Excessive daytime sleepiness, morning tiredness, and prognostic biomarkers in patients with chronic coronary syndrome

BACKGROUND

Sleep-related breathing disorders (SRBD) are related to cardiovascular outcomes in patients with chronic coronary syndrome (CCS). Whether SRBD-related symptoms are associated with prognostic biomarkers in patients with CCS is not established.

METHODS

Associations between frequency (never/rarely, sometimes, often, always) of self-reported SRBD-related symptoms (excessive daytime sleepiness [EDS]; morning tiredness [MT]; loud snoring; multiple awakenings/night; gasping, choking, or apnea when asleep) and levels of biomarkers related to cardiovascular prognosis (high-sensitivity C-reactive protein [hs-CRP], interleukin 6 [IL-6], high-sensitivity cardiac troponin T [hs-cTnT], N-terminal pro B-type natriuretic peptide [NT-proBNP], cystatin C, growth differentiation factor 15 [GDF-15] and lipoprotein-associated phospholipase A2 activity) were assessed at baseline in 15,640 patients with CCS on optimal secondary preventive therapy in the STABILITY trial. Cross-sectional associations were assessed by adjusted linear regression models testing for trends with the never/rarely category serving as reference.

RESULTS

EDS was associated (geometric mean ratio, 95% confidence interval) with increased levels of IL-6 (often 1.07 [1.03-1.10], always 1.15 [1.10-1.21]), GDF-15 (often 1.03 [1.01-1.06], always 1.07 [1.03-1.11]), NT-proBNP (always 1.22 [1.12-1.33]), and hs-cTnT (always 1.07 [1.01-1.12]). MT was associated with increased levels of IL-6 (often 1.05 [1.01-1.09], always 1.09 [1.04-1.15]), and GDF-15 (always 1.06 [1.03-1.10]). All symptoms were to some degree associated with higher levels of hs-CRP and loud snoring was also associated with decreased levels of NT-proBNP and hs-cTnT.

CONCLUSIONS

In patients with CCS, stepwise increased frequency of SRBD-related symptoms, such as EDS and MT, were associated with gradually higher levels of IL-6 and GDF-15, each reflecting distinct pathophysiological pathways.

Obstructive sleep apnea during rapid eye movement sleep and cognitive performance in adults

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) during rapid eye movement (REM) sleep is often characterized with more frequent and lengthy breathing events and greater oxygen desaturation than during other sleep stages. Current evidence suggests an association between OSA and cognitive decline, however whether OSA during REM sleep plays a vital role in this link is understudied.

METHODS

A cross-sectional sample of 728 men and women (aged 59.1 ± 11.3 years) underwent a full night polysomnography for determining apnea-hypopnea index (AHI) and sleep stages. Trail Making Test (TMT) part A and B were conducted during the following day for assessing participants' cognitive function. Linear regression analyses were performed to test the possible association between AHI and AHI during REM sleep with TMT-A and B results. Similar analyses were carried out in a subsample involving participants aged ≥60 years with ≥30 min of REM sleep (n = 356).

RESULTS

Despite a slight difference in TMT-B between participants with and without OSA (AHI ≥5 vs AHI <5, β-coefficient: 4.83, 95 % CI: [-9.44, -0.22], P = 0.040), no other association between AHI or REM-AHI and TMT results were found in the full sample. In older participants (aged ≥60 years), a REM-AHI ≥5 events/hour was associated with longer time taken to finish TMT-A (vs REM-AHI <5 events/hour, 3.93, [0.96, 6.90], P = 0.010). There was no association between REM-AHI and time taken to finish TMT-B in older participants.

CONCLUSIONS

The results indicate that OSA during REM sleep may be of particular concern for attention-related cognitive function in older adults.

Does obstructive sleep apnea increase the risk of cancer and cancer mortality in combined community-based cohorts?

Obstructive sleep apnea (OSA) has been linked to cancer in several clinical and community-based cohorts. The effect in community-based studies free of clinical referral bias needs to be replicated. In this observational prospective cohort study, we pooled data from three community-based prospective cohorts (Uppsala Sleep and Health in Men cohort [UMEN]; Sleep and health in women [SHE]; Men Androgen Inflammation Lifestyle Environment and Stress Cohort [MAILES]; nTotal  = 1467). All cohorts had objective data on obstructive sleep apnea and registry linkage data on cancer and cancer mortality. Analyses for different obstructive sleep apnea measures (apnea-hypopnea index [AHI], oxygen desaturation index [ODI], and minimal saturation) as risk factors for cancer incidence (all cancers) were performed using Cox proportional hazards models (follow-up 5-16 years). We did not find an overall increased risk of cancer after adjustment for age, sex, and BMI (HRAHI [95% CI] = 1.00 [0.98; 1.01] and HRODI [95% CI] = 0.99 [0.97; 1.01]). Stratifying by daytime sleepiness did not influence the association. Cancer mortality was not significantly associated with obstructive sleep apnea. Taken together, we did not observe an overall increased risk of cancer or cancer mortality in relation to obstructive sleep apnea, however, our confidence limits remain wide for important diagnostic categories of sleep apnea severity. The relationship between obstructive sleep apnea and cancer needs further investigation in a comprehensive multi-cohort approach with greater statistical precision. For future studies we may need to find and then combine every community-based cohort study that can provide a definitive answer to the question on the risk of cancer from obstructive sleep apnea in the general population.

Risk and outcomes of COVID-19 in patients with oxygen-dependent chronic respiratory failure- a national cohort study

BACKGROUND

We aimed to evaluate cumulative occurrence and impact of COVID-19 in patients with chronic respiratory failure (CRF) treated with long-term oxygen therapy (LTOT).

MATERIAL AND METHODS

Data were obtained from the SCIFI-PEARL study on the entire Swedish population and on patients with oxygen-dependent CRF and no COVID-19 diagnosis before start of LTOT. Analyses were performed for three time periods; pre-alpha (Jan-Dec 2020), alpha (Jan-Mar 2021) and delta/omicron (Apr 2021-May 2022). Cumulative incidence of laboratory-verified COVID-19 was compared between patients with CRF and the general population. Risk factors for severe (hospitalised) to critical (intensive care, or death ≤30 days after infection) COVID-19, and the impact of COVID-19 on one-year mortality, were analysed using multivariable Cox regression.

RESULTS

Cumulative incidence of COVID-19 was higher in patients with CRF than in the general population during the pre-alpha period (6.4%/4.9%, p = 0.002), but less common during the alpha and delta/omicron periods (2.9%/3.8% and 7.8%/15.5%, p < 0.0001 for both). The risk of severe/critical COVID-19 was much higher in CRF patients during all periods (4.9%/0.5%, 3.8%/0.2% and 15.5%/0.5%, p < 0.0001 for all). Risk factors for COVID-19 infection in people with CRF were higher age, cardiovascular and renal disease, and COVID-19 was associated with increased one-year mortality following infection in the pre-alpha (HR 1.79; [95% CI] 1.27-2.53) and alpha periods (1.43; 1.03-1.99).

CONCLUSION

Patients with CRF had higher risk of severe/critical COVID-19 than the general population. COVID-19 infection was associated with excess one-year mortality.

Economic evaluation of telemonitoring as a follow-up approach for patients with obstructive sleep apnea syndrome starting treatment with continuous positive airway pressure

Telemonitoring of obstructive sleep apnea patients is increasingly being adopted though its cost-effectiveness evidence base is scanty. This study investigated whether telemonitoring is a cost-effective strategy compared with the standard follow-up in patients with obstructive sleep apnea who are starting continuous positive airway pressure treatment. In total, 167 obstructive sleep apnea patients were randomised into telemonitoring (n = 79) or standard follow-up (n = 88), initiated continuous positive airway pressure treatment, and were followed up for 6 months. The frequencies of healthcare contacts, related costs (in USD 2021 prices), treatment effect and compliance were compared between the follow-up approaches using generalised linear models. The cost effectiveness analysis was conducted from a healthcare perspective and the results presented as cost per avoided extra clinic visit. Additionally, patient satisfaction between the two approaches was explored. The analysis showed no baseline differences. At follow-up, there was no significant difference in treatment compliance, and the mean residual apnea-hypoapnea index. There was no difference in total visits, adjusted incidence rate ratio 0.87 (0.72-1.06). Participants in the telemonitoring arm made eight times more telephone visits, 8.10 (5.04-13.84), and about 73% fewer physical healthcare visits 0.27 (0.20-0.36). This translated into significantly lower total costs for the telemonitoring approach compared with standard follow-up, -192 USD (-346 to -41). The form of follow-up seemed to have no impact on the extent of patient satisfaction. These results demonstrate the telemonitoring of patients with obstructive sleep apnea initiating continuous positive airway pressure treatment as a cost saving strategy and can be argued as a potential worthy investment.

Breathlessness and exercise performance to predict mortality in long-term oxygen therapy - The population-based DISCOVERY study

BACKGROUND

Patients with chronic respiratory failure treated with long-term oxygen therapy (LTOT) often have severe breathlessness, impaired exercise performance, and high but variable mortality that is difficult to predict. We aimed to evaluate breathlessness and exercise performance upon starting LTOT as predictors of overall and short-term mortality.

METHODS

This was a longitudinal, population-based study of patients who initiated LTOT between 2015-2018 in Sweden. Breathlessness was measured using the Dyspnea Exertion Scale, and exercise performance using the 30s-Sit-To-Stand test. Associations with overall and three-month mortality were analyzed using Cox-regression. Subgroup analyses were performed for patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) respectively. The predictive capacity of models was assessed using a C-statistic.

RESULTS

A total of 441 patients (57.6% female, aged 75.4 ± 8.3 years) were analyzed, of whom 141 (32%) died during a median follow-up of 260 (IQR 75-460) days. Both breathlessness and exercise performance were independently associated with overall mortality in the crude models, but only exercise performance remained independently associated with overall mortality when models were adjusted for other predictors, when short-term mortality was analyzed, or when breathlessness and exercise capacity were analyzed concurrently. The multivariable model including exercise performance but not breathlessness provided a relatively high predictive capacity for overall mortality, C-statistic 0.756 (95% CI 0.702-0.810). Similar results were seen in the COPD and ILD subgroups.

CONCLUSION

Exercise performance as measured by the 30s-STS may be useful to identify patients with higher mortality on LTOT for optimized management and follow-up.

Development and performance of a sleep estimation algorithm using a single accelerometer placed on the thigh: an evaluation against polysomnography

Accelerometers placed on the thigh provide accurate measures of daily physical activity types, postures and sedentary behaviours, over 24 h and across consecutive days. However, the ability to estimate sleep duration or quality from thigh-worn accelerometers is uncertain and has not been evaluated in comparison with the 'gold-standard' measurement of sleep polysomnography. This study aimed to develop an algorithm for sleep estimation using the raw data from a thigh-worn accelerometer and to evaluate it in comparison with polysomnography. The algorithm was developed and optimised on a dataset consisting of 23 single-night polysomnography recordings, collected in a laboratory, from 15 asymptomatic adults. This optimised algorithm was then applied to a separate evaluation dataset, in which, 71 adult males (mean [SD] age 57 [11] years, height 181 [6] cm, weight 82 [13] kg) wore ambulatory polysomnography equipment and a thigh-worn accelerometer, simultaneously, whilst sleeping at home. Compared with polysomnography, the algorithm had a sensitivity of 0.84 and a specificity of 0.55 when estimating sleep periods. Sleep intervals were underestimated by 21 min (130 min, Limits of Agreement Range [LoAR]). Total sleep time was underestimated by 32 min (233 min LoAR). Our results evaluate the performance of a new algorithm for estimating sleep and outline the limitations. Based on these results, we conclude that a single device can provide estimates of the sleep interval and total sleep time with sufficient accuracy for the measurement of daily physical activity, sedentary behaviour, and sleep, on a group level in free-living settings.

Association between obstructive sleep apnoea and cancer: a cross-sectional, population-based study of the DISCOVERY cohort

OBJECTIVES

Nocturnal hypoxia in obstructive sleep apnoea (OSA) is a potential risk factor for cancer. We aimed to investigate the association between OSA measures and cancer prevalence in a large national patient cohort.

DESIGN

Cross-sectional study.

SETTINGS

44 sleep centres in Sweden.

PARTICIPANTS

62 811 patients from the Swedish registry for positive airway pressure (PAP) treatment in OSA, linked to the national cancer registry and national socioeconomic data (the course of DIsease in patients reported to Swedish CPAP, Oxygen and VEntilator RegistrY cohort).

OUTCOME MEASURES

After propensity score matching for relevant confounders (anthropometric data, comorbidities, socioeconomic status, smoking prevalence), sleep apnoea severity, measured as Apnoea-Hypopnoea Index (AHI) or Oxygen Desaturation Index (ODI), were compared between those with and without cancer diagnosis up to 5 years prior to PAP initiation. Subgroup analysis for cancer subtype was performed.

RESULTS

OSA patients with cancer (n=2093) (29.8% females, age 65.3 (SD 10.1) years, body mass index 30 (IQR 27-34) kg/m²) had higher median AHI (n/hour) (32 (IQR 20-50) vs 30 (IQR 19-45), n/hour, p=0.002) and median ODI (n/hour) (28 (IQR 17-46) vs 26 (IQR 16-41), p<0.001) when compared with matched OSA patients without cancer. In subgroup analysis, ODI was significantly higher in OSA patients with lung cancer (N=57; 38 (21-61) vs 27 (16-43), p=0.012)), prostate cancer (N=617; 28 (17-46) vs 24, (16-39)p=0.005) and malignant melanoma (N=170; 32 (17-46) vs 25 (14-41),p=0.015).

CONCLUSIONS

OSA mediated intermittent hypoxia was independently associated with cancer prevalence in this large, national cohort. Future longitudinal studies are warranted to study the potential protective influence of OSA treatment on cancer incidence.

Adherence to CPAP therapy in Down syndrome: the population-based DISCOVERY study

STUDY OBJECTIVES

Persons with Down syndrome (DS) have an increased risk of obstructive sleep apnea (OSA) needing continuous positive airway pressure (CPAP), but data on the therapy and outcomes in this population are scarce. We aimed to compare patient characteristics and outcomes of CPAP treatment for patients with OSA with and without DS.

METHODS

This was a population-based, longitudinal study on patients initiating CPAP therapy between July 2010 and March 2018 in Sweden and a population-based sex- and age-matched control group (control:case ratio 5:1), with linked data from the Swedish National Patient Registry and the Prescribed Drug Registry (DISCOVERY study cohort).

RESULTS

Patients with DS (n = 64) had a higher apnea-hypopnea index (51.7 ± 30.3 vs 36.8 ± 29.1 events/h, P < .001), Epworth Sleepiness Scale score (13.7 ± 5.9 vs 11.0 ± 4.9, P = .001), rate of previous surgery of tonsils and/or adenoids (21.9% vs 8.2%, P = .001), and more thyroid replacement hormone therapy (45.3% vs 7.8%, P < .001), but lower use of cardiovascular drugs (7.8% vs 22.3%, P = .003) compared with controls. At follow-up after 1.3 ± 0.9 years, there were no differences in nocturnal CPAP usage time (5.6 ± 2.4 vs 5.5 ± 2.0 hours, P = .77), CPAP adherence ≥ 4 hours/night (62% vs 65%, P = .93), or improvement in Epworth Sleepiness Scale score (-5.4 ± 6.8 vs -5.0 ± 2.0, P = .84) between DS and non-DS patients.

CONCLUSIONS

OSA severity was substantially higher in patients with DS despite an increased rate of tonsil surgery. Treatment outcomes in terms of adherence and improved daytime sleepiness were comparable between groups, underlining the importance of both OSA diagnosis and treatment in patients with DS.

CITATION

Svensson M, Ekström M, Sundh J, Ljunggren M, Grote L, Palm A. Adherence to CPAP therapy in Down syndrome: the population-based DISCOVERY study. J Clin Sleep Med. 2023;19(3):453-458.

Nasal polyposis is a risk factor for nonadherence to CPAP treatment in sleep apnea: the population-based DISCOVERY study

STUDY OBJECTIVES

The aim was to evaluate nasal polyposis as a risk factor for nonadherence to continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea (OSA).

METHODS

This was a population-based, longitudinal analysis of patients starting CPAP treatment for OSA in the Swedish quality registry Swedevox between 2010 and 2018. Data were cross-linked with national registries. The impact of nasal polyposis on CPAP adherence was analyzed using uni- and multivariable logistic and linear regression models. Relevant confounders (age, sex, usage of nasal and oral steroids) were identified using a direct acyclic graph.

RESULTS

Of 20,521 patients with OSA on CPAP treatment (29.5% females), 331 (1.6%) had a diagnosis of nasal polyposis at baseline. At the 1-year follow-up, nasal polyposis was associated with an increased risk of CPAP usage < 4 hours/night (unadjusted odds ratio [OR] 1.21; 95% confidence interval [CI] 0.95-1.55); adjusted OR 1.38; 95% CI 1.08-1.77). In this group, unadjusted nocturnal mean CPAP usage was 15.4 minutes (95% CI -31.62 to 0.83) shorter and was an adjusted 24.1 minutes (95% CI -40.6 to -7.7) shorter compared with patients with OSA without nasal polyposis.

CONCLUSIONS

Nasal polyposis is associated with reduced CPAP usage per night. These results highlight the importance of diagnosing nasal polyposis in patients with OSA before the start of CPAP treatment. Treatment of the condition may improve adherence, efficacy, and patient outcomes.

CITATION

Bengtsson C, Grote L, Ljunggren M, Ekström M, Palm A. Nasal polyposis is a risk factor for nonadherence to CPAP treatment in sleep apnea: the population-based DISCOVERY study. J Clin Sleep Med. 2023;19(3):573-579.

Asthma and asthma-related comorbidity: effects on nocturnal oxygen saturation

STUDY OBJECTIVES

Nocturnal symptoms are very common in asthma, which is associated with worse sleep quality. The nocturnal oxygen saturation may be decreased in asthma; however, whether this association is dependent on nocturnal asthma symptoms, lung function, coexisting obstructive sleep apnea (OSA), or other asthma-related comorbidities is unknown. The objective of this study was to examine the effects of asthma, OSA, lung function, airway symptoms, and asthma-related comorbidities on the nocturnal oxygen saturation in a cross-sectional community-based population study.

METHODS

In total, 395 women and 392 men underwent overnight polysomnography, performed spirometry, and completed questionnaires on airway symptoms and asthma-related comorbidities.

RESULTS

Participants with asthma (n = 88) had a lower nocturnal oxygen saturation than those without asthma (93.8% vs 94.3%, P = .01) also after adjusting for comorbidity, age, body mass index, and smoking status (coefficient -0.38; CI -0.67, -0.10; P < .01). The nocturnal oxygen saturation was lower among participants with wheezing, nocturnal chest tightness, fixed airflow limitation, gastroesophageal reflux, obesity, and OSA than in those without these conditions. The associations between lower oxygen saturation and wheezing, forced expiratory volume in 1 second, gastroesophageal reflux, and apnea-hypopnea index were significant also after adjusting for age, sex, body mass index, and smoking status. Participants with both wheezing and OSA had a significantly lower nocturnal oxygen saturation (92.5 ± 0.5%) than participants with wheezing only (94.3 ± 0.3%) and OSA only (93.6 ± 0.2% %) (P < .01).

CONCLUSIONS

Participants with asthma displayed a lower mean oxygen saturation during sleep, which could not be explained only by coexisting OSA or obesity. Also, asthma symptoms and lung function were associated with lower nocturnal oxygen saturation. The lower oxygen saturation seen in asthma is hence multifactorial in origin and is a result of the combination of symptoms, lung function, and comorbidity.

CITATION

Sundbom F, Janson C, Ljunggren M, Lindberg E. Asthma and asthma-related comorbidity: effects on nocturnal oxygen saturation. J Clin Sleep Med. 2022;18(11):2635-2641.

Rapid eye movement sleep apnea and carotid intima thickness in men and women: a SHE-MUSTACHE cohort study

Rapid eye movement (REM) obstructive sleep apnea might be particularly harmful to the cardiovascular system. We aimed to investigate the association between sleep apnea during REM sleep and signs of atherosclerotic disease in the form of carotid intima thickness in a community-based sample of men and women and possible sex differences in this association. The association between sleep apnea during REM sleep and intima thickness was analysed cross-sectionally in women from the community-based "Sleep and Health in Women" (SHE) study (n = 253) and age- and body mass index (BMI)-matched men from the "Men in Uppsala; a Study of sleep, Apnea and Cardiometabolic Health" (MUSTACHE) study (n = 338). Confounders adjusted for were age, BMI, gender, alcohol, and smoking. All participants underwent a full-night polysomnography, high-resolution ultrasonography of the common carotid artery, anthropometric measurements, blood pressure measurements, and answered questionnaires. There was an association between sleep apnea during REM sleep and thicker carotid intima that remained after adjustment for confounding (adjusted β = 0.008, p = 0.032). The intima was increased by 9.9% in the group with severe sleep apnea during REM sleep, and this association between severe sleep apnea during REM sleep and increased intima thickness remained after adjustment for confounders (adjusted β = 0.043, p = 0.021). More women than men had severe sleep apnea during REM sleep; moreover, in sex-stratified analyses, the association between sleep apnea during REM sleep and intima thickness was found in women but not in men. We conclude that severe REM sleep apnea is independently associated with signs of atherosclerosis. When stratified by sex, the association is seen in women but not in men.

Insufficient sleep and new onset of nocturnal gastroesophageal reflux among women: a longitudinal cohort study

STUDY OBJECTIVES

Whether short or insufficient sleep were risk factors for new onset nocturnal gastroesophageal reflux (nGER).

METHODS

In this 10-year longitudinal study, adult general population women in Uppsala, Sweden, answered questionnaires on sleep, nGER and other conditions on two occasions. Participants at baseline totaled 6,790, while participants at follow-up totaled 4,925. "Short sleep" was defined as sleeping <6 hours/night and "insufficient sleep" was defined as reporting an average actual sleep duration below 80% of the self-estimated need for sleep duration but without "short sleep". nGER was defined as reporting heartburn or acid reflux after going to bed sometimes, often, or very often. The confounding factors age, body mass index, physical activity, caffeine intake, smoking habits, alcohol dependence, depression, anxiety, and snoring were defined from the questionnaire.

RESULTS

At baseline, 839 participants reported short sleep and 1,079 participants were defined as having insufficient sleep. Both participants with insufficient sleep and short sleep had nGER more often than those with sufficient sleep (26% vs 17% vs 10% respectively). At follow-up, a new onset of nGER was twice as common among those with insufficient or short sleep at baseline and follow-up, compared with those with sufficient sleep at baseline and follow-up, even after adjusting for confounding factors (OR 2.0 (1.5-2.8), p<0.001).

CONCLUSIONS

Insufficient sleep and short sleep were associated with nGER. Persistent insufficient and/or short sleep independently increased the risk of developing nGER over a 10-year follow-up. Women seeking for nGER should be questioned about their sleep habits to identify insufficient sleep as a possible causative factor.

Health risks related to polyurethan foam degradation in CPAP devices used for sleep apnoea treatment

A recent medical device recall notification from Philips Respironics reported on risk for degradation of polyurethane foam (PUF) in continuous positive airway pressure (CPAP) devices used for obstructive sleep apnoea (OSA) treatment [1]. The degraded foam particles may cause airway irritation, and the volatile gas products (diethylene glycol, toluene di-isocyanate isomers, toluene diamine isomers) released during the degradation process may also have cyto- and genotoxic effects [1]. Kendzerskaet al. [2] reported no increase in cancer incidence in 1220 patients using PUF devices over a mean observation time of 7.5 years. However, studies assessing airway symptoms and health outcomes other than cancer are lacking. Airway irritation from degraded foam particles may be particularly harmful for patients with pre-existing obstructive lung disease (OLD). This study aimed to evaluate the association between PUF-CPAP use and adverse health outcomes in OSA patients with/without comorbid OLD.

Patients with PUF-CPAP and especially those with pre-existing obstructive lung disease had increased use of anti-obstructive medication but there were no differences in hospitalisations and mortality, and data on cancer were inconclusivehttps://bit.ly/3uVIzXG

Sex-specific association of the lunar cycle with sleep

Using one-night sleep recordings from 852 subjects all living in Uppsala, Sweden, the present study represents one of the largest polysomnography investigations into the association of the 29.53-day long lunar cycle with sleep among men and women and across a wide age range (22-81 years). Following the day after the new moon until the day of the full moon (also named the waxing period), the moon's illumination increases, and the timing of the meridian of the moon is gradually shifted from noontime toward midnight. In contrast, from the day after the full moon until the day of the new moon (also named the waning period), the moon's illumination decreases, and the timing of the meridian of the moon is gradually shifted from early night hours toward noontime. Thus, we focused on the contrast between the waxing and waning periods. Sleep duration was shorter on nights during the waxing period as compared to waning period (P < 0.001). In addition, a significant interaction effect of participants' sex with the lunar period on sleep was noted (P < 0.05). Men, but not women, exhibited lower sleep efficiency (P < 0.001 and P = 0.748, respectively) and were longer awake after sleep onset (P = 0.010 and P = 0.890, respectively) on nights during the waxing period. All associations were robust to adjustment for confounders (including regular sleep disturbances). Our findings suggest that the effects of the lunar cycle on human sleep are more pronounced among men. Based on the cross-sectional design of the study, no firm conclusions can be drawn on the causality of the relations.

The negative health effects of having a combination of snoring and insomnia

STUDY OBJECTIVES

Insomnia and snoring are common sleep disorders. The aim was to investigate the association of having a combination of insomnia symptoms and snoring with comorbidity and daytime sleepiness.

METHODS

The study population comprised 25,901 participants (16-75 years, 54.4% women) from four Swedish cities, who answered a postal questionnaire that contained questions on snoring, insomnia symptoms (difficulties initiating and/or maintaining sleep and/or early morning awakening), smoking, educational level, and respiratory and non-respiratory disorders.

RESULTS

Snoring was reported by 4,221 (16.2%), while 9,872 (38.1%) reported ≥ 1 insomnia symptom. A total of 2,150 (8.3%) participants reported both insomnia symptoms and snoring. The association with hypertension (adj. OR 1.4, 95% CI: 1.2-1.6), chronic obstructive pulmonary disease (COPD) (adj. OR 1.8, 95% CI: 1.3-2.4), asthma (adj. OR 1.9; 95% CI: 1.6-2.3), daytime sleepiness (adj. OR 7.9, 95% CI 7.1-8.8) and the use of hypnotics (adj. OR 7.5, 95% CI: 6.1-9.1) was highest for the group with both insomnia symptoms and snoring.

CONCLUSIONS

Participants with both snoring and insomnia run an increased risk of hypertension, COPD, asthma, daytime sleepiness and the use of hypnotics. It is important to consider snoring in patients seeking medical assistance for insomnia and, vice versa, in patients with snoring inquiring about insomnia.

Snoring and environmental exposure: results from the Swedish GA2LEN study

OBJECTIVE

Habitual snoring is associated with fatigue, headaches and low work performance. This cross-sectional study aimed to investigate if snoring is affected by environmental factors such as home dampness and exposure to air pollution.

SETTING

General population sample from four Swedish cities.

PARTICIPANTS

25 848 participants from the Swedish part of the epidemiological Global Asthma and Allergy and European network of excellence study carried out in 2008. The participants completed a postal questionnaire on snoring and, indoor and outdoor environmental exposure as well as potential confounders including smoking, weight, height and educational level.

RESULTS

Of the participants, 4211 (16.3%) were habitual snorers. Habitual snorers reported water damage (8.3% vs 7.0% p<0.0001), floor dampness (4.6% vs 3.8% % p<0.0001) and visible mould (5.2% vs 3.8% p<0.0001) in their homes more often than non-snorers. Habitual snorers stated being annoyed by air pollution more often than non-snorers with habitual snorers reporting being irritated with the air in their residential area to a higher extent (sometimes 16.2% vs 13.9%, and daily 4.6% vs 3.1%) as well as annoyance from traffic fumes (somewhat 19% vs 18.5% and very 5% vs 3.6%) (p<0.0001). These results remained significant after adjustment for age, body mass index, smoking history and educational level.

CONCLUSION

Snoring is more prevalent in subjects reporting home dampness and air pollution. These association should be confirmed in further research using objective measurements and a longitudinal approach.

Socioeconomic Factors and Adherence to CPAP: The Population-Based Course of Disease in Patients Reported to the Swedish CPAP Oxygen and Ventilator Registry Study

Background

Early identification of poor adherence to CPAP treatment is of major clinical importance to optimize treatment outcomes in patients with OSA.

Research Question

How do socioeconomic factors influence CPAP adherence?

Study Design and Methods

Nationwide, population-based cohort study of patients with OSA receiving CPAP treatment reported to the Swedish quality registry Swedevox between 2010 and 2018 was cross-linked with individual socioeconomic data from Statistics Sweden. Socioeconomic factors associated with CPAP adherence were identified using a multivariate linear regression model, adjusted for age and sex.

Results

In total, 20,521 patients were included: 70.7% men; mean age ± SD, 57.8 ± 12.2 years; BMI, 32.0 ± 6.1 kg/m²; apnea-hypopnea index, 36.9 ± 22.1; Epworth Sleepiness Scale, 10.4 ± 5.0; and median nocturnal CPAP use, 355 min (interquartile range, 240-420 min). Adherence after 1.3 ± 0.8 years of CPAP use was significantly (all P < .001) associated with civil status (married vs unmarried: +20.5 min/night), education level (high, ≥ 13 years vs low, ≤ 9 years: +13.2 min/night), total household income (highest/third/second vs lowest quartile: +15.9 min/night, +10.4 min/night, and +6.1 min/night, respectively), and country of birth (born in Sweden with one native parent/born in Sweden with two native parents vs being born abroad: +29.0 min/night and +29.3 min/night, respectively).

Interpretation

Civil status, educational level, household income, and foreign background predict CPAP adherence in a clinically significant manner and should be considered when treating OSA with CPAP.

Course of DISease In patients reported to the Swedish CPAP Oxygen and VEntilator RegistrY (DISCOVERY) with population-based controls

PURPOSE

Chronic hypoxic and hypercapnic respiratory failure and obstructive sleep apnoea (OSA) are chronic diseases associated with decreased quality of life and increased mortality. The rationale behind the set up the retrospective nationwide DISCOVERY cohort was to study several questions including disease course and risk factors for incident disease, impaired quality of life, hospitalisation risk and mortality in patients with chronic respiratory failure with long-term oxygen therapy (LTOT), long-term mechanical ventilation (LTMV) and obstructive sleep apnoea (OSA) on treatment with continuous positive airway pressure (CPAP).

PARTICIPANTS AND SETTINGS

Data from the national quality registry for respiratory insufficiency and sleep apnoea (Swedevox) and a population-based control group from Statistics Sweden were merged with governmental registries, the Swedish Cancer Registry, the Swedish Cause of Death Registry, the Swedish Drug registry, the Swedish National Patient Registry and the Swedish Dental Health Registry and with national quality registries for diabetes, rheumatic diseases (Swedish Rheumatology Quality Registry), stroke (RiksStroke), heart failure (RiksSvikt), acute heart infarction care (SwedeHeart) and intensive care (SIR) and with socioeconomic data from Statistics Sweden (SCB).

FINDINGS TO DATE

The cohort comprises 25 804 unique patients with LTOT since 1987 (54.1% females, age 73.3±9.8 years, body mass index (BMI) 26.6±6.5 kg/m2), 8111 with LTMV since 1996 (48.6% women, age 60.6±16.9 years, BMI 32.9±10.8 kg/m2), 65 809 with OSA on CPAP since 2010 (29.5% women, age 57.2±12.5 years, BMI 31.9±6.2 kg/m2) and 145 224 persons in a population-based control group from same time span up to March 2018 (51.7% women, age 49.9±20.4 year, BMI 24.9±4.0 years).

FUTURE PLANS

In patients with chronic respiratory failure and sleep apnoea important questions regarding comorbidity burden, hospitalisation rate, mortality and treatment outcomes are still unexplored to a large extent. The DISCOVERY cohort will provide unique opportunities by its size and comprehensiveness to fill this clinically relevant gap of knowledge.

Association between lung function decline and obstructive sleep apnoea: the ALEC study

Purpose

To study changes in lung function among individuals with a risk of obstructive sleep apnoea (OSA), and if asthma affected this relationship.

Methods

We used data from the European Community Respiratory Health Survey II and III, a multicentre general population study. Participants answered questionnaires and performed spirometry at baseline and 10-year follow-up (n = 4,329 attended both visits). Subjects with high risk for OSA were identified from the multivariable apnoea prediction (MAP) index, calculated from BMI, age, gender, and OSA symptoms at follow-up. Asthma was defined as having doctor’s diagnosed asthma at follow-up. Primary outcomes were changes in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) from baseline to follow-up.

Results

Among 5108 participants at follow-up, 991 (19%) had a high risk of OSA based on the MAP index. Participants with high OSA risk more often had wheeze, cough, chest tightness, and breathlessness at follow-up than those with low OSA risk. Lung function declined more rapidly in subjects with high OSA risk (low vs high OSA risk [mean ± SD]: FEV1 = − 41.3 ± 24.3 ml/year vs − 50.8 ± 30.1 ml/year; FVC = − 30.5 ± 31.2 ml/year vs − 45.2 ± 36.3 ml/year). Lung function decline was primarily associated with higher BMI and OSA symptoms. OSA symptoms had a stronger association with lung function decline among asthmatics, compared to non-asthmatics.

Conclusion

In the general population, a high probability of obstructive sleep apnoea was related to faster lung function decline in the previous decade. This was driven by a higher BMI and more OSA symptoms among these subjects. The association between OSA symptoms and lung function decline was stronger among asthmatics.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02086-1) contains supplementary material, which is available to authorized users.

Smokers with insomnia symptoms are less likely to stop smoking

OBJECTIVES

Smoking is associated with sleep disturbances. The aim of this study was to analyze whether sleep disturbances are predictors of smoking cessation and whether continued smoking is associated with the development of sleep disturbances.

METHODS

A questionnaire was sent to randomly selected men and women in Northern Europe in 1999-2001 (RHINE II) and was followed up by a questionnaire in 2010-2012 (RHINE III). The study population consisted of 2568 participants who were smokers at baseline and provided data on smoking at follow-up. Insomnia symptoms were defined as having difficulty initiating and/or maintaining sleep and/or early morning awakening ≥3 nights/week. Multiple logistic regression analyses were performed to calculate odds ratios (OR).

RESULTS

Subjects with difficulty initiating sleep (adjusted odds ratio; 95% confidence interval: 0.6; 0.4-0.8), difficulty maintaining sleep (0.7; 0.5-0.9), early morning awakening (0.6; 0.4-0.8), any insomnia symptom (0.6; 0.5-0.8) or excessive daytime sleepiness (0.7; 0.5-0.8) were less likely to achieve long-term smoking cessation after adjustment for age, BMI, pack-years, hypertension, diabetes, chronic bronchitis, rhinitis, asthma, gender and BMI difference. There was no significant association between snoring and smoking cessation. In subjects without sleep disturbance at baseline, continued smoking increased the risk of developing difficulty initiating sleep during the follow-up period compared with those that had quit smoking (adj. OR 1.7, 95% CI 1.2-2.3).

CONCLUSIONS

Insomnia symptoms and excessive daytime sleepiness negatively predict smoking cessation. Smoking is a risk factor for the development of difficulty initiating sleep. Treatment for sleep disturbances should be included in smoking-cessation programs.

Risk Perception during Information System Development in Non-Profit Health Care Organizations

The perception of risk exposure among design team members during the early phases of information system development projects can provide valuable strategic information for clinical organizations. To develop a typology of perceived risks during information system development projects in health care, interviews were performed with key team members from a specialist clinic, primary health care, and an informatics research group, during the requirements specification. Phenomenological data analysis and secondary integration of the results in available theories were performed. System objectives, the user requirements definition procedure, the communication pattern between design team members and project management were found to be perceived as the main risk areas. In the secondary analysis, the technical factors, identified as preventing a maximization of the use of the resources, were lack of informatics knowledge among economic decision makers and differences between customers and suppliers regarding their views on the nature of system design. During the implementation of a given strategy, decision makers may consider the requests of their own sponsors in the first place and maximize the use ofthe project resources in the second place. Informatics knowledge plays a key role in risk perception during the development of an information system in health care. Political considerations by team members are important to take into regard, since these may influence technical and economic decisions.

Association between obstructive sleep apnea and elevated levels of type B natriuretic peptide in a community-based sample of women

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease. One contributory factor may be hemodynamic stress due to the negative intrathoracic pressure during each episode of apnea. Type B natriuretic peptide (BNP) is secreted by the cardiac ventricles in response to volume expansion and pressure load and the authors hypothesized that there would be an association between indices of OSA during the night and levels of BNP in the morning.

SETTING

Community-based in Uppsala, Sweden.

PARTICIPANTS

There were 349 women who participated.

MEASUREMENTS AND RESULTS

Participants underwent full-night polysomnography and anthropometric measurements, and answered questionnaires about medical conditions and current medication. The morning after the polysomnography, blood samples were drawn for analysis of plasma BNP, C-reactive protein, creatinine, and hemoglobin. There was an increase in mean BNP as the severity of sleep apnea increased, increasing from a mean value of 8.5 ng/L among women with an apnea-hypopnea index (AHI) < 5 to 18.0 ng/L in women with an AHI ≥ 30. Elevated BNP levels (≥ 20 ng/L) were found in 29.8% of the women, whereas 70.2% had normal levels. The odds ratio was 2.2 for elevated BNP levels for women with an AHI of 5-14.9 in relation to women with an AHI < 5, 3.1 for women with an AHI of 15-29.9, and 4.6 for women with an AHI ≥ 30 after adjustment for age, body mass index, systolic blood pressure, antihypertensive drugs, and creatinine.

CONCLUSIONS

There is a dose-response relationship in women between the severity of sleep apnea during the night and the levels of BNP in the morning.

Techno-economic comparison of a biological hydrogen process and a 2nd generation ethanol process using barley straw as feedstock

A process combining dark fermentation and photofermentation for production of hydrogen is interesting due to its potential of producing hydrogen at a high yields. In this study, the hydrogen process is compared to a 2nd generation ethanol process with respect to cost and with the aim of increasing our understanding of the pros and cons and giving a clear picture of the present status of the two processes. The hydrogen production cost was found to be about 20 times higher than the ethanol production cost, 421.7 €/GJ compared to 19.5 €/GJ. The main drawbacks of the hydrogen process are its low productivity, low energy efficiency, and the high cost of buffer and base required to control the pH.

Disc filtration for separation of flocs from a moving bed bio-film reactor

A Discfilter with 10 and 18 microm filter openings, respectively, was placed in parallel to a flotation plant for separation of biological flocs from a post-denitrifying Kaldnes Moving Bed Process, the last treatment step at the municipal wastewater treatment plant at Sjöunda, Malmö, Sweden. The effluent concentrations from the 10 and 18 microm filter were 2-5 and 2-8 mg SS L(-1), respectively, which is comparable to, or better than, the flotation plant. Comparison with experiences from activated sludge plants shows that the Discfilter works especially well after the Kaldnes process. Particle size distribution (PSD) studies show that particles larger than the filter openings of 10 and 18 microm are separated with approximately 90% efficiency, whereas most of the smaller particles pass the filter. This fact indicates that the major particle separation mechanism is physical blocking. These findings point to the possibility of improving the prediction of the separation efficiency by combining measurements of turbidity and suspended solids with particle size analysis.

Aggregation of inertial particles in random flows

We consider the trajectories of particles suspended in a randomly moving fluid. If the Lyapunov exponent of these trajectories is negative, the paths of these particles coalesce, so that particles aggregate. Here we give a detailed account of a method [B. Mehlig and M. Wilkinson, Phys. Rev. Lett. 92, 250602 (2004)] for calculating this exponent: it is expressed as the expectation value of a random variable evolving under a stochastic differential equation. We analyze this equation in detail in the limit where the correlation time of the velocity field of the fluid is very short, such that the stochastic differential equation is a Langevin equation. We derive an asymptotic perturbation expansion of the Lyapunov exponent for particles suspended in three-dimensional flows in terms of a dimensionless measure of the inertia of the particles, epsilon, and a measure of the relative intensities of potential and solenoidal components of the velocity field, Gamma. We determine the phase diagram in the epsilon-Gamma plane.

Particle visualisation--a tool for determination of rise velocities

Particles from a post denitrifying Kaldnes Moving Bed Process were studied using an optical borescope, a visualisation technique that provides opportunities for both qualitative and quantitative studies of the separation mechanism in Dissolved Air Flotation (DAF). Rise rates for particle/bubble aggregates were estimated showing great variability. Two groups of aggregates were distinguished; relatively small flocs (<100 microm) with single bubbles attached rising comparatively slowly and large flocs (>100 microm) with several bubbles attached rising very fast. The high rise rates for large aggregates are discussed, possibly explained and suggested as the reason for the effective separation of large particles noticed in previous studies. Removal efficiency of different size categories of particles in DAF were investigated on the basis of particle size analysis indicating increased separation efficiency with increasing particle size.

Separation characteristics in dissolved air flotation--pilot and full-scale demonstration

This study presents practical implications for particle separation in Dissolved Air Flotation (DAF). The objectives were to localise where particles are separated from the water phase and to determine what particles, in terms of size, are removed by the DAF-process. Both pilot- and full-scale plants were investigated. Particle sizes were analysed with a light-blocking particle counter and an optical borescope was used for visualisation of particle-bubble aggregates. It was found that particles are preferably separated upstream in the process, i.e. close to the contact zone. Furthermore, separation efficiency for particles increased with increasing particle size.

Risk perception during information system development in non-profit health care organizations

The perception of risk exposure among design team members during the early phases of information system development projects can provide valuable strategic information for clinical organizations. To develop a typology of perceived risks during information system development projects in health care, interviews were performed with key team members from a specialist clinic, primary health care, and an informatics research group, during the requirements specification. Phenomenological data analysis and secondary integration of the results in available theories were performed. System objectives, the user requirements definition procedure, the communication pattern between design team members and project management were found to be perceived as the main risk areas. In the secondary analysis, the technical factors, identified as preventing a maximization of the use of the resources, were lack of informatics knowledge among economic decision makers and differences between customers and suppliers regarding their views on the nature of system design. During the implementation of a given strategy, decision makers may consider the requests of their own sponsors in the first place and maximize the use of the project resources in the second place. Informatics knowledge plays a key role in risk perception during the development of an information system in health care. Political considerations by team members are important to take into regard, since these may influence technical and economic decisions.

Implementation of computer-based patient records in primary care: the societal health economic effects

OBJECTIVE

Exploration of the societal health economic effects occurring during the first year after implementation of Computerised Patient Records (CPRs) at Primary Health Care (PHC) centres.

DESIGN

Comparative case studies of practice processes and their consequences one year after CPR implementation, using the constant comparison method. Application of transaction-cost analyses at a societal level on the results.

SETTING

Two urban PHC centres under a managed care contract in Ostergötland county, Sweden.

MAIN OUTCOME MEASURES

Central implementation issues. First-year societal direct normal costs, direct unexpected costs, and indirect costs. Societal benefits.

RESULTS

The total societal effect of the CPR implementation was a cost of nearly 250,000 SEK (USD 37,000) per GP team. About 20% of the effect consisted of direct unexpected costs, accured from the reduction of practitioners' leisure time. The main issues in the implementation process were medical informatics knowledge and computer skills, adaptation of the human-computer interaction design to practice routines, and information access through the CPR.

CONCLUSIONS

The societal costs exceed the benefits during the first year after CPR implementation at the observed PHC centres. Early investments in requirements engineering and staff training may increase the efficiency. Exploitation of the CPR for disease prevention and clinical quality improvement is necessary to defend the investment in societal terms. The exact calculation of societal costs requires further analysis of the affected groups' willingness to pay.