Red blood cell distribution width in Obstructive Sleep Apnea Syndrome and its association with cardiovascular disease.

Background: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular disease (CVD). Red blood cell distribution width (RDW) is reported as a novel marker of cardiovascular disease (CVD) risk. We aimed to investigate the correlation of RDW level with the severity of Obstructive Sleep Apnea Syndrome (OSAS) defined with the apnea-hypopnea index (AHI) and to study the relationship between RDW and CVD in OSAS.

Methods: From retrospective analyses of patients admitted to our department for polygraphy between January 2018 and January 2020, OSAS patients with complete medical records and hemogram analyses were evaluated.

Results: The study population consisted of 160 patients (101 females/59 males). The mean age was 52.32 ± 10.83 years. RDW correlated positively with the apnea hypopnea index (AHI) (r=0.392; p < 0.0001) and C-reactive protein (CRP) (r = 0.3, p < 0.001). RDW and CRP were significantly higher in patients with CVD than whom without CVD (p < 0.0001). In multivariate analysis, the independent predictors of CVD in OSAS were RDW (p < 0.0001; OR=3.095; CI: 1.69-5.66), CRP (p=0.046; OR=1.136; CI: 1.002-1.287) and age (p=0.013; OR=1.085; CI: 1.017- 1.157). The cut-off level for RDW with optimal sensitivity and specificity was calculated as 14.45 with sensitivity of 81% and specificity of 75%.

Conclusions: The findings of this study suggest that RDW, a simple, relatively inexpensive and universally available marker could have the ability to predict CVD in OSAS.