Effects of Japanese policies and novel hypnotics on long-term prescriptions of hypnotics

AIM

The current study aimed to examine the effect of Japanese policies for appropriate hypnotics use and novel hypnotics (e.g. melatonin receptor agonist and orexin receptor antagonist [ORA]) on long-term prescriptions of hypnotics.

METHODS

This retrospective study was conducted using a large-scale health insurance claims database. Among subscribers prescribed hypnotics at least once between April 2005 and March 2021, those prescribed hypnotics for the first time after being included in the database in three periods (period 1: April 2012-March 2013; period 2: April 2016-March 2017; and period 3: April 2018-March 2019) were eligible. These were set considering the timing of the 2014 and 2018 medical fee revisions (2014 for polypharmacy of three or more hypnotics, 2018 for long-term prescription of benzodiazepine receptor agonists for >12 months). The duration of consecutive prescriptions of hypnotics over 12 months was evaluated. Factors associated with short-term prescriptions of hypnotics were also investigated.

RESULTS

In total, 186 535 participants were newly prescribed hypnotics. The mean duration of prescriptions was 2.9 months, and 9.3% of participants were prescribed hypnotics for 12 months. Prescription periods were not associated with short-term prescriptions of hypnotics. ORA use was associated with short-term prescriptions of hypnotics (adjusted hazard ratio, 1.077 [95% confidence interval, 1.035-1.120]; P < 0.001), but melatonin receptor agonist use was not.

CONCLUSION

Japanese policies had no statistically significant effect on long-term prescriptions of hypnotics. Although this study suggests initiating ORA for insomniacs as a candidate strategy to prevent long-term prescriptions of hypnotics, further research is necessary to draw conclusions.

Validity of an algorithm for determining sleep/wake states using FS-760 in school-aged children

Background

Actigraphy is a method used for determining sleep (S)/wakefulness (W) by actigraph, a device equipped with a built-in accelerometer and an algorithm validated for each device. The S/W determination algorithm for the waist-worn actigraph FS-760 has been formulated for adults. However, the algorithm for children has not been established. The purpose of this study was to formulate an algorithm for discriminating S/W in school-aged children using FS-760 and to evaluate its validity. We further tested the generalizability of existing algorithm for adults by applying it to the children’s activity data and then examined factors associated with adult algorithm agreement rates by multiple regression analysis using combined adult and children data.

Methods

Sixty-five, healthy, school-aged children (aged 6 to 15 years) were recruited and randomly assigned to two groups: A (n = 33) and B (n = 32). They underwent 8-h polysomnography (PSG) and wore FS-760 simultaneously to obtain activity data. To determine the central epoch of the sleep/wake states (𝑥), a five-order linear discriminant analysis was conducted using the activity intensity of group A for five epochs (𝑥₋₂, 𝑥₋₁, 𝑥, 𝑥₊₁, 𝑥₊₂; 10 min) and evaluate its accuracy with the activity of group B. To reveal the factors associated with adult algorithm agreement rate, we integrated the activity, age, sleep efficiency of 15 adults (aged 20 to 39 years) and those of 65 children for multiple regression analysis.

Results

The mean agreement rate of the developed algorithm was 91.0%, with a mean sensitivity (true sleep detection rate) of 93.0% and a mean specificity (true wakefulness detection rate) of 63.9%. The agreement rate of the adult algorithm applied to children’s activity was significantly lower (81.8%) than that of the children algorithm. Multiple regression analysis showed that the agreement rates calculated by the adult algorithm were significantly related to mean activity of the 𝑥 epoch in NREM and REM sleep as well as age and sleep efficiency.

Conclusions

The S/W states in school-aged children can be reliably assessed using the developed algorithm for waist-worn actigraph FS-760. Since the accuracy of the adult algorithms decreased when applied it to children which have different activity levels during sleep, the establishment and validation of population-specific S/W algorithms should be required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-022-00303-2.

Effect of residual insomnia and use of hypnotics on relapse of depression: a retrospective cohort study using a health insurance claims database

BACKGROUND

Residual insomnia is associated with a risk of depression recurrence.

METHODS

In this retrospective, longitudinal cohort study, the recurrence pattern of depression in patients with or without residual insomnia was assessed using a health insurance claims database. Patients who were diagnosed with major depressive disorder and prescribed antidepressants, between January 2006 and June 2017 in Japan, were enrolled in the study. Residual insomnia was defined by a prescription of hypnotics, and recurrence of depression by prescription of antidepressants. Main outcomes included time to recurrence and the 1-year recurrence rate. Factors associated with recurrence of depression were assessed by multivariate analyses. The effect of residual insomnia on the frequency of recurrence was assessed by Chi-square test.

RESULTS

Of the 30,381 patients analyzed, there were 4,166 and 26,215 patients with or without residual insomnia, respectively. Time to recurrence in patients with residual insomnia was significantly shorter compared with those without residual insomnia (p <0.001), with a 1-year recurrence rate (95% CI) of 43.4% (41.9-45.0) and 7.4% (7.1-7.7), respectively. The frequency of recurrence was significantly higher in patients with residual insomnia than in those without (p <0.0001). A higher risk of depression recurrence (odds ratio 9.98, 95% CI 9.22-10.81) was found for residual insomnia compared with other significant factors.

LIMITATIONS

The diagnosis stated in the receipt data may not accurately reflect the patient's condition, and medication adherence was unknown but assumed.

CONCLUSIONS

Residual insomnia is a significant risk factor for depression recurrence in Japanese patients.

Risk factors for low adherence to methylphenidate treatment in pediatric patients with attention-deficit/hyperactivity disorder

Poor adherence is a major concern in the treatment of attention-deficit/hyperactivity disorder (ADHD). The objective of this study was to evaluate factors linked to early interruption of and low adherence to treatment with osmotic-release oral system methylphenidate hydrochloride (OROS-MPH) in pediatric patients with ADHD. A total of 1353 young people (age 6–17 years) with a diagnosis of ADHD who newly started OROS-MPH were extracted from the pharmacoepidemiological data of 3 million people in Japan. The cohort was retrospectively surveyed every month for 12 months. Ten possible risk factors were extracted from the data and analyzed by multivariable logistic regression. Sensitivity analysis was conducted to ensure the robustness of the analysis. The results revealed that treatment adherence was generally poor, with a tendency for discontinuation in the early stage. Multivariable logistic regression results showed that adherence is reduced by female sex, lower starting dose, and concomitant atomoxetine or hypnotics. These findings may help clinicians to predict the risk of poor adherence in the early stage of treatment and improve not only patients’ symptoms, but also their quality of life.

Patterns of hypnotic prescribing for residual insomnia and recurrence of major depressive disorder: a retrospective cohort study using a Japanese health insurance claims database

BACKGROUND

Major depressive disorder (MDD) is highly prevalent in Japan and frequently accompanied by insomnia that may persist even with MDD remission. Hypnotics are used for the pharmacological treatment of insomnia, but their influence on MDD recurrence or residual insomnia following MDD remission is unclear. This retrospective, longitudinal, cohort study utilized a large Japanese health insurance claims database to investigate patterns of hypnotic prescriptions among patients with MDD, and the influence of hypnotic prescription pattern on MDD recurrence.

METHODS

Eligible patients (20-56 years) were those registered in the Japan Medical Data Center database between 1 January 2005 and 31 December 2018, and prescribed antidepressant and hypnotic therapy after being diagnosed with MDD. Patients who had ceased antidepressant therapy for > 180 days were followed for 1 year to evaluate depression recurrence, as assessed using Kaplan-Meier estimates. Logistic regression modelling was used to analyze the effect of hypnotic prescription pattern on MDD recurrence.

RESULTS

Of the 179,174 patients diagnosed with MDD who initiated antidepressant treatment between 1 January 2006 and 30 June 2017, complete prescription information was available for 2946 eligible patients who had been prescribed hypnotics. More patients were prescribed hypnotic monotherapy (70.8%) than combination therapy (29.2%). The most prescribed therapies were benzodiazepine monotherapy (26.2%), non-benzodiazepine monotherapy (28.9%), and combination therapy with two drugs (21.1%). Among patients prescribed multiple hypnotics, concomitant prescriptions for anxiolytics, antipsychotics, mood stabilizers and sedative antidepressants were more common. The 1-year recurrence rate for MDD was approximately 20%, irrespective of hypnotic mono- versus combination therapy or class of hypnotic therapy. Being a spouse (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.03-2.02) or other family member (OR, 1.46, 95% CI, 0.99-2.16) of the insured individual, or being prescribed a sedative antidepressant (OR, 1.50, 95% CI, 1.24-1.82) conferred higher odds of MDD recurrence within 1 year of completing antidepressant therapy.

CONCLUSIONS

Benzodiazepines are the most prescribed hypnotic among Japanese patients with MDD, though combination hypnotic therapy is routinely prescribed. Hypnotic prescription pattern does not appear to influence real-world MDD recurrence, though hypnotics should be appropriately prescribed given class differences in efficacy and safety.

Current state of hypnotic use disorders: Results of a survey using the Japanese version of Benzodiazepine Dependence Self-Report Questionnaire

Aims

Benzodiazepine receptor agonists (BZ‐RAs) are frequently prescribed to treat insomnia; however, their long‐term use is not recommended. To introduce an appropriate pharmaco‐therapy, the current state and background factors of BZ‐RAs' dependence must be elucidated. In this study, we developed a Japanese version of the Benzodiazepine Dependence Self‐Report Questionnaire (Bendep‐SRQ‐J) and conducted a study of BZ‐RAs' use disorder.

Methods

The Bendep‐SRQ‐J was created with permission from the original developer. Subjects were inpatients and outpatients receiving BZ‐RAs between 2012 and 2013. Clinical data collected were Bendep‐SRQ‐J scores, sleep disorders for which BZ‐RAs were prescribed, physical comorbidities, psychotropic drugs, and lifestyle factors. Logistic analysis was performed to extract factors associated with severe symptoms.

Results

Of the 707 patients prescribed BZ‐RAs, 324 had voluntarily tapered or discontinued their drugs. Logistic analysis showed that the total number of drugs administered in the last 6 months correlated with both worsening of symptoms or conditions. This was more notable among younger patients, and the proportion of patients with severe symptoms or conditions increased with the increasing number of drugs.

Conclusion

Using the Bendep‐SRQ‐J, we elucidated the current state of BZ‐RA dependence. Nearly half of the patients were non‐compliant. The proportion of patients with severe symptoms or disease conditions increased with the increase in the number of drugs administered. These findings highlight the need for clinicians to be aware of the likelihood of benzodiazepine dependence, especially in young patients and patients prescribed multiple hypnotics.

Using the Bendep‐SRQ‐J, we elucidated the current state of BZ‐RA dependence. Nearly half of the patients were non‐compliant.

Association Between the Use of Antidepressants and the Risk of Type 2 Diabetes: A Large, Population-Based Cohort Study in Japan

OBJECTIVE

This study aimed to reveal the associations between the risk of new-onset type 2 diabetes and the duration of antidepressant use and the antidepressant dose, and between antidepressant use after diabetes onset and clinical outcomes.

RESEARCH DESIGN AND METHODS

In this large-scale retrospective cohort study in Japan, new users of antidepressants (exposure group) and nonusers (nonexposure group), aged 20-79 years, were included between 1 April 2006 and 31 May 2015. Patients with a history of diabetes or receipt of antidiabetes treatment were excluded. Covariates were adjusted by using propensity score matching; the associations were analyzed between risk of new-onset type 2 diabetes and the duration of antidepressant use/dose of antidepressant in the exposure and nonexposure groups by using Cox proportional hazards models. Changes in glycated hemoglobin (HbA_1c) level were examined in groups with continuous use, discontinuation, or a reduction in the dose of antidepressants.

RESULTS

Of 90,530 subjects, 45,265 were in both the exposure and the nonexposure group after propensity score matching; 5,225 patients (5.8%) developed diabetes. Antidepressant use was associated with the risk of diabetes onset in a time- and dose-dependent manner. The adjusted hazard ratio was 1.27 (95% CI 1.16-1.39) for short-term low-dose and 3.95 (95% CI 3.31-4.72) for long-term high-dose antidepressant use. HbA_1c levels were lower in patients who discontinued or reduced the dose of antidepressants (F[2,49] = 8.17; P < 0.001).

CONCLUSIONS

Long-term antidepressant use increased the risk of type 2 diabetes onset in a time- and dose-dependent manner. Glucose tolerance improved when antidepressants were discontinued or the dose was reduced after diabetes onset.

Long-term use of hypnotics: Analysis of trends and risk factors

OBJECTIVE

Patients with chronic insomnia are prone to long-term use of hypnotics. Reported risk factors include aging, female sex, and comorbid psychiatric disorders. However, most previous studies have been cross-sectional cohort studies.

METHOD

We conducted a retrospective cohort study using medical service payment data for 330,000 people to determine the duration of prescription of hypnotics and the risk factors for long-term use. We followed up 3981 patients (2382 M, 1599 F, age 40.3 ± 12.4 years) who were prescribed hypnotics for the first time between April 2005 and March 2008.

RESULTS

Of these 3981 patients, 59.6% were prescribed hypnotics for only 1 month, 11.3% were prescribed hypnotics for 2 consecutive months, and 10.1% of patients continued receiving prescriptions for the entire 12-month observation period. In multiple logistic time-dependent Cox analyses, use of antidepressants, mean dose of hypnotics, and advanced age were significantly associated with long-term use of hypnotics (p < 0.01). In an analysis of the association between long-term use of hypnotics and prescribed dosage, high monthly dose, advanced age, and department of first visit were significantly associated with long-term use (p < 0.01).

CONCLUSION

These clinical indicators may be effective for early identification of patients with insomnia who are at high risk of developing physical dependence on hypnotics.

Placebo-controlled pilot study of the effects of an eggshell membrane-based supplement on mobility and serum biomarkers in dogs with osteoarthritis

Osteoarthritis (OA) is a debilitating disease in dogs. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat OA; however, many dogs do not obtain adequate pain relief with an NSAID alone. This pilot study evaluated the systemic anti-inflammatory and mobility enhancing effects of an eggshell membrane-based nutritional supplement in dogs with OA-associated pain and mobility impairment. Twenty-seven dogs with OA-associated pain were enrolled into a randomized, double-masked, placebo-controlled, proof of principle pilot study and received either placebo or an eggshell membrane-based nutritional supplement over a 12-week period. Inflammatory biomarkers (IL-2, IL-6, IL-8, tumor necrosis factor-α, C-reactive protein, S100A12, and N-methylhistamine) were measured at Day 0 and Day 84. Owner questionnaires (CBPI and LOAD) were completed at Day 0, Day 42, and Day 84. Differences between groups over time were calculated. Twenty-two dogs completed the pilot study. Inflammatory biomarker IL-2 decreased in the supplement group, compared to the placebo group. Although small, the difference was statistically significant at an alpha of 0.1 (P=0.069). LOAD scores were numerically lower in the supplement group, but not significantly different from the placebo group at Day 0. Day 84 LOAD scores were significantly lower in the supplement group compared to the placebo group (P=0.034). CBPI results did not show the same pattern. The changes in biomarkers and LOAD scores were small, and do not provide definitive evidence of positive effects. However, these pilot results provide a rationale for performing a larger placebo-controlled study of the potential effects of the eggshell membrane-based nutritional supplement.

Prevalence of childhood obstructive sleep apnea syndrome and its role in daytime sleepiness

Objectives

To investigate childhood obstructive sleep apnea syndrome (OSAS) and its role in daytime sleepiness among school-age children.

Methods

A questionnaire survey was conducted with 25,211 children aged 6–15 (mean, 10.39) years attending 148 elementary and 71 middle schools in 10 prefectures across Japan and their parents. Questions concerned 4 sleep habit items (bedtime, sleep onset latency, wake time after sleep onset, wake-up time) and 4 sleep disorder items (loud snoring, snorts/gasps, breathing pauses, seems very sleepy in the daytime). Total sleep time (TST) was calculated with sleep habits. Severe possible OSAS (p-OSAS) was defined as having loud snoring, snorts and gasps, or breathing pauses “frequently” (≥ 5 times per week), and mild p-OSAS was rated as having any of these “sometimes” (2–4 times per week). Severe daytime sleepiness was defined as seeming very sleepy “frequently” and mild daytime sleepiness as seeming very sleepy “sometimes”.

Results

Mean prevalence of mild to severe p-OSAS and severe p-OSAS in children across all grade levels was 9.5% and 1.6%, respectively. p-OSAS was particularly prevalent in children at lower elementary levels, decreasing with advancing grade levels. Prevalence of mild and severe daytime sleepiness was 6.1% and 0.9%, respectively, among all children (7.0%). Prevalence of daytime sleepiness increased with advancing grade levels, particularly in middle-school level. Average TST was 8.4 ± 2.2 h in both elementary and middle-school levels, and decreased as grades advanced, particularly in middle-school levels. Multivariate logistic regression analysis showed that middle-school level, TST < 8 h, and p-OSAS were independent factors for daytime sleepiness. Strong correlations were found between severe daytime sleepiness and severe p-OSAS or TST < 6 h, and between daytime sleepiness and loud snoring or breathing pauses.

Conclusion

p-OSAS may be an independent factor influencing daytime sleepiness in school-age children. Loud snoring and breathing pauses could be clinical markers for children with severe daytime sleepiness.

Initial evaluation of PetPace activity monitor

Mobility is considered a vital component of health and quality of life in humans and companion animals. Wearable devices for pets that can monitor activity and other aspects of health are increasingly being marketed to veterinarians and owners, with claims around their ability to monitor aspects of health. However, there is little scientific evidence to support the validity of these claims. To address this, the objective of this study was to assess the correlation of the activity measurement from the PetPace device compared to activity output from Actigraph and the validated Actical device. Ten client-owned, healthy dogs were used for the study. The three devices were mounted simultaneously on a dedicated collar and activity was recorded during a period of 7 days. There were moderate correlations between the Actical and the PetPace (r²=0.59, P=<0.001). There was high correlation between the PetPace and the Actigraph (r²=0.85, P=<0.001) and between the Actical and the Actigraph (r²=0.72, P=<0.001). If the Actical activity counts were limited under 50,000 per hour, there was strong correlation between the Actical and the PetPace (r²=0.71, P=<0.001) and between the Actical and the Actigraph (r²=0.86, P=<0.001). PetPace has a moderate correlation with the most validated activity monitor that has been used in veterinary medicine. Its real-time data acquisition, user friendly interface for owners and cost make this device an attractive tool for monitoring activity in dogs. Further studies maybe needed to evaluate its performance, validity and clinical utility in the field.

The presence of multiple NS5A RASs is associated with the outcome of sofosbuvir and ledipasvir therapy in NS5A inhibitor-naïve patients with chronic HCV genotype 1b infection in a real-world cohort

It is unclear whether multiple nonstructural (NS) 5A resistance-associated substitutions (RASs) correlate with the outcome of sofosbuvir (SOF) and ledipasvir (LDV) therapy. We investigated the effects of multiple NS5A RASs in NS5A inhibitor-naïve patients with chronic hepatitis C virus genotype 1b infection treated with SOF/LDV. In 313 patients treated with SOF/LDV, we assessed the effects of multiple NS5A RASs on the sustained virological response (SVR). RASs at L28, R30, L31, Q54, P58, Q62, A92, and Y93 in the NS5A region were examined by direct sequencing. The prevalence of RASs was as follows: 2.6% at L28, 8.7% at R30, 6.1% at L31, 48.7% at Q54, 9.9% at P58, 9.9% at Q62, 5.1% at A92, 13.8% at Y93, and 19.2% at L31 or Y93. A total of 133 patients had no RASs. SVR was achieved in 98.7% of the patients. SVR rates significantly differed between patients with and without the L31 or Y93 RAS (93.0% [53/57] vs 100% [250/250], P = .0011). In addition, among patients with the L31 or Y93 RAS, 29.8%, 45.6% and 24.6% had one, two and three or more NS5A RASs, respectively. The SVR rate was significantly lower in patients with the L31 or Y93 RAS with more than three NS5A RASs compared to those with fewer than three NS5A RASs (71.4% [10/14] vs 100% [43/43], P = .0025). Although the prevalence of multiple NS5A RASs at baseline was low in NS5A inhibitor-naïve patients, the presence of multiple NS5A RASs was associated with the effectiveness of SOF/LDV therapy.

Low incidence of hepatitis B virus reactivation and subsequent hepatitis in patients with chronic hepatitis C receiving direct-acting antiviral therapy

To determine the clinical characteristics of hepatitis B virus (HBV) reactivation in patients undergoing interferon-free antihepatitis C virus (HCV) therapy, we examined HBV DNA in 25 HBV co-infected patients and 765 patients with resolved HBV infection during and after treatment with direct-acting antiviral agents (DAAs). Among those with HCV genotype 1, asunaprevir plus daclatasvir was administered to 160 patients, sofosbuvir (SOF) plus ledipasvir to 438 patients and paritaprevir plus ombitasvir and ritonavir to 25 patients. In total, 167 patients with genotype 2 were treated with SOF plus ribavirin. Three patients with an HBV DNA level ≥2000 IU/mL were treated with entecavir before anti-HCV therapy, without reactivation of HBV. In 3 of 22 (12%) HBV surface antigen (HBsAg)-positive patients with an HBV DNA level <2000 IU/mL, the viral load increased during treatment. However, hepatitis flare did not occur in these patients. There was no significant difference in clinical history between patients with and without HBV reactivation. Among 765 patients with resolved HBV infection, HBV reactivation occurred in 1 (0.1%) patient after initial resolution, whose HBV DNA level spontaneously decreased after DAA therapy. We compared anti-HBs titres at baseline with those at post-DAA therapy in 123 patients without HBsAg. There was no significant difference in anti-HBs levels between the two points (P = .79). In conclusion, HBV reactivation was rare in HBsAg-negative patients treated with DAA therapy. Additionally, hepatitis did not occur in HBV-reactivated patients with a baseline HBV DNA level <2000 IU/mL before DAA therapy.

Estimating individual optimal sleep duration and potential sleep debt

In this study, we hypothesized that dynamics of sleep time obtained over consecutive days of extended sleep in a laboratory reflect an individual's optimal sleep duration (OSD) and that the difference between OSD and habitual sleep duration (HSD) at home represents potential sleep debt (PSD). We found that OSD varies among individuals and PSD showed stronger correlation with subjective/objective sleepiness than actual sleep time, interacting with individual's vulnerability of sleep loss. Furthermore, only 1 h of PSD takes four days to recover to their optimal level. Recovery from PSD was also associated with the improvement in glycometabolism, thyrotropic activity and hypothalamic-pituitary-adrenocortical axis. Additionally, the increase (rebound) in total sleep time from HSD at the first extended sleep would be a simple indicator of PSD. These findings confirmed self-evaluating the degree of sleep debt at home as a useful clinical marker. To establish appropriate sleep habits, it is necessary to evaluate OSD, vulnerability to sleep loss, and sleep homeostasis characteristics on an individual basis.

Toxicological Evaluation of Neosugar: Genotoxicity, Carcinogenicity, and Chronic Toxicity

Neosugar, a fructooligosaccharide mixture, was tested for genotoxicity in three assays: (1) microbial reverse mutation assays in Salmonella typhimurium (Ames assay) and Escherichia coli WP2 uvr A, (2) the L5178Y mouse lymphoma TK± mammalian cell mutation assay, and (3) an assay for the induction of unscheduled DNA synthesis (UDS) in human epithelioid cells (HeLa S3). Each assay was conducted at a wide range of dose levels, both with and without metabolic activation. Test results gave no indication that neosugar possessed any genotoxic potential. The carcinogenicity and chronic toxicity of neosugar were examined in Fischer 344 rats. Rats were fed diets containing 0, 8000, 20,000, or 50,000 ppm neosugar for 104 weeks. No dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or nonneoplastic lesions were observed. The incidence of rare and spontaneous tumors was comparable between control and neosugar treatment groups, with the exception of pituitary adenomas in male rats. In light of the background incidence of this tumor and an equivocal dose-response trend, it is unlikely that neosugar treatment is related to the incidence of pituitary adenomas in male rats. The results of this study indicate that neosugar is nonmutagenic and that rats are not adversely affected by chronic neosugar exposure.

Association between delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan

Background

Although delayed sleep timing causes many socio-psycho-biological problems such as sleep loss, excessive daytime sleepiness, obesity, and impaired daytime neurocognitive performance in adults, there are insufficient data showing the clinical significance of a ‘night owl lifestyle’ in early life. This study examined the association between habitual delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan.

Methods

Parents/caregivers of 708 community-dwelling 2-year-old children in Nishitokyo City, Tokyo, participated in the study. The participants answered a questionnaire to evaluate their child’s sleep habits and sleep-related problems for the past 1 month.

Results

Of the 425 children for whom complete data were collected, 90 (21.2%) went to bed at 22:00 or later. Children with delayed bedtime showed significantly more irregular bedtime, delayed wake time, shorter total sleep time, and difficulty in initiating and terminating sleep. Although this relationship indicated the presence of sleep debt in children with delayed bedtime, sleep onset latency did not differ between children with earlier bedtime and those with delayed bedtime. Rather, delayed bedtime was significantly associated with bedtime resistance and problems in the morning even when adjusting for nighttime and daytime sleep time.

Conclusions

Even in 2-year-old children, delayed bedtime was associated with various sleep-related problems. The causal factors may include diminished homeostatic sleep drive due to prolonged daytime nap as well as diurnal preference (morning or night type) regulated by the biological clock.

Sleepiness induced by sleep-debt enhanced amygdala activity for subliminal signals of fear

Background

Emotional information is frequently processed below the level of consciousness, where subcortical regions of the brain are thought to play an important role. In the absence of conscious visual experience, patients with visual cortex damage discriminate the valence of emotional expression. Even in healthy individuals, a subliminal mechanism can be utilized to compensate for a functional decline in visual cognition of various causes such as strong sleepiness. In this study, sleep deprivation was simulated in healthy individuals to investigate functional alterations in the subliminal processing of emotional information caused by reduced conscious visual cognition and attention due to an increase in subjective sleepiness. Fourteen healthy adult men participated in a within-subject crossover study consisting of a 5-day session of sleep debt (SD, 4-h sleep) and a 5-day session of sleep control (SC, 8-h sleep). On the last day of each session, participants performed an emotional face-viewing task that included backward masking of nonconscious presentations during magnetic resonance scanning.

Results

Finally, data from eleven participants who were unaware of nonconscious face presentations were analyzed. In fear contrasts, subjective sleepiness was significantly positively correlated with activity in the amygdala, ventromedial prefrontal cortex, hippocampus, and insular cortex, and was significantly negatively correlated with the secondary and tertiary visual areas and the fusiform face area. In fear-neutral contrasts, subjective sleepiness was significantly positively correlated with activity of the bilateral amygdala. Further, changes in subjective sleepiness (the difference between the SC and SD sessions) were correlated with both changes in amygdala activity and functional connectivity between the amygdala and superior colliculus in response to subliminal fearful faces.

Conclusion

Sleepiness induced functional decline in the brain areas involved in conscious visual cognition of facial expressions, but also enhanced subliminal emotional processing via superior colliculus as represented by activity in the amygdala. These findings suggest that an evolutionally old and auxiliary subliminal hazard perception system is activated as a compensatory mechanism when conscious visual cognition is impaired. In addition, enhancement of subliminal emotional processing might cause involuntary emotional instability during sleep debt through changes in emotional response to or emotional evaluation of external stimuli.

Validity of the Japanese version of the Munich ChronoType Questionnaire

To assess circadian preference with a score, the Morningness-Eveningness Questionnaire (MEQ) has been used for more than 3 decades now. More recently, the Munich ChronoType Questionnaire (MCTQ) was developed: it asks for sleep-wake behavior on work and free days and uses the midpoint of sleep on free days (MSF), corrected for sleep debt accumulated during the work week as an indicator of chronotype (MSFsc). In this study, we developed a Japanese version of the MCTQ by using a translation/back-translation approach including an examination of its semantic validity. In a subsequent questionnaire survey, 450 adult men and women completed the Japanese versions of the MCTQ and MEQ. Results showed that MEQ scores were significantly negatively correlated with mid-sleep parameters assessed by the MCTQ, on both, work and free days, as well as with the chronotype measure MSFsc (r = -0.580 to -0.652, all p < 0.001). As in the original German version, the strongest correlation was observed between MEQ score and MSF. A physiological validation study using dim light melatonin onset as a circadian phase marker (N = 37) showed a high correlation between chronotype as assessed with the MSFsc (r = 0.542, p < 0.001), and less so for MEQ score (r = -0.402, p = 0.055). These results demonstrate the validity of the Japanese MCTQ and provide further support of the adequacy of the MCTQ as a chronotype measure.

Sleep debt elicits negative emotional reaction through diminished amygdala-anterior cingulate functional connectivity

OBJECTIVES

Sleep debt reportedly increases emotional instability, such as anxiety and confusion, in addition to sleepiness and psychomotor impairment. However, the neural basis of emotional instability due to sleep debt has yet to be elucidated. This study investigated changes in emotional responses that are elicited by the simulation of short-term sleep loss and the brain regions responsible for these changes.

SUBJECTS AND METHODS

Fourteen healthy adult men aged 24.1±3.3 years (range, 20-32 years) participated in a within-subject crossover study consisting of 5-day sessions of both sleep debt (4 h for time in bed) and sleep control (8 h for time in bed). On the last day of each session, participants underwent polysomnography and completed the State-Trait Anxiety Inventory and Profile of Mood States questionnaires. In addition, functional magnetic resonance imaging was conducted while performing an emotional face viewing task.

RESULTS

Restricted sleep over the 5-day period increased the activity of the left amygdala in response to the facial expression of fear, whereas a happy facial expression did not change the activity. Restricted sleep also resulted in a significant decrease in the functional connectivity between the amygdala and the ventral anterior cingulate cortex (vACC) in proportion to the degree of sleep debt (as indicated by the percentage of slow wave sleep and δ wave power). This decrease was significantly correlated with activation of the left amygdala and deterioration of subjective mood state.

CONCLUSION

The results of this study suggest that continuous and accumulating sleep debt that can be experienced in everyday life can downregulate the functional suppression of the amygdala by the vACC and consequently enhance the response of the amygdala to negative emotional stimuli. Such functional alteration in emotional control may, in part, be attributed to the neural basis of emotional instability during sleep debt.

Alpha activity during rem sleep contributes to overnight improvement in performance on a visual discrimination task

The purpose of this preliminary study was to clarify the association between cortical and subcortical activities during REM and non-REM sleep with overnight improvement of performance on a procedural memory task. Eleven healthy volunteers (M age = 23.8 yr., SD = 3.1) participated in this study which was conducted over two consecutive nights: an adaptation night and the experimental night. They underwent a visual discrimination task before and after the experimental night. A positive correlation was observed between overnight performance improvement on the visual discrimination task and EEG alpha band power during REM sleep, while no significant correlation was observed between the performance and either the amount of Stage REM sleep, REM activity, or other sleep variables. The findings corroborate other studies and suggest that cortical activity during REM sleep contributed to procedural memory consolidation and highlights the importance of measuring quantitative REM sleep components to elucidate the role of physiological sleep on memory consolidation in humans.

Activity in the action observation network enhances emotion regulation during observation of risk-taking: an fMRI study

OBJECTIVES

The results of neuroimaging studies have indicated that viewing emotional stimuli can lead to activity increases in brain regions associated with processing actions. We hypothesized that observation of actions involving the potential for harm (i.e., risk-taking actions) would activate emotion- and pain-related processing.

METHODS

We used functional magnetic resonance imaging to examine the changes in neural activity during the observation of safe and risk-taking actions in 34 healthy participants (14 females, 20 males; mean age: 23·4±3·7 years).

RESULTS

Observation of risk-taking actions elicited significantly stronger neural activation in the inferior frontal gyrus, ventromedial prefrontal cortex, superior frontal gyrus/frontal pole, inferior parietal lobule, middle temporal gyrus, middle occipital gyrus, lingual gyrus, cuneus (including the calcarine sulcus), insula, and amygdala, than observation of safe actions. Interestingly, we observed significant activation of affect-related brain areas (ventromedial prefrontal cortex, amygdala, and insula), thought to be implicated in various aspects of emotion regulation during the observation of risk-taking actions. No brain regions exhibited greater activation during observation of safe actions than during observation of risk-taking actions associated with risk.

DISCUSSION

Our results reveal that the risk-related content of the observed actions in the video clips elicited activation of a network of visual input and processing regions, including the action observation network, that appears to encode the meanings of observed actions as well as the reflective or retrospective monitoring of their outcomes. These findings suggest that risk-taking situations may increase cognitive load on the entire action perception system, and may command more attention.

Increased cerebral blood flow in the right frontal lobe area during sleep precedes self-awakening in humans

BACKGROUND

Some people can subconsciously wake up naturally (self-awakening) at a desired/planned time without external time stimuli. However, the underlying mechanism regulating this ability remains to be elucidated. This study sought to examine the relationship between hemodynamic changes in oxyhemoglobin (oxy-Hb) level in the prefrontal cortex and sleep structures during sleep in subjects instructed to self-awaken.

RESULTS

Fifteen healthy right-handed male volunteers with regular sleep habits participated in a consecutive two-night crossover study. The subjects were instructed to wake up at a specified time ("request" condition) or instructed to sleep until the morning but forced to wake up at 03:00 without prior notice ("surprise" condition). Those who awoke within ± 30 min of the planned waking time were defined as those who succeeded in self-awakening ("success" group). Seven subjects succeeded in self-awakening and eight failed.No significant differences were observed in the amounts of sleep in each stage between conditions or between groups. On the "request" night, an increase in oxy-Hb level in the right prefrontal cortex and a decrease in δ power were observed in the "success" group around 30 min before self-awakening, whereas no such changes were observed in the "failure" group. On the "surprise" night, no significant changes were observed in oxy-Hb level or δ power in either group.

CONCLUSIONS

These findings demonstrate a correlation between self-awakening and a pre-awakening increase in hemodynamic activation in the right prefrontal cortex, suggesting the structure's contribution to time estimation ability.

Rhythmic expression of circadian clock genes in human leukocytes and beard hair follicle cells

Evaluating individual circadian rhythm traits is crucial for understanding the human biological clock system. The present study reports characterization of physiological and molecular parameters in 13 healthy male subjects under a constant routine condition, where interfering factors were kept to minimum. We measured hormonal secretion levels and examined temporal expression profiles of circadian clock genes in peripheral leukocytes and beard hair follicle cells. All 13 subjects had prominent daily rhythms in melatonin and cortisol secretion. Significant circadian rhythmicity was found for PER1 in 9 subjects, PER2 in 3 subjects, PER3 in all 13 subjects, and BMAL1 in 8 subjects in leukocytes. Additionally, significant circadian rhythmicity was found for PER1 in 5 of 8 subjects tested, PER2 in 2 subjects, PER3 in 6 subjects, and BMAL1 in 3 subjects in beard hair follicle cells. The phase of PER1 and PER3 rhythms in leukocytes correlated significantly with that of physiological rhythms. Our results demonstrate that leukocytes and beard hair follicle cells possess an endogenous circadian clock and suggest that PER1 and PER3 expression would be appropriate biomarkers and hair follicle cells could be a useful tissue source for the evaluation of biological clock traits in individuals.

Carryover effect on next-day sleepiness and psychomotor performance of nighttime administered antihistaminic drugs: a randomized controlled trial

BACKGROUND

Antihistamines with strong sedative-hypnotic properties are frequently prescribed for insomnia secondary to allergy, but the potential risks of such administration have not been fully elucidated.

SUBJECTS AND METHODS

This randomized, double-blind, placebo-controlled crossover study was conducted to evaluate next-day sleepiness and psychomotor performance following the administration of antihistamines. Twenty-two healthy male participants participated in four drug administration sessions with more than a 1-week interval between the sessions. Either zolpidem 10 mg, or diphenhydramine 50 mg, or ketotifen 1 mg, or a placebo was administered before sleep, and polysomnography was conducted to evaluate sleep. In the morning and afternoon of the day after administration, the participants were evaluated for subjective sleepiness, objective sleepiness, and psychomotor performance.

RESULTS

The antihistamines with high blood-brain barrier-crossing efficiency were significantly associated with sleepiness and psychomotor performance decline the next day. Ketotifen showed the strongest carryover effect, followed by diphenhydramine. Compared with the placebo, no significant carryover effect was observed with zolpidem.

CONCLUSION

The results suggest that the risk-benefit balance should be considered in the ready use of antihistamines that easily cross the blood-brain barrier for alleviating secondary insomnia associated with allergies.

Individual traits and environmental factors influencing sleep timing: a study of 225 Japanese couples

Behavioral and physiological processes, such as sleep-wakefulness, thermoregulation, and hormone secretion, exhibit 24-h rhythms in most organisms. These biological rhythms are driven by the circadian clock system and are entrained by the external environment, which in the case of humans includes social time schedules. Couples might be ideal experimental subjects to discriminate between individual traits and environmental factors, as they share lifestyle habits but not genetic backgrounds. In this study, sleep timing was compared between married Japanese couples (n = 225) who had lived together for 1 yr or more (mean 17 yrs). Additionally, the authors evaluated the influence of individual traits and environmental factors on an individual's sleep timing per each couple. The results reveal that the sleep timings of a couple are mainly associated with the chronotypes of the husband and wife, whereas the sleep timings are significantly influenced by certain environmental factors. The findings suggest that chronotype remains one of the major determinants of an individual's sleep onset and wake times. Understanding an individual's chronotype may help improve the quality of life issues surrounding sleep.

Evening preference is related to the incidence of depressive states independent of sleep-wake conditions

Although evening preference has recently been identified as a risk factor for depression, it has not been substantiated whether evening preference is a direct risk factor for depressive states, or if it is associated secondarily through other factors, such as delayed sleep timing and shortened sleep duration. The objective of this study is to investigate associations in Japanese adult subjects between evening preference and incidence of depressive states, adjusting for various sleep parameters related to depressive states. The Morningness-Eveningness Questionnaire (MEQ), the Pittsburgh Sleep Quality Index (PSQI), and the Center for Epidemiologic Studies Depression Scale (CES-D) were administered to 1170 individuals (493 males/677 females; mean and range 38.5 and 20-59 yrs) to assess their diurnal preferences, sleeping states, and presence of depression symptoms. Subjects were classified into five chronotypes based on MEQ scores. Evening preference was associated with delayed sleep timing, shortened sleep duration, deteriorated subjective sleep quality, and worsened daytime sleepiness. Logistic regression analysis demonstrated that the extreme evening type (odds ratio [OR] = 1.926, p = .018) was associated with increased incidence of depressive states and that the extreme morning type (OR = 0.342, p = .038) was associated with the decreased incidence of depressive states, independent of sleep parameters, such as nocturnal awakening (OR = 1.844, p < .001), subjective sleep quality (OR = 2.471, p < .001), and daytime sleepiness (OR = 1.895, p = .001). However, no significant associations were observed between the incidence of depressive states and sleep duration, sleep timing, and sleep debt (levels of insufficient sleep). Although the findings of this study do not demonstrate a causative relationship between evening preference and depression, they do suggest the presence of functional associations between mood adjustment and biological clock systems that regulate diurnal preference. They also suggest that evening preference might increase susceptibility to the induction of mood disorders.

Antenatal magnesium sulfate and the postnatal response of the ductus arteriosus to indomethacin in extremely preterm neonates

OBJECTIVE

The aim of this study is to evaluate the influence of antenatal magnesium sulfate (MgSO(4)) treatment on the clinical responsiveness of the ductus arteriosus to indomethacin prophylaxis and on that of symptomatic patent ductus arteriosus (sPDA) to indomethacin treatment in premature neonates.

STUDY DESIGN

This is a retrospective study of 160 consecutively admitted neonates with a gestational age of <28 weeks (41 MgSO(4) exposed and 119 controls) who received indomethacin prophylaxis.

RESULT

Incidence of early closure of the ductus arteriosus was lower in the MgSO(4)-exposed neonates than in the control group (59 vs 84%, respectively; P=0.002), whereas incidence of an sPDA was higher (46 vs 24%, respectively; P=0.006). Response to indomethacin treatment was similar between the two groups. Logistic regression analysis indicated increased risk of failure of early ductus arteriosus closure following antenatal MgSO(4) treatment (odds ratio, 4.03; P=0.002).

CONCLUSION

In extremely preterm neonates, antenatal MgSO(4) treatment reduces clinical responsiveness of the ductus arteriosus to indomethacin prophylaxis but not that of sPDA to indomethacin treatment.

Relationship between late-life depression and life stressors: large-scale cross-sectional study of a representative sample of the Japanese general population

AIM

The purpose of the present study was to clarify the relationship between late-life depression and daily life stress in a representative sample of 10 969 Japanese subjects.

METHODS

Data on 10 969 adults aged > or =50 who participated in the Active Survey of Health and Welfare in 2000, were analyzed. The self-administered questionnaire included items on 21 reasons for life stressors and the magnitude of stress, as well as the Japanese version of the Center for Epidemiologic Studies Depression Scale (CES-D). The relationship between the incidence of life stressors and mild-moderate (D(16)) and severe (D(26)) depressive symptoms was examined using logistic regression analysis.

RESULTS

A total of 21.9% of subjects had D(16) symptoms, and 9.3% had D(26) symptoms. Further, increased age and being female were associated with more severe depressive state. Logistic regression analysis indicated that the strongest relationship between both the incidence of D(16) and D(26) symptoms and life stressors stemmed from 'having no one to talk to' (odds ratio = 3.3 and 5.0, respectively). Late-life depression was also associated with 'loss of purpose in life', 'separation/divorce', 'having nothing to do', 'health/illness/care of self', and 'debt'.

CONCLUSION

There is a relationship between late-life depression and diminished social relationships, experiences involving loss of purpose in life or human relationships, and health problems in the Japanese general population.

Diurnal fluctuations in subjective sleep time in humans

Humans have the ability to estimate the passage of time in the absence of external time cues. In this study, we subjected 22 healthy males (aged 21.8±1.9 years) to a 40-min nap trial followed by 80min of wakefulness repeated over 28h, and investigated the relationship between various sleep parameters and the discrepancy (ΔST) of time estimation ability (TEA) during sleep, defined by the difference between actual sleep time (ST) and subjective sleep time (sub-ST) in each nap interval. Both ST and sub-ST were significant diurnal fluctuations with the peak in the early morning (9h after dim-light melatonin onset time, 2h after nadir time of core body temperature rhythm), and subjective sleep duration was estimated to be longer than actual times in all nap intervals (sub-ST>ST). There were significant diurnal fluctuations in discrepancy (sub-ST-ST) of TEA during sleep, and the degree of discrepancy correlated positively with increase in the amount of REM sleep and decrease in the amount of slow-wave sleep. These findings suggest that human TEA operates at a certain level of discrepancy during sleep, and that this discrepancy might be related to the biological clock and its associated sleep architecture.

Sleep-related problems and use of hypnotics in inpatients of acute hospital wards

OBJECTIVE

Although sleep disorders are highly prevalent among patients with physical disorders, only limited information is available about the actual status of sleep-related problems in inpatients of acute hospital wards. We conducted a multicenter cross-sectional observational survey investigating the prevalence of sleep disorders and use of hypnotic-sedative drugs among inpatients of acute wards in 44 general hospitals in Japan.

METHOD

Questionnaire-, actigraph- and observation-based sleep evaluations were simultaneously performed in 557 adult inpatients [mean age 72.8 + or - 12.8 (S.D.) years] of acute wards during a one-month period in July 2007.

RESULTS

Of the 421 patients with data available, 22.3% had at least one of the following sleep disorders: sleep apnea syndrome, restless legs syndrome, periodic limb movement disorder and nocturnal behavior disorder. Similarly, 62.7% had insomnia, 6.9% had severe daytime sleepiness and 12.8% had other sleep-related symptoms. Only 13.8% were free of any sleep-related problem. Although 33.7% of insomnia patients were taking hypnotic-sedative drugs, 65.2% of them complained of residual insomnia symptoms.

CONCLUSION

The findings obtained in this study have revealed the remarkably high prevalence of sleep-related problems experienced by inpatients of acute hospital wards in Japan. Proper diagnosis of sleep disorders should be made among patients with physical disorders.

Add-on combination therapy with adefovir dipivoxil induces renal impairment in patients with lamivudine-refractory hepatitis B virus

Combination therapy with adefovir dipivoxil (ADV) and lamivudine (LAM) is recommended for patients infected with LAM-refractory hepatitis B virus (HBV). However, the effects of such therapy on renal function and serum phosphorus levels have not been fully evaluated. Combination therapy with ADV and LAM was given to 37 patients infected with LAM-refractory HBV, including 17 with hepatic cirrhosis. Serum HBV DNA levels decreased to below 2.6 log(10) copies/mL in 23 (62%) of 37 patients at 12 months, 25 (78%) of 32 patients at 24 months, and 16 (84%) of 19 patients at 36 months. Except for one cirrhotic patient, serum alanine aminotransferase levels were below 50 IU/L in all patients during combination therapy. Serum creatinine levels increased in 14 (38%) of 37 patients, and serum phosphate levels decreased to below 2.5 mg/mL in 6 (16%) of 37 patients during combination therapy. Patients who received combination therapy for 36 months or longer had a significantly incidence of elevated serum creatinine levels. Fanconi syndrome occurred in a 57-year-old woman with cirrhosis after ADV was added to LAM. Combination therapy with ADV and LAM can maintain biochemical remission in patients with LAM-refractory HBV. However, the dosing interval of ADV should be adjusted according to renal function and serum phosphate levels in patients receiving long-term treatment.