New data presented last week at the American Society of Nephrology’s Kidney Week confirms a suspicion that sleep apnea seems to have a marked impact on the progress of kidney disease. Researchers looked at the results of sleep apnea screening questionnaires given to 56 patients who had both diabetes and chronic kidney disease (CKD). They found that 61% of patients had a high score (increased likelihood of sleep apnea), and that those with a high score had significantly worse kidney function than those that had a low risk of sleep apnea. Although this study relies on the use of a screening tool and not an actual sleep test, it reminds us that there is likely a strong association between sleep apnea and kidney disease.
The only trouble is: we’re not sure how strong the association is and whether there’s an actual causal effect.
Diabetes, Sleep Apnea, and Kidney Disease
Kidney disease is common complication of diabetes.
The function of the kidneys is to separate useful material in the blood from waste. To accomplish this, the kidneys have numerous tiny blood vessels that have tiny holes in them. Broken and small molecules fit through the holes and enter the urine. Larger molecules, like proteins, can’t fit and are kept in the blood. Kidney disease is when these filters start to break and let larger molecules through. Uncontrolled blood sugar levels cause the body to send more blood through the kidneys, which causes them to wear out faster.
Most currently believe that sleep apnea contributes to kidney failure through high blood pressure. Since sleep apnea leads to chronic elevated blood pressure that is hard to control, it causes the blood to hit up against the filters in the kidneys with more force, causing them to break down faster.
A Direct Link?
Although it is currently believed that the link between sleep apnea and kidney disease is mediated primarily through elevated blood pressure, it’s possible that there is a more direct link. Although at this point it’s impossible to do more than speculate about the possible connection, it is known that sleep apnea worsens outcomes for people with kidney disease, and the sooner it is treated, the more effective treatment can be at preventing problems such as kidney disease.
If you are a diabetic, you should be tested for sleep apnea, even if you are not overweight. For more information about testing or treatment for sleep apnea, please call (402) 493-4175 for an appointment with an Omaha sleep dentist at the Advanced Dental Sleep Treatment Center.