Sleep-disordered breathing in women: Associations with cardiovascular disease and the significance of sleep apnea during REM sleep
- Location: Enghoffsalen, Akademiska sjukhuset, Ing 50 bv, Uppsala
- Doctoral student: Ljunggren, Mirjam
- About the dissertation
- Organiser: Lung- allergi- och sömnforskning
- Contact person: Ljunggren, Mirjam
Aim: To investigate associations between different aspects of SDB and cardiovascular disease in women.
Background: Sleep-disordered breathing (SDB) is associated with an increased risk of cardiovascular disease, but it is unclear which elements of SDB that are most harmful to the cardiovascular system and whether the associations observed in men also apply to women.
Aim: To investigate associations between different aspects of SDB and cardiovascular disease in women
Methods and results: All four papers were based on participants in “Sleep and Health in Women” (SHE), a population-based cohort study of women.
Paper I is a cross-sectional study of 349 women with polysomnographic assessments of obstructive sleep apnea (OSA) and measurements of plasma BNP, clinically used as a marker of heart failure, in the morning. There was a dose-response relationship between the severity of OSA and levels of BNP.
In Paper II, with a study population of 5,990 women, questionnaire data on symptoms of obstructive sleep apnea were combined with register data from the Swedish National Patient Register regarding a diagnosis of heart failure (mean follow-up 11.4 years). Women with the combination of snoring and daytime sleepiness had a two-fold increase in the risk of incident heart failure after adjustment for confounding.
Paper III was based on 201 women without known cardiovascular disease, with a polysomnography at baseline, assessing OSA during REM sleep, and a carotid artery ultrasound with measurements of intima thickness at follow-up. Severe OSA during REM sleep was associated with a thicker carotid intima.
Paper IV comprised 253 women with polysomnographic data on severe OSA and severe OSA during REM sleep, as well as proteomic analyses of cardiac and inflammatory proteins. After adjustment for confounding and multiple testing, severe OSA during REM sleep was associated with decreased levels of Sirt2, LAP-TGF-β1 and Axin1, while there were no significant associations for OSA based on a whole night and protein levels.
Conclusions: Women with symptoms of OSA run an increased risk of developing heart failure and OSA is associated with increased levels of BNP. Severe OSA during REM sleep is associated with an early sign of atherosclerosis and reduced levels of proteins with anti-inflammatory effects linked to atherosclerosis and metabolic regulation.