Findings from a new study suggest that a misalignment of sleep timing is associated with metabolic risk factors that predispose to diabetes and atherosclerotic cardiovascular disease . The study asked participants to sleep 12 hours out of time with their normal sleep-wake routine. It mimicked a phenomenon known as “Social Jet Lag” where work schedules or other environmental factors interrupt the person’s biological circadian rhythm.
The results are a cautionary tale, not only for shift workers or those who class themselves as night owls rather than early risers, but for those who like to splurge on weekend sleep-ins only to struggle through to the world of routine again on Monday.
Looking first at the ‘morning person’ vs. ‘evening person’ chronotypes, the study reinforced old literature that advised the following: “Relative to morning types, evening types prefer later bedtimes and later awakening. Evening types are also more likely to be depressed, overweight, diabetic, and hypertensive, in comparison to morning types.” Don’t panic yet though: the degree to which chronotype-tendencies are associated with preclinical endocrine, metabolic, and hemodynamic alterations among otherwise healthy adults is yet to be thoroughly explored.
The second group can be harder to manage – the shift workers. These people are often the hard-working, life-saving faces we see in occupations like nursing, paramedics, the police force and others. Yet the clash between their body clocks and the socially-imposed schedules is potentially sabotaging their health, according to the study.
“The participants who showed a greater difference in their sleep schedules on work days compared to days off were more likely to have a larger waist circumference, higher body mass index, higher fasting insulin levels and poorer cholesterol profiles. Almost 85% had a later halfway point in their sleep cycle — a measurement known as “mid-sleep” — on their free days compared to when they had to work .
There are numerous concerns in this piece of research. Insulin resistance alone has a raft of issues that may be associated with it. But the tricky question is – what can one do about it if you are a shift worker or a natural night owl, the latter being something heavily impacted by genetics? The good news is that genetics doesn’t determine everything. You can intervene. It just takes dedication and commitment. Here are some tips:
- Change career? Okay this is a big one, and not everyone can change career. If you are a shift worker, then there may be precious few ways to get yourself out of ‘social jet lag’ mode and into ‘master of my own circadian rhythm’ mode. But that’s not to say that healthy lifestyles, including diet and exercise, can’t undo some of the damage done by social jetlag.
- Start gradually and commit to change. If you usually go to bed at midnight, a sudden jump to 9 pm is going to confuse your body clock and get you frustrated after hours of staring at the ceiling. Try moving your routine forward gradually. But stick to it .
- Refine your routine, and make sure it involves cutting down technology an hour before shuteye. Routine has the power to tell your brain that it’s time to wake up, or to signal to your brain that it’s time to wind-down and sleep. Some experts suggest that keeping your mornings bright and your evenings dark is a good way to keep the brain clued in to what’s going on . Exercising or stretching may help you wake up in the morning, just like a warm bath or calming music may help you relax and get ready for sleep in the evenings. Find what works for you and stick to it.
Word to the wise though: all of your good work relaxing before bed can be undone by spending time on your phone or computer prior to sleep. The electromagnetic stimulation and flood of light to the face can confuse your brain and body clock .
- Ditch the stimulants. This is a warning you’ve probably heard before, and if you’re dependant on your afternoon brew to get you through the 3pm slump, you won’t like it either. Ditch the afternoon coffee, especially after 3pm.“Caffeine begins to affect your body very quickly. It reaches a peak level in your blood within 30 to 60 minutes. It has a half-life of 3 to 5 hours. The half-life is the time it takes for your body to eliminate half of the drug. The remaining caffeine can stay in your body for a long time. Effects can last from 8 to 14 hours .”
- Get up when your alarm says to get up – and make it say the same time every day. This helps reinforce your new sleep routine and keep it on track. It’s best you skip the snooze button too . After all, sleeping through the snooze button isn’t adding much to your life in the way of good restorative sleep.
- Skip the weekend sleep-ins. Once you have found a good routine, stick to it! Sleeping all day on a Saturday may be tempting if you’ve had a big week, but you’ll be imposing social jetlag on yourself the next week when your work-imposed schedule resumes. Yes, it’s tempting to snuggle further inside the blankets and stay there. But now we know just how social jetlag may impact health, it could be time to think of other ways to recharge on the weekends.
Note: This is not an exhaustive list of sleep hygiene and body clock tips. This is only a brief summary of some information available.
 Wong, P, Hasler, B, Kamarck, T, Muldoon, M and Manuck, S (2015), “Social Jetlag, Chronotype and Cardiometabolic Risk,” Journal of Clinical Endocrinology and Metabolism
Boscamp, E (2015), “What Sleeping In On The Weekends Could Be Doing To Your Body,” Mind Body Green
 Graffagna, S (2014) “Thirteen Steps to Becoming a Morning Person,” Superhero You
 Watson, S and Ratini, M (2015), “How to Reset Your Sleep Cycle,” Web MD
 Heffron, T (2013), “Sleep and Caffeine,” American Academy of Sleep Medicine