U. PITTSBURGH (US) — Loud snoring and sleep problems could be early signs of a slippery-slope health condition known as metabolic syndrome linked to heart disease, diabetes, and stroke.
A person with at least three of these five risk factors is considered to have metabolic syndrome: excess abdominal fat, high triglycerides, low HDL cholesterol, high blood pressure, and high blood sugar.
A new study reported in the journal Sleep provides the first prospective evidence to support a link between common sleep complaints—such as difficulty falling asleep and unrefreshing sleep—and metabolic syndrome. The study emphasizes the importance of screening for common sleep complaints in routine clinical practice.
“This study shows us that a broader array of commonly reported sleep symptoms, including insomnia and sleep-disordered breathing symptoms, predict the development of metabolic syndrome, a key risk factor for cardiovascular disease,” says Wendy Troxel, lead author and assistant professor of psychiatry and psychology the University of Pittsburgh.
“It was rather striking that the effects of difficulty falling asleep and loud snoring were largely independent of one another.”
Loud snoring significantly predicted the development of high blood sugar and low HDL cholesterol. Difficulty falling asleep and unrefreshing sleep did not predict any of the individual metabolic abnormalities.
The study involved 812 participants in Heart SCORE, an ongoing community-based study of adults between 45 and 74 years of age. Individuals who were classified as having metabolic syndrome or diabetes at baseline were excluded from the analyses. During the three-year follow-up period, 14 percent of participants developed metabolic syndrome.
“Our results show that the risk of developing metabolic syndrome over a three-year follow-up period was more than two times higher in adults who reported frequent loud snoring,” notes Troxel. “This risk also was increased by 80 percent in adults who reported having difficulty falling asleep and by 70 percent in those who reported that their sleep was unrefreshing.”
Further analysis showed that unrefreshing sleep was reduced to marginal significance with additional adjustment for loud snoring. However, both loud snoring and difficulty falling asleep remained significant independent predictors of metabolic syndrome.
“We believe these results emphasize the importance of screening for common sleep complaints in routine clinical practice,” adds Troxel.
Loud snoring continued to predict the development of metabolic syndrome even after accounting for the number of metabolic risk factors present at baseline. Troxel suggests that these findings “may implicate loud snoring as a causal risk factor for adverse cardiovascular and metabolic changes.”
The study is supported by funding provided by the Commonwealth of Pennsylvania Department of Health, National Institutes of Health, and the National Heart, Lung, and Blood Institute.
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