By Don Rauf
Loud, ongoing snoring may not only be annoying; it also could be a sign of sleep apnea. In diabetes patients, the condition may lead to many health problems, including complete kidney failure.
Some people with diabetes develop a condition called diabetic nephropathy, or kidney damage caused by their diabetes. More protein than usual collects in the urine, and over time, the condition may destroy kidneys to a point where they can no longer function.
Diabetes patients are also more likely to have obstructive sleep apnea, a sleep disorder that causes breathing to stop (for seconds or minutes) or become shallow.
Scientists have recently discovered that patients with type 2 diabetes who have sleep apnea may be more likely to have diabetic nephropathy than diabetes patients without sleep apnea.
For this study, Abd Tahrani, PhD, with the Centre of Endocrinology, Diabetes and Metabolism at the University of Birmingham and Department of Diabetes and Endocrinology at Heart of England National Health Service Foundation Trust in the United Kingdom, and colleagues followed 224 patients with type 2 diabetes.
The prevalence of obstructive sleep apnea was noted in 144 of the patients, and 90 of them had diabetic nephropathy. Patients with sleep apnea tended to be older and overweight. They usually had higher blood pressure and typically had diabetes for a longer duration than others in the study.
Diabetic nephropathy was more often found in patients with sleep apnea than in those without. About 49 percent of individuals with sleep apnea had diabetic nephropathy, compared with 24 percent of those who did not have sleep apnea.
Obstructive sleep apnea increases oxidative stress. As people breathe in oxygen and their cells produce energy, molecules called free radicals are created. The radicals place oxidative stress on cells.
Oxidative stress damages healthy cells, and for diabetes patients with OSA, the higher level of oxidative stress appears to contribute to kidney damage, according to the authors of this study.
Diabetic neuropathy is the leading cause of end-stage renal (kidney) disease. In this investigation, renal function was assessed by eGFR (estimated glomerular filtration rate), which is a measure of how well the kidneys are removing wastes and excess fluid from the blood.
The researchers found that the eGFR declined faster in patients with sleep apnea and type 2 diabetes than in those with type 2 diabetes alone.
“We demonstrated a robust association between obstructive sleep apnea and diabetic nephropathy,” wrote the authors. “This study could form the basis for interventional studies to examine the impact of obstructive sleep apnea treatment on the development and progression of diabetic nephropathy in patients with type 2 diabetes.”
The American Academy of Sleep Medicine (AASM) advises anyone with type 2 diabetes or hypertension to be evaluated for sleep apnea.
This study was published online September 23 in Diabetes Care. This project was funded by the National Institute for Health Research (UK), the UK Novo Nordisk Research Foundation and Sanofi.
Related on HuffPost:
Sleep Apnea Increases Risk Of Heart Attack
The sleep disorder has a number of poor effects on the heart. "It's as if somebody's choking you, so your heart rate goes up, your blood pressure goes up," Charles Czeisler, M.D., the Baldino Professor of Sleep Medicine at Harvard Medical School told <em>Health</em> magazine. "Over time, even your daytime blood pressure is higher." Sleep apnea may be responsible for a third of all cases of <a href="http://www.huffingtonpost.com/2012/03/14/sleep-health_n_1310353.html">high blood pressure</a> in Americans, he told the magazine. A 2007 study showed just how serious these cardiovascular effects of sleep apnea are. The research found that people with sleep apnea were <a href="http://www.sciencedaily.com/releases/2007/05/070520183533.htm">30 percent more likely to have a heart attack</a> or die of any cause over a four to five year period.
Sleep Apnea May Increase Depression Risk
The under diagnosed sleep condition takes a <a href="http://www.huffingtonpost.com/2012/03/30/sleep-apnea-depression-risk_n_1391707.html">serious toll on the mood</a>, according to March research from the CDC. In fact, men with sleep apnea were more than twice as likely and women more than five times as likely to feel hopeless, lose interest in their regular activites and display other signs of clinical depression, Health.com reported. Snoring did not seem to be associated with depression. Luckily, the very same <a href="http://www.huffingtonpost.com/2012/06/15/sleep-apnea-treatment-depression-cpap_n_1597703.html">treatment for sleep apnea may also ease depression</a>, according to Cleveland Clinic research.
Sleep Apnea May Be A Risk Factor For Diabetes
There is a growing body of research supporting a link between the presence of sleep apnea and <a href="http://www.huffingtonpost.com/2012/05/24/sleep-apnea-diabetes-type-2-_n_1539933.html">metabolic disorders like diabetes</a>, HuffPost reported in May. Both moderate and severe obstructive sleep apnea were found to be predictors of the disease. A previous study found that people with sleep apnea had more than <a href="http://news.yale.edu/2007/05/24/sleep-apnea-increases-risk-heart-attack-and-diabetes">double the risk of developing diabetes</a>.
Sleep Apnea May Increase Cancer Risk
Not only do people with sleep apnea have a <a href="http://well.blogs.nytimes.com/2012/05/20/sleep-apnea-tied-to-increased-cancer-risk/">higher risk of developing cancer</a>, but they also have a higher risk of dying from the disease, the <em>New York Times</em> reported. Two studies in May examined this link. One found people with sleep apnea had a 65 percent higher change of developing any kind of cancer. The second found that disordered breathing contributed to a five-times higher rate of dying from the disease.
Sleep Apnea May Sap Your Libido
Excessive sleepiness is certainly enough to kill the mood, but research suggests that sleep apnea in particular has an effect on sexual function in both men and women. It may <a href="http://well.blogs.nytimes.com/2011/10/10/really-the-claim-sleep-apnea-causes-sexual-problems/">drive down sex hormones</a> like testosterone in a way that can extinguish the flame for women and cause erectile dysfunction in men, according to the <em>New York Times</em>. And while the typical treatment -- a CPAP machine -- is not exactly an aphrodisiac, Dr. Michael J. Breus writes, it can help not only with sleep apnea, but <a href="http://www.huffingtonpost.com/dr-michael-j-breus/sleep-apnea_b_1661687.html">with the sexual side effects as well</a>.
Sleep Apnea May Increase Stroke Risk
Researchers have long studied the link between the sleep disorder and the risk of stroke, but a small recent study found that 51 of 56 stroke patients evaluated -- or <a href="http://www.huffingtonpost.com/dr-michael-j-breus/sleep-apnea_b_1342311.html">91 percent of patients</a> -- had sleep apnea, Dr. Michael J. Breus wrote for HuffPost. More research is still needed to determine just what role disrupted breathing plays in this elevated risk.
Sleep Apnea Increases Accident Risk
It's not rocket science -- excessive sleepiness during the day leads to sleepier drivers who are at a higher risk of crashing. But a 2008 study found that people with sleep apnea have double the risk of being in a car accident and are <a href="http://www.sciencedaily.com/releases/2008/02/080218214401.htm">three to five times more likely to be in a serious crash</a>. The study was the first to examine the severity of car crashes among people with sleep apnea, and found that even mild disordered breathing was linked to increased risk.
Sleep Apnea Is Linked To Pregnancy Complications
Granted, Perry doesn't have to worry about this particular concern. While sleep apnea is often perceived as a problem predominately for men, <a href="http://www.huffingtonpost.com/2012/08/16/sleep-apnea-in-women-may-_n_1779127.html">women are not immune</a>. And, in fact, sleep apnea presents unique complications for women. A recent study found that women with sleep apnea were more likely to develop high blood pressure during their pregnancies, to require a C-section birth and their babies were more <a href="http://www.huffingtonpost.com/2012/09/21/sleep-apnea-in-pregnancy-_n_1903534.html">likely to be admitted to the neonatal intensive care unit</a>.