Psychophysiological insomnia and respiratory tract infections: results of an infection-diary-based cohort study

Demystifying roles of exercise in immune response regulation against acute respiratory infections: A narrative review

The benefits of physical activity and exercise, especially those classified as moderate-to-vigorous activity (MVPA), have been well-established in preventing non-communicable diseases and mental health problems in healthy adults. However, the relationship between physical activity and exercise and the prevention and management of acute respiratory infection (ARI), a global high-burden disease, has been inconclusive. There have been debates and disagreements among scientific publications regarding the relationship between exercise and immune response against the causative agents of ARI. This narrative review aims to explore the theory that sufficiently explains the correlation between exercise, immune response, and ARI. The potential root causes of discrepancies come from research associated with the "open window" hypothesis. The studies have several limitations, and future improvements to address them are urgently needed in the study design, data collection, exercise intervention, subject recruitment, biomarkers for infection and inflammation, nutritional and metabolism status, and in addressing confounding variables. In conclusion, data support the clinical advantages of exercise have a regulatory contribution toward improving the immune response, which in turn potentially protects humans fromARI. However, the hypothesis related to its negative effect must be adopted cautiously.

Repeated electrical vestibular nerve stimulation (VeNS) reduces severity in moderate to severe insomnia; a randomized, sham-controlled trial; The Modius Sleep Study

BACKGROUND

Insomnia is a prevalent health concern in the general population associated with a range of adverse health effects. New, effective, safe and low-cost treatments, suitable for long-term use, are urgently required. Previous studies have shown the potential of electrical vestibular nerve stimulation (VeNS) in improving insomnia symptoms, however only one sham-controlled trial has been conducted on people with chronic insomnia.

OBJECTIVES

/Hypothesis: Repeated VeNS delivered by the Modius Sleep device prior to sleep onset will show superior improvement in Insomnia Severity Index (ISI) scores over a 4-week period compared to sham stimulation.

METHODS

In this double-blinded, multi-site, randomised, sham-controlled study, 147 participants with moderate to severe insomnia (ISI≥15) were recruited and allocated a VeNS or a sham device (1:1 ratio) which they were asked to use at home for 30 minutes daily (minimum 5 days per week) for 4 weeks.

RESULTS

After 4 weeks, mean ISI score reduction was 2.26 greater in the VeNS treatment group than the sham group (p=0.002). In the per protocol analysis, the treatment group had a mean ISI score decrease of 5.8 (95% CI [-6.8, -4.81], approaching the clinically meaningful threshold of a 6-point reduction, with over half achieving a clinically significant decrease. Furthermore, the treatment group showed superior improvement to the sham group in the SF-36 (Quality of Life) energy/fatigue component (PP p=0.004, effect size 0.26; ITT p=0.006, effect size 0.22).

CONCLUSIONS

Modius sleep has the potential to provide a viable, non-invasive and safe clinically meaningful alternative treatment option for insomnia.

Pre-existing sleep problems as a predictor of post-acute sequelae of COVID-19

Several months after COVID-19 many individuals still report persisting symptoms, the so-called 'post-COVID-19 syndrome'. An immunological dysfunction is one of the main pathophysiological hypotheses. As sleep is central to the functioning of the immune system, we investigated whether self-reported pre-existing sleep disturbance might be an independent risk factor for the development of post-COVID-19 syndrome. A total of 11,710 participants of a cross-sectional survey (all tested positive for severe acute respiratory syndrome coronavirus-2) were classified into probable post-COVID-19 syndrome, an intermediate group, and unaffected participants at an average of 8.5 months after infection. The case definition was based on newly occurring symptoms of at least moderate severity and ≥20% reduction in health status and/or working capacity. Unadjusted and adjusted odds ratios were calculated to investigate the association between pre-existing sleep disturbances and subsequent development of post-COVID-19 syndrome while controlling for a variety of demographic, lifestyle, and health factors. Pre-existing sleep disturbances were found to be an independent predictor of subsequent probable post-COVID-19 syndrome (adjusted odds ratio 2.7, 95% confidence interval 2.27-3.24). Sleep disturbances as part of the post-COVID-19 syndrome were reported by more than half of the participants and appeared to be a new symptom and to occur independent of a mood disorder in most cases. Recognition of disturbed sleep as an important risk factor for post-COVID-19 syndrome should promote improved clinical management of sleep disorders in the context of COVID-19. Further, it may stimulate further research on the effect of improving sleep on the prognosis of COVID-19 long-term sequelae and other post-viral conditions.

Self-reported short and long sleep duration, sleep debt and insomnia are associated with several types of infections: Results from the Norwegian practice-based research network in general practice - PraksisNett

Objective

The objective was to assess the association between self-reported infections and sleep duration, sleep debt, chronic insomnia, and insomnia severity.

Methods

In total, 1023 participants were recruited from the Norwegian practice-based research network in general practice to a cross-sectional online survey with validated questions about sleep habits and insomnia symptoms (Bergen Insomnia Scale (BIS) and Insomnia Severity Index (ISI)), and whether they had experienced various infections during the last three months. Data were analyzed with chi-square tests and logistic regressions with adjustment for relevant confounders.

Results

Self-reported short sleep duration (<6 h) was significantly associated with increased odds of throat infection (OR = 1.60), ear infection (OR = 2.92), influenzalike illness (OR = 1.81) and gastrointestinal infection (OR = 1.91) whereas long sleep duration (>9 h) was associated with increased odds of throat (OR = 3.33) and ear infections (OR = 5.82), compared to sleep duration of 6-9 h, respectively. Sleep debt of >2 h was associated with increased odds of the common cold (OR = 1.67), throat infection (OR = 2.58), ear infection (OR = 2.84), sinusitis (OR = 2.15), pneumonia/bronchitis (OR = 3.97), influenzalike illness (OR = 2.66), skin infection (OR = 2.15), and gastrointestinal infection (OR = 2.80), compared to no sleep debt. Insomnia (based on BIS and ISI) was associated with throat infection (OR = 2.06, 2.55), ear infection (OR = 2.43, 2.45), sinusitis (OR = 1.82, 1.80), pneumonia/bronchitis (OR = 2.23, 3.59), influenzalike illness (OR = 1.77, 1.90), skin infection (OR = 1.64, 2.06), gastrointestinal infection (OR = 1.94, 3.23), and eye infection (OR = 1.99, 2.95).

Conclusions

These novel findings support the notion that people who have insufficient sleep or sleep problems are at increased risk of infections.

The public health impact of poor sleep on severe COVID-19, influenza and upper respiratory infections

BACKGROUND

Poor sleep is associated with an increased risk of infections and all-cause mortality but the causal direction between poor sleep and respiratory infections has remained unclear. We examined if poor sleep contributes as a causal risk factor to respiratory infections.

METHODS

We used data on insomnia, influenza and upper respiratory infections (URIs) from primary care and hospital records in the UK Biobank (N ≈ 231,000) and FinnGen (N ≈ 392,000). We computed logistic regression to assess association between poor sleep and infections, disease free survival hazard ratios, and performed Mendelian randomization analyses to assess causality.

FINDINGS

Utilizing 23 years of registry data and follow-up, we discovered that insomnia diagnosis associated with increased risk for infections (FinnGen influenza Cox's proportional hazard (CPH) HR = 4.34 [3.90, 4.83], P = 4.16 × 10-159, UK Biobank influenza CPH HR = 1.54 [1.37, 1.73], P = 2.49 × 10-13). Mendelian randomization indicated that insomnia causally predisposed to influenza (inverse-variance weighted (IVW) OR = 1.65, P = 5.86 × 10-7), URI (IVW OR = 1.94, P = 8.14 × 10-31), COVID-19 infection (IVW OR = 1.08, P = 0.037) and risk of hospitalization from COVID-19 (IVW OR = 1.47, P = 4.96 × 10-5).

INTERPRETATION

Our findings indicate that chronic poor sleep is a causal risk factor for contracting respiratory infections, and in addition contributes to the severity of respiratory infections. These findings highlight the role of sleep in maintaining sufficient immune response against pathogens.

FUNDING

Instrumentarium Science Foundation, Academy of Finland, Signe and Ane Gyllenberg Foundation, National Institutes of Health.

Insomnia, Poor Sleep Quality and Sleep Duration and Risk for COVID-19 Infection and Hospitalization

BACKGROUND

Medical comorbidities increase the risk of severe acute COVID-19 illness. Although sleep problems are common after COVID-19 infection, it is unclear whether insomnia, poor sleep quality and extremely long or short sleep increase risk of developing COVID-19 infection or hospitalization.

METHODS

Cross-sectional survey of a diverse sample of 19,926 U.S. adults RESULTS: COVID-19 infection and hospitalization prevalence rates were 40.1% and 2.9% respectively. Insomnia and poor sleep quality were reported in 19.8% and 40.1% respectively. In logistic regression models adjusted for comorbid medical conditions and sleep duration but excluding participants who reported COVID-19 associated sleep problems, poor sleep quality but not insomnia was associated with COVID-19 infection (aOR: 1.16, 95%CI: 1.07-1.26) and COVID-19 hospitalization (aOR: 1.50, 95% CI: 1.18-1.91). In comparison to habitual sleep duration of 7-8 hours, sleep durations less than 7 hours (aOR: 1.14, 95% CI: 1.06-1.23) and sleep duration of 12 hours (aOR: 1.61, 95% CI: 1.12-2.31) were associated with increased odds of COVID-19 infection. Overall, the relationship between COVID-19 infection and hours of sleep followed a quadratic (U shaped) pattern. No association between sleep duration and COVID-19 hospitalization was observed.

CONCLUSION

In a general population sample, poor sleep quality and extremes of sleep duration are associated with greater odds of having had a COVID-19 infection; poor sleep quality was associated with an increased requirement of hospitalization for severe COVID-19 illness. These observations suggest that inclusion of healthy sleep practices in public health messaging may reduce the impact of the COVID-19 pandemic.

The association between self-reported sleep problems, infection, and antibiotic use in patients in general practice

Objectives

There is emerging evidence that sleep problems and short sleep duration increase the risk of infection. We aimed to assess whether chronic insomnia disorder, chronic sleep problems, sleep duration and circadian preference based on self-report were associated with risk of infections and antibiotic use among patients visiting their general practitioner (GP).

Methods

We conducted a cross-sectional study of 1,848 unselected patients in Norway visiting their GP during 2020.The patients completed a one-page questionnaire while waiting for the consultation, that included the validated Bergen Insomnia Scale (BIS), questions on self-assessed sleep problem, sleep duration and circadian preference and whether they have had any infections or used antibiotics in the last 3 months. Relative risks (RR) were estimated using modified Poisson regression models.

Results

The risk of infection was 27% (95% CI RR 1.11-1.46) and 44% higher (95% CI 1.12-1.84) in patients sleeping < 6 h and >9 h, respectively, compared to those sleeping 7-8 h. The risk was also increased in patients with chronic insomnia disorder or a chronic sleep problem. For antibiotic use, the risk was higher for patients sleeping < 6 h, and for those with chronic insomnia disorder or a chronic sleep problem.

Conclusions

Among patients visiting their GP, short sleep duration, chronic insomnia and chronic sleep problem based on self-report were associated with higher prevalence of infection and antibiotic use. These findings support the notion of a strong association between sleep and infection.

Evaluating the Efficacy of Electrical Vestibular Stimulation (VeNS) on Insomnia Adults: Study Protocol of a Double-Blinded, Randomized, Sham-Controlled Trial

Insomnia is a common health problem in the general population. There are different ways to improve sleeping habits and quality of sleep; however, there is no clinical trial using transdermal neurostimulation to treat individuals with symptoms of insomnia in Asia. This gives us the impetus to execute the first study in Asia which aims to evaluate the efficacy of Electrical Vestibular Stimulation (VeNS) on individuals with insomnia in Hong Kong. This study proposes a two-armed, double-blinded, randomized, sham-controlled trial including the active VeNS and sham VeNS group. Both groups will be measured at baseline (T1), immediately after the intervention (T2), and at the 1-month (T3) and 3-month follow-up (T4). A total of 60 community-dwelling adults aged 18 to 60 years, with insomnia symptoms will be recruited in this study. All subjects will be computer randomized into either the active VeNS group or the sham VeNS group on a 1:1 ratio. All subjects in each group will receive twenty 30-min VeNS sessions during weekdays, which will be completed in a 4-week period. Baseline measurements and post-VeNS evaluation of the psychological outcomes (i.e., insomnia severity, sleep quality and quality of life) will also be conducted on all participants. The 1-month and 3-month follow-up period will be used to assess the short-and long-term sustainability of the VeNS intervention. For statistical analysis, a mixed model will be used to analyze the repeated measures data. Missing data will be managed by multiple imputations. The level of significance will be set to p < 0.05. Significance of the study: The results of this study will be used to determine whether this VeNS device can be considered as a self-help technological device to reduce the severity of insomnia in the community setting. We registered this clinical trial with the Clinical trial government, identifier: NCT04452981.

SARS-CoV-2 infection is associated with increased odds of insomnia, RLS and dream enactment behavior

BACKGROUND

Literature suggests that the COVID-19 pandemic has resulted in poor sleep quality, especially among the infected population. However, literature regarding the effect of COVID-19 pandemic and SARS-CoV-2 infection on occurrence of insomnia, restless legs syndrome and dream enactment behavior is either scarce or unavailable.

METHODS

This study was planned to assess the effect of SARS-CoV-2 infection on the occurrence of insomnia, restless legs syndrome (RLS) and dream enactment behavior (DEB). For this cross-sectional study, a questionnaire comprising of items related to demographic details, past medical history, and information related to SARS-CoV-2 infection was distributed through social media. Insomnia was diagnosed using clinical criteria. RLS, DEB, sleep quality, depression and anxiety were assessed using a validated questionnaire. Information regarding the use of hypnotic medications was also gathered.

RESULTS

Of the 1596 respondents, 37.2% reported disturbed sleep while insomnia was reported by 22.6% respondents. 27.3% of respondents reported RLS and 17.4% suffered DEB. The odds of insomnia were greater among males (OR = 1.27; 95% CI: 1.03-1.58; P < 0.02) and among those who had SARS-CoV-2 infection (OR = 1.76; 95% CI = 1.42-2.19; P < 0.001). Similarly, SARS-CoV-2 infection was also associated with increased odds of RLS (OR = 2.48; 95% CI = 1.98-3.11; P < 0.001) and DEB (OR = 1.58; 95%CI = 1.21-2.06; P < 0.001). Insomnia, RLS and DEB were more frequent among respondents who required oxygen therapy, those who experienced loss of taste and/or smell, depression and anxiety. Prevalence of insomnia, DEB and RLS was higher than said prevalence among respondents with no history of SARS-CoV-2 infection, but lower than that of those with positive history of SARS-CoV-2 infection. 5.3% of respondents reported taking hypnotic medications before infection, 7% during infection and 5.3% after infection.

CONCLUSION

SARS-CoV-2-infection-related factors in association with environmental factors have increased the prevalence of insomnia, DEB and RLS among subjects having infection. SARS-CoV-2-associated immunological changes, hypoxia and neurotropism may play a role in occurrence of insomnia, DEB and RLS.

Differential effects of an experimental model of prolonged sleep disturbance on inflammation in healthy females and males

Sleep disturbances, including disrupted sleep and short sleep duration, are highly prevalent and are prospectively associated with an increased risk for various widespread diseases, including cardiometabolic, neurodegenerative, chronic pain, and autoimmune diseases. Systemic inflammation, which has been observed in populations experiencing sleep disturbances, may mechanistically link disturbed sleep with increased disease risks. To determine whether sleep disturbances are causally responsible for the inflammatory changes reported in population-based studies, we developed a 19-day in-hospital experimental model of prolonged sleep disturbance inducing disrupted and shortened sleep. The model included delayed sleep onset, frequent nighttime awakenings, and advanced sleep offset, interspersed with intermittent nights of undisturbed sleep. This pattern aimed at providing an ecologically highly valid experimental model of the typical sleep disturbances often reported in the general and patient populations. Unexpectedly, the experimental sleep disturbance model reduced several of the assessed proinflammatory markers, namely interleukin(IL)-6 production by monocytes and plasma levels of IL-6 and C-reactive protein (CRP), presumably due to intermittent increases in the counterinflammatory hormone cortisol. Striking sex differences were observed with females presenting a reduction in proinflammatory markers and males showing a predominantly proinflammatory response and reductions of cortisol levels. Our findings indicate that sleep disturbances causally dysregulate inflammatory pathways, with opposing effects in females and males. These results have the potential to advance our mechanistic understanding of the pronounced sexual dimorphism in the many diseases for which sleep disturbances are a risk factor.

The public health impact of poor sleep on severe COVID-19, influenza and upper respiratory infections

Background

Poor sleep is associated with an increased risk of infections and all-cause mortality, and acute sleep loss and disruption have been linked with inflammation and poorer immune control. Previous studies, however, have been unable to evidence causality between the chronic effects of poor sleep and respiratory infection risk. In light of the ongoing COVID-19 pandemic and potential future disease outbreaks, understanding the risk factors for these infections is of great importance.

Aim

Our goal was to understand if chronic poor sleep could be identified as a causal risk factor for respiratory infections including influenza, upper respiratory infections and COVID-19.

Methods

We used population cohorts from the UK Biobank (N ≈ 231,000) and FinnGen (N ≈ 327,000) with ICD-10 based electronic health records and obtained diagnoses of insomnia, influenza and upper respiratory infections (URIs) from primary care and hospital settings. We computed logistic regression to assess association between poor sleep and infections, disease free survival hazard ratios, and used summary statistics from genome-wide association studies of insomnia, influenza, URI and COVID-19 to perform Mendelian randomization analyses and assess causality.

Findings

Utilizing 23 years of registry data and follow-up, we saw that insomnia diagnosis associated with increased risk for infections in FinnGen and in UK Biobank (FinnGen influenza HR = 5.32 [4.09, 6.92], P = 1.02×10-35, UK Biobank influenza HR = 1.54 [1.37, 1.73], P = 2.49×10-13). Mendelian randomization indicated that insomnia causally predisposed to influenza (OR = 1.59, P = 6.23×10-4), upper respiratory infections (OR = 1.71, P = 7.60×10-13), COVID-19 infection (OR = 1.08, P = 0.037) and risk of hospitalization from COVID-19 (OR = 1.47, P = 4.96×10-5).

Conclusions

Our findings indicate that chronic poor sleep is a causal risk factor for contracting respiratory infections, and in addition contributes to the severity of respiratory infections. These findings highlight the role of sleep in maintaining sufficient immune response against pathogens as suggested by earlier work. As the current COVID-19 pandemic has increased the number of people suffering from poor sleep, safe interventions such as sleep management and treating individuals with insomnia could be promoted to reduce infections and save lives.

Diversity and molecular network patterns of symptom phenotypes

Symptom phenotypes have continuously been an important clinical entity for clinical diagnosis and management. However, non-specificity of symptom phenotypes for clinical diagnosis is one of the major challenges that need be addressed to advance symptom science and precision health. Network medicine has delivered a successful approach for understanding the underlying mechanisms of complex disease phenotypes, which will also be a useful tool for symptom science. Here, we extracted symptom co-occurrences from clinical textbooks to construct phenotype network of symptoms with clinical co-occurrence and incorporated high-quality symptom-gene associations and protein-protein interactions to explore the molecular network patterns of symptom phenotypes. Furthermore, we adopted established network diversity measure in network medicine to quantify both the phenotypic diversity (i.e., non-specificity) and molecular diversity of symptom phenotypes. The results showed that the clinical diversity of symptom phenotypes could partially be explained by their underlying molecular network diversity (PCC = 0.49, P-value = 2.14E-08). For example, non-specific symptoms, such as chill, vomiting, and amnesia, have both high phenotypic and molecular network diversities. Moreover, we further validated and confirmed the approach of symptom clusters to reduce the non-specificity of symptom phenotypes. Network diversity proposes a useful approach to evaluate the non-specificity of symptom phenotypes and would help elucidate the underlying molecular network mechanisms of symptom phenotypes and thus promotes the advance of symptom science for precision health.

The Prospective Association Between Physical Activity, Insomnia Symptoms and Productivity in an Australian Population-based Cohort

OBJECTIVES

To investigate the joint, prospective associations of physical inactivity and insomnia symptoms and productivity using the 2013 and 2014 Household Income and Labor Dynamics in Australia Survey panel data.

METHODS

The association between i) presenteeism (yes/no, n=5864) and ii) absenteeism (sick leave days, n = 4324) and the mutually exclusive groups "active without insomnia", "active with insomnia", "inactive without insomnia" and "inactive with insomnia" was assessed.

RESULTS

Participants "active with insomnia" or "inactive with insomnia" had greater odds of presenteeism than those "active without insomnia" (OR = 1.41, 95%CI: 1.07-1.85 and OR=1.44, 95%CI: 1.14-1.83 respectively). Participants "inactive with insomnia" had a greater incidence of absenteeism than participants "active without insomnia" (IRR=1.28, 95%CI: 1.07-1.54).

CONCLUSIONS

Findings suggest improving physical activity levels and insomnia symptoms concurrently may improve productivity by reducing presenteeism and sick leave.

Occurrence and Long-term Prognosis of Insomnia Disorder among Survivors of Acute Respiratory Distress Syndrome in South Korea

RATIONALE

As a most common type of sleep disorder, insomnia disorder can develop as a sequela among acute respiratory distress syndrome (ARDS) survivors. However, insomnia prevalence, its associated factors, and its impact on long-term survival remain controversial.

OBJECTIVES

This study aimed to investigate insomnia prevalence and its associated factors among ARDS survivors. We also examined the association between insomnia and 2-year all-cause mortality.

METHODS

The National Health Insurance Database of South Korea was used for this nationwide cohort study. We included adult patients (≥18 years old) admitted to intensive care units for ARDS treatment from January 1, 2010, to December 31, 2018, and survived for ≥1 year after diagnosis, defined as ARDS survivors. ARDS survivors diagnosed with insomnia disorder before ARDS diagnosis were defined as the pre-ARDS insomnia disorder group, whereas those who had no history of insomnia disorder but were newly diagnosed with insomnia disorder within 1 year of diagnosis of ARDS were defined as the post-ARDS insomnia disorder group.

RESULTS

A total of 4,452 ARDS survivors were included in this study, with 895 patients (20.1%) in the pre-ARDS insomnia disorder group and 536 (12.6%) patients in the post-ARDS insomnia disorder group. In the multivariable logistic regression analysis, delirium occurrence (odds ratio [OR]:1.61, 95% confidence interval [CI]: 1.24-2.10; P<0.001), underlying anxiety disorder (OR:1.34, 95% CI: 1.08-1.66; P=0.007), depression (OR: 1.48, 95% CI: 1.17-1.86; P=0.001), and substance abuse (OR:1.51, 95% CI: 1.01-2.26; P=0.042) were associated with a higher prevalence of post-ARDS insomnia disorder. In multivariable Cox regression analysis, the pre-ARDS insomnia disorder and post-ARDS insomnia disorder groups were associated with 1.33-fold (hazard ratio [HR]:1.33, 95% CI: 1.08-1.64; P=0.007) and 1.36-fold (HR:1.36, 95% CI: 1.06-1.74; P=0.016) increased prevalence of 2-year all-cause mortality among ARDS survivors, respectively.

CONCLUSIONS

At 1 year after diagnosis of ARDS, 12.6% of ARDS survivors were newly diagnosed with insomnia disorder in South Korea. Delirium and underlying psychiatric illness (anxiety disorder, depression, and substance abuse) were potential risk factors for the diagnosis of post-ARDS insomnia disorder. Moreover, both pre-and post-ARDS insomnia disorders were associated with 2-year all-cause mortality among ARDS survivors.

Understanding insomnia as systemic disease

Sleep plays a critical role in homeostasis of the body and mind. Insomnia is a disease that causes disturbances in the initiation and maintenance of sleep. Insomnia is known to affect not only the sleep process itself but also an individual’s cognitive function and emotional regulation during the daytime. It increases the risk of various neuropsychiatric diseases such as depression, anxiety disorder, and dementia. Although it might appear that insomnia only affects the nervous system, it is also a systemic disease that affects several aspects of the body, such as the cardiovascular, endocrine, and immune systems; therefore, it increases the risk of various diseases such as hypertension, diabetes mellitus, and infection. Insomnia has a wide range of effects on our bodies because sleep is a complex and active process. However, a high proportion of patients with insomnia do not seek treatment, which results in high direct and indirect costs. This is attributed to the disregard of many of the negative effects of insomnia. Therefore, we expect that understanding insomnia as a systemic disease will provide an opportunity to understand the condition better and help prevent secondary impairment due to insomnia.

Narcolepsy type 1: what have we learned from genetics?

Type-1 narcolepsy is a severe neurological disorder with distinct characteristic of loss of hypocretin neurotransmitter. Genetic analysis in type-1 narcolepsy have revealed a unique signal pointing toward autoimmune, rather than psychiatric origin. While type-1 narcolepsy has been intensively studied, the other subtypes of hypersomnolence, narcolepsy, and hypersomnia are less thoroughly understood. This review summarizes the latest breakthroughs in the field in narcolepsy. The goal of this article is to help the reader to understand better the risk from genetic factors and their interplay with immune, genetic, and epidemiological aspects in narcolepsy.

Targeting FcRn for immunomodulation: Benefits, risks, and practical considerations

The neonatal fragment crystallizable (Fc) receptor (FcRn) functions as a recycling mechanism to prevent degradation and extend the half-life of IgG and albumin in the circulation. Several FcRn inhibitors selectively targeting IgG recycling are now moving rapidly toward clinical practice in neurology and hematology. These molecules accelerate the destruction of IgG, reducing pathogenic IgG and IgG immune complexes, with no anticipated effects on IgA, IgM, IgE, complement, plasma cells, B cells, or other cells of the innate or adaptive immune systems. FcRn inhibitors have potential for future use in a much wider variety of antibody-mediated autoimmune diseases. Given the imminent clinical use, potential for broader utility, and novel mechanism of action of FcRn inhibitors, here we review data from 4 main sources: (a) currently available activity, safety, and mechanism-of-action data from clinical trials of FcRn inhibitors; (b) other procedures and treatments that also remove IgG (plasma donation, plasma exchange, immunoadsorption); (c) diseases resulting in loss of IgG; and (d) primary immunodeficiencies with potential mechanistic similarities to those induced by FcRn inhibitors. These data have been evaluated to provide practical considerations for the assessment, monitoring, and reduction of any potential infection risk associated with FcRn inhibition, in addition to highlighting areas for future research.

Risk of transition from occasional neck/back pain to long-duration activity limiting neck/back pain: a cohort study on the influence of poor work ability and sleep disturbances in the working population in Stockholm County

OBJECTIVES

The prevalence of neck/back pain (NBP) is high worldwide. Limited number of studies have investigated workers with occasional NBP regarding the risk of developing long-duration activity limiting NBP (LNBP). The objectives were to assess (1) the effect of poor work ability and sleep disturbances in persons with occasional NBP on the risk of LNBP, and (2) the interaction effect of these exposures.

DESIGN

Cohort study based on three subsamples from the Stockholm Public Health Cohort.

SETTINGS

The working population in Stockholm County.

PARTICIPANTS

Persons aged 18-60 years, reporting occasional NBP the past 6 months at baseline year 2010 (n=16 460).

MEASURES

Work ability was assessed with items from the Work Ability Index, perceived mental and/or physical work ability. Sleep disturbances were self-reported current mild/severe disturbances. The outcome in year 2014 was reporting NBP the previous 6 months, occurring ≥couple of days per week and resulting in decreased work ability/restricted other daily activities. The additive effect of having both poor work ability and sleep disturbances was modelled with a dummy variable, including both exposures. Poisson log-linear regression was used to calculate risk ratios (RRs) and 95% CIs.

RESULTS

At follow-up, 9% had developed LNBP. Poor work ability and sleep disturbances were independent risk factors for LNBP; adjusted RR 1.7 (95% CI: 1.4 to 2.0) and 1.4 (95% CI: 1.2 to 1.5), respectively. No additive interaction was observed.

CONCLUSION

Workers with occasional NBP who have poor work ability and/or sleep disturbances are at risk of developing LNBP. Having both conditions does not exceed additive risk.

[Self-reported infections in the German National Cohort (GNC) in the context of the current research landscape]

BACKGROUND

Infectious diseases continue to play an important role for disease perception, health-economic considerations and public health in Germany. In recent years, infectious diseases have been linked to the development of non-communicable diseases. Analyses of the German National Cohort (GNC) may provide deeper insights into this issue and pave the way for new targeted approaches in disease prevention.

OBJECTIVES

The aim was to describe the tools used to assess infectious diseases and to present initial data on infectious disease frequencies, as well as to relate the GNC assessment tools to data collection methods in other studies in Germany.

METHODS

As part of the baseline examination, questions regarding infectious diseases were administered using both an interview and a self-administered touchscreen questionnaire. Data from the initial 101,787 GNC participants were analysed.

RESULTS

In the interview, 0.2% (HIV/AIDS) to 8.6% (shingles) of respondents reported ever having a medical diagnosis of shingles, postherpetic neuralgia (in cases where shingles was reported), hepatitis B/C, HIV/AIDS, tuberculosis or sepsis if treated in hospital. In the questionnaire, 12% (cystitis) to 81% (upper respiratory tract infections) of respondents reported having experienced at least one occurrence of upper or lower respiratory tract infections, gastrointestinal infections, cystitis or fever within the past 12 months.

OUTLOOK

The cross-sectional analyses of data and tools presented here - for example on determinants of susceptibility to self-reported infections - can be anticipated from the year 2021 onward. Beyond that, more extensive research into infectious disease epidemiology will follow, particularly once analyses of GNC biological materials have been performed.