Insufficient sleep may raise nighttime blood pressure

Having prolonged periods of insufficient sleep is linked to significant increases in blood pressure during nighttime hours.

Insufficient sleep is linked to occupational errors.

This was the finding of a small study from Mayo Clinic that was presented at the 64th Annual Scientific Session of the American College of Cardiology in San Diego on Sunday.

The Centers for Disease Control and Prevention (CDC) say insufficient sleep is a public health epidemic in the US.

Insufficient sleep is linked to motor vehicle accidents, industrial disasters and medical and other occupational errors.

People who do not get enough sleep are also at higher risk for chronic diseases such as high blood pressure,diabetes, obesity and depression, as well as cancer, premature death and reduced quality of life and productivity.

For their study, the Mayo team enrolled eight healthy people of normal weight, aged from 19 to 36, in a 16-day inpatient trial.

The first 4 days was an acclimatization period. Then followed 9 days of either sleep restriction (4 hours of sleep a night) or normal sleep (9 hours a night), and 3 days of recovery.

The participants' blood pressure was monitored regularly over the study period.

The results showed that in the nighttime, the average blood pressure readings in the sleep restriction phase compared with the normal sleep phase were 115/64 mm/Hg versus 105/57 mm/Hg.

Normally, one expects blood pressure to fall during the night, but the researchers found this was not the case during the restricted sleep period.

The researchers also found that nighttime heart rate was higher during the sleep restriction phase than the normal sleep phase.

"We know high blood pressure, particularly during the night, is one of the major risk factors for heart disease, and Americans typically do not get enough sleep.

For the first time, we demonstrated that insufficient sleep causes increases in nighttime blood pressure and dampens nocturnal blood pressure dipping by using a controlled study that mimics the sleep loss experienced by many people."

The results are part of an ongoing Mayo Clinic study funded by the National Heart, Lung, and Blood Institute (NHLBI).

Tips for getting a good night's sleep

The National Sleep Foundation suggest a number of things you can do to make your bedroom sleep-friendly:

• Dim the lights about an hour before bed to signal to your body that sleep time is approaching
• Make your bedroom peaceful and relaxing by decorating it lovingly and keeping it clutter-free
• Keep your bedroom cool for sleep - 60-67 °F (16-19°C) is ideal
• Choose mattresses and pillows that are comfortable for you
• Keep noise to a minimum - a fan or noise conditioner can help by giving a soothing consistent backdrop
• Surround yourself with soothing scents - they can improve mood before bedtime
• Turn off electronics while sleeping - light receptors in the retina signal to the brain about the status of the outside world and may affect sleep-wake rhythms.

Other habits for promoting good sleep include going to bed at the same time each night and getting up at the same time each morning, plus avoiding large meals, caffeine and alcohol close to bedtime, and avoiding nicotine.

References:

1.  Mayo Clinic news release, accessed 16 March 2015.
2.  Additional source: CDC, Insufficient sleep is a public health epidemic, accessed 16 March 2015.