Clinical characteristics, comorbidities, and response to treatment of veterans with obstructive sleep apnea, Cincinnati Veterans Affairs Medical Center, 2005-2007

Largest Neck Circumference Associated With Obstructive Sleep Apnea: A Case Report

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder associated with obesity markers such as neck circumference (NC), waist circumference (WC), and body mass index (BMI). A greater NC has been linked to a higher risk of OSA. To date, the largest reported NC has been 20.5 inches. We present a case of a patient who came to our clinic for OSA management and was found to have an NC of 25 inches, the largest reported to date. The primary objective of this case is to stimulate discussion and research on the specific limits of NC that indicate a higher risk of OSA, the impact of extreme obesity on the severity of the condition and its treatment challenges, and the importance of basic physical measurements of NC in assessing a patient's level of risk and providing appropriate care. This case highlights an extreme clinical observation of a common medical problem. It illustrates the importance of physical examination findings and their relevance in OSA.

Effect of cloud-based sleep coaches on positive airway pressure adherence

STUDY OBJECTIVES

Decreased early positive airway pressure (PAP) adherence is predictive of poor long-term adherence. We hypothesized that cloud-based sleep coaches (CBSC) providing protocol-driven live telephone contact with patients starting treatment would improve early adherence.

METHODS

At PAP set-up patients were randomized to: (1) standard care (SC) including respiratory therapist PAP setup, wireless adherence monitoring, and elective use of a mobile adherence feedback application (PAPapp); or (2) SC+CBSC. Primary 3-month endpoints were adherence (all nights, nights used, % of nights ≥ 4 hours use, and % participants with ≥ 4 hours use on ≥ 70% of nights [% ≥ 4 ≥ 70%]) and secondary endpoints were change in Epworth sleepiness scale (ESS) and satisfaction with treatment and PAPapp use.

RESULTS

Two hundred fifty participants were randomized (SC 126, SC+CBSC 124). Characteristics SC versus SC+CBSC (mean ± SD) for age (55.2 ± 13.4 versus 54.9 ± 11.5 years), diagnostic apnea-hypopnea index (36.7 ± 21.1 versus 36.6 ± 20.6 events/h), and ESS (10.8 ± 6.1 versus 11.2 ± 6.0) did not differ. At 3 months, the % of days with ≥ 4 hours of PAP use (SC: 48.1 ± 36.8% versus SC+CBSC: 57.9 ± 35.4%, P = 0.032), use all nights (SC:3.7 ± 2.7 hours versus SC + CBSC: 4.4 ± 2.6 hours, P=0.027), and PAPapp use satisfaction were greater with SC+CBSC (intention to treat analysis). The [% ≥ 4 ≥ 70%] did not differ between groups in the intention to treat analysis but was higher in those completing CBSC interventions. The ESS improvement and patient satisfaction did not differ between groups.

CONCLUSIONS

The CBSC system improved PAP adherence at 3 months.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: ThErapy Adherence Management in Veterans; Identifier: NCT03243487; URL: https://clinicaltrials.gov/ct2/show/NCT03243487.

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy

INTRODUCTION

Obstructive sleep apnea (OSA) results in chronic intermittent hypoxia leading to systemic inflammation, increases in pro-inflammatory cytokines TNF-Alpha and IL-6, and increased risk for a number of life threatening medical disorders such as cardiovascular and kidney disease.

METHODS

A BioPlex Array was used to examined the serum levels of four cytokines also expressed in endothelial cells and/or macrophages and associated with cardiovascular and kidney disease risk.

RESULTS

Relative to untreated OSA patients, airways treated OSA patients had a 5.4-fold higher median level of MMP2 (p = 9.1x10-11), a 1.4-fold higher level of TWEAK (p = 1.8x10-7), a 1.7-fold higher level of CD163 (p = 1.4x10-6), but a 2.0-fold lower level of MMP3 (p = 7.9x10-7). Airway treatment resulted in levels more similar to or indistinguishable from control subjects. Both t-SNE or UMAP analysis of the global structure of these multi-dimensional data revealed two data clusters, one populated primarily with data for controls and most airways treated OSA patients and a second populated primarily with data for OSA patients.

DISCUSSION

We discuss a concept in which the aberrant levels of these cytokines in untreated OSA patients may represent a chronic response after years of experiencing intermittent nightly hypoxia, which attenuated the acute response to hypoxia. A balanced therapeutic correction of the aberrant levels of these cytokines may limit the progression of CVD and kidney disease in OSA patients.

Patients with obstructive sleep apnea have suppressed levels of soluble cytokine receptors involved in neurodegenerative disease, but normal levels with airways therapy

Purpose

Obstructive sleep apnea (OSA) results in systemic intermittent hypoxia. By one model, hypoxic stress signaling in OSA patients alters the levels of inflammatory soluble cytokines TNF and IL6, damages the blood brain barrier, and activates microglial targeting of neuronal cell death to increase the risk of neurodegenerative disorders and other diseases. However, it is not yet clear if OSA significantly alters the levels of the soluble isoforms of TNF receptors TNFR1 and TNFR2 and IL6 receptor (IL6R) and co-receptor gp130, which have the potential to modulate TNF and IL6 signaling.

Methods

Picogram per milliliter levels of the soluble isoforms of these four cytokine receptors were estimated in OSA patients, in OSA patients receiving airways therapy, and in healthy control subjects. Triplicate samples were examined using Bio-Plex fluorescent bead microfluidic technology. The statistical significance of cytokine data was estimated using the nonparametric Wilcoxon rank-sum test. The clustering of these high-dimensional data was visualized using t-distributed stochastic neighbor embedding (t-SNE).

Results

OSA patients had significant twofold to sevenfold reductions in the soluble serum isoforms of all four cytokine receptors, gp130, IL6R, TNFR1, and TNFR2, as compared with control individuals (p = 1.8 × 10⁻¹³ to 4 × 10⁻⁸). Relative to untreated OSA patients, airways therapy of OSA patients had significantly higher levels of gp130 (p = 2.8 × 10⁻¹³), IL6R (p = 1.1 × 10⁻⁹), TNFR1 (p = 2.5 × 10⁻¹⁰), and TNFR2 (p = 5.7 × 10⁻⁹), levels indistinguishable from controls (p = 0.29 to 0.95). The data for most airway-treated patients clustered with healthy controls, but the data for a few airway-treated patients clustered with apneic patients.

Conclusions

Patients with OSA have aberrantly low levels of four soluble cytokine receptors associated with neurodegenerative disease, gp130, IL6R, TNFR1, and TNFR2. Most OSA patients receiving airways therapy have receptor levels indistinguishable from healthy controls, suggesting a chronic intermittent hypoxia may be one of the factors contributing to low receptor levels in untreated OSA patients.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02205-y) contains supplementary material, which is available to authorized users.

Obstructive Sleep Apnoea in Pakistan: A Single Tertiary Care Center Experience

INTRODUCTION

Considerable interest has been shown in the field of sleep medicine in recent decades. Obstructive sleep apnoea (OSA) is a common condition that remains neglected in most parts of the world. Data are scarce, if any, when it comes to developing countries. We sought to describe the patient population in a single private tertiary care center from such a country.

MATERIALS AND METHODS

A cross-sectional study that included a total of 203 patients over a five-year period was conducted. Polysomnographic studies were conducted in a dedicated sleep laboratory, under the supervision of sleep physicians. Data were described and analyzed based on clinical and self-reported outcomes, as well as polysomnographic characteristics, and compared them between genders and severity.

RESULTS

With the participants having an average age of 50.84 years and a BMI of 34.7 kg/m², the study found that the increase in age and BMI was significantly correlated with an increase in the severity of obstructive sleep apnea in the Pakistani population. There was a significant difference in sleep latency (20.6 min in women vs. 10.8 min in men; p-value = 0.001) and efficiency (63.7% in women vs. 69.8 in men; p-value = 0.02) between the two genders. Decreases in nadir saturation, total sleep time, and sleep latency were also associated with an increase in the level of severity.

CONCLUSION

There is a dire need for Pakistani, and in extension Asian, medical professionals to ramp up their pace to meet the needs of their population with regard to sleep medicine.

Utility of home sleep apnea testing in high-risk veterans

PURPOSE

Many Veterans Affairs Medical Centers (VAMCs) have implemented home sleep apnea testing (HSAT) in lieu of traditional in-lab testing to establish a timely and cost-sensitive diagnosis of obstructive sleep apnea (OSA). However, concern remains for the sensitivity and specificity of said technology in this population as many veterans are at increased risk for many of the comorbid conditions that can limit the accuracy of HSAT results. Hence, the purpose of this study is to evaluate rate of incongruent outcomes (e.g., negative HSAT results despite high clinical symptomology) as well as differences in study quality metrics and predictors of OSA between veteran sleep patients and general sleep patients being evaluated by a home sleep test.

METHODS

A random sample of HSAT outcomes from 1500 veterans and 1500 general sleep clinic patients was retrieved from a repository of anonymized HSAT outcomes from 2009 to 2013. General sleep clinic data were from patients referred for home sleep testing from a variety of clinical practices across North America, whereas VAMC patients were tested using a central dissemination process. All patients were tested for OSA using the Apnea Risk and Evaluation System (ARES), an HSAT that simultaneously records airflow, pulse oximetry, snoring, accelerometry, and EEG. Sample differences and rates of comorbidities, HSAT outcomes, predictors of OSA, and pretest OSA risk information were evaluated between groups. The presence of OSA was defined as an apnea-hypopnea index (AHI; using 4% desaturation criterion) of ≥5 and ≥15 events per hour. Sample differences in predictors of OSA were evaluated using logistic multiple regression.

RESULTS

Veterans (91.3% male) were more likely to report comorbidities, especially depression, insomnia, hypertension, diabetes, restless legs syndrome (RLS), and use of sleep and pain medications compared to general sleep clinic patients (57.1% male). Despite differences in the rate of medical comorbidities, no differences were observed between groups with regard to rates of positive studies, study integrity indicators, or predictors of OSA. Veterans, on average, had 30 min less recording time compared to those in the general clinic sample (p < .01). However, these differences did not impact the amount of the record that was deemed valid nor were veterans more likely to have wakefulness after sleep onset. Predictors of OSA for both groups included advancing age, and increased measures of adiposity (neck circumference and BMI). Mean AHI and respiratory disturbance index (RDI) were statistically similar for both groups and were similar for sleep stage and position.

CONCLUSIONS

Home sleep apnea testing for the diagnosis of OSA appears to yield similar results for VAMC patients deemed at high risk for OSA as it does with general sleep clinic patients.

Clinical and polysomnographic predictors of severe obstructive sleep apnea in the South Indian population

Background:

With the emergence of lifestyle diseases in epidemic proportions, obstructive sleep apnea (OSA) is being increasingly recognized in less developed countries as well.

Aim:

We sought to study the demographic, clinical, and polysomnographic (PSG) predictors of OSA severity in a cohort of South Indian patients.

Materials and Methods:

Consecutive patients with PSG proven OSA [apnea hypopnea index (AHI) ≥5/h] were prospectively recruited. The study period was from January 2012 to December 2012. Demographic data, history of vascular risk factors, substance abuse, sleep quality, snoring, and witnessed apneas were collected using a structured pro forma. In addition, PSG variables such as AHI, sleep latency and efficiency, duration of slow wave and rapid eye movement (REM) sleep, and other parameters were collected. Correlations between AHI severity and clinical and PSG parameters were done.

Results:

There were 152 (119 males and 33 females) subjects with a mean age of 53.8 years and body mass index (BMI) of 29.31. Mean AHI was 36.2/h (range: 5.1-110) and 66 subjects had severe OSA. Around 12% had the presenting complaint as insomnia, mainly of sleep maintenance. Of the subjects, 35% had witnessed apneas and 67% had excessive daytime sleepiness (EDS); 40% of patients had ≥2 risk factors. PSG parameters showed short sleep onset latency with a high arousal index. Mean apnea duration was 24.92 s. We found that age >55 years, BMI >25 kg/m², witnessed apneas, EDS, hypertension, dyslipidemia, reduced slow wave sleep duration, mean apnea duration >20 s, and desaturation index >10/h correlated well with OSA severity while the arousal index, sleep latency and efficiency, and exposure to smoking and alcohol showed no association.

Conclusions:

Older subjects with witnessed apneas are likely to have more severe OSA. Even though overall sleep architecture was similar between the groups, severe OSA had shorter slow wave sleep, longer apneas, and higher nocturnal hypoxemia.

Obstructive sleep apnea and type 2 diabetes: is there a link?

Type 2 diabetes is a chronic illness that is increasing in epidemic proportions worldwide. Major factors contributing to the development of type 2 diabetes include obesity and poor lifestyle habits (e.g., excess dietary intake and limited physical activity). Despite the proven efficacy of lifestyle interventions and the use of multiple pharmacological agents, the economic and public health burden of type 2 diabetes remains substantial. Obstructive sleep apnea (OSA) is a treatable sleep disorder that is pervasive among overweight and obese adults, who represent about two thirds of the U.S. population today. An ever-growing number of studies have shown that OSA is associated with insulin resistance, glucose intolerance and type 2 diabetes, independent of obesity. Evidence from animal and human models that mimic OSA provides potential mechanisms for how OSA may alter glucose metabolism. Up to 83% of patients with type 2 diabetes suffer from unrecognized OSA and increasing severity of OSA is associated with worsening glucose control. However, it is still unclear whether OSA may lead to the development of diabetes over time. More data from large-scale longitudinal studies with rigorous assessments of diabetes and OSA are needed. In addition, there is still controversy whether continuous positive airway pressure (CPAP) treatment of OSA improves glucose metabolism. Large-scale randomized-controlled trials of CPAP treatment of OSA with well-validated assessments of insulin sensitivity and glucose tolerance are needed. These studies may reveal that OSA represents a novel, modifiable risk factor for the development of prediabetes and type 2 diabetes.