CPAP Influence on Readily Available Inflammatory Markers in OSA—A Pilot Study

Abstract

Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse, chronic hypoxia and a proinflammatory phenotype. The purpose of our study was to evaluate readily available inflammatory biomarkers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), WBC-to-MPV ratio (WMR) and lymphocyte-to-C-reactive protein ratio (LCR)) before and after CPAP in patients with moderate–severe OSA. We performed a prospective study that included patients with newly-diagnosed moderate–severe OSA. The control groups (patients without OSA and with mild OSA) were selected from the hospital polygraphy database. All subjects underwent routine blood panel, which was repeated in moderate–severe OSA patients after 8 weeks of CPAP. Our final study group included 31 controls, 33 patients with mild, 22 patients with moderate and 37 patients with severe OSA. CRP, ESR, NLR and WMR were correlated with OSA severity. After 8-week CPAP therapy, we documented a decrease in weight status, which remained statistically significant in both CPAP-adherent and non-adherent subgroups. Readily available, inexpensive inflammatory parameters can predict the presence of moderate–severe OSA, but are not influenced by short-term CPAP.

Association between Red Blood Cell Distribution Width and Obstructive Sleep Apnea Syndrome: A Systematic Review and Meta-Analysis

“…Three studies [46,58,60] reported lower RDW values in OSAS subjects than non-OSAS controls (mean difference range, −0.10 to −0.60), with one reporting a statistically significant difference [60], whereas no between-group difference was reported in another study [57]. In the remaining 16 studies [14,44,45,47-50,52-56,58,61,62], OSAS patients had higher RDW values than non-OSAS subjects (mean difference range, 0.05 to 3.99), with a significant difference in eight [45,47,48,[51][52][53]61]. Since a substantial heterogeneity between studies was observed (I 2 = 91.6%, p < 0.001), random-effects models were used.…”

“…Of these, 48 were removed because they did not report the studied endpoint (n = 30), did not include the control group (n = 9), investigated pediatric cohorts (n = 4) or different patient groups (n = 2), or were not written in English (n = 3), leaving 17 articles. Since three additional records were identified from Google Scholar and reference lists, a total of 20 manuscripts [14,[44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] were included in the final analysis (Figure 1). The included studies were published between 2012 [44] and 2022 [60][61][62].…”

“…Since three additional records were identified from Google Scholar and reference lists, a total of 20 manuscripts [14,[44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] were included in the final analysis (Figure 1). The included studies were published between 2012 [44] and 2022 [60][61][62]. The majority were conducted in Turkey (n = 15) [14,[44][45][46][47][48]52,54,55,57,58,60,62], whereas the remaining (n = 5) were conducted in Spain [49], Egypt [50], Pakistan [53], China [56], and Romania [61].…”

“…The included studies were published between 2012 [44] and 2022 [60][61][62]. The majority were conducted in Turkey (n = 15) [14,[44][45][46][47][48]52,54,55,57,58,60,62], whereas the remaining (n = 5) were conducted in Spain [49], Egypt [50], Pakistan [53], China [56], and Romania [61]. Eight studies were retrospective [48,51,52,54,[56][57][58]62] (Table 1).…”

“…A second sub-group analysis based on study design revealed no significant differences (p = 0.53) in RDW values between prospective (SMD = 0.39; 95% CI 0.13 to 0.65, p = 0.002; I 2 = 76.1%, p < 0.001) and retrospective studies (SMD = 0.24; 95% CI −0.6 to 0.55, p = 0.12; I 2 = 93.8%, p < 0.001) (Figure 5), even though the effect size in retrospective studies was not statistically significant. Finally, 13 studies [14,44,45,48,51,52,54,[56][57][58][60][61][62] also reported RDW values based on disease severity. RDW values in OSAS subjects were significantly higher in comparison to non-OSAS controls, in a progressive manner, from mild (SMD = 0.18; 95% CI 0.05 to 0.314, p = 0.006; I 2 = 45.5%, p = 0.037, Figure 6A) to moderate (SMD = 0.39; 95% CI 0.10 to 0.67, p = 0.009; I 2 = 89.1%, p < 0.001, Figure 6B) and to severe disease (SMD = 0.56; 95% CI 0.30 to 0.81, p < 0.001; I 2 = 88.4%, p < 0.001, Figure 6C).…”