Archive for the 'Circadian Rhythms' Category

Old people are known to be lousy sleepers, but a new study suggests it might all be in their heads, at least for many of them.

Medications, poor health, bad bedtime habits (such as watching a movie or drinking coffee or booze), circadian rhythms, and too much or too little in their personal “sleep bank” have all taken the blame for seniors’ common complaints of insomnia.

Elizabeth Klerman of Brigham and Women’s Hospital and the Harvard Medical School set out to clear it up once and for all with a controlled study of 18 subjects ages 60 to 76 and 35 younger subjects, ages 18 to 32, all healthy and not on medication that might affect sleep.

Even people who had crossed more than one time zone in the past 3 months were disqualified, as well as those who had worked night or rotating shifts in the past three years.

After monitoring their sleep at home, the subjects were regularly instructed to lie quietly with their eyes closed and to try to sleep, for as much as 16 hours daily for several days in a row. They had all the time in the world.

Growing evidence indicates that exposure to irregular patterns of light and darkness can cause the human circadian system to fall out of synchrony with the 24-hour solar day, negatively affecting human health - but scientists have been unable to effectively study the relationship between circadian disruptions and human maladies.

A study by researchers in Rensselaer Polytechnic Institute’s Lighting Research Center (LRC) provides a new framework for studying the effects of circadian disruption on breast cancer, obesity [Effects of Obesity], sleep disorders, and other health problems.

Light and dark patterns are the major synchronizer of circadian rhythms - the biological cycles that repeat approximately every 24 hours - to the solar day.

Inadequate or irregular light exposure can cause circadian rhythm disruptions that are believed to manifest into a variety of health ailments.

However, ecological studies to measure human light exposure are virtually nonexistent, making it difficult to determine if, in fact, light-induced circadian disruption directly affects human health.

LRC researchers have created a small, head-mounted device to measure an individual’s daily rest and activity patterns, as well as exposure to circadian light - short-wavelength light, particularly natural light from the blue sky, that stimulates the circadian system.

Your endocrine, immune and nervous system difficulties work together to affect one of the less measurable causes of bipolar disorders.

Bipolar disorder is disturbances in body rhythms. Your nervous system with bipolar disorder frequently makes specific types of regulatory errors.

Many of them involve body’s internal clock, which controls the phenomena called as circadian rhythm.

Circadian rhythms are the regular rhythmic changes in waking and sleeping. The chemical clock that governs these rhythms is located in a part of the hypothalamus gland called the suprachiamatic nucleus.

It regulates the pineal gland’s secretion of the hormone melatonin. Hypothalamus is the link between nervous and endocrine systems.

Nervous system is associated with immune system and hypothalamus exerts it effect on the immune system. The combination of these systems can alter your body chemistry, contributing to shifts in body rhythms such as circadian, social and seasonal rhythms.

Circadian rhythm is a 24 hour cycle of the body. When circadian rhythm is upset, mood disturbances can result. In some people sleep deprivation causes mania and in some it can alleviate depression.

For maintaining mental health, regulation of circadian rhythm is important. If the system is not regulated, it can lead to stress.

Following are the tips to prevent circadian rhythm sleep disorder:

1. Exercise increases the amplitude of daily rhythms and tells the body to endorse deeper sleep cycles to help refill the muscle tissues from daily physical exertion. Aerobic and anaerobic exercise seems to work as well. But exercise too close to bedtime can disrupt the sleep cycle. The best time to exercise is 4 - 6 hours before bedtime.
2. Napping during the day can harm a good sleep rhythm and keep you from enjoying a full sleep at night. If you suffer from insomnia, the best thing to do is don’t nap during the day.
3. Maintain a regular routine. Getting up and going to bed around the same time, even on holidays, is the most important thing you can do to establish good sleep habits. By following the regular time schedule, the circadian rhythm will not be disturbed.
4. If you don’t get very bright light in the morning, your body clock perhaps will not work in a right way. If you don’t get dark signals in the evening and keep your room bright, your body clock won’t produce a full amount of sleep hormones at night.

Circadian rhythm refers to the inner body clock.

Your circadian rhythm is in charge of coordinating your daily sleep-wake cycle.

Your body in fact has hundreds of circadian rhythms.

Your circadian rhythm operates on a 24-hour cycle.

To set your circadian rhythm each day your brain relies on outside influences such as daylight. To set our internal body clocks our bodies depend on these external cues.

Our sleep and wake patterns, body temperature, hormones, performance, moods, digestion, and other bodily functions are all genetically programmed to take place at certain times.

As a result, certain universal rules apply. For example, body temperature is at its highest at around 5 P.M. and then starts to drop.

Alertness and performance follow the same pattern. For someone working through the night, when psycho-motor functions are crucial, the importance of being fully awake is obvious.

Taxi drivers, pilots, machinery operators, medical staff, police, and power station workers all need to be vigilant around this time.

Any time that your circadian rhythm becomes interrupted for instance, if you experience several nights of sleep deprivation - your circadian rhythm is thrown out of sync.