Five Dimensions to Assess Sleep
In "Sleep Health: Can We Define it? Does it Matter?," Dr. Daniel J. Buysse underscores the following five dimensions of sleep:
- Sleep Timing - the hours when sleep occurs within a 24 hour period,
- Sleep Duration - how much sleep one person accumulates in a 24 hour period,
- Sleep Efficiency - how easily a person reaches a state of being asleep and returns to this state after being awakened,
- Sleepiness/Alertness - the ability to be attentive when awake, and
- Sleep Quality (Satisfaction with Sleep) - a personal, subjective assessment of one's sleep.
Linking Sleep to Possible Health Outcomes
Dr. Buysse explains how these five dimensions can be used to indicate the status of one's overall health. By including a table, "Dimensions of sleep and potential health outcomes", he links each of the five dimensions of sleep to specific health outcomes with associated research. For example, the table shows if you don't get enough sleep (i.e., assessing Dimension #2 - Sleep Duration), then you increase the likelihood of having the following health outcomes:
- metabolic syndrome,
- coronary heart disease and
- impaired neurobehavioral performance.
Insufficient Sleep May Impair Immune System
Sleep and Health, published by the Division of Sleep Medicine at Harvard Medical School, echoes the potential health impacts Dr. Buysse noted when you don't get enough sleep. Sleep and Health also cites impaired immune function and the common cold as more likely to happen to people who didn't sleep enough each night. The article includes two videos which briefly explain the negative impacts of insufficient sleep.
Dr. Buysse highlights the need to consider more than sleep duration (i.e., it's only one of the five dimensions) when determining if you're getting enough sleep. He cites the 2011 National Institutes of Health Sleep Disorders Research Plan which notes sleep deficiencies occur when sleep is insufficient in duration, done at the wrong time of day or perceived to be of poor quality.
Sleep Helps Maintain Vital Functions
In Sleep and Health, the article wraps up by noting "sleeping well is no guarantee of good health, it does help to maintain many vital functions." Sleep provides time for our cells and tissues to recover from our daily activities. The article mentions the major restoration of tissue and muscles as well as protein synthesis which happen almost only when we're sleeping.
While Dr. Buysse's article primarily seeks to define "sleep health", he also suggests using public service campaigns to raise awareness of how sleep can positively or negatively impact health. Looking at the various health outcomes due to insufficient sleep, he has succeeded in raising my awareness of the need to get at least seven hours of good quality sleep.