A new study found that loud snoring and two common insomnia symptoms - difficulty falling asleep and unrefreshing sleep - each significantly predicted the development of the metabolic syndrome.
The study emphasizes the importance of screening for common sleep complaints in routine clinical practice.
Results of multivariate logistic regression models show that the risk of developing the metabolic syndrome over a three-year follow-up period was more than two times higher in adults who reported frequent loud snoring.
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 found that unrefreshing sleep was reduced to marginal significance with additional adjustment for loud snoring. However, when simultaneously entered in a statistical model, both loud snoring and difficulty falling asleep remained significant independent predictors of the metabolic syndrome.
"This is the first prospective study to show that a broader array of commonly reported sleep symptoms, including insomnia and sleep-disordered breathing symptoms, predict the development of the metabolic syndrome, a key risk factor for cardiovascular disease," said lead author Wendy M. Troxel, assistant professor of psychiatry and psychology at the University of Pittsburgh in Pittsburgh, Pa.
"It was rather striking that the effects of difficulty falling asleep and loud snoring were largely independent of one another."
The study appears in the Dec. 1 issue of the journal SLEEP.