Association between physical activity over a 10-year period and current insomnia symptoms, sleep duration and daytime sleepiness: a European population-based study.

OBJECTIVES: To explore the relationship between physical activity over a 10-year period and current symptoms of insomnia, daytime sleepiness and estimated sleep duration in adults aged 39-67. DESIGN: Population-based, multicentre cohort study. SETTING: 21 centres in nine European countries. METHODS: Included were 4339 participants in the third follow-up to the European Community Respiratory Health Survey (ECRHS III), who answered questions on physical activity at baseline (ECRHS II) and questions on physical activity, insomnia symptoms, sleep duration and daytime sleepiness at 10-year follow-up (ECRHS III). Participants who reported that they exercised with a frequency of at least two or more times a week, for 1 hour/week or more, were classified as being physically active. Changes in activity status were categorised into four groups: persistently non-active; became inactive; became active; and persistently active. MAIN OUTCOME MEASURES: Insomnia, sleep time and daytime sleepiness in relation to physical activity. RESULTS: Altogether, 37% of participants were persistently non-active, 25% were persistently active, 20% became inactive and 18% became active from baseline to follow-up. Participants who were persistently active were less likely to report difficulties initiating sleep (OR 0.60, 95% CI 0.45-0.78), a short sleep duration of ≤6 hours/night (OR 0.71, 95% CI 0.59-0.85) and a long sleep of ≥9 hours/night (OR 0.53, 95% CI 0.33-0.84) than persistently non-active subjects after adjusting for age, sex, body mass index, smoking history and study centre. Daytime sleepiness and difficulties maintaining sleep were not related to physical activity status. CONCLUSION: Physically active people have a lower risk of some insomnia symptoms and extreme sleep durations, both long and short.

Group B streptococcal infections in infants in Iceland: clinical and microbiological factors.

Introduction. Group B streptococcus (GBS) is a leading cause of invasive neonatal infections. These have been divided into early-onset disease (EOD; <7 days) and late-onset disease (LOD; 7-89 days), with different GBS clonal complexes (CCs) associated with different disease presentations.Hypothesis. Different GBS CCs are associated with timing of infection (EOD or LOD) and clinical presentation (sepsis, meningitis or pneumonia).Aim. To study infant GBS infections in Iceland from 1975 to 2019. Are specific GBS CCs related to disease presentation? Is CC17 overrepresented in infant GBS infections in Iceland?Methodology. All culture-confirmed invasive GBS infections in infants (<90 days) in Iceland from 1975 to 2019 were included. Clinical information was gathered from medical records.Results. A total of 127 invasive GBS infections in infants were diagnosed, but 105 infants were included in the study. Of these, 56 had EOD and 49 had LOD. The incidence of GBS infections declined from 2000 onwards but increased again at the end of the study period. Furthermore, there was a significant increase in LOD over the study period (P=0.0001). The most common presenting symptoms were respiratory difficulties and fever and the most common presentation was sepsis alone. Approximately one-third of the cases were caused by GBS CC17 of serotype III with surface protein RIB and pili PI-1+PI-2b or PI-2b. CC17 was significantly associated with LOD (P<0.001).Conclusion. CC17 is a major cause of GBS infection in infants in Iceland. This clone is associated with LOD, which has been increasing in incidence. Because intrapartum antibiotic prophylaxis only prevents EOD, it is important to continue the development of a GBS vaccine in order to prevent LOD infections.

Are symptoms of insomnia related to respiratory symptoms? Cross-sectional results from 10 European countries and Australia.

OBJECTIVES: To compare the prevalence of different insomnia subtypes among middle-aged adults from Europe and Australia and to explore the cross-sectional relationship between insomnia subtypes, respiratory symptoms and lung function. DESIGN: Cross-sectional population-based, multicentre cohort study. SETTING: 23 centres in 10 European countries and Australia. METHODS: We included 5800 participants in the third follow-up of the European Community Respiratory Health Survey III (ECRHS III) who answered three questions on insomnia symptoms: difficulties falling asleep (initial insomnia), waking up often during the night (middle insomnia) and waking up early in the morning and not being able to fall back asleep (late insomnia). They also answered questions on smoking, general health and chronic diseases and had the following lung function measurements: forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and the FEV1/FVC ratio. Changes in lung function since ECRHS I about 20 years earlier were also analysed. MAIN OUTCOME MEASURES: Prevalence of insomnia subtypes and relationship to respiratory symptoms and function. RESULTS: Overall, middle insomnia (31.2%) was the most common subtype followed by late insomnia (14.2%) and initial insomnia (11.2%). The highest reported prevalence of middle insomnia was found in Iceland (37.2%) and the lowest in Australia (22.7%), while the prevalence of initial and late insomnia was highest in Spain (16.0% and 19.7%, respectively) and lowest in Denmark (4.6% and 9.2%, respectively). All subtypes of insomnia were associated with significantly higher reported prevalence of respiratory symptoms. Only isolated initial insomnia was associated with lower FEV1, whereas no association was found between insomnia and low FEV1/FVC ratio or decline in lung function. CONCLUSION: There is considerable geographical variation in the prevalence of insomnia symptoms. Middle insomnia is most common especially in Iceland. Initial and late insomnia are most common in Spain. All insomnia subtypes are associated with respiratory symptoms, and initial insomnia is also associated with lower FEV1.

Definition of excessive daytime sleepiness in the general population: Feeling sleepy relates better to sleep-related symptoms and quality of life than the Epworth Sleepiness Scale score. Results from an epidemiological study.

Many different subjective tools are being used to measure excessive daytime sleepiness (EDS) but the most widely used is the Epworth Sleepiness Scale (ESS). However, it is unclear if using the ESS is adequate on its own when assessing EDS. The aim of this study was to estimate the characteristics and prevalence of EDS using the ESS and the Basic Nordic Sleep Questionnaire (BNSQ) in general population samples. Participants aged 40 years and older answered questions about sleepiness, health, sleep-related symptoms and quality of life. Two groups were defined as suffering from EDS: those who scored >10 on the ESS (with increased risk of dozing off) and those reporting feeling sleepy during the day ≥3 times per week on the BNSQ. In total, 1,338 subjects (53% male, 74.1% response rate) participated, 13.1% reported an increased risk of dozing off, 23.2% reported feeling sleepy and 6.4% reported both. The prevalence of restless leg syndrome, nocturnal gastroesophageal reflux, difficulties initiating and maintaining sleep and nocturnal sweating was higher among subjects reporting feeling sleepy compared to non-sleepy subjects. Also, subjects reporting feeling sleepy had poorer quality of life and reported more often feeling unrested during the day than non-sleepy subjects. However, subjects reporting increased risk of dozing off (ESS > 10) without feeling sleepy had a similar symptom profile as the non-sleepy subjects. Therefore, reporting only risk of dozing off without feeling sleepy may not reflect problematic sleepiness and more instruments in addition to ESS are needed when evaluating daytime sleepiness.

Group B Streptococcal Neonatal and Early Infancy Infections in Iceland, 1976-2015.

BACKGROUND: Despite a risk-based peripartum chemoprophylaxis approach in Iceland since 1996, Streptococcus agalactiae [group B streptococci (GBS)] remains an important cause of early-onset [<7 days, early-onset disease (EOD)] and late-onset disease (LOD; 7 days to 3 months). METHODS: We studied GBS invasive disease in children <1 year in Iceland in 1976-2015. Bacteria (n = 98) were characterized by susceptibility to a panel of antimicrobials, capsular serotyping, resistance genes, surface protein and pilus-locus profiling and multilocus sequence typing. RESULTS: Both EOD and LOD increased during the early years, but while EOD subsequently decreased from 0.7/1000 live births in 1991-1995 to 0.2/1000 in 2011-2015, LOD showed a nonsignificant decrease from its peak value of 0.6/1000 in 2001-2005 to 0.4/1000 in 2006-2015. Serotype III was the most frequently found (n = 48), represented mostly by the hypervirulent lineage CC17/III/rib/PI-1+PI-2b (62%), but also by CC19/III/rib/PI-1+PI-2a (35%) frequently associated with colonization. Serotype Ia (n = 22) was represented by CC23/Ia/eps/PI-2a (68%) and CC7/Ia/bca/PI-1+PI-2b (23%) of possible zoonotic origin. Resistance to erythromycin and clindamycin was increasingly detected in the last years of the study (5 of the 9 cases were isolated after 2013), including representatives of a multiresistant CC17/III/rib/PI-2b sublineage described recently in other countries and expressing resistance to erythromycin, clindamycin and streptomycin. CONCLUSIONS: The risk-based chemoprophylaxis adopted in Iceland possibly contributed to the decline of EOD but has had limited effect on LOD. GBS causing neonatal and early infancy invasive infections in Iceland are genetically diverse, and the recent emergence of antimicrobial resistant lineages may reduce the choices for prophylaxis and therapy of these infections.

PAP treatment in patients with OSA does not induce long-term nasal obstruction.

We hypothesized that positive airway pressure treatment would induce nasal obstruction and decrease nasal cavity due to mucosal swelling. We further hypothesized that subjective and objective nasal obstruction at baseline would negatively affect positive airway pressure adherence. A total of 728 patients with sleep apnea were investigated in the Icelandic Sleep Apnea Cohort at baseline and 2 years after starting positive airway pressure. Patients underwent home sleep apnea testing at baseline. Questionnaires were answered and acoustic rhinometry was completed at baseline and follow-up. The proportion of patients reporting subjective nocturnal nasal obstruction was reduced (baseline: 35% versus follow-up: 24%; p < 0.001). Small interior nasal dimensions increased (p < 0.001) independent of adherence to treatment. Small nasal volume at baseline was a determinant for becoming a non-user of positive airway pressure treatment (odds ratio 2.22, confidence interval 95% 1.35-3.67, p = 0.002). Subjective nasal obstruction decreased 2 years after initiating positive airway treatment in sleep apnea, and objectively small nasal dimensions increased. Small nasal volume at baseline was a negative predictor for positive airway pressure treatment adherence. Maybe most importantly, positive airway pressure treatment did not cause long-term objective or subjective nasal obstruction.

Obesity modulates the association between sleep apnea treatment and CHI3L1 levels but not CHIT1 activity in moderate to severe OSA: an observational study.

PURPOSE: The inflammatory markers chitinase-3-like protein 1 (CHI3L1) and chitotriosidase (CHIT1) have both been associated with cardiovascular complications. The aim of this preliminary observational study was to assess the roles and interaction of obstructive sleep apnea (OSA) severity and body mass index (BMI) with plasma CHI3L1 levels and CHIT1 activity in patients with moderate to severe OSA. The second aim was to assess the roles and interaction of positive airway pressure (PAP) treatment and BMI on the expression of the same proteins. METHODS: The study included 97 OSA patients with an apnea-hypopnea index (AHI) ≥ 15 and full usage of PAP treatment after 4 months. Plasma CHI3L1 levels and CHIT1 activity were measured before and after treatment. RESULTS: Multiple linear regression analysis demonstrated an independent association of BMI on CHI3L1 levels (p < 0.05) but not on CHIT1 activity. The OSA severity markers (AHI and oxygen desaturation index) did not independently or in interaction with BMI levels associate with CHI3L1 levels or with CHIT1 activity (p > 0.05). A two-way repeated measures ANOVA revealed a significant interaction between PAP treatment effect (before vs. after) and BMI groups (< 35 kg/m2 vs. ≥ 35 kg/m2) on CHI3L1 levels (p = 0.03) but not on CHIT1 activity (p = 0.98). CONCLUSIONS: Obesity independently associated with CHI3L1 levels. Association between OSA severity and CHI3L1 levels or CHIT1 activity (independent of or dependent on obesity level) could not be confirmed. However, decrease was observed in CHI3L1 levels after PAP treatment in severely obese OSA patients but not in those less obese.

Changing Faces of Obstructive Sleep Apnea: Treatment Effects by Cluster Designation in the Icelandic Sleep Apnea Cohort.

Study Objectives: Distinct clinical phenotypes of obstructive sleep apnea (OSA) have been identified: Disturbed Sleep, Minimally Symptomatic, and Sleepy. Determining whether these phenotypes respond differently to standard treatment helps us to create a foundation for personalized therapies. We compared responses to positive airway pressure (PAP) therapy in these clinical OSA phenotypes. Methods: The study sample included 706 patients from the Icelandic Sleep Apnea Cohort with moderate-to-severe OSA who were prescribed PAP. Linear and logistic mixed models were used to compare 2-year changes in demographics, comorbid diseases, and sleep-related health issues within and across OSA clinical phenotypes. Relationships between changes in symptoms and PAP adherence were also examined. Results: Overall, effect sizes were moderate to large when comparing sleepiness, insomnia-related, and apneic symptom changes in the Sleepy group with changes in other two groups, especially those in the Minimally Symptomatic group. Within the Disturbed Sleep group, PAP users and nonusers demonstrated similar changes in insomnia-related symptoms. The Minimally Symptomatic group remained relatively asymptomatic, but reported significant decreases in daytime sleepiness and physical fatigue; PAP users generally had larger improvements. The Sleepy group had reductions in nearly all measured symptoms, including large reductions in drowsy driving; almost all of these improvements were greater among PAP users than nonusers. Conclusions: OSA treatment response patterns differed by initial clinical phenotype and PAP adherence. Individuals with insomnia-related symptoms may require additional targeted therapy for these complaints. These findings underscore the need for a personalized approach to management that recognizes patients with a range of OSA presentations.

Nocturnal nasal obstruction is frequent and reduces sleep quality in patients with obstructive sleep apnea.

The prevalence and consequences of nasal obstruction in untreated obstructive sleep apnea patients are not known. The study objectives were to investigate the frequency of subjective and objective nasal obstruction in untreated sleep apnea patients and the associations with sleep and quality of life. Patients in the Icelandic Sleep Apnea Cohort were subjected to a type 3 sleep study, answered questionnaires and had their nasal dimensions measured by acoustic rhinometry. In total, 810 patients participated (including 153 females), aged 54.5 ± 10.6 years [mean ± standard deviation (SD)] with an apnea/hypopnea index 44.7 ± 20.7 h-1 . Nocturnal nasal obstruction (greater than or equal to three times per week) was reported by 35% of the patients. These patients had smaller nasal dimensions measured by the minimum cross-sectional area within the smaller nasal valve (0.42 ± 0.17 versus 0.45 ± 0.16 cm2 , P = 0.013), reported more daytime sleepiness (Epworth Sleepiness Scale score 12.5 ± 4.9 versus 10.8 ± 5.0; P < 0.001) and slightly lower mental quality of life than patients without nocturnal nasal obstruction. Nocturnal nasal obstruction is reported in one-third of the sleep apnea patients and they are more likely to suffer from daytime sleepiness and slightly reduced quality of life than other sleep apnea patients.

Respiratory symptoms are more common among short sleepers independent of obesity.

INTRODUCTION: Sleep length has been associated with obesity and various adverse health outcomes. The possible association of sleep length and respiratory symptoms has not been previously described. The aim of this study was to investigate the association between sleep length and respiratory symptoms and whether such an association existed independent of obesity. METHODS: This is a multicentre, cross-sectional, population-based study performed in 23 centres in 10 different countries. Participants (n=5079, 52.3% males) were adults in the third follow-up of the European Community Respiratory Health Survey III. The mean±SD age was 54.2±7.1 (age range 39-67 years). Information was collected on general and respiratory health and sleep characteristics. RESULTS: The mean reported nighttime sleep duration was 6.9±1.0 hours. Short sleepers (<6 hours per night) were n=387 (7.6%) and long sleepers (≥9 hours per night) were n=271 (4.3%). Short sleepers were significantly more likely to report all respiratory symptoms (wheezing, waking up with chest tightness, shortness of breath, coughing, phlegm and bronchitis) except asthma after adjusting for age, gender, body mass index (BMI), centre, marital status, exercise and smoking. Excluding BMI from the model covariates did not affect the results. Short sleep was related to 11 out of 16 respiratory and nasal symptoms among subjects with BMI ≥30 and 9 out of 16 symptoms among subjects with BMI <30. Much fewer symptoms were related to long sleep, both for subjects with BMI <30 and ≥30. CONCLUSIONS: Our results show that short sleep duration is associated with many common respiratory symptoms, and this relationship is independent of obesity.

Insomnia complaints in lean patients with obstructive sleep apnea negatively affect positive airway pressure treatment adherence.

The objective of this study was to evaluate the determinants of long-term adherence to positive airway pressure treatment among patients with obstructive sleep apnea, with special emphasis on patients who stop positive airway pressure treatment within 1 year. This is a prospective long-term follow-up of subjects in the Icelandic Sleep Apnea Cohort who were diagnosed with obstructive sleep apnea between 2005 and 2009, and started on positive airway pressure treatment. In October 2014, positive airway pressure adherence was obtained by systematically evaluating available clinical files (n = 796; 644 males, 152 females) with moderate to severe obstructive sleep apnea (apnea-hypopnea index ≥15 events per h). The mean follow-up time was 6.7 ± 1.2 years. In total, 123 subjects (15.5%) returned their positive airway pressure device within the first year, 170 (21.4%) returned it later and 503 (63.2%) were still using positive airway pressure. The quitters within the first year had lower body mass index, milder obstructive sleep apnea, less sleepiness, and more often had symptoms of initial and late insomnia compared with long-term positive airway pressure users at baseline. Both initial and late insomnia were after adjustment still significantly associated with being an early quitter among subjects with body mass index <30 kg m-2 , but not among those with body mass index ≥30 kg m-2 . The prevalence of early quitters decreased significantly during the study period (2005-2009). Almost two-thirds of patients with moderate to severe obstructive sleep apnea are positive airway pressure users after 7 years. Obesity level, obstructive sleep apnea severity and daytime sleepiness are important determinants of long-term adherence. Symptoms of initial and late insomnia are associated with early quitting on positive airway pressure among non-obese subjects.

[The short-and long term effect of multidisciplinary obesity treatment on body mass index and mental health].

INTRODUCTION: The aim of this treatment study was to evaluate both short- and long-term effects of a multidisciplinary obesity treatment. Long-term outcomes of patients receiving gastric bypass surgery in addition to behavioral obesity treatment were compared with those who did not undergo surgery. MATERIAL AND METHODS: The participants were 100 patients undergoing a four week inpatient obesity treatment at the Hospital in Neskaupsstaður (Fjórðungsjúkrahúsið í Neskaupstað (FSN). After treatment was completed, 28 of these patients underwent further treatment, receiving gastric bypass surgery. All patients were followed for two years after completing the four week treatment. Body mass index (BMI), quality of life and symptoms of depression and anxiety were measured for all participants before and after treatment, and again using mailed questionnaires in a cross-sectional data collection in the summer of 2012. RESULTS: Participants achieved statistically significant weight loss (median 1,85 BMI points), improved their quality of life and mental health after four week obesity treatment, and long term results remained significant. Three years after the conclusion of treatment, statistically significant weight loss was still present for patients that had not undergone gastric bypass surgery (median 2.13 BMI points), but improvements in mental health and quality of life were no longer present among subjects who did not undergo surgery. Patients who underwent gastric bypass surgery achieved greater weight loss (median 13.12 BMI points) and longer lasting improvements in mental health and quality of life. CONCLUSION: Results show that the multidisciplinary obesity treatment is effective in reducing obesity and improving mental health and quality of life in the short term. With follow-up treatment, the weight loss is maintained for up to three years after treatment for all participants. The bypass surgery group lost more weight and showed more permanent improvements in mental health and quality of life. These results underline the necessity of providing long-term treatment in maintaining improvements when treating obesity. 1Municipal Service Centre for Miðborg and Hlíðar 2University of Iceland, 3National University Hospital of Iceland, 4East Coast Regional Hospital in Iceland, 5The Health Care Institution of South Iceland. KEY WORDS: obesity, short- and long term treatment outcomes, weight loss, quality of life, mental health, interdisciplinary treatment. Correspondence: Bjarni Kristinn Gunnarsson bjarnikris@gmail.com.

Obstructive sleep apnoea in the general population: highly prevalent but minimal symptoms.

The aim was to assess the prevalence of obstructive sleep apnoea (OSA) as defined by an apnoea-hypopnea index (AHI) ≥15 in the middle-aged general population, and the interrelationship between OSA, sleep-related symptoms, sleepiness and vigilance.A general population sample of 40-65-year-old Icelanders was invited to participate in a study protocol that included a type 3 sleep study, questionnaire and a psychomotor vigilance test (PVT).Among the 415 subjects included in the study, 56.9% had no OSA (AHI <5), 24.1% had mild OSA (AHI 5-14.9), 12.5% had moderate OSA (AHI 15-29.9), 2.9% had severe OSA (AHI ≥30) and 3.6% were already diagnosed and receiving OSA treatment. However, no significant relationship was found between AHI and subjective sleepiness or clinical symptoms. A relationship with objective vigilance assessed by PVT was only found for those with AHI ≥30. Subjects already on OSA treatment and those accepting OSA treatment after participating in the study were more symptomatic and sleepier than others with similar OSA severity, as assessed by the AHI.In a middle-aged general population, approximately one in five subjects had moderate-to-severe OSA, but the majority of them were neither symptomatic nor sleepy and did not have impaired vigilance.

The Prevalence of Depression among Untreated Obstructive Sleep Apnea Patients Using a Standardized Psychiatric Interview.

STUDY OBJECTIVES: The aims of this study were: (1) to use a standardized psychiatric interview, conducted by a trained psychologist to assess the prevalence of depression among patients with untreated OSA, and (2) to identify if OSA severity or other comorbid disorders (insomnia, hypertension, and diabetes) are related to depression among patients with untreated OSA. METHODS: Participants were newly diagnosed patients with OSA (n = 284) waiting to start positive airway pressure (PAP) treatment. The Mini International Neuropsychiatric Interview (MINI) was used to assess depression. RESULTS: Overall, 15.5% of the sample met the diagnosis for dysthymia. Women had a significantly higher prevalence (29.5% versus 11.7% among men, p < 0.001). The prevalence of major depression was 6% in the overall sample and there was no difference in the prevalence among sexes (5.8% among men versus 6.6 % among women). Obesity, daytime sleepiness, low physical activity, initial and late insomnia, low quality of life, and sleep medication and antidepressant use were all related to depression, whereas OSA severity, as measured by apnea-hypopnea index or oxygen desaturation index, was not. Daytime sleepiness, initial insomnia, and sleep medication use were the strongest predictors of depression in multivariable analyses. CONCLUSIONS: Sleep medication use, daytime sleepiness, and symptoms of initial insomnia were independently related to depression but OSA severity was not. Increased awareness of the relationship between depression and OSA and the appropriate use of assessment tools might substantially improve diagnostic accuracy as well as treatment outcome for both disorders.

[Effectiveness of an online cognitive behavioral therapy for insomnia]. / Árangur hugrænnar atferlismeðferðar við svefnleysi sem veitt er á netinu.

INTRODUCTION: Insomnia is a common health problem with serious mental and physical consequences as well as increased economical costs. The use of hypnotics in Iceland is immense in spite of cognitive behavioral therapy for insomnia (CBT-I) being recommended as the first choice treatment of chronic insomnia. To meet the needs of more individuals suffering from insomnia, online CBT-I was established at betrisvefn.is. The objective of this research was to evaluate the effectiveness of this internet-based CBT-I. MATERIAL AND METHODS: One hundred seventy-five users (mean age 46 y (18-79 y)) started a 6 week online intervention for insomnia. The drop-out rate was 29%, leaving a final sample of 125 users. The intervention is based on well-established face-to-face CBT-I. Sleep diaries were used to determine changes in sleep efficiency, sleep onset latency and wake after sleep onset. Treatment effects were assesed after 6 weeks of treatment and at the 6 week follow-up. RESULTS: Significant improvement was found in all main sleep variables except for 5% decrease in total sleep time (TST). Effects were sustained at 6 week follow-up and TST increased. The use of hypnotics decreased significantly. This form of treatment seems to suit its users very well and over 94% would recommend the treatment. CONCLUSION: Internet interventions for insomnia seem to have good potential. CBT-I will hopefully be offered as the first line treatment for chronic insomnia in Iceland instead of hypnotics as the availability of the CBT-I is growing. Thus, the burden on health care clinics might reduce along with the hypnotics use and the considerable costs of insomnia.

Quality of life among untreated sleep apnea patients compared with the general population and changes after treatment with positive airway pressure.

Obstructive sleep apnea leads to recurrent arousals from sleep, oxygen desaturations, daytime sleepiness and fatigue. This can have an adverse impact on quality of life. The aims of this study were to compare: (i) quality of life between the general population and untreated patients with obstructive sleep apnea; and (ii) changes of quality of life among patients with obstructive sleep apnea after 2 years of positive airway pressure treatment between adherent patients and non-users. Propensity score methodologies were used in order to minimize selection bias and strengthen causal inferences. The enrolled obstructive sleep apnea subjects (n = 822) were newly diagnosed with moderate to severe obstructive sleep apnea who were starting positive airway pressure treatment, and the general population subjects (n = 742) were randomly selected Icelanders. The Short Form 12 was used to measure quality of life. Untreated patients with obstructive sleep apnea had a worse quality of life when compared with the general population. This effect remained significant after using propensity scores to select samples, balanced with regard to age, body mass index, gender, smoking, diabetes, hypertension and cardiovascular disease. We did not find significant overall differences between full and non-users of positive airway pressure in improvement of quality of life from baseline to follow-up. However, there was a trend towards more improvement in physical quality of life for positive airway pressure-adherent patients, and the most obese subjects improved their physical quality of life more. The results suggest that co-morbidities of obstructive sleep apnea, such as obesity, insomnia and daytime sleepiness, have a great effect on life qualities and need to be taken into account and addressed with additional interventions.

The different clinical faces of obstructive sleep apnoea: a cluster analysis.

Although commonly observed in clinical practice, the heterogeneity of obstructive sleep apnoea (OSA) clinical presentation has not been formally characterised. This study was the first to apply cluster analysis to identify subtypes of patients with OSA who experience distinct combinations of symptoms and comorbidities. An analysis of baseline data from the Icelandic Sleep Apnoea Cohort (822 patients with newly diagnosed moderate-to-severe OSA) was performed. Three distinct clusters were identified. They were classified as the "disturbed sleep group" (cluster 1), "minimally symptomatic group" (cluster 2) and "excessive daytime sleepiness group" (cluster 3), consisting of 32.7%, 24.7% and 42.6% of the entire cohort, respectively. The probabilities of having comorbid hypertension and cardiovascular disease were highest in cluster 2 but lowest in cluster 3. The clusters did not differ significantly in terms of sex, body mass index or apnoea-hypopnoea index. Patients with OSA have different patterns of clinical presentation, which need to be communicated to both the lay public and the professional community with the goal of facilitating care-seeking and early identification of OSA. Identifying distinct clinical profiles of OSA creates a foundation for offering more personalised therapies in the future.

Symptoms of insomnia among patients with obstructive sleep apnea before and after two years of positive airway pressure treatment.

STUDY OBJECTIVES: To assess the changes of insomnia symptoms among patients with obstructive sleep apnea (OSA) from starting treatment with positive airway pressure (PAP) to a 2-y follow-up. DESIGN: Longitudinal cohort study. SETTING: Landspitali--The National University Hospital of Iceland. PARTICIPANTS: There were 705 adults with OSA who were assessed prior to and 2 y after starting PAP treatment. INTERVENTION: PAP treatment for OSA. MEASUREMENTS AND RESULTS: All patients underwent a medical examination along with a type 3 sleep study and answered questionnaires on health and sleep before and 2 y after starting PAP treatment. The change in prevalence of insomnia symptoms by subtype was assessed by questionnaire and compared between individuals who were using or not using PAP at follow-up. Symptoms of middle insomnia were most common at baseline and improved significantly among patients using PAP (from 59.4% to 30.7%, P < 0.001). Symptoms of initial insomnia tended to persist regardless of PAP treatment, and symptoms of late insomnia were more likely to improve among patients not using PAP. Patients with symptoms of initial and late insomnia at baseline were less likely to adhere to PAP (odds ratio [OR] 0.56, P = 0.007, and OR 0.53, P < 0.001, respectively). CONCLUSION: Positive airway pressure treatment significantly reduced symptoms of middle insomnia. Symptoms of initial and late insomnia, however, tended to persist regardless of positive airway pressure treatment and had a negative effect on adherence. Targeted treatment for insomnia may be beneficial for patients with obstructive sleep apnea comorbid with insomnia and has the potential to positively affect adherence to positive airway pressure.

Nocturnal sweating--a common symptom of obstructive sleep apnoea: the Icelandic sleep apnoea cohort.

OBJECTIVES: To estimate the prevalence and characteristics of frequent nocturnal sweating in obstructive sleep apnoea (OSA) patients compared with the general population and evaluate the possible changes with positive airway pressure (PAP) treatment. Nocturnal sweating can be very bothersome to the patient and bed partner. DESIGN: Case-control and longitudinal cohort study. SETTING: Landspitali-The National University Hospital, Iceland. PARTICIPANTS: The Icelandic Sleep Apnea Cohort consisted of 822 untreated patients with OSA, referred for treatment with PAP. Of these, 700 patients were also assessed at a 2-year follow-up. The control group consisted of 703 randomly selected subjects from the general population. INTERVENTION: PAP therapy in the OSA cohort. MAIN OUTCOME MEASURES: Subjective reporting of nocturnal sweating on a frequency scale of 1-5: (1) never or very seldom, (2) less than once a week, (3) once to twice a week, (4) 3-5 times a week and (5) every night or almost every night. Full PAP treatment was defined objectively as the use for ≥4 h/day and ≥5 days/week. RESULTS: Frequent nocturnal sweating (≥3× a week) was reported by 30.6% of male and 33.3% of female OSA patients compared with 9.3% of men and 12.4% of women in the general population (p<0.001). This difference remained significant after adjustment for demographic factors. Nocturnal sweating was related to younger age, cardiovascular disease, hypertension, sleepiness and insomnia symptoms. The prevalence of frequent nocturnal sweating decreased with full PAP treatment (from 33.2% to 11.5%, p<0.003 compared with the change in non-users). CONCLUSIONS: The prevalence of frequent nocturnal sweating was threefold higher in untreated OSA patients than in the general population and decreased to general population levels with successful PAP therapy. Practitioners should consider the possibility of OSA in their patients who complain of nocturnal sweating.

The joint contribution of insomnia and obstructive sleep apnoea on sickness absence.

Several studies have indicated a high degree of overlap between insomnia and obstructive sleep apnoea, but little is known regarding how the overlap may affect adverse outcomes associated with each of the disorders. The aim of the current study was to examine the separate and combined effects of symptoms of insomnia and obstructive sleep apnoea on long-term sick leave. We used an historical cohort design with 4 years follow-up. Information on sick leave was obtained from Norwegian official registry data, and merged with health information from the Hordaland Health Study in western Norway, 1997-99. A total of 6892 participants aged 40-45 years were assessed for self-reported symptoms of insomnia and obstructive sleep apnoea (snoring and breathing cessations), as well as confounding factors. The level of overlap between insomnia and obstructive sleep apnoea was low (7-12%). Both insomnia and obstructive sleep apnoea alone were significant risk factors for subsequent sick leave after adjusting for confounding factors (odds ratios ranging from 1.4 to 2.3). Having comorbid insomnia and obstructive sleep apnoea increased the risk significantly. There was an additive interaction effect between the two conditions in the unadjusted analyses, but this was reduced to a non-significant level when adjusting for confounders. This study is the first to report the separate and combined effects of insomnia and obstructive sleep apnoea on any adverse outcome. Having both insomnia and obstructive sleep apnoea increased the risk of later sick leave, but there was no evidence of an independent synergy effect of the two conditions.