Longer and Deeper Desaturations Are Associated With the Worsening of Mild Sleep Apnea: The Sleep Heart Health Study

Abstract

Study ObjectivesObesity, older age, and male sex are recognized risk factors for sleep apnea. However, it is unclear whether the severity of hypoxic burden, an essential feature of sleep apnea, is associated with the risk of sleep apnea worsening. Thus, we investigated our hypothesis that the worsening of sleep apnea is expedited in individuals with more severe desaturations.MethodsThe blood oxygen saturation (SpO2) signals of 805 Sleep Heart Health Study participants with mild sleep apnea [5 ≤ oxygen desaturation index (ODI) < 15] were analyzed at baseline and after a mean follow-up time of 5.2 years. Linear regression analysis, adjusted for relevant covariates, was utilized to study the association between baseline SpO2-derived parameters and change in sleep apnea severity, determined by a change in ODI. SpO2-derived parameters, consisting of ODI, desaturation severity (DesSev), desaturation duration (DesDur), average desaturation area (avg. DesArea), and average desaturation duration (avg. DesDur), were standardized to enable comparisons between the parameters.ResultsIn the group consisting of both men and women, avg. DesDur (β = 1.594, p = 0.001), avg. DesArea (β = 1.316, p = 0.004), DesDur (β = 0.998, p = 0.028), and DesSev (β = 0.928, p = 0.040) were significantly associated with sleep apnea worsening, whereas ODI was not (β = −0.029, p = 0.950). In sex-stratified analysis, avg. DesDur (β = 1.987, p = 0.003), avg. DesArea (β = 1.502, p = 0.024), and DesDur (β = 1.374, p = 0.033) were significantly associated with sleep apnea worsening in men.ConclusionLonger and deeper desaturations are more likely to expose a patient to the worsening of sleep apnea. This information could be useful in the planning of follow-up monitoring or lifestyle counseling in the early stage of the disease.

Diabetes and cardiovascular diseases are associated with the worsening of intermittent hypoxaemia

“…Because some of the originally scored desaturation event annotations had disappeared due to known data corruption (The National Sleep Research Resource, 2021), SpO 2 signals were rescored automatically with Noxturnal software (version 5.1.19824, Nox Medical, Reykjavík, Iceland). Agreement between the automatic and manual scorings using the same methods in the same dataset has been previously presented extensively and been shown to be excellent (Karhu et al, 2021). No desaturation scoring criteria exist in the American Academy of Sleep Medicine (AASM) guidelines besides a minimum transient drop of 3% or 4% from the baseline (Berry et al, 2017).…”

“…Moreover, as no scoring criteria for desaturations exist in the AASM guidelines (Berry et al, 2017) besides a transient drop of 3% or 4%, the alteration of the used scoring criteria would affect the number and severity of desaturation events. However, the used scorings can be assumed to be valid, as in the exact same dataset correlations and median differences between automatic scorings and a subset of manual scorings have been shown to be excellent (Karhu et al, 2021). Furthermore, apneas and hypopneas were not automatically rescored as they were found to be insufficiently accurate without manual editing.…”

“…shown to be excellent (Karhu et al, 2021). Furthermore, apneas and hypopneas were not automatically rescored as they were found to be insufficiently accurate without manual editing.…”

Factors Associated With Undiagnosed Obstructive Sleep Apnea in Overweight and Obese High-Tech Employees: A Multisite Cross-Sectional Study

“…In our study 58.9% of high-tech employees were found to have mild OSA. Karhu et al (2021) stated that if patients with long-term apnea do not receive treatments, their OSA would be aggravated by prolonged exposure to deoxygenation saturation concentration. A study on the natural evolution of apnea found that even if there is no increase in BMI, patients with mild to moderate OSA tended to develop severe OSA after an average of 17 months (Pendlebury et al, 1997).…”

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“…However, other configurations may lead to different results. On the other hand, we included Nadir SpO2 in our analyses because it has been observed that the depth of desaturations is associated with increased OSA-related negative consequences in adults (Kulkas et al, 2013;Karhu et al, 2021). However, it would be an interesting future goal to assess other oximetric variables such as oxygen desaturation index or hypoxic burden.…”