Differences in Anthropometric, Sleep and Respiratory Characteristics between Hypercapnic and Normocapnic Patients with COPD-OSA Overlap Syndrome.

BACKGROUND: Overlap syndrome (OS), the coexistence of chronic obstructive pulmonary disease and obstructive sleep apnea, is frequently characterized by the presence of daytime hypercapnia (pCO2 ≥ 45 mmHg). The aim of this study was to investigate potential differences in anthropometric, sleep and respiratory characteristics between hypercapnic and normocapnic patients with OS. METHODS: Consecutive patients who underwent polysomnography, pulmonary function testing and arterial blood gases and had been diagnosed with OS were enrolled in the study. RESULTS: According to pCO2 levels in wakefulness, the patients were divided into group A, consisting of OS patients without hypercapnia (n = 108) or group B, consisting of OS patients with hypercapnia (n = 55). The majority of included patients in both groups were males (n = 92 in group A vs. n = 50 in group B). Group B had increased BMI (p = 0.001), neck (p = 0.017) and waist circumference (p = 0.013), higher scores in Epworth sleepiness scale (ESS) (p = 0.008), increased sleep efficiency (p = 0.033), oxygen desaturation index (p = 0.004) and time with oxyhemoglobin saturation <90% (p = 0.006) than group A. Also, Group B had decreased average and minimum oxyhemoglobin saturation during sleep (p < 0.001). Hypercapnic patients had lower FEV1% (p = 0.003), FVC% (p = 0.004), pO2 and pCO2 (p < 0.001 for both) values compared with normocapnic patients. In binary regression analysis, which assessed various predictors on the likelihood of having hypercapnia, it was found that BMI (OR: 1.313, 95% CI: 1.048-1.646, p = 0.018) and FVC (OR: 0.913, 95% CI: 0.845-0.986, p = 0.020) were the major determinants of hypercapnia in OS patients. CONCLUSIONS: Hypercapnic OS patients were more obese and sleepy and presented worse respiratory function in wakefulness and sleep hypoxia characteristics compared with normocapnic OS patients.

Sleepiness and Vitamin D Levels in Patients with Obstructive Sleep Apnea.

STUDY OBJECTIVES: The aim of this cross-sectional study is to explore the association between serum 25-hydroxyvitamin D [25(OH)D] levels, a marker of Vitamin D status, and excessive daytime sleepiness (EDS), expressed as increased scores of the Epworth Sleepiness Scale (ESS), in a group of prospectively enrolled patients with obstructive sleep apnea (OSA). METHODS: Newly diagnosed patients with OSA, divided into two groups, those with EDS (ESS > 10) and those without EDS (ESS < 10). All patients underwent night polysomnography. Measurement of serum 25(OH)D vitamin was performed using a radioimmunoassay. RESULTS: In total, 217 patients with OSA (197 males and 20 females) were included. Patients with EDS had higher AHI (p < 0.001) values and lower mean serum 25(OH)D levels, compared with those of non-somnolent patients [17.4 (12.2-25.7) versus 21.1 (15.3-28.8) ng/mL, respectively, p = 0.005]. In patients with EDS, serum 25(OH)D levels correlated with average oxyhemoglobin saturation during sleep (r = 0.194, p = 0.043), and negatively with ESS score (r = -0.285, p = 0.003), AHΙ (r = -0.197, p = 0.040) and arousal index (r = -0.256, p = 0.019). Binary regression analysis identified Vit D serum levels (ß = -0.045, OR: 0.956, 95% CI: 0.916-0.997, p = 0.035), total sleep time (ß = 0.011, OR: 1.011, 95% CI: 1.002-1.021, p = 0.016) and AHI (ß = 0.022, OR: 1.022, 95% CI: 1.003-1.043, p = 0.026) as independent predictors of EDS in patients with OSA. In patients with EDS, multiple regression analysis indicated that ESS score was negatively associated with Vit D serum levels (ß = -0.135, p = 0.014) and minimum oxyhemoglobin saturation during sleep (ß = -0.137, p = 0.043). CONCLUSIONS: In the present study, EDS in patients with OSA is associated with low levels of Vitamin D, while sleep hypoxia may play a role in this process.

Challenging subjective excessive daytime sleepiness as an insomnia symptom: a retrospective study.

Diagnostic manuals describe insomnia disorder (ID) characterised by fatigue and sleepiness as diurnal consequences of nocturnal symptoms. However, patients with ID do not frequently report sleepiness in the clinical setting. The present study aimed to investigate subjective sleepiness in ID measured through the Epworth Sleepiness Scale (ESS) and its independence towards daytime functioning and fatigue, and to evaluate cognitive behavioural therapy for insomnia (CBT-I) improvement in daytime consequences and their relationship to sleepiness and fatigue. We retrospectively collected the ESS evaluation in a large sample of 105 healthy controls (HCs), 671 patients with ID, and 602 patients with sleep disorders characterised by excessive daytime sleepiness (EDS). Moreover, we conducted a pre-post evaluation of the ESS in a sub-sample of patients with ID who underwent CBT-I. Component 2 of the Insomnia Severity Index and Profile of Mood States-Fatigue Inertia Scale was used to evaluate daytime functioning and fatigue. Patients with ID reported ESS levels comparable to that observed in HCs and significantly lower than the EDS group. No significant correlation arose between ESS and the diurnal impact of the disorder, suggesting the independence between daytime functioning and sleepiness in ID. Contrarily, insomnia severity and diurnal impact significantly correlated with fatigue. Data showed a statistically significant increase in sleepiness after CBT-I, despite significantly improving daytime consequences and fatigue. Although diagnostic manuals report sleepiness and fatigue as daytime consequences of sleep symptoms in patients with ID, these retrospective data indicate a dissociation between these entities. This evidence aligns with the core feature of ID: the hyperarousal status that pervades patients also during wakefulness.

Polymorphisms in LRP2 and CUBN genes and their association with serum vitamin D levels and sleep apnea.

PURPOSE: Vitamin D deficiency has been associated with the occurrence of obstructive sleep apnea syndrome (OSAS). Megalin (LRP2) and cubilin (CUBN) are implicated in vitamin D metabolism, whereas LRP2 and CUBN polymorphisms have been previously associated with variable serum vitamin D levels. The present study aimed to evaluate the role of LRP2 rs2228171 c.8614C > T and CUBN rs1801222 c.758A > G polymorphisms in OSAS susceptibility, independently or in synergy with vitamin D levels. METHODS: Vitamin D serum concentration of consecutive individuals was measured. PCR-RFLP was used for LRP2 rs2228171 and CUBN rs1801222 genotyping. RESULTS: A total of 176 individuals was enrolled, including 144 patients with OSAS and 32 controls. Frequency of LRP2 rs2228171 c.8614 T and CUBN rs1801222 c.758G alleles was estimated at 22.4% and 79.8%, respectively. LRP2 and CUBN polymorphisms were not associated with OSAS occurrence (rs2228171Τ allele: 22.9% in OSAS group vs. 20.3% in controls, p = 0.651; rs1801222A allele 19.4% in OSAS group vs. 23.4% in controls, p = 0.471). Frequency of CUBN rs1801222A allele carriers was increased in patients with moderate or severe OSAS compared to mild OSAS (p = 0.028). Patients with OSAS homozygous for LRP2 CC and CUBN GG genotypes had lower vitamin D serum concentration compared to controls carrying the same genotype (18.0 vs 27.0 ng/mL, p = 0.006 and 19.0 vs 27.5 ng/mL, p = 0.007, respectively). CONCLUSION: CUBN rs1801222 polymorphism may affect OSAS severity. Among other factors, low vitamin D concentration is associated with OSAS occurrence, irrespectively of LRP2 and CUBN polymorphisms.

Lung Nodules and Hypoxemia: Any Association?

Pulmonary arteriovenous malformations (PAVMs) consist of aberrant circulation between pulmonary arteries and veins causing right-to-left shunt, uncommon and asymptomatic in the general population. We presented two patients, one presented with unexplained dyspnea and disease limited to the lung and the other with neurologic signs and systematic disease. Both patients were diagnosed with arteriovenous malformations and received embolization treatment successfully. Both patients received embolization treatment successfully.