In patients with obstructive sleep apnea, nocturnal hypoxemia measured by time spent below 90% oxygen saturation was associated with an increased risk of cardiovascular diseases (OR 2.20; 95% CI 1.61-305.93).
Cohort (n=997)
Does nocturnal hypoxemia increase the risk of cardiovascular disease and all-cause mortality in patients with obstructive sleep apnea?
In patients with obstructive sleep apnea, nocturnal hypoxemia (time spent below 90% SpO2) is associated with an increased risk of incident cardiovascular diseases but not all-cause mortality after adjusting for comorbidities.
Effect estimate: OR 2.20 (95% CI 1.61-305.93)
Abstract Rationale Alongside the apnea-hypopnea index (AHI), hypoxic burden has gained attention as a marker of obstructive sleep apnea (OSA) severity and prognosis. Previous studies have shown that patients with similar AHIs may have different cardiovascular risks due to differences in hypoxic burden. We aimed to evaluate this relationship and assess the effect of hypoxic burden on all-cause mortality in OSA patients using nocturnal hypoxemia measures. Methods We developed and validated a rule-based natural language processing (NLP) algorithm to extract the sleep parameters stored as the table in the home sleep apnea test (HSAT, Stardust) report. We extracted AHI, heart rates, times spent in saturation less than 95, 90, and 85 percent, average of oxygen saturation, lowest oxygen saturation, and total snores per time. We curated the patients’ demographic and clinical variables, including age, sex, race, ethnicity, Body Mass Index (BMI), Charlson Comorbidity Index (CCI), cardiovascular disease prevalence at index test date, and all-cause mortality using Veterans Health Administration Electronic Medical records. We performed a multivariate logistic regression and reported the odds ratios and 95% confidence intervals (OR 95%CI) considering p-value 0.05 as a significant level. The dependent variables were all-cause mortality and incident of cardiovascular diseases post index date of Stardust report. The independent variables were age, sex, BMI≥30, race-White, ethnicity-Hispanic, CCI≥2, AHI, T90, and mean of heart rate. Results We analyzed complete data of 997 patients who underwent HSAT (mean age 50.3±14.1 years; BMI 33.4±4.8; AHI 15.4±16.5). Most were male (90%) and white (58.3%); 18.6% had a CCI≥2. Only the percentage of total sleep time with peripheral oxygen saturation (SpO2)90% was associated with increases risk of cardiovascular diseases (OR,2.20; 95%CI: 1.61,305.93). Older age (OR,1.08;95%CI: 1.05,1.102), white race (OR,1.62; 95%CI: 1.008,2.597) and CCI≥2 (OR,3.39;95%CI: 2.15,532) were independently associated with mortality. Measures of nocturnal hypoxemia including percentage of time with oxygen saturation less than T95% or T90%, lowest SpO2, and mean SpO2 were not associated with mortality in adjusted models. Mean heart rate was the only physiologic parameter independently associated with mortality (OR,1.03;95%CI: 1.01,1.05). Conclusion In this cohort of patients with obstructive sleep apnea, although nocturnal hypoxemia, measured by time spent below 90% oxygen saturation was associated with increased risk of cardiovascular diseases, it was not independently associated with all-cause mortality after adjusting for comorbidities and demographic factors. This abstract is funded by: Supported by the Airborne Hazards and Burn Pits Center of Excellence (award FY2024-002 to J.R.); the Center for Innovations in Quality, Effectiveness, and Safety (CIN 13-413); the VA Post-Deployment Health Services (now Health Outcomes Military Exposures (HOME)); and VA Merit (award 5I01CX002841-02), Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas. The opinions expressed are those of the authors and not necessarily those of the Department of Veterans Affairs, the U.S. government, or Baylor College of Medicine.
Weerasinghe et al. (Fri,) conducted a cohort in Obstructive Sleep Apnea Syndrome (n=997). Time spent below 90% oxygen saturation (T90) was evaluated on Incident cardiovascular diseases (OR 2.20, 95% CI 1.61-305.93). In patients with obstructive sleep apnea, nocturnal hypoxemia measured by time spent below 90% oxygen saturation was associated with an increased risk of cardiovascular diseases (OR 2.20; 95% CI 1.61-305.93).