Mahssa Karimi

A sleep apnea-related risk of motor vehicle accidents is reduced by continuous positive airway pressure: Swedish traffic accident registry data

STUDY OBJECTIVES Obstructive sleep apnea (OSA) is associated with an increased risk of motor vehicle accidents (MVAs). The rate of MVAs in patients suspected of having OSA was determined and the effect of continuous positive airway pressure (CPAP) was investigated. DESIGN MVA rate in patients referred for OSA was compared to the rate in the general population using data from the Swedish Traffic Accident Registry (STRADA), stratified for age and calendar year. The risk factors for MVAs, using demographic and polygraphy data, and MVA rate before and after CPAP were evaluated in the patient group. SETTING Clinical sleep laboratory and population based control (n = 635,786). PATIENTS There were 1,478 patients, male sex 70.4%, mean age 53.6 (12.8) y. INTERVENTIONS CPAP. MEASUREMENTS AND RESULTS The number of accidents (n = 74) among patients was compared with the expected number (n = 30) from a control population (STRADA). An increased MVA risk ratio of 2.45 was found among patients compared with controls (P < 0.001). Estimated excess accident risk was most prominent in the elderly patients (65-80 y, seven versus two MVAs). In patients, driving distance (km/y), EDS (Epworth Sleepiness score ≥ 16), short habitual sleep time (≤5 h/night), and use of hypnotics were associated with increased MVA risk (odds ratios 1.2, 2.1, 2.7 and 2.1, all P ≤ 0.03). CPAP use ≥ 4 h/night was associated with a reduction of MVA incidence (7.6 to 2.5 accidents/1,000 drivers/y). CONCLUSIONS The MVA risk in this large cohort of unselected patients with OSA suggests a need for accurate tools to identify individuals at risk. Sleep apnea severity (e.g., apnea-hypopnea index) failed to identify patients at risk.

Impaired vigilance and increased accident rate in public transport operators is associated with sleep disorders

OBJECTIVES Sleep disturbances can impair alertness and neurocognitive performance and increase the risk of falling asleep at the wheel. We investigated the prevalence of sleep disorders among public transport operators (PTOs) and assessed the interventional effects on hypersomnolence and neurocognitive function in those diagnosed with obstructive sleep apnea (OSA). METHODS Overnight polygraphy and questionnaire data from 101 volunteers (72 males, median age 48 range [22-64] years, 87 PTOs) employed at the Gothenburg Public Transportation Company were assessed. Treatment was offered in cases with newly detected OSA. Daytime sleep episodes and neurocognitive function were assessed before and after intervention. RESULTS At baseline, symptoms of daytime hypersomnolence, insomnia, restless legs syndrome as well as objectively assessed OSA (apnea hypopnea index (AHI, determined by polygraphic recording)=17[5-46]n/h) were highly present in 26, 24, 10 and 22%, respectively. A history of work related traffic accident was more prevalent in patients with OSA (59%) compared to those without (37%, p<0.08). In the intervention group (n=12) OSA treatment reduced AHI by -23 [-81 to -5]n/h (p=0.002), determined by polysomnography. Reduction of OSA was associated with a significant reduction of subjective sleepiness and blood pressure. Measures of daytime sleep propensity (microsleep episodes from 9 [0-20.5] to 0 [0-12.5], p<0.01) and missed responses during performance tests were greatly reduced, indices of sustained attention improved. CONCLUSIONS PTOs had a high prevalence of sleep disorders, particularly OSA, which demonstrated a higher prevalence of work related accidents. Elimination of OSA led to significant subjective and objective improvements in daytime function. Our findings argue for greater awareness of sleep disorders and associated impacts on daytime function in public transport drivers.

Driving habits and risk factors for traffic accidents among sleep apnea patients - a European multi-centre cohort study

Obstructive sleep apnea is associated with increased motor vehicle accident risk, and improved detection of patients at risk is of importance. The present study addresses potential risk factors in the European Sleep Apnea Database and includes patients with suspected obstructive sleep apnea [n = 8476, age 51.5 (12.5) years, body mass index 31.0 (6.6) kg m−2, 82.4% drivers licence holders]. Driving distance (km year−1), drivers licence type, sleep apnea severity, sleepiness and comorbidities were assessed. Previously validated risk factors for accident history: Epworth Sleepiness Scale ≥16; habitual sleep time ≤5 h; use of hypnotics; and driving ≥15 000 km year−1 were analysed across European regions. At least one risk factor was identified in male and female drivers, 68.75 and 51.3%, respectively. The occurrence of the risk factors was similar across Europe, with only a lower rate in the eastern region (P = 0.001). The mean number of risk factors increased across classes of sleep apnea severity. Frequent driving was prevalent [14.0 (interquartile range 8.0–20.0) × 103 km year−1] and 32.7% of drivers had severe obstructive sleep apnea [apnea–hypopnea index 50.3 (38.8–66.0) n h−1]. Obesity, shorter sleep time and younger age were associated with increased traffic exposure (P ≤ 0.03). In conclusion, the risk factors associated with accident history were common among European patients with suspected obstructive sleep apnea, but varied between geographical regions. There was a weak covariation between occurrence of risk factors and clinically determined apnea severity but frequent driving, a strong risk factor for accidents, was over‐represented. Systematic evaluation of accident‐related risk factors is important to detect sleep apnea patients at risk for motor vehicle accidents.

Zonisamide reduces obstructive sleep apnoea: a randomised placebo-controlled study

Carbonic anhydrase inhibition reduces apnoeic events in sleep disordered breathing. Zonisamide inhibits carbonic anhydrase, and induces weight loss in obese patients. This study explored the relative influence of these two properties, which may both alleviate obstructive sleep apnoea (OSA). Continuous positive airway pressure (CPAP) was used as a standard care comparator. 47 patients with moderate-to-severe OSA and a body mass index of 27–35 kg·m−2 were randomised to receive either zonisamide, placebo or CPAP for 4 weeks. The open extension phase (20 weeks) compared CPAP and zonisamide. Polysomnography, biochemistry and symptoms were evaluated. At 4 weeks, zonisamide reduced apnoea/hypopnoea index (AHI) by a mean±sd 33±39% and oxygen desaturation index by 28±31% (p=0.02 and 0.014, respectively; placebo adjusted). The mean compliance adjusted reduction of AHI after zonisamide and CPAP was 13 and 61%, respectively, (p=0.001) at 24 weeks. Body weight was marginally changed at 4 weeks, but reduced after zonisamide and increased after CPAP at 24 weeks (-2.7±3.0 kg versus 2.3±2.0 kg, p<0.001). Zonisamide decreased bicarbonate at 4 and 24 weeks. Side-effects were more common after zonisamide. Zonisamide reduced OSA independent of body weight potentially by mechanisms related to carbonic anhydrase inhibition. The effect was less pronounced than that obtained by CPAP. The carbonic anhydrase inhibitor zonisamide reduces sleep apnoea, but the effect is inferior to CPAP treatment http://ow.ly/tnmQ1

Attention deficits detected in cognitive tests differentiate between sleep apnea patients with or without a motor vehicle accident

OBJECTIVES Obstructive sleep apnea (OSA) is associated with an increased motor vehicle accident (MVA) risk. Conventional measures of OSA severity do not predict individual risk. Cognitive function tests have failed to incorporate outcomes in risk prediction. We aimed to identify markers of cognitive function for MVA risk prediction in OSA. METHODS OSA patients [n = 114, 75% male, median age 51 (43-61) years, body mass index (BMI) 30 (27-33) kg/m2, apnea-hypopnea index 25 (6-49) n/h, and Epworth Sleepiness (ESS) score 11 (8-16)] were recruited from a sleep laboratory. Two cognitive function tests, the Attention Network Test (ANT) and a modified Oxford Sleep Resistance Test (OSLER) test (GOSLING), were assessed. RESULTS OSA patients with (n = 11) or without (n = 103) a MVA record in the Swedish traffic accident registry were identified. In patients with a MVA, 64% were commercial drivers. In patients with a MVA history, more lapses [42 (5-121) vs. 5 (1-25), P = 0.02] and fewer responses [238 (158-272) vs. 271 (256-277), P = 0.03] to stimuli in the ANT were found. In the GOSLING, the number of lapses was higher (29 (10-97) vs. 7 (2-19), P = 0.01) and the reaction time was longer [462 (393-551) vs. 407 (361-449) ms, P = 0.05]. OSA severity and ESS score poorly predicted MVAs (P > 0.2). CONCLUSIONS We have demonstrated that deficit in sustained attention, assessed by daytime neurocognitive function tests, was associated with MVA risk in OSA patients. We were unable to detect an association between MVA history and severity of OSA or the ESS score. The findings provide a rationale for further development of objective MVA risk assessment tools in OSA.

A sleep apnea related risk of vehicle accident is reduced by CPAP - Swedish traffic accident data acquisition (STRADA) registry

Objective: The aim of this study was to describe the prevalence and characteristics of periodic legs movements of sleep (PLMS) in theadult general population. Methods: Data from 2162 subjects (51.2% women, mean SD age:58, 11 years, range: 40.5-84.4 years) participating in a population-based cohort study (HypnoLaus, Lausanne, Switzerland) wascollected. They completed a series of sleep related questionnaires and underwent polysomnographic recordings at home. PLMS index(PLMSI) was determined according to AASM 2007 criteria. APLMSI>15/h was considered to be of potential clinical significance. Conclusions: PLMS are highly prevalent in the general population. Age, male gender and RLS are independent predictors of a PLMSIhigher than 15/h. Further studies are needed to evaluate the clinical impact of PLMS.16 Social burden and management of sleep disorders P. Jennum Danish Center for Sleep Medicine, Department of Clinical Neurophysiology Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark Sleep disorders, such as insomnias, obstructive sleep apnoea, and central hypersomnias (narcolepsy, idiopathic hypersomnia), short sleep or sleep loss, and restless leg syndrome, are common disorders or complaints with a significant healthcare burden with consequences for healthcare contacts, medication use, education, employment and the risk of traffic accidents. There is now compelling evidence that the health-related (direct) and social (indirect) costs are significant, and comparable to those of other major disease areas. Thus, in order to care properly for patients presenting with sleeprelated morbidity, and to reduce the consequential economic burden, accurate screening efforts and effective, cost-effective treatments need to be developed and employed. Disclosure: Nothing to disclose.Objective: There is limited knowledge about the prospective relation between work characteristics (stress, physical work environment, work hours) and disturbed sleep. The present study sought to provide such knowledge. Method: The study was based on self-rated questionnaire data from two waves of the SLOSH cohort, The Swedish Longitudinal Occu- pational Survey of Health, an approximately representative sample of the working population in Sweden. In total, 5741 persons (54% women, age 24–72, gainfully employed at both waves) were included in the analyses. Results: Work-related factors at T1 (e.g. work demands, control, social support, physical work environment, work hours and stress) were analyzed with logistic regression with sleep disturbances at T2 as the outcome. Work demands (OR 95% CI, 1.57; 1.28–1.93) and stress (1.51; 1.27–1.85) at T1 predicted sleep disturbances at T2. When the work related predictors from T1 and T2 were combined, persistent high work demands and stress levels related to disturbed sleep at T2, as did an increase in stress and decrease in social support. A reverse relation between disturbed sleep at T1 and stress and high work demands at T2 was also found, suggesting a bidirectional relationship. Neither shift work, long hours, heavy physical work, noise at work, nor poor lighting conditions predicted disturbed sleep. Conclusions: Psychosocial risk factors at work related to subse- quent self-reported disturbed sleep, but long hours, shift work and physical work environment variables did not. The results are important for understanding the role of work factors in sleep disturbances. Disclosure: Nothing to disclose.