The Risk of Hospitalization for Motor Vehicle Accident Injury in Narcolepsy and the Benefits of Stimulant Use: A Nationwide Cohort Study in Taiwan

Psychomotor Vigilance Performance in Participants with Excessive Daytime Sleepiness in Obstructive Sleep Apnea or Narcolepsy Compared with SAFTE-FAST Model Predictions

INTRODUCTION

Excessive daytime sleepiness (EDS) associated with narcolepsy or obstructive sleep apnea (OSA) can impair vigilance/attention. Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved to treat EDS associated with narcolepsy (75-150 mg/day) or OSA (37.5-150 mg/day). The analysis reported here explored the use of the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) model (used in transport industries to model performance based on accumulated sleep and circadian variability) as a substitute for healthy controls using psychomotor vigilance task (PVT) data collected during clinical studies.

METHODS

Data were analyzed from two phase 2 studies of solriamfetol in adults with OSA (NCT02806895, EudraCT 2015-003930-28) or narcolepsy (NCT02806908, EudraCT 2015-003931-36). Participants were randomly assigned 1:1 to solriamfetol 150 mg/day (3 days) followed by 300 mg/day (4 days), or placebo (7 days), then crossed over to the other treatment. Actual task effectiveness scores were calculated from average PVT inverse reaction time (pre-dose; 2 h post-dose; 6 h post-dose). Actigraphy-derived sleep intervals were used in SAFTE to determine modeled healthy control task effectiveness scores.

RESULTS

In participants with OSA (N = 31) on placebo or solriamfetol, actual and modeled healthy control task effectiveness did not differ at any time point. In participants with narcolepsy (N = 20) on placebo, actual task effectiveness at 2 h post-dose was lower than modeled healthy control task effectiveness (nominal P = 0.03), a difference not present with solriamfetol. There was no main effect of solriamfetol on actual or modeled healthy control task effectiveness across time points.

CONCLUSION

This study represents a novel application of the SAFTE biomathematical model to approximate healthy controls in sleep disorder research and provides valuable lessons that may optimize future research. Future studies should perform a priori power analyses for model-tested outcomes and use sleep measures that capture sleep fragmentation characteristic of sleep disorders for sleep input (e.g., total sleep time rather than time in bed).

TRIAL REGISTRATION

NCT02806895, EudraCT 2015-003930-28: A Randomized, Double-Blind, Placebo-Controlled, Crossover On-Road Driving Study Assessing the Effect of JZP-110 on Driving Performance in Subjects With Excessive Sleepiness Due to Obstructive Sleep Apnea. NCT02806908, EudraCT 2015-003931-36: A Randomized, Double-Blind, Placebo-Controlled, Crossover On-Road Driving Study Assessing the Effect of JZP-110 on Driving Performance in Subjects With Excessive Sleepiness Due to Narcolepsy.

Effects of solriamfetol on on-the-road driving in participants with narcolepsy: A randomised crossover trial

OBJECTIVE

To evaluate the impact of solriamfetol, a dopamine and norepinephrine reuptake inhibitor, on on-the-road driving performance in participants with narcolepsy.

METHODS

In this randomised, double-blind, placebo-controlled, crossover study, driving performance during a 1 h on-road driving test was assessed at 2 and 6 h post-dose following 7 days of treatment with solriamfetol (150 mg/day for 3 days, followed by 300 mg/day for 4 days) or placebo. The primary endpoint was standard deviation of lateral position (SDLP) at 2 h post-dose.

RESULTS

The study included 24 participants (54% male; mean age, 40 years); 22 had evaluable SDLP data. At 2 h post-dose, median SDLP was significantly lower (improved) with solriamfetol compared with placebo (19.08 vs. 20.46 cm [median difference, -1.9 cm], p = 0.002). Four participants on solriamfetol and 7 on placebo had incomplete driving tests. At 6 h post-dose, median SDLP was not statistically significantly different with solriamfetol compared with placebo (19.59 vs. 19.78 cm [median difference, -1.1 cm], p = 0.125). Three participants on solriamfetol and 10 on placebo had incomplete driving tests. Common adverse events (≥5%) included headache, decreased appetite, and somnolence.

CONCLUSIONS

Solriamfetol 300 mg/day improved on-the-road driving performance, at 2 h post-administration in participants with narcolepsy.

How hypocretin agonists may improve the quality of wake in narcolepsy

Excessive daytime sleepiness (EDS) is a complex symptom characterized by a strong urge to sleep during daytime accompanied by problems such as attention deficits, anxiety, and lower cognitive performance. The efficacy of treatments for EDS is determined by their ability to decrease sleepiness, and less attention has been given to the effects these compounds have on the quality of the wake itself. Hypocretin (HCRT; orexin) signalling is implicated in narcolepsy, and hypocretin receptor 2 (HCRTR2) agonists are in clinical trials for treating EDS in narcolepsy. Here, we review preclinical research to determine how HCRTR2 agonists may affect attention and anxiety compared with other EDS treatment strategies. We conclude that such compounds may improve not only the quantity but also the quality of wake, and we hope that they will create opportunities for more nuanced treatment strategies in narcolepsy.

Age and sex differences on the association between anxiety disorders and obstructive sleep apnea: A nationwide case-control study in Taiwan

AIM

The aim of this study was to examine the association between anxiety disorders and obstructive sleep apnea (OSA).

METHODS

This is a population-based, retrospective case-control study using Taiwan's nationwide database. We included patients with OSA aged ≥12 years, diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes: 327 and 780. Each enrolled patient with OSA needed to undergo a polysomnography examination within 1 year pre- or post-OSA occurrence. Patients with OSA and controls were selected in a 1:4 ratio. Patients with anxiety disorders (ICD-9-CM code 300) were diagnosed by board-certified psychiatrists and required to visit the outpatient clinic at least three times per year. Multivariate logistic regression and interaction analyses were used to evaluate the objective association.

RESULTS

This study enrolled 7987 and 31 948 participants with and without OSA, respectively. A significant difference in anxiety exposure was observed only pre-OSA diagnosis but not post-OSA diagnosis. Compared with patients without anxiety disorders: (i) those with anxiety disorders had an adjusted odds ratio (aOR) of ≈1.864 in OSA comorbidity (aOR = 1.864; 95% confidence interval [CI] = 1.337-2.405); and (ii) subgroup analysis showed a significant interaction that anxiety patients of male sex, aged 18 to 44 years, aged 45 to 64 years, and hypertension had a higher aOR in OSA comorbidity (aOR = 2.104 [95% CI = 1.436-2.589], aOR = 1.942 [95% CI = 1.390-2.503], aOR = 2.179 [95% CI = 1.564-2.811], and aOR = 2.092 [95% CI = 1.497-2.706], respectively).

CONCLUSION

The study revealed a higher ratio of previous anxiety exposure in patients with OSA. Compared with those without anxiety, anxiety patients of male sex, aged 18 to 64 years, and with hypertension had a higher risk of OSA comorbidity.

The Usage of Histamine Type 1 Receptor Antagonist and Risk of Dementia in the Elderly: A Nationwide Cohort Study

Background

The histamine type 1 receptor antagonist (H1RA) has been commonly used. This study aimed to examine the association between the usage of H1RA and the risk of dementia.

Methods

A total of 8,986 H1RA users aged ≥50 and 26,958 controls matched a ratio of 1:3 for age, sex, and comorbidity, were selected between January 1, and December 31, 2000, from Taiwan’s National Health Insurance Research Database. Fine and Gray’s survival analysis (competing with mortality) was used to compare the risk of developing dementia during a 15-year follow-up period (2000–2015).

Results

In general, the H1RA usage was not significantly associated with dementia (adjusted subdistribution hazard ratio [SHR] = 1.025, 95% confidence interval [CI] = 0.883–1.297, p = 0.274) for the H1RA cohort. However, a differential risk was found among the groups at risk. The patients with the usage of H1RA aged ≥65 years (adjusted SHR: 1.782, 95% CI = 1.368–2.168, p < 0.001) were associated with a higher risk of dementia, in comparison to the control groups. Furthermore, the patients with the usage of H1RA that were male, or had more comorbidities, were also associated with an increased risk of dementia.

Conclusion

The usage of H1RA was associated with the risk of developing dementia in the patients aged ≥ 65 years.

Long-term atomoxetine-oxybutynin combination use may be beneficial for the prevention of obstructive sleep apnea

One recent study showed that atomoxetine-oxybutynin combination (AOC) use is effective in reducing obstructive sleep apnea (OSA) severity. We used a nationwide database to examine the association between AOC use and the risk of OSA incidence. This retrospective cohort study used Taiwan's National Health Insurance Research Database between the years 2000 and 2015. The patients who used atomoxetine or oxybutynin were included as an exposed cohort. The exposed and unexposed groups were selected in a ratio of 1:3 with sex, age, and index year matching. We used the multivariate Cox proportional regression model to evaluate the association between AOC use and the risk of an incident diagnosis of OSA. The incidence rates of OSA in the exposed cohort (N = 8940) and the unexposed cohort (N = 26,820), were 21.92 and 22.93 per 100,000 person-years, respectively. The adjusted hazard ratio of oxybutynin use only and AOC with a treatment duration of ≥ 366 days were 0.307 (95% CI 0.204-0.995, P = 0.045) and 0.299 (95% CI 0.102-0.933, P = 0.002), respectively. Long-term atomoxetine-oxybutynin combination therapy may be beneficial to reduce the risk of obstructive sleep apnea. Further studies to examine these mechanisms are warranted.

The Association Between Asthma and Narcolepsy: A Nationwide Case-Control Study in Taiwan

PURPOSE

Asthma, which is caused by inflammation of the airways, affects the sensitivity of nerve endings. Narcolepsy is a chronic sleep disorder that may be caused by autoimmunity. Recent studies have reported a positive association between narcolepsy and asthma. We aimed to examine the association between asthma and narcolepsy and determine the effects of therapeutic corticosteroid or bronchodilator use.

MATERIALS AND METHODS

We conducted a nationwide population-based, nested case-control study using Taiwan's National Health Insurance Research Database (NHIRD) between 2000 and 2013. Subjects with narcolepsy (ICD-9-CM code 347) were enrolled, with 1:3 estimated propensity score-matched controls based on sex, age, and index year. The association between narcolepsy and asthma was assessed using multiple logistic regression analyses. The covariates included sex, age, monthly insurance premiums, geographical area of residence, urbanization level of residence, level of care, and presence of diseases related to immune response and central nervous system. The effects of corticosteroid and bronchodilator use were also analyzed.

RESULTS

Overall, 2008 subjects were identified from the NHIRD (502 patients with narcolepsy and 1506 controls). The participants with narcolepsy had almost three times the level of previous asthma diagnosis than controls. Compared to those without asthma, patients with asthma had an adjusted odds ratio (OR) of 3.181 for narcolepsy comorbidity (95% confidence interval [CI]: 2.048-4.941, p<0.001). The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity, with an adjusted OR of 0.465 (95% CI, 0.250-0.634; p<0.001), in patients with asthma when compared to those without treatment.

CONCLUSION

This study demonstrated a significantly higher level of previous asthma diagnosis in patients with narcolepsy. The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity in asthma patients, compared to those without treatment.

Therapeutic Strategies for Mitigating Driving Risk in Patients with Narcolepsy

Narcolepsy is a central nervous system hypersomnia disorder characterized by uncontrollable episodes of daytime sleep, sleep state instability, and cataplexy (sudden loss of muscle tone precipitated by emotion). Individuals with narcolepsy report more frequent sleep-related crashes, near crashes, and drowsy driving than drivers with other sleep disorders. As such, evaluating risk of sleep-related crashes is of great importance for this patient population. There are no established guidelines for ensuring driving safety in patients with narcolepsy; however, many providers currently use a combination of subjective report, report of prior crashes or near-misses, report of previously falling asleep while driving, sleepiness screening tools, and maintenance of wakefulness testing (MWT) to determine risk. Driving simulator tests, though often unavailable to the clinician, provide data to support the use of MWT for evaluation of alertness in drivers with narcolepsy. Treatments such as modafinil may improve driving performance; however, the impact of other treatments such as stimulants and sodium oxybate on driving has not been extensively studied. Behavioral and lifestyle modifications may also reduce risk, including scheduled naps, driving only short distances, and avoiding driving after meals, sedating medications, and alcohol intake. Even with effective treatment, alertness in patients with narcolepsy may never reach that of normal drivers; however, studies have suggested that narcolepsy patients may be able to drive safely with appropriate limitations.

Real-world evidence on the use of benzodiazepine receptor agonists and the risk of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a life-threatening disease, and some studies reported that benzodiazepine receptor agonist (BZRA) use could increase the risk of VTE, but this association lacks population-based evidence.

OBJECTIVES

To investigate the association between BZRA use and the risk of VTE.

PATIENTS/METHODS

A nested case-control study analyzing Taiwan's claims database was conducted of patients with at least one new BZRA prescription on record from January 1, 2002, to December 31, 2012. We included new users who did not have any BZRA prescriptions in the preceding 2 years and identified cases with VTE and disease risk score matched control subjects. We used a logistic regression model to investigate the association between BZRA exposure and the risk of VTE. The exposure duration, dose, and classes of BZRAs were comprehensively evaluated.

RESULTS

We identified 2800 VTE cases and 2800 matched controls. Current BZRA prescription (≤90 days) was associated with VTE occurrence (adjusted odds ratio [aOR]: 1.83; 95% confidence interval [CI], 1.62-2.06). The point estimates of benzodiazepine hypnotics (aOR: 2.00; 95% CI, 1.45-2.76) had a marginally higher risk of VTE than nonbenzodiazepine hypnotics (aOR: 1.39; 95% CI, 1.07-1.81). The VTE risk was increased with combination BZRA use, number of BZRA used, and a higher dose of BZRA. On examination of individual BZRA, the risk of VTE was higher with flunitrazepam use (aOR: 2.99; 95% CI, 1.43-6.28) than other BZRAs.

CONCLUSIONS

This study presents that current BZRA use may increase the risk of VTE. Also, benzodiazepine hypnotics, especially flunitrazepam, have a higher risk of VTE.

Sex and age differences in the association between anxiety disorders and narcolepsy: A nationwide population-based case control study

BACKGROUND

To examine the association between narcolepsy and anxiety disorders.

METHODS

This population-based, retrospective case-control study analyzed Taiwan's National Health Insurance Research Database between 2000 and 2013. We included narcoleptic patients aged at least 12 years, diagnosed according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 347. The cases and the propensity score-matched controls were selected in a 1:4 ratio. Each subject with anxiety disorders (ICD-9-CM code 300) was required to visit the outpatient clinic at least three times within a year. Multivariate logistic regression and interaction analyses were used to calculate the association between anxiety disorders and narcolepsy.

RESULTS

This study enrolled 478 and 1912 subjects with and without narcolepsy, respectively. After adjusting for covariates, patients with anxiety disorders had an approximately 2.7 odds ratio of developing narcolepsy when compared to the control subjects (adjusted odds ratio [aOR)] = 2.7; 95% confidence interval [CI] = 1.699-4.344). Interaction analysis and subgroup analysis showed a higher incidence of previously diagnosed anxiety disorders in narcoleptic patients aged 12 to 17 years and female patients (aOR = 25.9; 95% CI = 15.194-42.896; aOR = 3.6; 95% CI = 1.818-7.062, respectively).

LIMITATIONS

The narcolepsy and anxiety disorders were not distinguished by validated structural diagnostic instruments.

CONCLUSIONS

The results of this study revealed higher comorbidity rates of anxiety disorders in narcoleptic patients. The incidence of previously diagnosed anxiety disorders was higher in narcoleptic patients aged 12 to 17 years and female patients.

Lisdexamfetamine to improve excessive daytime sleepiness and weight management in narcolepsy: a case series

Objective:

To report the successful use of lisdexamfetamine in the management of narcolepsy.

Methods:

Five narcoleptic patients received lisdexamfetamine, at different dosages and for different periods, for management of excessive daytime sleepiness and weight control.

Results:

All patients experienced improvement of excessive daytime sleepiness and lost weight without side effects.

Conclusion:

Lisdexamfetamine appears promising for the treatment of two of the most common symptoms of narcolepsy: excessive daytime sleepiness and weight gain.