mayo Clinic in Scottsdale, AZ explains a way to reduce the impact of electronic devises on sleep cycles.

Lois Krahn, M.D., a psychiatrist and sleep expert at the Mayo Clinic and co-author of the study said, “In the old days, people would go to bed and read a book. More commonly, people go to bed and they have their tablet on which they read a book or newspaper or look at material. The problem is it's a lit device, and how problematic is the light source from the mobile device?"

That question prompted Dr. Krahn to wonder, is the light from screens always a negative factor for sleep?" To find out, Krahn and his colleagues experimented with two tablets and a smartphone in a dark room, using a meter on its most sensitive setting to measure the light the devices emitted at various settings when held various distances from a person's face.

They discovered that when the brightness settings were lowered and the devices were held just over a foot from a user's face, it reduced the risk that the light would be bright enough to suppress melatonin secretion and disrupt sleep.

Explains Krahn, “We found that only at the highest setting was the light over a conservative threshold that might affect melatonin levels. If it's at the mid setting or at a low setting, it's bright enough to use."

The new Mayo Clinic research, which was presented in June at SLEEP 2013, the 27th annual meeting of the Associated Professional Sleep Societies LLC, in Baltimore, Md., also suggests things you can do to help prevent screen light from interfering with melatonin and affecting sleep.

These tips include dimming the smartphone or tablet brightness settings and holding the device at least 14 inches from your face while using it.

Other general tips include moving the TV and computer out of the bedroom, or at the very least, do not watch TV or work on the computer to bedtime.

With so many electronic distractions in our lives, it's important to re-claim the bedroom for its intended purpose: rest, relaxation, and sleep.

Can more sleep help ease pain? Yes, says new study!

Chalk another one up for the benefits of sleep. Researchers at the Sleep Disorders and Research Center at the Henry Ford Hospital in Detroit have found that getting more sleep improves daytime alertness and reduces pain sensitivity in healthy adults.

The study was led by Timothy A. Roehrs, Ph.D. of the Sleep Disorders and Research Center at the Henry Ford Hospital and supported by the Fund for Henry Ford Health System. Roehrs and his colleagues studied 18 pain-free, but mildly sleepy volunteers.

For the study, the participants were randomly assigned to four nights of either their normal amount of sleep, or extending their sleep time to 10 hours in bed per night. Their daytime sleepiness was measured on days one and four using the Multiple Sleep Latency Test (MSLT), a tool that measures how quickly a person falls asleep. Their pain sensitivity was also measured using finger withdrawal latency pain testing to a radiant heat stimulus.

The first study to prove sleep reduces pain.

The results of the study were published in the Dec. 1 issue of the journal Sleep. It is the first research of its kind to prove that extended sleep in mildly sleep-deprived adults can significantly reduce their sensitivity to pain.

The results showed that the extended sleep group—those who slept more than normal—slept 1.8 hours more per night than the normal sleep group. It also showed that they experienced less daytime sleepiness. This increase in sleep time during the four nights correlated to increased daytime alertness, as well as less sensitivity to pain.

Regarding the pain test, the extended sleep group showed a greater tolerance for pain/reduced pain sensitivity. The length of time before participants removed their finger from a radiant heat source increased by 25 percent. The researchers noted that this increase in “finger withdrawal latency” is greater than the effect found in a previous study where participants used 60 milligrams of codeine.

In their report, the researchers stated that the results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.

Timothy Roehrs, PhD, the study’s principal investigator and lead author said, “The results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures. We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine.”
Read the press release for the study, “Extended sleep reduces pain sensitivity.”

Lack of sleep and an increase in strokes.

Roehrs’ study adds to growing evidence that more regular, restorative sleep can help reduce the risk of health problems, and the opposite is true, as well.

Last June, the University of Alabama at Birmingham released the results of a study that regularly sleeping less than six hours a night significantly increases the risk of stroke symptoms in middle-age to older adults who are of normal weight and at low risk for obstructive sleep apnea (OSA). That’s worth repeating: Less than six hours of sleep per night increases the risk of strokes in adults of normal weight and not at risk for OSA.
It seems that under six hours of sleep per night is the critical variable, but why? Let’s take a look at the study. The University of Alabama researchers followed 5,666 people  for up to three years who had no history of strokes or stroke-like symptoms, transient ischemic attacks (when blood flow to the brain stops for a brief period causing stroke-like symptoms), or high risk for OSA at the start of the study.

For a period of three years, the researchers followed and studied the subjects’ first stroke symptoms, stroke risk factors, depression symptoms, demographic information and other various health behaviors. What they found was—after adjusting for body-mass index (BMI)—there was a strong association between daily sleep periods of less than six hours and a greater incidence of stroke symptoms for middle-age to older adults, even beyond other risk factors. Interestingly, the researchers did not find any link between short sleep periods and stroke symptoms in overweight and obese participants.

Still, the connection between short sleep and strokes is worthy of great attention from the medical community and general public. I agree with the Alabama study’s lead author, Megan Ruiter, PhD., who said, “The results of the Alabama study provide a strong argument for increasing physician and public awareness of the impact of sleep as a risk factor for stroke symptoms, especially among persons who appear to have few or no traditional risk factors for stroke.”

It looks like the medical community is taking this message to heart, no pun intended. Another study announced in late July is going on at the Alberta Health Services and the University of Calgary. There, Dr. Patrick Hanly of the university’s Hotchkiss Brain Institute is leading a study to learn more about the physiological connection between sleep apnea and stroke—specifically, the brain’s blood flow response in people with and without sleep apnea.

For the study, participants with sleep apnea stay overnight in the sleep laboratory at Calgary’s Foothills Medical Centre, where their breathing and cardiovascular responses are continuously monitored while they sleep. The next day, their brain blood flow response to reduced oxygen levels is assessed while they are awake. Then, the participants receive supplemental oxygen during sleep for two weeks, and are tested again to see if their cerebral defense mechanisms have improved. The researchers are also studying people without sleep apnea to see if their cerebral defense mechanisms function better than in those with sleep apnea. Hanly and team’s theory is that it is the lack of oxygen, or hypoxia, that people with sleep apnea experience during sleep that impairs the body’s normal defense mechanisms in the brain. A better understanding of this connection will lead to better prevention and treatment strategies.

I applaud the work of the Alabama and Calgary researchers. It’s time we all wake up to the health benefits of regular, restorative sleep

For more information, read the University of Alabama at Birmingham study, “Under 6 Hours of Sleep Tops Risks for Stroke in a Low-risk Population.”