Respiratory Muscle Strength as an Indicator of the Severity of the Apnea-Hypopnea Index: Stepping Towards the Distinction Between Sleep Apnea and Breath Holding

Abstract

Background and objective The aim of this study was to investigate whether the maximum inspiratory and expiratory pressure are correlated with the apnea-hypopnea index (AHI) in patients with obstructive sleep apnea syndrome (OSAS). Methods Fifty-two patients with OSAS were divided into two groups (AHI, events/hours: <30, n=28, versus ≥30, n=24). For each patient, anthropometric characteristics, spirometry parameters, maximum inspiratory (MIP) and expiratory pressure (MEP), and cardiopulmonary function (CPF) parameters (oxygen uptake at rest (VO 2 ), carbon dioxide output (VCO 2 ), heart rate (HR), minute ventilation (V E ), tidal volume at inspiratory (TVin) and expiratory (TVex), breath frequency ( f β ), end-tidal carbon dioxide pressure (P ET CO 2 ), end-tidal oxygen pressure (P ET O 2 ), and mean arterial pressure (MAP)) in sitting position for three minutes were recorded. The independent t-test was used to measure the differences between groups (events/hours <30 versus ≥30) and Pearson correlation analysis was used for statistical comparison between parameters. Results Results showed differences between groups (AHI, events/h ≥30 versus <30) in MIP (102.0±18.3 versus 91.1±12.1 % of predicted, p=0.013) and CPF parameters TVin (0.8±0.2 versus 0.7±0.1, L, p=0.047), P ET CO 2 (34.6±4.2 versus 31.4±3.7, mmHg, p=0.007), and MAP (88.4±6.5 versus 82.9±6.2, mmHg, p=0.003). Pearson correlation analysis between respiratory muscle strength (MIP and MEP) and polysomnography (PSG) parameters, MIP is related to AHI (r=.332, p=0.016) and desaturation index (r=.439, p=0.001), as well as MEP to percent of REM sleep stage (r=-.564, p<0.001). Conclusion The data from the present study support that maximal inspiratory pressure relates to the severity of AHI and intermittent breath-holding during sleep increases the inspiratory muscle strength.

The 6-Minute Walk Test and Anthropometric Characteristics as Assessment Tools in Patients with Obstructive Sleep Apnea Syndrome. A Preliminary Report during the Pandemic

“…These effects are the substrate of the observable diminished physical activity and proneness to breath shortness elicited via the 6MWT. The latter furthermore corresponds to less effective chest expansion and, hence, lower VO 2 [ 36 ] and METs, independent of AHI severity [ 37 ]. Therefore, tools that assess fitness indicators, such as 6MWT, in conjunction with a more thorough recording of anthropometric and morphological characteristics could contribute to a more optimal characterization of OSAS patients and OSAS’ impact on their lives, while demystifying BMI.…”

Obstructive Sleep Apnea Syndrome: The Effect of Acute and Chronic Responses of Exercise

“…Six-minute walk test (6 MWT) is an additional assessment tools in patients with OSAS (11). 6 MWT is a non-invasive submaximal test it reviews the responses of exercise and evaluates the global and integrated responses of all the systems involved during exercise, including the pulmonary and cardiovascular systems, systemic circulation, peripheral circulation, blood, neuromuscular units, and muscle metabolism (12).…”

“…OSAS consists of repetitive episodes of apneas and hypopneas which activate the circle of intermittent hypoxia-hypercapnia, resulting in increased end-tidal CO 2 while bicarbonate buffer system will attempt compensation by generating bicarbonate ions in addition to hydrogen ions, resulting in metabolic acidosis and alkalosis (17,36,39). Moreover, in patients with OSAS were observed higher values in maximum inspiratory pressure, which is associated with the severity of AHI (11). Concomitant with training programs in athletes, the intermittent breath holding during hypoxia-re-oxygenation, in patients with OSAS increases the intrathoracic pressure with successive alteration in the transmural pressure of the cardiac cavities, resulting increased respiratory muscles strength (11).…”

“…Moreover, in patients with OSAS were observed higher values in maximum inspiratory pressure, which is associated with the severity of AHI (11). Concomitant with training programs in athletes, the intermittent breath holding during hypoxia-re-oxygenation, in patients with OSAS increases the intrathoracic pressure with successive alteration in the transmural pressure of the cardiac cavities, resulting increased respiratory muscles strength (11).…”

Respiratory Muscle Strength: New Technology for Easy Assessment

“…Twenty-one male professional athletes (runners, n=6; cyclists, n= 11; triathletes, n=4, Table 1) were included in our study on a voluntary basis and randomly (using block randomization) used the devices for RMS assessment (MicroRPM versus AirOFit PRO™). Inclusion criteria were age between ≥20-and ≤50-years-old, training age ≥4 years (≥5 hours per week with HR ≥70 % of max), without recent injury (for the last 12 months) [8], respiratory and/or cardiological disorders [9] and taking any medication and ergospirometry parameters (VE/MVV <85% and TV/IC <85% and Borg scale dyspnea score <5). All volunteers have lived and been trained in less than 100 m altitudes at sea level, for above 10 months [10].…”