Sleep is a major problem for the majority of people who I see in clinical practice. It is both a diagnostic feature and a primary disorder. It is not uncommon for me to see people in their 30s or 40s who have had consistent sleep problems since childhood. Environmental, medical problems, and alcohol/substance use are also common causes of insomnia. After cessation of opioids, cannabis, or alcohol there can be disrupted sleep that lasts for months or longer. The treatment of insomnia is partially effective. Behavioral methods like sleep hygiene measures and CBTi are useful for some people. Medications can be helpful but they are a mixed bag for practitioners. Sleep medications that are typically recommended have significant side effects including tolerance to the sedative effects that can lead to dose escalation and addiction. The non-FDA approved medications like trazodone are widely used but routinely criticized in the literature for not having enough of an evidence base. Physicians often face patients who are not sleeping well and ask for practical ways on catching up. The news media lately has a lot of stories about the dangers of sleep deprivation creating some desperation in the sleep deprived population. A common question is: "Can a sleep deprived person make up for lost sleep?"
There was a very interesting study released by a research group this month on sleep and whether or not the sleep deprived can make up for lost sleep on the weekends. The study looked at 38,015 participants in the Swedish National March Study who returned a general health questionnaire on medical history and lifestyle in 1997. There were two questions about sleep:
How many hours approximately, do you sleep during a workday/weekday night?
How many hours approximately, do you sleep per night on days off?
The authors considered short sleep < 5 hours per night and long sleep > 9 hours per night. The considered days off to be the equivalent of weekend sleep and simplified the response categories to reduce cells with low numbers of subjects. The reference category was considered to be 7 hours. The formed the following 6 categories based on that sleep classification and the pattern over the weekday/weekend (S=short, M=medium, L=-long): SS, MM, LL, SML, ML, and LS. Patient were following to the endpoints of death, emigration or study termination on December 31, 2010.
The authors used a Cox proportional hazards model with attained age to estimate mortality hazard ratios and 95% confidence intervals for each group adjusted for a number of variables including sex, BMI, smoking status, physical activity, alcohol intake, educational level, shift work, and a weighted index based on an inpatient register.
The main finding with the correlations of mortality with short weekend sleep. For subjects less that the age of 65, short weekend sleep was associated with a hazard ratio (HR) or 1.52 95% CI 1.15-2.02. In other words subjects with short weekend sleep had a 52% greater mortality rate. There was no different in mortality for short weekend sleep in subjects older than 65 years of age. Forest plots were provided to look at adjusted and unadjusted HR across 5 sleep categories (≤ 5 hrs, 6 hrs, 7 hours, 8 hrs, ≥ 9 hrs). A weekend sleep duration of ≤ 5 hours in subjects less than 65 clearly had the highest mortality ratio. In other analyses short sleep on both the weekdays and weekends and consistently long sleep were also associated with higher mortality.
Interestingly from a psychiatric perspective self reported sleep medication use did not alter the outcomes. Sleep medication use was reported in every sleep category by 9.5 to 28% of the subjects in those categories (the short sleepers reporting more medication use). Snoring, napping, restorative sleep, general health and high work demand did not affect results. The initial model also corrected for shift work.
This is very interesting research because it suggests that there is a way to catch up on sleep debt at least on a short term basis. Chronic sleep debt like the kind that physicians endure in medical school and residency training is probably gone forever. But in clinical practice, it is theoretically possible to sleep in on the weekends after getting 5 hour blocks during the week and erase that debt - at least from mortality standpoint. Even though the authors seem to be doing a lot of analysis from 12 data points on a survey - the structure of that data allowed them to look at sleep from a different perspective than it is typically analyzed from. In their introductory section, they discuss the typical analysis focuses on typical sleep patterns and there are no distinctions between weekday and weekend hours. Analyzing that data typically results in a J-shaped mortality curve with the highest mortality for too little sleep or a U-shaped mortality curve with highest mortality for too little and too much sleep.
The authors discuss the strength of their study (large N, good follow-up) and the potential weaknesses (misinterpretation of the questions by some subjects). From their exclusion process they did a good job of cleaning up the sample. Their recommendation for closer follow-up studies on a longitudinal basis with more frequent data points is a good one. From a clinical perspective, it would be useful to know what the time frame is that would allow for the cancellation of sleep debt. Does it all have to happen in the space of a week or can you sleep very long at the end of two or three weeks and get back on track? There may be some insights from people with prolonged insomnia from substance use (cannabis, methamphetamine, opioids, alcohol) and how they recover.
George Dawson, MD, DFAPA
1: Åkerstedt T, Ghilotti F, Grotta A, Zhao H, Adami HO, Trolle-Lagerros Y, Bellocco R. Sleep duration and mortality - Does weekend sleep matter? J Sleep Res. 2018 May 22:e12712. doi: 10.1111/jsr.12712. [Epub ahead of print] PubMed PMID: 29790200.
Sleep duration on successive nights from the smartphone of a person who is off work on the 19th and the 24th and works 20-23 - showing total hours of sleep as 8.19, 5.15, 5.51, 5.45, 5.49, 8.17. This is a workday/weekend pattern described by the authors in the study.