We recently had our seasonal time change. Known as when Daylight Savings Time Ends. Fall back in November. Gain and hour! It took me a week before I gained my extra hour of sleep. I kept walking up at the same time every day that I normally would have. Meaning, if it is 8 am, I woke up at 7 am! Personally I don’t like the time change, fall or spring! In fact most Americans want to end seasonal time changes. Here in California, we voted to do away with it. It passed but we are still doing it! Why, I don’t know! It has known health implications that affect us due to this time change! As I start to write this is is 4pm. I know in 10 minutes the sun will begin to move and the room gets a little darker. At this time of year as the sun sinks it becomes like a shadow coming over. It will be mid-January before the light begins to change again.
“Evidence of the negative impacts of seasonal time changes continue to accumulate, and there is real momentum behind the push to end seasonal time changes,” said Dr. Kannan Ramar, president of the American Academy of Sleep Medicine (AASM), which favors a fixed, nationwide time.
A recent position statement from AASM said public health and safety would benefit if seasonal time changes were eliminated. It called for permanent use of standard time, which it said more closely aligns with the daily rhythms of the body’s internal clock.
AASM noted that time changes increase the risk of stroke, hospital admissions and sleep loss, and also add to inflammation, one of the body’s responses to stress. Researchers recently reported an 18% increase in adverse medical events due to human error in the week after switching to daylight saving time in the spring.
During the week after the spring time change a significant increase in daily total mortality of about 3% per day was observed. This was not the case during the week after the fall transition.
In Europe and many countries worldwide, a general scheme of daylight savings time (DST) has been implemented. On a night between Saturday and Sunday in spring clocks are set forward one hour to take advantage of the prolonged daylight with the main intention of saving energy. As the expectations for reduced net energy demand were finally not met. In 2018 the European Commission decided to discontinue DST regulation, opening the discussion on possible alternatives in member states. They expressed their preference for the implementation of a permanent standard time because of the negative impact of a lack of morning light for the circadian system and concomitant tiredness, impaired attention, and performance. However, there was a general agreement among us (AASM) on the assumption that ending the bi-annual transition might be of higher relevance than the decision between summer- and standard time.
Daylight Savings Time (DST) seems to interrupt our circadian rhythms. This implicates our cardiovascular health. The available evidence suggest the existence of an association between DST and a modest increase of occurrence of acute myocardial infarction. Especially in the first week after the spring shift. Possible mechanisms include sleep deprivation circadian misalignment and environmental conditions. The role of gender and individual preference in circadian rhythms will need further research.
Circadian rhythms, the most widely studied, are driven by either central or peripheral clocks. The central circadian clock (known and the ‘master clock’ is located within the brain known as the hypothalamus and accounts for approximately 20,000 neurons. Circadian clocks roughly consist of a set of proteins, capable of generating self-sustained positive and negative transcriptional feedback loops with a free-running period of approximately 24 hours. The central clock and the peripheral clocks can directly and indirectly influence numerous functions, including sleep/rest and locomotor activities, feeding and drinking behavior, core body temperature, endocrine activity, metabolism, autonomic and sympathetic activity. The circadian clock within cardiomyocytes directly regulates myocardial metabolic gene expression, most likely in anticipation of the sleep/wake and feeding/fasting cycle. thus, the results obtained on murine models (Murine models are studies done with mice and rats) show that the circadian clock within the cardiomyocytes allows for the rapid adaptation of the heart to the prolongation of fasting. Thus, a desynchronization of an organism with its environment, through circadian clock derangements, may also lead to the development of cardiovascular diseases.
Circadian clocks regulate metabolism in many systems and organs, including the heart, skeletal muscle, liver, and adipose tissue. In particular, the cardiomyocytes circadian clock is essential for the responsiveness of the heart to fatty acids. When the cell cannot face increased fatty acid availability due to its inability to adequately increase fatty acid utilization, an accumulation of detrimental intracellular long-chain fatty acid derivates occurs. this accumulation, occurring via multiple mechanisms, may affect the contractile function of the heart, as well as a series of other components, such as glucose intolerance, insulin resistance and insufficiency, dyslipidemia, and increased vascular resistance. Conversely, the circadian clock within the heart is altered in various animal models of human disease, including hypertension, diabetes, myocardial infarction, and simulated shift work.
Shift work, a circadian misalignment resulting from a 12 hour inversion of the behavioral cycle (including sleep/wake and fasting/feeding cycles), is a typical example of rhythm disruption. Shift workers are exposed to a misalignment of their behavioral and environmental cycles, which is a risk factor for hypertension, inflammation, and cardiovascular disease. It has been observed that compared with circadian alignment, circadian misalignment can (a) increase both systolic and diastolic blood pressure (BP); (b) decrease heart rate (HR) during wake periods and increase HR during sleep time; (c) reduce the sleep opportunity-associated dip in BP and HR; (d) affect the 24 hour urinary epinephrine and norepinephrine excretion rates; (e) decrease markers of cardiac vagal modulation; (f) increase inflammatory markers, particularly 24 hour interleukin-6 (IL-6), 24-h C-reactive protein (CRP), tumor necrosis factor (TNF)’ and (g) decrease plasminogen activator inhibitor-1 (PAI-1) levels. Taken together, all these effects can explain the increased prevalence of cardiovascular disease in night workers versus day workers.
A disruption in the circadian rhythm is your body’s natural 24-hour cycle. A disruption in this rhythm, like Daylight Saving, is typically environmental, not genetic. therefore, individuals can easily adjust behaviors that may cause issues, such as a poor sleep schedule. The rule of thumb is that for each hour of time change, it takes a day to adjust. So, if you get seven to eight hours of sleep and go to bed a little early the night before, you should wake feeling refreshed. However, if you already lack sleep and perhaps consume some caffeine or alcohol the night before, you might wake feeling sleep-deprived.
Your circadian rhythm is internal, but influence by environment, behavior and medications. Light is a principal environmental cue, and light suppresses the secretion of melatonin, a natural sleep-inducing substance. So it’s important to get plenty of light during your waking hours and not to expose yourself to bright light when it is dark outside.
Having a sleep-friendly environment will improve your chances of falling asleep, staying asleep and sleeping soundly. That means reducing or eliminating caffeine and alcohol, exercising (at least several hours before bedtime) and using relaxation techniques (a hot bath, ear plugs or a sleep mask) before bed.
