0560 The Effect of Smoking on OSA Endotypes: A Retrospective Cohort Study

Introduction

Smoking is a purported risk factor for obstructive sleep apnea (OSA), but the mechanisms through which smoking may cause OSA are largely unclear. Our goal is to assess the effect of smoking on the pathophysiological traits (“endotypes”) underlying OSA.

Methods

Based on a chart review we are creating a retrospective cohort of consecutive patients who were newly diagnosed with OSA based on an inlab polysomnogram between 1/2016 and 6/2018 and who have a documented smoking status. For each subject we are quantifying the endotypes (e.g. arousal threshold, loop gain, upper airway muscle recruitment) via a validated polysomnography-based algorithm. Additionally, we are estimating the arousal threshold based on a clinical prediction score. We are comparing OSA endotypes (primary outcomes), sleep apnea severity (apnea-hypopnea index, SpO2 nadir) and sleep parameters (e.g. total sleep time, sleep efficiency, sleep stages) in current vs former vs never smokers using Kruskal-Wallis tests (+Dunn’s test for post hoc comparisons).

Results

To date we have screened 334 of 2,138 subjects and identified 99 eligible subjects (5 current smokers at the time of polysomnography, 37 former smokers, and 57 never smokers). The clinical arousal threshold was similar across groups (P=.69); polysomnography-based endotype measures are pending. Further, there was no significant difference in sleep apnea severity or sleep parameters across groups, except stage N2 which was less in current vs former smokers (median-percentage 48.5 vs 66.3%, P<.05) and less in never vs former smokers (61.6 vs 66.3%, P<.05).

Conclusion

Overall, former vs never smokers appear to be similar with regards to sleep and sleep apnea parameters. Prevalence of current smokers appears to be low (5%) in our cohort; larger sample size and polysomnography-based endotypes are needed before firm conclusions about the effects of smoking on OSA mechanisms can be reached (data collection continues).

Support

This study had no specific funding. Christopher Schmickl is supported by NIH T32 grant HL134632.

Accuracy of WatchPAT for the Diagnosis of Obstructive Sleep Apnea in Patients with Chronic Obstructive Pulmonary Disease

The co-existence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), termed the overlap syndrome (OVS), is associated with adverse outcomes that may be reversed with treatment. However, diagnosis is limited by the apparent need for in-laboratory polysomnography (PSG). WatchPAT is a portable diagnostic device that is validated for the diagnosis of OSA that might represent an attractive tool for the diagnosis of OVS.Subjects with established COPD were recruited from a general population. Subjects underwent PSG and simultaneous recording with WatchPAT. Pulmonary function testing and questionnaires were also performed.A total of 36 subjects were recruited and valid data was obtained on 33 (age 63 ± 7, BMI 28 ± 7, 61% male, FEV₁ 56 ± 20% predicted). There was no significant difference in the apnea-hypopnea index (AHI) between PSG and WatchPAT (19 ± 20 versus 20 ± 15 events/h; mean difference 2(-2, 5) events/h; p = 0.381). The AHI was not significantly different in rapid eye movement (REM) and non-rapid eye movement (NREM) determined by PSG versus REM and NREM determined by WatchPAT. WatchPAT slightly overestimated total and REM sleep time, and sleep efficiency. The sensitivity of WatchPAT at an AHI cut-off of ≥5, ≥15, and ≥30 events/h for corresponding PSG AHI cut-offs was 95.8, 92.3, and 88.9, respectively; specificity was 55, 65.0, and 95.8, respectively.WatchPAT is able to determine OSA reliably in patients with COPD. The availability of this additional diagnostic modality may lead to improved detection of OVS, which may in turn lead to improved outcomes for a group of COPD patients at high risk of poor outcomes.

Streptococcus bovis meningitis in an infant

Streptococcus bovis is a nonenterococcal, group D streptococcus which has been identified as a causative agent for serious human infections, including endocarditis, bacteremia, and septic arthritis. Several cases of adult S. bovis meningitis have been reported, usually in association with underlying disease. In the neonatal period, it is an uncommon agent of meningitis. We report, to our knowledge, the third documented case of neonatal S. bovis meningitis in the English language literature. As in the previous cases, this neonate showed no anatomical or congenital immunologic lesion which might be expected to predispose the patient to meningitis. Sequencing of the 16S ribosomal DNA gene was performed and a new PCR test was used to secure a more reliable identification of the strain.

Cementifying fibroma presenting as proptosis

Cementifying fibromas are rare fibro-osseous tumors that arise from the periodontal ligament. These tumors are usually small, asymptomatic lesions noted on routine dental radiography, but they can develop into aggressive, expansile masses. The authors report the case of a 12-year-old boy with a tumor involving the maxillary, ethmoid, and frontal sinuses that extended to the right orbit, causing proptosis and disfigurement of the right side of his face. Removal of the tumor with facial reconstruction resulted in significant improvement of vision, despite long-standing disc edema and tension on the optic nerve. On histopathologic examination the lesion was found to be a cementifying fibroma.

The Bethesda System. Impact on reporting cervicovaginal specimens and reproducibility of criteria for assessing endocervical sampling

This study examined the impact of applying the Bethesda System guidelines for specimen adequacy on cytopathologic diagnosis at the Johns Hopkins Hospital laboratory of cytopathology during a one-year period. Application of the Bethesda guidelines resulted in a 1.3% unsatisfactory rate. In addition, 3.8% of specimens were satisfactory but contained an inadequate endocervical component (IEC). Smears obtained after a cone biopsy or an initial IEC smear were IEC in 16.5% and 18.7% of cases, respectively. The IEC rate following an initial smear lacking an endocervical component was 11.8% in repeat specimens obtained with an endocervical brush as compared to 29.4% in those obtained with a spatula alone. The reproducibility of the Bethesda criteria for assessing endocervical sampling was evaluated by comparing the level of agreement between three independent reviewers examining 40 test cases. Three-way agreement was achieved in 75% of cases. Two-way agreement ranged from 80.0% to 87.5%. We conclude that implementation of the Bethesda System guidelines for assessing specimen adequacy should produce a minimal impact on cytopathologic reporting and gynecologic practice. Repeat specimens lacking an endocervical component may be encountered relatively frequently in certain subsets of patients.

Primary diagnosis of disseminated fungal disease by fine-needle aspiration of soft-tissue lesions

Two cases of disseminated fungal infections diagnosed by fine-needle aspiration of soft-tissue masses are presented. Both patients were initially treated on an outpatient basis for a presumed musculoskeletal disorder before the diagnostic biopsy was obtained. The first patient apparently contracted Coccidioides immitis infection while residing in Arizona, but the diagnosis was rendered on an aspirate of a buttock mass performed in Boston. The second patient, a non-insulin-dependent diabetic, was diagnosed with a cryptococcal abscess on an aspirate of a shoulder mass performed in the emergency room. The diagnosis of coccidioidomycosis was confirmed by culture and that of Cryptococcus by serology. Fungal infection was clinically unsuspected in both patients and the cytologic diagnosis facilitated rapid implementation of therapy.

A haemorheological study of lignocaine

Eight volunteers received lignocaine 75 mg i.m. Peak plasma lignocaine concentrations (mean 0.80 microgram ml-1; range 0.31-1.86 micrograms ml-1) were attained at 30 min. Haematocrit and red cell deformability remained unchanged. Lignocaine caused small but significant decreases in plasma viscosity and whole blood viscosity at both high and low shear rates (94 and 0.94 s-1). The small reductions in plasma viscosity and high shear blood viscosity observed ex vivo may be the result of alterations in plasma proteins. The reductions in low shear blood viscosity are considered to result from decreased red cell aggregation.