Page 33 - Portuguese Journal - SPORL - Vol 61. Nº1

an AHI above 5 events/h, and have a very low Graph 1
AHI in the remaining time in the non-supine Distribution of the included cases by OSAS
severity according to the 2018 AASM criteria
position, which is very short, can easily fulfill
the criterion of an AHI in the supine position
that is twice the AHI in the non-supine position.
Quantitative data were described as medians
and interquartile ranges, and categorical data
as frequencies and percentages. Statistical
analysis was performed using the SPSS®
software (Statistical Package for the Social
Sciences - IBM Corp. Released 2017, IBM SPSS
Statistics for Windows, Version 25.0. Armonk,
NY: IBM Corp.) for Microsoft Windows®. The
Mann-Whitney U test and the chi-square test
were used for comparing the data. Binomial
logistic regression was also performed to
determine the most significant predictors of
positional dependence. A value of p≤0.05 was
considered statistically significant.
Abbreviations: OSAS, obstructive sleep apnea syndrome; AASM,
American Academy of Sleep Medicine.
Results
Of the 372 patients who underwent type 3 PSG 43% in mild OSAS to 22% in severe OSAS, while
between 2020 and 2021, 245 were included the prevalence of eP-OSAS decreased from
in the study, while the remaining 127 were 71% in mild OSAS to 4% in severe OSAS.
excluded after applying the exclusion criteria. When compared to patients with non-
The mean age was 57(±20) years and 159 positional OSAS (NP-OSAS), patients with
patients (64.9%) were men. The majority were P-OSAS demonstrated a lower BMI, less
overweight or obese (median BMI 29.4±6.3 sleep time in the non-supine position, and
kg/m ), and as shown in Graph 1, were mostly had lower AHI, ODI, and snoring time. On the
2
classified as mild OSAS (median AHI of 17.8 other hand, they exhibited a higher MDD in
events/h ± 21.3, with a range from 5.1 to 110.8). the supine position and slept longer in the
The median ODI was 19 ± 21.5 events/h and the supine position (Table 1). When compared to
median MDD was 4.6% ± 1.6. When adjusted patients with exclusive non-positional OSAS
for the patient position, AHI, ODI, and MDD (eNP-OSAS), patients with eP-OSAS had lower
were higher in the supine position (Table ages, lower BMI, slept longer in the supine
2), although the median time in the supine position, and exhibited a lower AHI, ODI, MDD,
position was shorter (65.8% ± 37.3). and snoring time (Table 2).
Snoring was present for 14.3% ± 29 of the The binomial logistic regression model showed
examination duration and mainly in the non- that the predictors with statistical significance
supine position (13.7% ± 35). were BMI (β=-0.073, p=0.02), time in the supine
Of the 245 patients included, 136 (55.5%) were position (β=0.022, p=0.001), and ODI (β=-0.037,
classified as P-OSAS according to the APOC p<0.001) for P-OSAS (Table 3). This binomial
criteria and 52 (21.2%) were classified as eP- logistic regression model (including BMI, time
OSAS, which accounted for 38% of the P-OSAS in the supine position, and ODI) correctly
cases according to the APOC criteria. The classified 71% of the patients. Sensitivity,
prevalence of P-OSAS and eP-OSAS according specificity, positive predictive value, and
to the severity of OSAS is shown in Graph 2. negative predictive value were 83.1%, 56%,
The prevalence of P-OSAS decreased from 70.2%, and 72.6%, respectively.

Volume 61 . Nº1 . March 2023 33