Updated: Aug 10, 2021
By: W. Joseph Newman, MD June 2021
Eastern Nephrology Associates, New Bern North Carolina
The apocalypse for a chronic kidney disease (CKD) patient is dialysis. Just as in the Biblical accounting, four horsemen determine that fate for most CKD patients: obesity, diabetes, hypertension, and sleep apnea. I call them the Perfect Storm (PS)
Of the four, diabetes and hypertension have garnered the most nephrological attention in an effort to hold dialysis at bay. Yet, despite new medications for them, many of which are touted to be kidney protective, and when control is deemed optimal, CKD still advances seemingly continuously toward that apocalyptic day when dialysis needs to be started.
As a practicing nephrologist for 30 years, I have been dismayed by such progression and have asked myself why this should be. Years of study tell me the reason lies within the other two horsemen, obesity and sleep apnea (OSA). To learn more visit: https://www.sleepapnea.org/ or watch: https://youtu.be/yloiMLsUaU0
Obesity will be discussed in a later blog but suffice it to say that by obesity I’m really talking about is poor food & lifestyle choices that are replete with processed meats and animal proteins. Animal proteins are pro-inflammatory as well as acidic to blood vessels which puts kidneys in its sight whereas Plant-based proteins are anti-inflammatory and alkaline. All CKD patients should learn about such protein sources and employ them in the diet in lieu of animal protein.
In 2007 the World Health Organization (WHO) stated that 100 million people world-wide had OSA. Last year, the WHO reported that number to be 957 million, which means 1 in 8 people of the 8 billion people on the earth have OSA. Removing children from that equation means the ratio is closer to 1 in 4 to 5 adults on earth suffer from OSA. It is directly related to obesity and has become the most common lung disorder on earth. Yet, a meagre 5% of those with OSA have actually been diagnosed.
OSA is changing the face of clinical nephrology. To wit, I have coined the term, the “Perfect Storm”. Sleep apnea is quite simply the most under diagnosed & treated but most harmful entity I have seen in my 30 years of clinical practice. Recognition of this fact has not been embraced by most nephrologists, yet most of any new hospital or office referrals I see suffer along the spectrum of the PS, from early CKD to dialysis.
OSA has been termed “The Elephant in the Room”. Its onset is subtle and takes time, years, to develop. But once the elephant makes its presence known as pulmonary hypertension, OSA has already weakened a CKD patient’s right heart ventricle, where an apocalyptic countdown toward dialysis begins. Evidence suggests that 40-50% of CKD 3 patients have OSA, most of which is not being treated. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3558239/)
Although it has not been well studied in CKD stages 1 and 2, studies suggest a linear relationship reaching 80% prevalence in dialysis patients. (https://www.sciencedirect.com/science/article/pii/S0272638612012620?via%3Dihub )
Why does sleep apnea worsen CKD? There are several ways.
First, significant OSA implies less oxygen (apnea means “without breath”) delivery to all organs including the kidneys. To summarize, a very complex array of metabolic events occur, from which the kidneys become deprived of blood & oxygen by a vasoconstrictive effect which further diminishes kidney blood flow and kidney tissue starts to die. Therefore inadequate oxygen delivery advances CKD.
Second, as OSA’s effects on pulmonary hypertension increase over time, the right ventricle (RV) of the heart begins to fail, making fluid back up against the liver, and becomes evident as edema in the legs. The process changes blood volume distribution leading to yet another decrease in kidney blood flow. Again, the kidneys suffer.
The evidence has shown that just after 4 months of treatment of OSA has been shown to improve both right heart ventricular strain and pulmonary hypertension, thus implying improvement in kidney function.
CKD patients of any stage should be OSA tested especially if one awakens tired and has unexplained daytime fatigue, whether or not one snores. The sooner OSA is diagnosed and treated in a CKD patient, the greater the impact on CKD progression one could expect. The dreaded sleep lab experience may be avoided with new home tests which are insurance accepted. Here is an example of a home sleep testing device I have experience with to learn more: https://www.itamar-medical.com/patients/watchpat-home-sleep-testing/
…Realize that ~ 80% of existing dialysis patients have the PS and suffer from OSA.
…Realize that the PS, and OSA is largely controllable and or preventable.
…Realize that means the 80% may could have avoided dialysis.
My simple take home message? Heed the words of the famous philosopher “Smokey The Bear”, who said “…only you can prevent a forest fire”. You, the CKD patient, are the person in charge of your health. If you think you have sleep apnea or wish to be tested, please pursue with your medical team to get evaluated. Just Imagine... better sleep, energy, health and kidney function.
Please take or download this sleep apnea questionnaire (STOPBANG) to determine if you need to be evaluated for a sleep study and/or be treated for sleep apnea.
I welcome and encourage any comments or questions about this topic. Any and all questions/comments will be responded to promptly.