Not only is obstructive sleep apnea (OSA) linked to cardiovascular disease (CVD), but adequate treatment of OSA can normalize excess CVD risk, according to results of a study published in the July 15 issue of the American Journal of Respiratory and Critical Care Medicine.
“When OSA was incompletely treated, the independent risk for CVD increased up to 11-fold, whereas effective treatment of OSA significantly reduced the excess risk,” lead author Yüksel Peker, MD, PhD, from Sahlgrenska University Hospital in Gothenburg, Sweden, says in a news release.
This consecutive cohort from a sleep clinic included 182 men, mean age 47+/-9 years, who were free of hypertension, other CVD, pulmonary disease, diabetes mellitus, psychiatric disorder, alcohol dependency, or malignancy at baseline. Follow-up data over a seven-year period were collected via the Swedish Hospital Discharge Register.
At follow-up, 22 (36.7%) of 60 cases with OSA, based on overnight oxygen desaturations of 30 or more, had at least one CVD, as did eight (6.6%) of 122 subjects without OSA (P<.001). Multiple logistic regression revealed that significant predictors of CVD were OSA at baseline (odds ratio [OR], 4.9; 95% confidence interval [CI], 1.8-13.6) and age (OR, 23.4; 95% CI, 2.7-197.5).
In the OSA group, CVD developed in 21 (56.8%) of 37 incompletely treated cases and in one (6.7%) of 15 efficiently treated subjects (P<.001; OR for efficient treatment, 0.1; 95% CI, 0.0-0.7 after adjustment for baseline age and systolic blood pressure).
Of five deaths in the original cohort, two were in the incompletely treated group and were attributed to CVD, one was in the effectively treated OSA group and was cancer-related, and two were in the non-OSA group, one caused by cancer and the other by a central neurologic disorder.
“We conclude that the risk of developing CVD is increased in middle-aged OSA subjects independently of age, [body mass index], systolic blood pressure, diastolic blood pressure, and smoking,” the authors write. “Furthermore, efficient treatment of OSA reduces the excess CVD risk and may be considered also in relatively mild OSA without regard to daytime sleepiness.”
Laurie Barclay, MD, American Journal of Respiratory Critical Care Medicine. 2002;166:159-165. Reviewed by Gary D. Vogin, MD