How do misaligned circadian rhythms affect the body?

How our bodies and brains process light and other time cues provides the foundation for our sleep-wake cycles. These cues keep our circadian rhythms properly aligned so that we sleep and awaken at the proper time (at least for some of us). However, the body houses circadian clocks that do more than promote sleep. These timekeepers may serve the main biological clock in the brain (known as the suprachiasmatic nucleus, or SCN), and this is due to the body's need to synchronize its various processes, like digestion, to match with our activity levels. When the SCN fails to keep the body's main rhythms entrained to the natural light-dark cycles of the planet, this can lead to imbalances across all the clocks in the body (and there are, actually, millions... even our cells have their own clocks). These imbalances can become a biological sandbox that helps create opportunities for diseases to emerge. Check out this broad sampling of our biological systems to see how circadian misalignment can lead to problems with chronic illness.

From the top down: Organ systems influenced by disrupted circadian rhythms

The impacts of circadian rhythms on biological systems is wide ranging.

Below is just a tiny sampling of the situations that occur when shifted rhythms result. These shifts can be caused by:

• a temporary act like changing the clocks
• working night shifts or odd hours
• medical conditions, including sleep disorders
• medications which may mess with one’s sleep-wake drive

Ultimately, frequent disruptions to one’s rhythms will lead to problems with chronic illness and a reduced quality of life. They should not be dismissed, but tended to, which may even mean actively working to reset these rhythms.

Nervous system

This includes all of the brain matter and nerves in the body as well as the spinal cord. The nervous system exists as a two-way communicator between the brain and the body.

♦ ALZHEIMER’S DISEASE

MAR 13, 2015 || Experimental & Molecular Medicine
Sleep, circadian rhythms, and the pathogenesis of Alzheimer Disease

♦ AUTISM

MAR 10 || Our Crazy Adventures in AutismLand
Surviving the Daylight Savings Time Change with Autism

♦ EPILEPSY

APR 30, 2016 || Sleep Science via Science Direct
The relationship between epilepsy, sleep disorders, and attention deficit hyperactivity disorder (ADHD) in children: A review of the literature

♦ HEADACHE

MAR 14 || Neurology
Chronobiology differs between men and women with cluster headache, clinical phenotype does not (abstract)

♦ HUNTINGTON’S DISEASE

OCT 7, 2014 || HDBuzz
Melatonin alterations in Huntington’s disease help explain trouble with sleep

MAR 25, 2013 || HDBuzz
Simple rules for a good night’s sleep in Huntington’s disease

FEB 6, 2013 || HDBuzz
Why do many Huntington’s disease patients have trouble sleeping, and what can be done about it?

♦ MENTAL AND EMOTIONAL HEALTH & MOOD DISORDERS

JAN 25 || SLEEP
Prevalence of Circadian Misalignment and Its Association With Depressive Symptoms in Delayed Sleep Phase Disorder

DEC 4, 2016 || Quartz
Pulling an all-nighter could be a temporary fix for depression

APR 13, 2013 || Psychology Today
When The Brain’s Biological Clock Goes Haywire

♦ PARKINSONISM

MAR 16 || Medical News Bulletin
To Go to Sleep, Parkinson’s Patients May Need to Turn the Light On

SEPT 13, 2016 || NIUME: Science
Blue Glasses and Dyskinesia Control in Parkinson’s Disease?

♦ TRAUMATIC BRAIN INJURY

FEB 20 || Monash University
Sleep and circadian rhythm disturbances following traumatic brain injury: the treatment and efficacy of melatonin supplementation

Circulatory system

This includes the heart and all of the blood vessels which transport blood to every part of the body.

♦ HYPERTENSION

DEC 12, 2016 || Knowridge Science Report
With a broken circadian clock, even a low-salt diet can raise blood pressure and promote disease

♦ STROKE

FEB 29, 2016 || MedicineNet
Daylight Saving Time Tied to Brief Spike in Stroke Risk

Respiratory system

This includes the lungs and airways which facilitate breathing, which is an important function because it allows for the critical exchange of oxygen for carbon dioxide.

OCT 25, 2016 || Sleep Review
Blast of Thin Air Can Reset Circadian Clocks

Immune system

This includes the gut microbiome and all the factors residing in the bloodstream and tissues which work to heal and repair damage and respond to viruses, bacteria, and other unwelcomed microorganisms in the body.

♦ CROHN’S DISEASE

MAY 21, 2014 || PLOS One
Circadian Disorganization Alters Intestinal Microbiota

♦ IMMUNE SYSTEM DYSFUNCTION

MAR 2 || Mastopedia
Circadian Clocks and Immune Functions (abstract)

FEB 27 || Clinical Reviews in Allergy & Immunology
Air Travel, Circadian Rhythms/Hormones, and Autoimmunity (abstract)

♦ MULTIPLE SCLEROSIS

FEB 13, 2013 || Journal of Research in Medical Sciences
Circadian rhythm sleep disorders in patients with multiple sclerosis and its association with fatigue: A case-control study

♦ PREECLAMPSIA

JUN 7, 2014 || Renal Failure
Melatonin secretion is impaired in women with preeclampsia and an abnormal circadian blood pressure rhythm (abstract)

♦ PSORIASIS

MAR 17 || The British Journal of Dermatology
A cross-sectional survey of the nature and correlates of sleep disturbance in people with psoriasis

♦ RHEUMATOID ARTHRITIS

AUG 3, 2016 || FASEB Journal
The circadian clock regulates inflammatory arthritis

Endocrine system

This system helps the body to keep blood chemistry in balance as well as to facilitate metabolism.

♦ DIABETES
(PSSST! Don’t miss our article from March 9, “Survival tips for diabetics during the transition to daylight saving time“)

MAR 13 || Diabetes.co.uk
Men with prediabetes are more carbohydrate sensitive in the evening, study finds

JAN 2 || EndocrineWeb
Circadian Rhythm Disruptions May Alter Sleep, Propelling Some People Towards Diabetes

AUG 3, 2016 || Sound Sleep Health
People with sleep apnea: Are you diabetic?

♦ LIVER FUNCTION

JAN 21 || WRVO Public Media
Liver health impacted by circadian clock

OCT 28, 2016 || Chronoceuticals
Circadian clock in the liver found to regulate hunger and metabolism

♦ OBESITY

MAR 15 || The JAMA Network
Resetting the Circadian Clock Might Boost Metabolic Health

NOV 43, 2016 || Newswise
A Functioning Circadian Clock May Help Maximize Weight Loss Following Bariatric Surgery

DEC 13, 2016 || Sound Sleep Health
When sleep loss leads to weight gain

Digestive and excretory systems

This includes everything from the mouth to the rectum which is involved in the ingesting of substances (food, water, medications). The esophagus, stomach, and bowel are major players. These are processed through a complex system which draws out nutrients and expels the remainder.

MAR 13 || Very Well
Why IBD Affects Your Sleep

JUL 12, 2016 || CHEST
GERD and sleep disorders often go hand in glove

APR 20, 2016 || Sound Sleep Health
Peristalsis and Sleep: How both work in tandem with circadian rhythms

APR 14, 2016 || Sound Sleep Health
Food and Sleep: What and when we eat matters to the body clock

Urinary system

This part of the body serves to excrete wastes and excessive fluids via the bladder.

MAR 4 || SleepApnea.org
Research: Sleep problems impact kidney health

APR 22, 2016 || Chronobiology
How the Circadian Rhythm of Your Kidneys Affects You

APR 22, 2016 || Investigative and Clinical Urology
Nocturia: The circadian voiding disorder

Reproductive system

This includes male and female sex organs and fertility processes.

MAR 10 || Chronobiology
Spring Forward Found to Affect IVF Success Rates

MAR 10 || Fertility Tips
Daylight Saving Time and Its Impact on Miscarriage Rates

FEB 24 || Men’s Journal
How Poor Sleep Affects Your Sex Drive

NOV 21, 2016 || PLOS One
Sleep Duration, Exercise, Shift Work and Polycystic Ovarian Syndrome-Related Outcomes in a Healthy Population: A Cross-Sectional Study

NOV 20, 2016 || Latin Post
Inadequate or excessive sleeping may cause men to reduce chances of impregnating their partners, study finds

Cancer

Cancer can strike any system in the body, so it is included here because of its unique relationship to chronotherapy and circadian regulation.

FEB 14 || Knowridge Science Report
Is hormone melatonin the link between sleep and breast cancer?

JAN 22 || iTech Post
Sleep Problems And Cancer May Be Lessened By Turning Lights Off

DEC 21, 2016 || Sleep Review
How Circadian Clocks May Influence Cancer Pathway

NOV 30, 2016 || Sleep Review
Jet Lag, Obesity Share Similar Pathways to Liver Cancer

NOV 17, 2016 || Reuters
Walking may improve the sleep of lung cancer patients

If, during the recent clock change to Daylight Saving Time, you wondered whether you might need to be paying more attention to your own biological rhythms, ask yourself this: What would your organs want you to do? What happens if you don’t reset your rhythms? Therein lies your answer.

Should you wish to reset your rhythms, there are many options, including the relatively painless experience known as camping, cognitive behavioral therapy, sleep restriction therapy, and more. Or you could jump on the bandwagon and try to push for the end of the fall and spring time changes.