Investigators used the Baveno classification to group patients at diagnosis of obstructive sleep apnea and again after 5 years.
Data from a recent study found a significant percentage of patients who were not eligible for positive airway pressure (PAP) therapy at diagnosis of obstructive sleep apnea (OSA) developed major cardiovascular morbidities (CVC) or end-organ damage (EOD). Investigators, led by Mariana Serino, MD, department of pneumology, Centro Hospitalar de São João, Porto, Portugal, further identified significant predictors of CVC and EOD, including a higher body mass index (BMI), higher percentage of central apneas, and higher age.
The study included a total of 76 patients, 58% of whom were male (n = 44), with a mean age of 51.9 years (standard deviation [SD], 10.1). At diagnosis in 2015, participants were separated into Baveno groups A and B, with 46% (n = 35) in group A and 54% (n = 41) in group B. Five years after OSA diagnosis, patients were evaluated for the development of a major CVC or EOD, defined as evolution to Braveno groups C (n = 6; 8%) or D (n = 10; 13%). Patients who did not develop major CVC or EOD after 5 years were again classified into group A (n = 38; 50%) or B (n = 22; 29%).
Following the 5-year period, 21% of patients developed a major CVC or EOD, and 16 patients (21%) were reallocated to group C or group D. Evolution to these groups was significantly predicted is the patient had a higher age (OR, 1.10 [95% CI, 1.02-1.18]; P = .004), higher percentage of central apneas (OR, 1.11 [95% CI, 1.02-1.20]; P = .012), or higher BMI (OR, 1.26 [95% CI, 1.10-1.48]; P = .004). Comparably, other variables, namely sex, sleepiness, insomnia, apnea-hypopnea index (AHI), ODI, and an oxygen saturation below 90% were not significant predictors.
“Our results support the hypothesis that untreated OSA is associated with the development of major CVC and EOD over time. This association has mainly been reported in patients with mild to moderate OSA, aged between 40 and 60 years, regardless of changes in BMI,” Serino et al wrote. “We emphasize that our population is representative of this subgroup of patients. Although other studies have already analyzed the evolution of OSA over time in untreated patients, they mainly assessed the evolution in relation to the AHI and typical symptoms of OSA. Our study is the first to focus on the analysis of risk predictors of developing major CVC and EOD.”
Comparing results from 2020 to 2015, investigators found that 20 patients (26%) remained in group A, 14 (18%) remained in group B, and 42 (53%) were redesignated to another group. Investigators noted the Baveno criteria was slightly adapted due to limited data availability, with symptomatic patients—defined as the presences of insomnia, hypersomnia (subjective sleep length ≥ 11 hours), or daytime sleepiness (Epworth Sleepiness Scale score ≥ 11)—allocated to group B or D.
Participants had a mean body mass index of 30.3 kg/m2 (SD, 5.0), as well as an AHI of 8.9 events per hour (interquartile range, 5.9-12.0), according to home sleep apnea test (HSAT) results. Eligible patients had an AHI of 5 events per hour or greater and were also ineligible for PAP therapy OSA diagnosis and following 5 years.
Limitations were the small sample size of patients, which investigators note was compensated for via the use of Baveno classification criteria, as well as through the exclusion of patients who had bariatric surgery, upper airway surgery, a mandibular advancement device, of any of those who had PAP therapy during the 5-year period. Other noted limitations were the onset of the COVID-19 pandemic, which occurred at the end of the study period, and led investigators to conduct final assessments over the phone as opposed to in-person. Lastly, the HSAT results were not reviewed at the 5-year mark. According to investigators, future research efforts should include a larger number of patients to confirm the findings from the present study.