Sleep Troubles Tied to High Blood Sugar Levels

Sleep apnea linked to blood sugar rise and an increased risk of developing diabetes

(RxWiki News) Never underestimate the value of a good night’s sleep. Mounting evidence shows that sleep apnea, characterized by repeated pauses in breathing while sleeping, may be tied to diabetes.

Recent research has shown that up to 40 percent of individuals with sleep apnea will have type 2 diabetes, according to the International Diabetes Federation. Apnea is also linked to hypertension, stroke and heart failure.

A new investigation found that blood sugar levels were associated with the severity of sleep apnea in people without diabetes.

"Take steps to treat sleep apnea to reduce diabetes risk."

Walter McNicholas, MD, with the School of Medicine and Medical Science at University College Dublin and the Pulmonary and Sleep Disorders Unit at St. Vincent’s University Hospital in Dublin, Ireland, and colleagues followed 5,294 individuals without diabetes who were participating in multinational European sleep apnea research.

Dr. McNicholas and colleagues recorded HbA1c levels of all participants. HbA1c is a measure that provides an average of blood glucose (sugar) levels over time. For those without diabetes, normal target levels are between 4 and 5.9 percent, while those with diabetes typically want to keep their HbA1c under 6.5 percent. Higher levels over time are related to developing cardiovascular problems.

Dr. McNicholas and this team categorized participants in terms of sleep apnea severity. They observed that average HbA1C levels were lowest in those with milder apnea (5.25 percent) and highest in those with those with the most severe apnea (5.5 percent).

The authors also noted that patients with the most severe apnea faced greater odds of having HbA1c levels over 6 percent.

Dr. Barry Sears, President of the non-profit Inflammation Research Foundation in Marblehead, MA and creator of The Zone Diet, offered his explanation for this association.

"Sleep apnea and diabetes are different manifestations of increased inflammation," Dr. Sears said. "The sleep apnea causes sleep deprivation that can cause insulin resistance. With insulin resistance, blood sugar levels will become elevated.  The pancreas responds to this evevation in blood sugar with the greater secretion of insulin. This increased insulin forces omega-6 fatty acids into enhanced production of arachidonic acid (AA) that causes further inflammation."

He continued, "In addition, the increase in HbA1c is reflective of a general increase in glycosylated proteins known as Advanced Glycosylated End (AGE) products. Even a slight increase in AGE products can promote additional inflammation.  Eventually this increased inflammation caused by the increase in AA and AGE products spreads to the pancreas and burns out the cells responsible for producing insulin. When that happens, blood sugar levels raise dramatically and diabetes is end result."

Obstructive sleep apnea (OSA) disorder affects at least 4 percent of men and 2 percent of women in developed countries, according to the report.

"This is the largest study of its kind showing a link between sleep apnea severity and glucose levels,” said Dr. McNicholas in a press release. “Clinicians need to focus on diabetes as an important co-existing illness when treating people with sleep apnea. Further studies are needed to understand the mechanisms behind these two conditions.”

Dr. McNicholas also underscored the role that weight plays. Subjects with more severe apnea were likely to be obese and male.

“I would emphasize to patients the importance of weight control as a way to reduce the risks associated with the condition,” added Dr. McNicholas.

This study was published online in April in the European Respiratory Journal.

Review Date: 
April 7, 2014