Background:
Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease (CVD). Several of the proposed mechanisms for the development of CVD in OSA are similar to those proposed for the increased risk of CVD in obesity, being difficult to determine the influence of OSA on these pathogenic mechanisms in obese individuals.
Objectives:
The purpose of this study was to evaluate the relationship of OSA with endothelial function, oxidative stress, inflammatory biomarkers, metabolic profile, sympathetic nervous system activity and blood pressure (BP) in obese individuals.
Methods:
In this cross-sectional study, were included 53 obese adults (28 women). Sleep study was performed with Watch-PAT200® and the diagnosis of OSA was made when apnea-hipopnea index (AHI) ≥5 events/h (n=33). All participants underwent evaluation of: body adiposity, BP, plasma catecholamines, high sensitivity C-reactive protein (hs-CRP), adiponectin, malondialdehyde, glucose, insulin, lipid profile and endothelial function (Endo-PAT 2000®).
Results:
Mean age (39.6 ± 1.5 vs. 32.5 ± 2.1y) and percentage of male participants (61% vs. 25%) were significantly higher in participants with OSA than in those without OSA (p=0.01). In univariate analysis participants with OSA compared with those without OSA exhibited higher values of neck circumference (40.98 ± 0.63 vs. 38.65 ± 0.75 cm, p=0.02), glucose (92.54 ± 1.97 vs. 80.2 ± 1.92 mg/dL, p=0.0001), noradrenaline (0.16±0.02 vs. 0.12±0.03 ng/mL, p=0.02) and systolic BP (126.05 ± 1.61 vs. 118.16 ± 1.86 mmHg, p=0.003). After adjustment for confounders, only glucose and hs-CRP were significantly higher in OSA patients. In correlation analysis, after controlling for confounders, AHI was associated with neck circumference (r=0.31,p=0.03) and hs-CRP (r=0.30,p=0.04), while minimum O2 saturation was associated with neck circumference (r=-0.31,p=0.03), insulin (r=-0.29,p=0.04) and HOMA-IR (r=-0.30,p=0.04).
Conclusion:
The present study suggests that in obese individuals OSA is associated with inflammation and worse glycemia; higher AHI correlates with increased central adiposity and inflammation; and lower oxygen saturation is related with insulin resistance.