Increase in Body Mass Index Decreases Duration of Apneas and Hypopneas in Obstructive Sleep Apnea

Abstract

BACKGROUND: Obesity is one of the most prominent risk factors for obstructive sleep apnea (OSA). Weight loss decreases the number of shorter respiratory events (<40 s), whereas the number of longer events remains almost unchanged. However, it is unknown how body mass index (BMI) affects individual obstruction event severity within OSA severity categories when age, sex, smoking, daytime sleepiness, snoring, hypertension, heart failure, and sleeping posture are considered. Therefore, we investigated whether individual obstruction event severity varies with BMI within the OSA severity categories when considering the most important confounding factors. METHODS: Polygraphic recordings of 723 subjects without CPAP treatment and with an apnea-hypopnea index (AHI) of >5 events/hour were reanalyzed retrospectively. The effect of BMI on the severities of OSA and individual obstruction events was evaluated in general, within OSA severity categories, and between different BMI groups (ie, BMI < 25; 25 < BMI < 30; 30 < BMI < 35; 35 < BMI < 40; and BMI > 40 kg/m 2). RESULTS: AHI increased in mild and severe (␤ > 0.10, P < .001) OSA categories, with increasing BMI. However, the proportion of apneas from all respiratory events decreased (␤ ‫؍‬ ؊0.55, P ‫؍‬ .068) with increasing BMI in all the OSA categories. An increase in BMI led to a decrease in the median duration of individual apneas, hypopneas, and desaturations in all OSA categories, whereas desaturation depth increased statistically significantly in the severe category (␤ ‫؍‬ 0.20, P < .001). CONCLUSIONS: Because BMI is related to the duration of individual obstruction events, its effect on OSA severity is more complex than its effect on AHI would implicate. Therefore, overall severity of OSA may not be the same for non-obese patient and obese patient who have similar AHI. Thus, these patient-specific characteristics of individual breathing cessations should be considered when estimating the severity of disease and risk of related adverse health effects.

Use of mandibular advancement devices for the treatment of primary snoring with or without obstructive sleep apnea (OSA): A systematic review

“…A retrospective study reported a direct relationship of age with OSAS prevalence and that the OSAS prevalence was 13% in participants aged 30e70 y [56]. This confirms the influence of age but also the influence of BMI on the AHI, OSAS severity, and snoring (apneic and non-apneic) [57]. These findings are consistent with a positive correlation of OSAS severity with BMI; in other words, patients with OSAS had higher BMI values than patients with PS [32].…”

Association between the Mallampati score and maximal mouth opening in patients with obstructive sleep apnea

“…The association found between BMI and AHI was also consistent with previous reports. 14 Thus, this study has shown that although there was initially no significant association between the Mallampati score and AHI found in a previous report, 1 an association between the Mallampati score and the mouth opening capacity and between BMI and AHI does exist. Physicians should consider the extent of mouth opening when assessing OSA based on the Mallampati score.…”

Polysomnographic characteristics of severe obstructive sleep apnea vary significantly between hypertensive and normotensive patients of both genders

“…Hypertension has been strongly linked to OSA and the prevalence of hypertension increases with increasing severity of OSA [22,23]. In OSA patients, it has been reported that sympathetic activity is elevated during sleep due to repeated inspiratory efforts against obstructed airways, hypoxia, and respiratory event-related arousals [22].…”