EVALUATION OF A MODIFIED EPWORTH SLEEPINESS SCALE TO RELIABLY ASSESS EXCESSIVE DAYTIME SLEEPINESS IN LOW-INCOME COUNTRIES: RESULTS FROM THE BENIN SOCIETY AND SLEEP (BESAS) STUDY

Background

The Epworth Sleepiness Scale (ESS) is a tool widely used to assess excessive daytime sleepiness. Unfortunately, it is not reliable in low-income countries where situations such as reading a book, watching TV or driving a car are not common. The aim of this study was thus to assess the performance of a modified version of the Epworth scale in a low-income country.

Methods

We used data from the Benin Society and Sleep (BeSAS) study where the ESS and a modified ESS (mESS) were administered to participants. In the mESS, questions four questions over eight were redesigned to reflect common living situations in Benin. The internal coherence of the mESS was assessed using the Cronbach alpha coefficient (CAC). The discriminatory ability of the scale was assessed by comparing the mean scores according to reported sleep quality, insomnia complaints and apnea-hypopnea index (AHI).

Results

A total of 2909 participants were recruited, 1129 were male (38.9%) with a mean age (SD) of 44.7 (14.5) y. Overall, 52.4% (1526) completed all the mESS questions while 453 (15.6%) completed the standard ESS. The CAC of the mES was 0.86 showing good internal coherence. Concerning the discriminatory ability, mean scores for mESS were 7.8 for participants with ISI < 8 vs 9.2 for participants with ISI≥8 (p<0.001), 7.8 for participants withPSQI<5 vs 8.3 for participants with PSQI≥5 (p=0.03). No difference was found when comparing the participants participants using different cut-offs of AHI (15 and 30).

Conclusion

The mES is more reliable than ES in the Beninese population. mESS shows good internal coherence and differentiates between insomniacs vs non-insomniacs and between good and poor sleepers. Although the mES is not a perfect score, it appears more relevant in the Benin population than the original Epworth scale but needs further validation/improvement in other low-income countries.

PERFORMANCE OF SIX SCREENING SCORES FOR OBSTRUCTIVE SLEEP APNOEA IN AN AFRICAN POPULATION

Introduction

A screening tool for obstructive sleep apnoea (OSA) is useful in low-income countries where it may be difficult to access sleep recordings. The objective of this study was to assess the performance of six screening scores compared with objective sleep recording in an African population sample.

Methods

This analysis is based on the "Benin Sleep and Society" (BeSAS) populational study in which respiratory polygraphy (PG) was performed using a type III device and OSA screening questionnaires (STOP, STOP-Bang, Berlin, NOSAS [≥ 8 and ≥ 5), No-Apnea, GOAL) were administered to participants. PG-defined OSA severity categories were defined according to the apnoea-hypopnoea index (AHI): mild (AHI 5 to <15/h), moderate (AHI 15 to <30/h) or severe (AHI≥30/h), and these were compared to score findings.

Results

A total of 1810 subjects (mean age 45.4±14.6 years; 57.3% women) were included. For moderate to severe OSA, the area under the receiving operating characteristic (ROC) curve was greatest for GOAL and No-Apnea (0.70), followed by NoSAS5 (0.69). The highest sensitivity values were for NoSAS5 (0.73), No-Apnea (0.72), and GOAL (0.69), while NoSAS8 had the highest specificity (0.91), followed by Berlin (0.88) and GOAL (0.71). All scores performed poorly with respect to the positive predictive value (PPV), which was highest with NoSAS8 (0.38). Conclusion: This study provides the first comparison of the performance of screening scores for OSA in an African population. Although still low, PPV was highest with NoSAS8. Hence, NoSAS8 would be the screening method of choice for OSA in resource-constrained settings where formal sleep recordings are not accessible.

Effect of oxybutynin and reboxetine on obstructive sleep apnea: a randomized, placebo-controlled, double blind, crossover trial

STUDY OBJECTIVES

Although recent investigations combining noradrenergic and antimuscarinic drugs have shown promising short-term results to treat obstructive sleep apnea (OSA), the mid-term effect and optimal dosage remain uncertain. The present study aimed to evaluate the effect of one week of 5 mg oxybutynin and 6 mg reboxetine (oxy-reb) on OSA versus placebo.

METHODS

We performed a randomized, placebo-controlled, double-blind, crossover trial comparing the effect of one week of oxy-reb versus one week of placebo on OSA severity. At-home polysomnography was performed at baseline and after each week of intervention.

RESULTS

Fifteen participants (male 66.7%) aged 59 [44-62] years (median [interquartile range]) with a mean body mass index of 33.1 ± 6.6 kg.m -2 were included. No significant difference in apnea-hypopnea index (AHI) was observed between conditions (estimated marginal means (95% confidence interval) at baseline: 39.7 (28.5-55.3); oxy-reb: 34.5 (22.7-52.3); placebo: 37.9 (27.1-52.9); p=0.652), but oxy-reb improved average oxygen desaturation (p=0.016) and hypoxic burden (p=0.011) and lowered sleep efficiency (p=0.019) and rapid eye movement (REM) sleep (p=0.002). Moreover, participants reported reduced sleep quality during the week of oxy-reb compared to the week of placebo (4.7 (3.5; 5.9) vs. 6.5 (5.5; 7.5) on a 0-10 visual analogic scale, respectively; p=0.001). No significant differences in sleepiness, vigilance and fatigue were observed. No serious adverse events occurred.

CONCLUSION

Administration of oxybutynin 5 mg and reboxetine 6 mg did not improve OSA severity assessed by AHI, but did alter sleep architecture and sleep quality. Reduced average oxygen desaturation and hypoxic burden were also observed.

0699 Effect Of Kidney Transplantation On Sleep Apnea Severity: A Prospective Controlled Polysomnographic Study

Introduction

Renal failure-associated fluid overload has been associated with a high prevalence of sleep apnea (SA) in patients with end-stage kidney disease (ESKD). Kidney transplantation has been shown to restore a normal renal function but its effect on SA remains unclear. In this prospective study, we hypothesized that improvement of kidney function and hydration status after kidney transplantation (Tx) may result in an improvement of SA severity.

Methods

A total of 196 patients on kidney transplant waiting list were screened for SA using home nocturnal polysomnography (PSG) to measure the Apnea-Hypopnea Index (AHI) and underwent bioimpedance to assess body composition. Polysomnography and bioimpedance were repeated 6 months after kidney transplant. Patients still on the waiting list after 6 months underwent same investigations as a control group.

Results

Of 88 participants (44.9%) with SA (AHI ≥15/h) at baseline, 42 patients were reassessed 6 months post-Tx and were compared to 27 control patients remaining on the waiting list after 6 months. There was a significant, although partial, post-Tx improvement in SA severity as measured by the AHI (from 44.2±24.3/h to 34.7±20.9/h, p=0.02), with a concomitant reduction in body water (from 54.9% to 51.6%, p=0.003), suggesting a causal implication of fluid overload. A post-Tx increase in body fat mass (from 26% to 30%, p=0.003) may have blunted the beneficial impact of kidney Tx on SA. These parameters remained unchanged in the control group.

Conclusion

SA is a frequent condition in ESKD patients. Kidney transplantation is associated with a reduction of fluid overload but an increase in fat mass, yielding only a partial improvement in SA severity. These results suggest that SA should be systematically assessed before and after kidney Tx

Support

Swiss Kidney Foundation, the Pulmonary League and the Organ Transplant Foundation of Lausanne

Body Silhouette Trajectories Over the Lifespan and Insomnia Symptoms: The Paris Prospective Study 3

Insomnia symptoms are highly prevalent and associated with several adverse medical conditions, but only few determinants, including non-modifiable ones, have been highlighted. We investigated associations between body silhouette trajectories over the lifespan and insomnia symptoms in adulthood. From a community-based study, 7 496 men and women aged 50–75 years recalled their body silhouette at age 8, 15, 25, 35 and 45, and rated the frequency of insomnia symptoms on a standardized sleep questionnaire. An Epworth Sleepiness Scale ≥11 defined excessive daytime sleepiness (EDS). Using a group-based trajectory modeling, we identified five body silhouette trajectories: a ‘lean-stable’ (32.7%), a ‘heavy-stable’ (8.1%), a ‘moderate-stable’ (32.5%), a ‘lean-increase’ (11%) and a ‘lean-marked increase’ (15.7%) trajectory. In multivariate logistic regression, compared to the ‘lean-stable’ trajectory, the ‘lean-marked increase’ and ‘heavy-stable’ trajectories were associated with a significant increased odd of having ≥1 insomnia symptoms as compared to none and of having a proxy for insomnia disorder (≥1 insomnia symptom and EDS). The association with the ‘lean-marked increase' trajectory’ was independent from body mass index measured at study recruitment. In conclusion, increasing body silhouette over the lifespan is associated with insomnia symptoms in adulthood, emphasizing the importance of weight gain prevention during the entire lifespan.

Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study

BACKGROUND

Sleep-disordered breathing is associated with major morbidity and mortality. However, its prevalence has mainly been selectively studied in populations at risk for sleep-disordered breathing or cardiovascular diseases. Taking into account improvements in recording techniques and new criteria used to define respiratory events, we aimed to assess the prevalence of sleep-disordered breathing and associated clinical features in a large population-based sample.

METHODS

Between Sept 1, 2009, and June 30, 2013, we did a population-based study (HypnoLaus) in Lausanne, Switzerland. We invited a cohort of 3043 consecutive participants of the CoLaus/PsyCoLaus study to take part. Polysomnography data from 2121 people were included in the final analysis. 1024 (48%) participants were men, with a median age of 57 years (IQR 49-68, range 40-85) and mean body-mass index (BMI) of 25·6 kg/m(2) (SD 4·1). Participants underwent complete polysomnographic recordings at home and had extensive phenotyping for diabetes, hypertension, metabolic syndrome, and depression. The primary outcome was prevalence of sleep-disordered breathing, assessed by the apnoea-hypopnoea index.

FINDINGS

The median apnoea-hypopnoea index was 6·9 events per h (IQR 2·7-14·1) in women and 14·9 per h (7·2-27·1) in men. The prevalence of moderate-to-severe sleep-disordered breathing (≥15 events per h) was 23·4% (95% CI 20·9-26·0) in women and 49·7% (46·6-52·8) in men. After multivariable adjustment, the upper quartile for the apnoea-hypopnoea index (>20·6 events per h) was associated independently with the presence of hypertension (odds ratio 1·60, 95% CI 1·14-2·26; p=0·0292 for trend across severity quartiles), diabetes (2·00, 1·05-3·99; p=0·0467), metabolic syndrome (2·80, 1·86-4·29; p<0·0001), and depression (1·92, 1·01-3·64; p=0·0292).

INTERPRETATION

The high prevalence of sleep-disordered breathing recorded in our population-based sample might be attributable to the increased sensitivity of current recording techniques and scoring criteria. These results suggest that sleep-disordered breathing is highly prevalent, with important public health outcomes, and that the definition of the disorder should be revised.

FUNDING

Faculty of Biology and Medicine of Lausanne, Lausanne University Hospital, Swiss National Science Foundation, Leenaards Foundation, GlaxoSmithKline, Ligue Pulmonaire Vaudoise.

[Positional obstructive sleep apnea syndrome]

Obstructive sleep apnea (OSA) tends to worsen on the supine posture due to the effect of gravity on tongue position. In some cases, OSA is present exclusively on the supine posture (exclusive postural OSA). These patients may benefit from positional therapy (PT), which aim is to prevent sleep in the supine posture using different types of devices. Before opting for this therapeutic option, a sleep study with PT should be perform in order to confirm its efficacy and assess the patients' tolerance. Because the efficacy of PT is inferior to continuous positive airway pressure (CPAP), the latter treatment remains the first line of therapy. Also, the discomfort of the existing devices appears to limit the long term use of PT. Further studies assessing the long term effects of PT on metabolic and neurocognitive outcomes are needed.

[HypnoLaus sleep cohort study]

Normal sleep patterns and prevalence of sleep disorders in the general population are largely unknown. The aim of HypnoLaus cohort study is to record sleep and analyze sleep characteristics in a large population-based sample, which had undergone comprehensive genetic, somatic, and psychiatric investigations. Full polysomnography has already been performed in more than 1100 middle aged men and women randomly selected from Lausanne general population (goal 2000-3000 sleep recordings). Over 4000 additional subjects from the same population have filled various questionnaires on their sleep habits and complaints. These results combined with genetic, cardiovascular, metabolic, and psychiatric data provide a unique opportunity to determine the interaction between sleep, its genetic determinants and cardiovascular, psychiatric, or metabolic diseases.

Restless legs syndrome and low brain iron levels in patients with haemochromatosis

Regional brain iron levels of two patients with haemochromatosis and severe restless legs syndrome (RLS) were assessed using R2' magnetic resonance imaging (MRI) sequences in both patients and in nine healthy controls. R2' relaxation rates in the patients were decreased in the substantia nigra, red nucleus, and pallidum when compared with the controls. These results indicate that local brain iron deficiency may occur in patients with haemochromatosis and suggest a role for brain iron metabolism in the pathophysiology of RLS.

Performance vigilance task and sleepiness in patients with sleep-disordered breathing

Altered vigilance performance has been documented in patients with sleep-related breathing disorders (SRBDs). Sleep fragmentation, sleepiness, respiratory disturbances and nocturnal hypoxaemia have been suggested as the pathogenesis of these deficits, yet it remains difficult to find a good correlation between performance deficits and the above factors. In the present study, which performance measure better characterised SRBD patients and the main factors implicated in these disturbances were examined. The study group consisted of 152 patients and 45 controls, all examined using a performance vigilance task and subjective sleepiness assessment. Speed and accuracy in the psychomotor vigilance task (PVT) were measured in patients and controls. Objective daytime sleepiness was assessed in the patient group using the maintenance of wakefulness test. In comparison with controls, PVT accuracy rather than speed seems to be affected in SRBD patients, with lapses and false responses significantly greater in patients with more severe objective sleepiness and higher apnoea/hypopnoea index. Although slowing and increased variability in reaction time were associated with shorter sleep latency in the maintenance of wakefulness test, subjective sleepiness, sleep fragmentation, nocturnal hypoxaemia and apnoea/hypopnoea index influenced mainly PVT accuracy. It is concluded that vigilance impairment, sleep fragmentation and severity of disease may partially and differentially contribute to the diurnal performance consequences found in sleep-related breathing disorders. Since the psychomotor vigilance task worsening is more marked in accuracy that in speed, measurement of lapses and false responses would better characterise the degree of diurnal impairment in these patients.