Older Men Who Sleep Well May Avoid High Blood Pressure

Sleep-Lab studies show that sleep is divided into two broad types: rapid eye movement (REM) and non-rapid eye movement (non-REM) sleep. Non-REM is further divided into three stages: N1, N2, and N3, the latter being also called delta sleep or slow-wave sleep (SWS).  SWS is the deepest type of sleep, when being aroused requires more effort.  Researchers are now examining the different types of sleep in relation to common diseases.  One study has turned up interesting findings, which are reported online in the journal Hypertension.  

Researchers from the San Diego Veterans Affairs Healthcare System wanted to see whether high blood pressure (hypertension) is associated with sleep-disturbed breathing, sleep duration, and sleep architecture in older men.  They studied 784 men 65 or older who did not have hypertension at recruitment in 2003–2005.  After 3½ years, on average, 243 of them had developed hypertension.  They underwent in-home polysomnography at enrollment and at the end of the study; this revealed the duration of the various stages of sleep.

After adjustment for age, race, study site, and body mass index (BMI), the only sleep stage that was significantly associated with hypertension was the percentage of SWS.  Those in the shortest 25% of SWS duration were 1.85-times more likely to have developed hypertension as those in the longest 25%.  (The average time spent in SWS for the lowest 25% was less than 4.1% of their total sleep time; for the deep-sleeping 25% more than 16.9% was spent in SWS.) 

This study shows clearly that deep-sleeping older men have a reduced likelihood of developing hypertension.  Other health benefits associated with the SWS stage include better cognitive skills, and improved glucose metabolism.  I’ve discussed this in an earlier blog, 4 years ago.  It clearly behooves people with health problems impeding their sleep pattern – e.g. chronic obstructive pulmonary disease, or COPD - to get effective treatment to give them a ‘good night’s rest’.