SLEEP: How it affects Kidneys?
On average, any individual spends 25%-30% of one’s life sleeping, that itself is the evidence of how indispensable and significant sleep is for everyone.
Studies say that lack of sleep or poor quality sleep has an impact on blood pressure, obesity or weight gain, blood sugars, mental stress etc.
Chronic Kidney disease progresses 2 fold faster towards dialysis requiring stage, in those who sleep </=5 hours or 1.5 times faster in those who sleep more than 8 hours.
Many a time an individual sleeps for 6-7 hours but doesn’t wake up fresh and rejuvenated.This could be due to the poor quality of sleep. Based on the depth of Sleep, there are 4 stages of sleep and 2 types of sleep( NREM and REM). If there is appropriate time spent in these stages then one feels properly relaxed otherwise one may sleep but still not experience sleepiness or fatigue during the day time.
What are the causes of poor sleep?
The common reasons for poor quality of sleep apart from the external circumstances or mental stress, are Obesity & Chronic Kidney disease. Obesity and CKD are commonly associated with Obstructive sleep apnea which means when we sleep the airway is partly collapsed causing loud snoring and as the depth of sleep increases, the airway passage becomes narrower to the point that blood oxygen levels drop to dangerous levels, arousing the brain to lighter levels of sleep so that the muscle tone in the airways is restored and oxygen levels improve. This cycle of the drop in oxygen levels, bringing the sleep to lighter level goes on throughout the sleep and a person wakes up less relaxed despite of having slept adequate hours. This causes excessive day time sleepiness and fatigue. It also affects one’s blood pressure and hence the protective physiological dip in BP of 10-15% that should happen when we sleep doesn’t happen and that is an additional and independent risk factor for heart attacks/stroke/progression of Kidney disease.
How do I know I have OSA(Obstructive sleep apnea)/CSA( Central sleep apnea)?
This obstructive sleep apnea can be assessed by a Sleep study. Sleep study tells us how much time we spend in which stage of sleep and whether that is adequate or not. It also tells us whether the individual has OSA/CSA. Many centers in the city offer this test. Pulmonologists generally perform this test and advise regarding the management.
What if I have OSA?
It is correctable. First and foremost requirement is to lose weight if you are obese. For those with CKD, most important is to lose that extra weight accumulated due to fluid retention in the body. If these measures don’t help then , one needs to sleep with a devise fit over the face. This device is called a CPAP machine. CPAP means continuous positive airway pressure. The device keeps a positive airway pressure, preventing the airway to collapse while sleeping and thus maintains appropriate oxygen levels throughout the sleep.
Conclusion:
Good quality 6-7 hours of sleep is essential for retarding the progression of Kidney disease and preventing heart attacks and stroke. ABPM ambulatory blood pressure monitoring can suggest whether our night time average blood pressure is dipping by 10-15% as compared to the day time average. A sleep study can help us in understanding the sleep quality of an individual. Losing weight and avoiding fluid overload can help reduce OSA.CPAP can help those who have significant OSA affecting their quality of sleep and consequentially their kidney and heart health.