Abstract 13361: Combined Effects of Sleep Disordered Breathing and Metabolic Syndrome on Endothelial Function in the Wisconsin Sleep Cohort
Background: Sleep disordered breathing (SDB) and the metabolic syndrome (MetS) are associated with increased cardiovascular morbidity and mortality. We hypothesized that the combined presence of SDB and MetS has a more deleterious effect on endothelial function than the expected from the sum of their individual effects.
Methods: A total of 454 participants from the population based Wisconsin Sleep Cohort were studied. MetS was defined following the NCEP ARP III criteria. Overnight polysomnnograms were obtained (mean [standard deviation]) 1.6 (0.6) years from the assessment of MetS status and brachial artery flow-mediated dilation (FMD, %) measurement. SDB severity was defined using the Apnea-Hypopnea Index (AHI, events/hr of sleep). Spearman correlations for FMD were adjusted for artery diameter, sex and age. Multivariable regression analysis was used to assess associations of FMD with SDB and MetS and their interactions. Subjects using CPAP in the lab were excluded.
Results: The subjects were 60 (8) years old, 44% female, and 97% Caucasian with similar distributions between participants with MetS vs. no-MetS. Of the participants, 37% had MetS, and of these, 26% had AHI≥15. Of the no-MetS group, 10% had AHI≥15. FMD (5.5 [3.5]%) partial correlation analysis (adjusted for baseline diameter, sex, and age) was negatively correlated with age (ρ=-0.122, p=0.009) and baseline diameter (ρ =-0.33, p<0.001). A multivariate model adjusted for age, sex, diameter, body-mass index, alcohol consumption, smoking, antihypertensive medication use, AHI, MetS and AHI *MetS (r2=0.176, p<0.0001) showed that the interaction of these two variables was a significant predictor of FMD response; every increment in one AHI events/h when MetS was present was associated with a decrease in FMD of 0.051% (p=0.048).
Conclusions: SDB and concurrent MetS have a synergistic effect on worsening endothelial function. Individuals with both of these conditions may be at a significantly higher risk for cardiovascular complications.
- © 2012 by American Heart Association, Inc.