From the Guidelines
Circadian rhythm disturbances have a profound impact on overall health, leading to severe inflammatory conditions, endothelial dysfunction, blood pressure increases, and altered insulin signaling, ultimately affecting the risk of diabetes, heart disease, and other diseases.
Effects on Health
The effects of circadian rhythm disturbances on health are multifaceted, including:
- Inflammatory conditions: Sleep deprivation causes changes similar to those triggered by circadian rhythm dysregulation, leading to severe inflammatory conditions 1.
- Endothelial dysfunction and blood pressure increases: Circadian rhythm dysregulation can cause endothelial dysfunction, blood pressure increases, structural vascular changes, vascular senescence, and recruitment of immune cells in mice 1.
- Altered insulin signaling: The association between disrupted circadian rhythm and altered insulin signaling is supported by human data on the adverse effects of sleep restriction on insulin sensitivity and the risk of diabetes 1.
- Impact on glucose response: The glucose response to meals depends on circadian phase, with implications for metabolism and diabetes management 1.
Mechanisms
The circadian clock system regulates and controls various fundamental processes, including:
- Inflammation: The circadian clock system regulates inflammation via the NF-κB pathway 1.
- DNA repair and antioxidant defense: The circadian clock system regulates DNA repair proteins and antioxidant defense 1.
- Stress hormone levels and endocrine factors: The circadian clock system affects stress hormone levels and other endocrine factors 1.
Clinical Implications
Understanding the effects of circadian rhythm disturbances on health is crucial for the diagnosis, treatment, and monitoring of individuals with various disorders, including:
- Diabetes: The management of diabetes can be impacted by circadian rhythm disturbances, with meal timing relative to the circadian clock influencing blood glucose levels 1.
- Asthma: The worsening of asthma at night may be due to the endogenous circadian rhythm, behavioral/environmental influences, or a combination of both 1.
- Other diseases: Circadian rhythm disturbances can affect the risk of heart disease, cancer, neurodegenerative diseases, and other diseases 1.
From the Research
Effects of Circadian Rhythm Disturbances on Health
The effects of circadian rhythm disturbances on overall health are numerous and can have significant consequences. Some of the key effects include:
- Adverse health outcomes associated with later sleep timing and greater sleep variability 2
- Increased risk of metabolic syndrome, type II diabetes, gastrointestinal dysfunction, compromised immune function, cardiovascular disease, and certain types of cancer 3
- Cognitive impairment, metabolic syndrome, and psychiatric illness, including depression 4
- Disturbances in the 24-hour sleep-wake cycle and the underlying circadian system, which can contribute to the development of depressive disorders in young people 5
- Bidirectional relationship between circadian disruption and human health, with changes in circadian amplitude often preceding the classical symptoms of neurodegenerative disorders 6
Health Outcomes Associated with Circadian Rhythm Disturbances
Some of the specific health outcomes associated with circadian rhythm disturbances include:
- Metabolic health: obesity, metabolic syndrome, type II diabetes 3
- Cancer risk: increased risk of certain types of cancer 3
- Cardiovascular health: cardiovascular disease, excessive sleepiness 3
- Mental health: mood and social disorders, depression 3, 5
- Sleep health: sleep deficiency, sympathovagal and hormonal imbalance, inflammation, impaired glucose metabolism 3
Mechanisms Underlying the Effects of Circadian Rhythm Disturbances
The mechanisms underlying the effects of circadian rhythm disturbances on health are complex and involve:
- Disruption of the body's natural circadian rhythms, leading to changes in sleep-wake cycles, hormone secretion, and other physiological processes 2, 3, 4
- Interactions between biological disturbances and behavioral and societal factors, shaping the effects of shift work on health and well-being 3
- Genetic mutations in clock-controlled genes, which can contribute to the development of sleep, mental health, and metabolic disorders 4