Abstract
Introduction: OSA is a known cardiovascular risk factor. Decreased HRV proved to be a predictor of cardiovascular mortality. Aims: To evalute HRV and its changes due to CPAP therapy in severe OSA patients. Methods: Severe OSA patients (n=39) (A) treated with CPAP and control non-OSA patients (n=15) (B) were studied. Group A underwent 3 sleep studies: basal, with CPAP titration and after 3-month CPAP therapy. Group B underwent basal sleep study. Basal 24-hour electrocardiograms (ECG) were performed and standard deviations of NN intervals (SDNN) in 24-hour period were analyzed. Sequent 24-hour ECGs were performed and changes of SDNN were evaluated after a 3-month CPAP therapy. Results: In A group mean age was 54.4 (±2.9) yrs vs. 55.2 (±2.7) in B group, mean body mass index (BMI) was 33.92 (±2.41) kg/m² vs. 31.73 (±1.16), mean apnea-hypopnea index (AHI) was 51.31 (±15,23) per hour vs. 2.45 (±1.28), overall desaturation index (ODI) was 49.28 (±18.5) per hour vs. 1.91 (±0,98), respectively. Basal SDNN was 117.03 (±24.33) ms in A group vs. 137.73 (±13.87) in B group, (p<0.05). There was a negative correlation between AHI, ODI and SDNN in A group (Table 1). After a 3-month CPAP therapy SDNN rose to 140.9 (±22.72) ms vs. basal value 117.03 (±24.33), (p<0.01). More intense CPAP usage correlated positively with SDNN improvement (Table 1).
Conclusion: OSA patients are characterized by decreased HRV. CPAP therapy normalizes HRV in severe OSA patients.
- © 2014 ERS