(RxWiki News) Diabetes is a major risk factor for kidney disease. It can damage tiny blood vessels in the kidneys that filter waste from the blood. Add sleep apnea to the mix, and kidneys may decline even faster, new research suggests.
The two leading causes of kidney failure are type 2 diabetes and high blood pressure, according to the National Kidney Foundation. Diabetes patients also face a greater risk of having obstructive sleep apnea — the most common form of sleep disordered breathing.
A new study found that diabetes patients who had sleep apnea lost kidney function more rapidly than those who did not have the sleep disorder.
Roberto Pisoni, MD, from the Medical University of South Carolina in Charleston, and colleagues reviewed data on 56 patients with diabetes and chronic kidney disease. Kidney disease or kidney damage that occurs in diabetes patients is called diabetic nephropathy.
The patients completed a survey with questions that could indicate whether they also had obstructive sleep apnea.
Based on the survey answers, Dr. Pisoni and team found that 61 percent of the patients had a high-risk score for obstructive sleep apnea. They had a much greater loss of kidney function than those with a low-risk apnea score.
Obstructive sleep apnea causes breathing to stop repeatedly during sleep. With this condition, muscles in the throat relax during sleep and tissues block the airway. Past research has found that obesity can worsen sleep apnea.
Sleep apnea is thought to contribute to high blood pressure, hypoxia (depriving a region of the body of oxygen) and inflammation — all factors that may contribute to kidney disease.
Dr. Pisoni and colleagues measured kidney damage by loss of estimated glomerular filtration rate (eGFR). This is a test used to check how well the kidneys are working. It measures the amount of blood that passes through the glomeruli in one minute. Glomeruli in the kidneys filter waste from the blood.
“This study shows that a high-risk score for obstructive sleep apnea is common in [chronic kidney disease] patients with diabetic nephropathy and is associated with more rapid loss of [kidney] function,” the authors wrote. “This simple approach identifies patients at higher risk of [chronic kidney disease] progression."
Almost 18 million people in the US have confirmed diabetes, reports the Centers for Disease Control and Prevention. An estimated 5.7 million have the condition but are undiagnosed.
Type 2 diabetes is a disease in which the body becomes increasingly resistant to insulin. Insulin helps cells use blood sugar. With type 1 diabetes, the body does not produce insulin.
This study was presented Nov. 14 at the American Society of Nephrology Kidney Week 2014 in Philadelphia. Research presented at conferences has not necessarily been peer-reviewed.
The authors disclosed no funding sources or conflicts of interest.