Sleep disorders are prevalent in the general U.S. adult population, and their impact on overall quality of life has been well-documented. In patients with kidney disease, sleep disorders are more frequent, which may increase both mortality and morbidity. Sleep disorders and kidney health have a complex bidirectional relationship that remains under investigated.
- Poor sleep has been associated with decreasing hormone regulation, increased levels of inflammation, and insulin resistance.
- More than 50% of end-stage renal disease (ESRD) patients have sleep apnea, with the reason for the increased rate of sleep-related issues multifactorial.
- Obstructive sleep apnea (OSA) and chronic kidney disease potentially have a bidirectional relationship.
Sleep and Kidney Function
Sleep plays an essential role in the functioning and good health of the body, such as the regulation of hormones, metabolism, thinking and memory (brain function), respiratory and immune systems, and the heart and circulatory systems.
Sleep is regulated by the circadian rhythm, a 24-hour internal clock in the brain that controls cycles of sleepiness and awakeness. This sleep-wake cycle regulates memory consolidation, metabolic functioning, and body healing. Poor sleep patterns and inadequate sleep may significantly impact essential daily body functions and increase the risk of chronic diseases.
Common sleeping difficulties that have been reported include, but are not limited to:
- Waking up frequently (more than once) during the night, with difficulty falling back to sleep
- Suffering from daytime sleepiness
- Routinely having difficulty falling asleep
- Waking up in the morning and not feeling rested
- Waking up earlier than you intended
- Being diagnosed with sleep apnea or snoring
Disruptors of sleep:
- Nutrient deficiencies. Some nutrients that are implicated in sleep disruptions include vitamin D, tryptophan, and magnesium and zinc deficiencies.
- Toxins. The sleep-wake cycle plays a vital role in the liver detoxification of medications and other toxins. Toxins such as PFAs (polyfluoroalkyl compounds), pesticides, arsenic, and phthalates have been specifically linked to sleep disturbances.
- Medications. Prescription medications, such as antidepressants, blood pressure, and asthma medications, are common causes of sleep disruptions. Additionally, many over-the-counter drugs for pain, allergies, weight loss, flu and colds contain stimulants that may disrupt sleep.
- Alcohol. While alcohol is a common “over-the-counter” sleep aid, studies show that sleep is disrupted during the second half of the sleep cycle.
- Biological factors. Multiple hormones (peptides and steroids) have been found to play an essential role in the sleep cycle. Stress is a well-known causative agent of poor sleep quality. Another biological factor negatively impacting sleep quality is genetics and its role in internal clocks.
There are over 80 different types of sleep disorders, with about 70 million adults in the U.S. suffering from at least one.
The most common type of sleep disorders include:
How sleep affects kidney function
Kidney function is regulated by the sleep-wake cycle, which helps manage the kidney’s workload over a 24-hour period. Under normal circumstances, the sleep-wake cycle regulates renal blood flow, glomerular filtration, sodium reabsorption, the renin-angiotensin system, and filtration fraction. The regulation of these kidney functions is vital to allow the kidney to respond to and anticipate any metabolic changes that occur through the 24-hour cycle.
Disrupted, short sleep durations and night shift work are directly and indirectly associated with risk factors for the development of chronic kidney diseases, such as hypertension, cardiovascular disease, and diabetes. Poor sleep also affects the regulation of the renin-angiotensin-aldosterone system (RAAS), which plays an essential role in the development and progression of CKD.
Obstructive sleep apnea (OSA) is another risk factor for developing kidney disease and is characterized by an obstruction of airflow to the lungs caused by a collapse in the airway. OSA is the most common form of sleep apnea, with 10-30% of the population estimated to suffer from it. Most people with OSA will experience symptoms such as daytime sleepiness and loud snoring. OSA is associated with causing increased oxidative stress and inflammation, which sometimes leads to kidney damage or an increased progression of CKD.
Chronic Kidney Disease and Sleep Disorders
Chronic kidney disease (CKD) is a risk factor for sleep disorders. As kidney function declines, the natural rhythms of the sleep-wake cycle can be disrupted, causing fragmented, short challenges in falling asleep. Common sleep disorders in CKD patients include sleep apnea, restless leg syndrome (RLS), excessive sleepiness, insomnia, and periodic limb movement (PLM).
Sleep disorders in CKD patients may be caused by underlying comorbidities (hypertension, cardiovascular disease, and diabetes), uremia, or mental health issues such as anxiety, depression, worry, stress, and sadness.
Although sleep disorders in CKD and ESRD patients are essential to uncover and cause a decrease in quality of life and mortality rate, they are often under-recognized and undertreated. Treating sleep disorders in CKD patient populations may improve both patient quality of life and survival.
Insomnia and poor sleep
Insomnia has frequently been reported in CKD and ESRD patients who are treated with CHD or CAPD. Insomnia is diagnosed by a healthcare professional based on a clinical assessment, with symptoms such as chronic difficulty falling and staying asleep or waking up too early with impaired daytime function.
Insomnia treatment options may include treating underlying medical conditions or prescribing medications to improve sleep-related symptoms.
Restless leg syndrome (RLS)
RLS typically occurs when the legs are at rest, while lying or sitting in bed or on a recliner couch for example. The sensations associated with RLS differ from patient to patient and can be itchy, painful, or irritating. These mild or intense sensations generally occur in the evening, making falling asleep difficult. Some people may find that moving their legs decreases RLS sensations.
Certain medications, caffeine, tobacco, alcohol, iron deficiency, genetics, and diabetes have all been linked to causing RLS. Treatment of RLS depends on the intensity of symptoms and if it is due to medical disorders such as CKD.
A study found that more than 50% of end-stage renal disease (ESRD) patients presented with sleep apnea. Sleep apnea is caused by both upper airway occlusion and destabilization of central ventilatory control during sleep. Symptoms present as interrupted or stopped breathing for more than 10 seconds while you are asleep.
CKD patients with sleep apnea may experience increased daytime fatigue and sleepiness and impaired brain or memory function. ESRD patients may experience increased heart complications.
ESRD patients with sleep apnea may experience nocturnal hypertension, increased cardiovascular complications and left ventricular hypertrophy.
Treatment options for sleep apnea include lifestyle modifications and the use of continuous positive airway pressure to help keep the upper airway open. Some ESRD patients may find night-time hemodialysis improves their sleep apnea and blood pressure control.
At Panoramic Health, we offer patients holistic and seamless CKD care coordination from a dedicated team of nephrologists and care experts. Our value-based care platform helps CKD patients slow disease progression, manage the full spectrum of their health, and experience a better quality of life.