Wednesday, February 24, 2016

Bedtime and metabolic health

Research has shown an association between shift work and metabolic health. Specifically, shift workers are prone to obesity and type 2 diabetes. However, there is less research data about a variable sleep schedule that is not related to shift work. I'm referring to individuals who have one bedtime during the work week but a later bedtime on the weekends. This study researched the effects of going to bed later on weekends and obesity as well as metabolic health. They studied all women with a mean age of 52 years. The researchers collected information annually on sleep times and duration with a sleep diary for about 5 years. They recorded the patient's weight and drew blood to check for insulin resistance (a marker for pre-diabetes). The results showed that a greater variability in bedtime and going to bed early was associated with an elevated body mass index. Interestingly, the mean bedtime and going to bed later were not related to body mass index. However, variability in bedtime and going to bed later on the weekends was associated with an increased rate of insulin resistance, even after adjusting for factors including sleep duration.

The authors speculate on the reason why later weekend bedtimes could contribute to insulin resistance. One possibility is that there is more exposure to light at night which could alter melatonin and possibly increased consumption of food. However there was no significant increase in weight over time despite later bedtime. It may be that people who go to bed later on weekends are eating more simple carbs but don't necessarily gain weight. Increased carb intake could be contributing to the insulin resistance. More studies will need to be done to see how clinically important these effects are, as the statistical differences were real, but small.

Wednesday, February 17, 2016

UNM hospital room lighting

Light affects sleep - especially our circadian rhythm, or the timing of our sleep. The University of New Mexico has built a hospital room with special lighting equipment that researchers will be able use to study the circadian rhythm of humans. The researchers will also be able to study how light effects certain neurological and psychiatric disorders such as delirium after surgery, depression, dementia, and psychosis that develops in ICU patients. Apparently, the lighting is "smart" in that it can alert a nurse that a patient has fallen, but the lighting uses no cameras! Not sure how that works, but it sounds pretty cool to me.

Wednesday, February 10, 2016

Importance of sleep

This article discusses a survey of Americans and New Years resolutions. I don't have access to the study, only the article that describes it. The article says that more half of respondents prefer a resolution of more sleep than going to the gym. Seems fairly obvious to me. Exercising is hard, but sleeping (usually) isn't. The article goes on to detail how sleep is viewed as important to many Americans. Again, fairly obvious responses. Since we all have to sleep, and we do it for about one-third of our life, it's going to be pretty important to humans. Right up there with eating, drinking, and shelter.

Friday, February 5, 2016

Sleep and attention

This article discusses research in animals regarding the "yin and yang" of sleep and our ability to pay attention when awake. Probably seems fairly obvious to most of you, but it's interesting to see research findings supporting our clinical knowledge.