Age modulates the predictive value of self-reported sleepiness for all-cause mortality risk: insights from a comprehensive national database of veterans.

STUDY OBJECTIVES: Excessive daytime sleepiness (EDS) is prevalent and overwhelmingly stems from disturbed sleep. We hypothesized that age modulates the association between EDS and increased all-cause mortality. METHODS: We utilized the Veterans' Health Administration data from 1999-2022. We enrolled participants with sleep related ICD9/10 codes or sleep services. A natural language processing (NLP) pipeline was developed and validated to extract the Epworth Sleepiness Scale (ESS) as a self-reported tool to measure EDS from physician progress notes. The NLP's accuracy was assessed through manual annotation of 470 notes. Participants were categorized into Normal-ESS, n-ESS, (ESS 0-10) and high-ESS, h-ESS, (ESS 11-24). We created three age groups: < 50 years; 50 to < 65 years; and ≥ 65 years. The adjusted odds ratio (aOR) of mortality was calculated for age, BMI, sex, race, ethnicity, and the Charlson Comorbidity Index (CCI), using n-ESS as the reference. Subsequently, we conducted age stratified analysis. RESULTS: The first ESS records were extracted from 423,087 veterans with a mean age of 54.8 (±14.6), mean BMI of 32.6 (±6.2), and 90.5% male. The aOR across all ages was 17% higher (1.15,1.19) in the h-ESS category. The aORs only became statistically significant for individuals aged ≥ 50 years in the h-ESS compared to the n-ESS category (< 50 years: 1.02 [0.96,1.08], 50 to < 65 years 1.13[1.10,1.16]; ≥ 65 years: 1.25 [1.21-1.28]). CONCLUSIONS: High ESS, predicted increased mortality only in participants aged 50 and older. Further research is required to identify this differential behavior in relation to age.

Comparison of Ring Pulse Oximetry Using Reflective Photoplethysmography and PSG in the Detection of OSA in Chinese Adults: A Pilot Study.

Objective: A novel ring-worn oximeter (Circul) uses reflective photoplethysmography and automated signal processing to calculate oxygen desaturations. We evaluated the ability of Circul to detect obstructive sleep apnea in Chinese adults. Methods: We recruited 207 Chinese Han subjects: 70% males, mean age 48.2±14.7 years, mean BMI 27.6±4.8 kg/m2 and mean AHI 28.6±25.2 events/h. All participants underwent simultaneous polysomnography (PSG) and Circul testing in a sleep laboratory. Oxygen desaturation index (ODI), mean oxygen saturation (MSpO2), cumulative time at SpO2<90% (CT90), cumulative percentage of sleep time spent with SpO2<90% (CT90/TST) were derived and compared for the Circul and the PSG. Results: The ODI was 25.3±24.5 events/h using PSG and 22.2±24.5 events/h using Circul (P<0.0001), with an intraclass correlation coefficient (ICC) of 0.884. CT90 and CT90/TST between the two methods were not different; the MSpO2 level calculated by PSG was slightly lower than Circul, 95.0% (93.0-96.0%) vs 95.3% (93.9-96.6%), P<0.0001. Circul-ODI had a good correlation (r=0.91, p<0.0001) and close agreement with PSG-AHI (Bland-Altman analysis: Mean Difference 6.4, 95% CI -14.8 to 27.5 events/h). Using a threshold of AHI ≥5 events/h, the Circul had 87% sensitivity, 83% specificity, 5.09 positive likelihood ratio (LR+), 86% accuracy, and 0.929 area under the curve (AUC). Conclusion: Circul ring pulse oximetry can detect OSA with reasonable reliability. The Circul system is a reliable and comfortable choice for OSA assessment.

Can the complete blood count be used as a reliable screening tool for obstructive sleep apnea?

PURPOSE: Since hypoxia increases erythropoietin production and inflammation, the complete blood count (CBC) has been proposed as an inexpensive alternative for obstructive sleep apnea (OSA) screening. The objective of this study was to determine whether or not intermittent hypoxia and OSA severity, as measured by the mean oxygen saturation (SpO2) and apnea-hypopnea index (AHI), affect parameters measured by the CBC. METHODS: This retrospective study included a total of 941 surgical patients who had a pre-operative home sleep study. The pre-operative CBC was extracted from the electronic patient records. Patients were stratified according to their AHI scores, into mild (AHI ≥ 5 - < 15), moderate (AHI ≥ 15 - < 30), and severe (AHI ≥ 30) OSA groups. RESULTS: There were 244 patients without OSA, 294 with mild, 223 with moderate, and 180 with severe OSA. Our analysis showed that hemoglobin (P = 0.010), hematocrit (P = 0.027), and basophils (P = 0.006) showed significant changes among the different severities of OSA. For mean SpO2, there were negative associations with body mass index (r = - 0.287; P < 0.001), age (r = - 0.077; P = 0.021), hemoglobin (r = - 0.208; P < 0.001), hematocrit (r = - 0.220; P < 0.001), red blood cells (r = - 0.107; P = 0.001), mean corpuscular volume (MCV) (r = - 0.159; P < 0.001), mean corpuscular hemoglobin (r = - 0.142; P < 0.001), and basophils (r = - 0.091; P = 0.007). All analyzed parameters remained within normal clinical range. Multivariable regression identified hemoglobin, MCV, and basophils to be independent predictors of mean SpO2 and AHI. CONCLUSION: Hemoglobin, MCV, and basophils were independently associated with intermittent hypoxia defined by mean SpO2 and AHI. Adding CBC parameters to other screening tools for OSA may have additional value due to its association with changes in mean SpO2.