Biomarkers of the L-arginine / dimethylarginine / nitric oxide pathway in people with chronic airflow obstruction and obstructive sleep apnoea

Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) are common chronic diseases that are associated with chronic and intermittent hypoxemia, respectively. Patients affected by the overlap of COPD and OSA have a particularly unfavourable prognosis. The L-arginine/nitric oxide (NO) pathway plays an important role in regulating pulmonary vascular function. Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) interfere with NO production. Methods: We analysed the serum concentrations of ADMA, SDMA, L-arginine, L-citrulline, and L-ornithine in a large sample of the Icelandic general population together with chronic airflow obstruction (CAO), a key physiological marker of COPD that was assessed by post-bronchodilator spirometry (FEV1/FVC 0.5. SDMA was significantly higher in individuals with CAO (0.518 [0.461–0.616] vs. 0.494 [0.441–0.565] µmol/L; p = 0.005), but ADMA was not. However, ADMA was significantly associated with decreasing FEV1 percent predicted among those with CAO (p = 0.002). ADMA was 0.50 (0.44–0.56) µmol/L in MAP ≤ 0.5 versus 0.52 (0.46–0.58) µmol/L in MAP > 0.5 (p = 0.008). SDMA was 0.49 (0.44–0.56) µmol/L versus 0.51 (0.46–0.60) µmol/L, respectively (p = 0.004). The highest values for ADMA and SDMA were observed in individuals with overlap of CAO and MAP > 0.5, which was accompanied by lower L-citrulline levels. Conclusions: The plasma concentrations of ADMA and SDMA are elevated in COPD patients with concomitant intermittent hypoxaemia. This may account for impaired pulmonary NO production, enhanced pulmonary vasoconstriction, and disease progression

Reaction norm analysis reveals rapid shifts toward delayed maturation in harvested Lake Erie yellow perch (Perca flavescens )

Harvested marine fish stocks often show a rapid and substantial decline in the age and size at maturation. Such changes can arise from multiple processes including fisheries‐induced evolution, phenotypic plasticity, and responses to environmental factors other than harvest. The relative importance of these processes could differ systematically between marine and freshwater systems. We tested for temporal shifts in the mean and within‐cohort variability of age‐ and size‐based maturation probabilities of female yellow perch (Perca flavescens Mitchill) from four management units (MUs) in Lake Erie. Lake Erie yellow perch have been commercially harvested for more than a century, and age and size at maturation have varied since sampling began in the 1980s. Our analysis compared probabilistic maturation reaction norms (PMRNs) for cohorts when abundance was lower and harvest higher (1993–1998) to cohorts when abundance was higher and harvest lower (2005–2010). PMRNs have been used in previous studies to detect signs of evolutionary change in response to harvest. Maturation size threshold increased between the early and late cohorts, and the increases were statistically significant for the youngest age in the western MU1 and for older ages in the eastern MU3. Maturation envelope widths, a measure of the variability in maturation among individuals in a cohort, also increased between early and late cohorts in the western MUs where harvest was highest. The highest rates of change in size at maturation for a given age were as large or larger than rates reported for harvested marine fishes where declines in age and size at maturation have been observed. Contrary to the general observation of earlier maturation evolving in harvested stocks, female yellow perch in Lake Erie may be rapidly evolving delayed maturation since harvest was relaxed in the late 1990s, providing a rare example of possible evolutionary recovery

Ash generation and distribution from the April-May 2010 eruption of Eyjafjallajökull, Iceland

The 39-day long eruption at the summit of Eyjafjallajökull volcano in April–May 2010 was of modest size but ash was widely dispersed. By combining data from ground surveys and remote sensing we show that the erupted material was 4.8±1.2·1011 kg (benmoreite and trachyte, dense rock equivalent volume 0.18±0.05 km3). About 20% was lava and water-transported tephra, 80% was airborne tephra (bulk volume 0.27 km3) transported by 3–10 km high plumes. The airborne tephra was mostly fine ash (diameter <1000 µm). At least 7·1010 kg (70 Tg) was very fine ash (<28 µm), several times more than previously estimated via satellite retrievals. About 50% of the tephra fell in Iceland with the remainder carried towards south and east, detected over ~7 million km2 in Europe and the North Atlantic. Of order 1010 kg (2%) are considered to have been transported longer than 600–700 km with <108 kg (<0.02%) reaching mainland Europe

Heart rate variability during wakefulness as a marker of obstructive sleep apnea severity.

Study objectives: Patients with obstructive sleep apnea (OSA) exhibit heterogeneous heart rate variability (HRV) during wakefulness and sleep. We investigated the influence of OSA severity on HRV parameters during wakefulness in a large international clinical sample. Methods: 1247 subjects (426 without OSA and 821 patients with OSA) were enrolled from the Sleep Apnea Global Interdisciplinary Consortium. HRV parameters were calculated during a 5-minute wakefulness period with spontaneous breathing prior to the sleep study, using time-domain, frequency-domain and nonlinear methods. Differences in HRV were evaluated among groups using analysis of covariance, controlling for relevant covariates. Results: Patients with OSA showed significantly lower time-domain variations and less complexity of heartbeats compared to individuals without OSA. Those with severe OSA had remarkably reduced HRV compared to all other groups. Compared to non-OSA patients, those with severe OSA had lower HRV based on SDNN (adjusted mean: 37.4 vs. 46.2 ms; p &lt; 0.0001), RMSSD (21.5 vs. 27.9 ms; p &lt; 0.0001), ShanEn (1.83 vs. 2.01; p &lt; 0.0001), and Forbword (36.7 vs. 33.0; p = 0.0001). While no differences were found in frequency-domain measures overall, among obese patients there was a shift to sympathetic dominance in severe OSA, with a higher LF/HF ratio compared to obese non-OSA patients (4.2 vs. 2.7; p = 0.009). Conclusions: Time-domain and nonlinear HRV measures during wakefulness are associated with OSA severity, with severe patients having remarkably reduced and less complex HRV. Frequency-domain measures show a shift to sympathetic dominance only in obese OSA patients. Thus, HRV during wakefulness could provide additional information about cardiovascular physiology in OSA patients. Clinical trial information: A Prospective Observational Cohort to Study the Genetics of Obstructive Sleep Apnea and Associated Co-Morbidities (German Clinical Trials Register - DKRS, DRKS00003966) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003966. Keywords: autonomic nervous activity; frequency domain analysis; heart rate variability; nonlinear dynamic analysis; obstructive sleep apnea; time domain analysis; wakefulness.Peer reviewe

Twilight foraging enables European shags to survive the winter across their latitudinal range

Species breeding at high latitudes face a significant challenge of surviving the winter. Such conditions are particularly severe for diurnal marine endotherms such as seabirds. A critical question is therefore what behavioural strategies such species adopt to maximise survival probability. We tested 3 hypotheses: (1) they migrate to lower latitudes to exploit longer day length (‘sun-chasing’), (2) they forage at night (‘night-feeding’), or (3) they target high-quality food patches to minimise foraging time (‘feasting’). We studied the winter migration and foraging strategies of European shags Phalacrocorax aristotelis from 6 colonies across a latitudinal gradient from temperate regions to north of the Arctic Circle using geolocators deployed over 11 winters. We found evidence for ‘sun-chasing’, whereby average southerly movements were greatest from colonies at higher latitudes. However, a proportion of individuals from higher latitudes remained resident in winter and, in the absence of daylight, they foraged during twilight and only very occasionally during the night. At lower latitudes, there was little evidence that individuals migrated south, nocturnal feeding was absent, and twilight feeding was infrequent, suggesting that there was sufficient daylight in winter. There was no evidence that winter foraging time was lowest at higher latitudes, as predicted by the ‘feasting’ hypothesis. Our results suggest that shags adopt different behavioural strategies to survive the winter across their latitudinal range, dictated by the differing light constraints. Our study highlights the value of multi-colony studies in testing key hypotheses to explain population persistence in seabird species that occur over large latitudinal ranges

Management of obstructive sleep apnea in Europe – A 10-year follow-up

Funding Information: Sleep medicine has been further established and recognized in the past 10 years. This is also shown by the fact that sleep-related diseases may receive a separate chapter in the new ICD-11 (International Classification of Diseases 11th Revision) [11]. However, the initial expansion in sleep laboratories and sleep centers seems to be over, at least in Europe, which stands in contradiction to the growing need. While sleep medical care still seems to be secured by the established structures, the gap between the increasing need and existing structures is still widening [ 12–14]. There is a lack of sleep medicine specialists, new outpatient structures, and new billing models with the sponsoring institutions. Approaches to solve these problems include the establishment and expansion of home sleep apnea testing (HSAT) [15] and telemedicine-based technologies in the diagnosis and treatment of OSA [16,17]. Telemedicine found its way into sleep medicine around 10 years ago [ 18–20]. One of the very first approaches as early as 1994 used a telephone circuit and a computer-controlled support system to improve OSA treatment by improving lifestyle through tele-guidance on nutrition and exercise [21]. Publisher Copyright: © 2022 The Authors Copyright © 2022 Elsevier B.V. All rights reserved.Objective: In 2010, a questionnaire-based study on obstructive sleep apnea (OSA) management in Europe identified differences regarding reimbursement, sleep specialist qualification, and titration procedures. Now, 10 years later, a follow-up study was conducted as part of the ESADA (European Sleep Apnea Database) network to explore the development of OSA management over time. Methods: The 2010 questionnaire including questions on sleep diagnostic, reimbursement, treatment, and certification was updated with questions on telemedicine and distributed to European Sleep Centers to reflect European OSA management practice. Results: 26 countries (36 sleep centers) participated, representing 20 ESADA and 6 non-ESADA countries. All 21 countries from the 2010 survey participated. In 2010, OSA diagnostic procedures were performed mainly by specialized physicians (86%), whereas now mainly by certified sleep specialists and specialized physicians (69%). Treatment and titration procedures are currently quite homogenous, with a strong trend towards more Autotitrating Positive Airway Pressure treatment (in hospital 73%, at home 62%). From 2010 to 2020, home sleep apnea testing use increased (76%–89%) and polysomnography as sole diagnostic procedure decreased (24%–12%). Availability of a sleep specialist qualification increased (52%–65%) as well as the number of certified polysomnography scorers (certified physicians: 36%–79%; certified technicians: 20%–62%). Telemedicine, not surveyed in 2010, is now in 2020 used in diagnostics (8%), treatment (50%), and follow-up (73%). Conclusion: In the past decade, formal qualification of sleep center personnel increased, OSA diagnostic and treatment procedures shifted towards a more automatic approach, and telemedicine became more prominent.Peer reviewe

Sex differences in reported and objectively measured sleep in COPD

Jenny Theorell-Hagl&ouml;w,1 Inga Sif &Oacute;lafsd&oacute;ttir,1&ndash;3 Brynd&iacute;s Benediktsd&oacute;ttir,2,3 Th&oacute;rarinn G&iacute;slason,2,3 Eva Lindberg,1 Christer Janson1 1Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden; 2Department of Respiratory Medicine and Sleep, Landspitali University Hospital, 3Medical Faculty, University of Iceland, Reykjav&iacute;k, Iceland Background: The aim was to assess and compare reported sleep disturbances and objectively measured sleep in men and women with COPD compared with controls and also explore sex differences. Methods: A total of 96 patients with COPD and 90 age- and sex-matched controls answered a sleep questionnaire, underwent ambulatory polysomnography, a post-bronchodilatory spirometry, and blood sampling. Results: Of the patients with COPD, 51% reported sleep disturbances as compared with 31% in controls (P=0.008). Sleep disturbances were significantly more prevalent in males with COPD compared with controls, whereas there was no significant difference in females. The use of hypnotics was more common among patients with COPD compared with controls, both in men (15% vs 0%, P=0.009) and women (36% vs 16%, P=0.03). The men with COPD had significantly longer recorded sleep latency than the male control group (23 vs 9.3 minutes, P&lt;0.001), while no corresponding difference was found in women. In men with COPD, those with reported sleep disturbances had lower forced vital capacity, higher C-reactive protein, myeloperoxidase, and higher prevalence of chronic bronchitis. Conclusion: The COPD was associated with impaired sleep in men while the association was less clear in women. This was also confirmed by recorded longer sleep latency in male subjects with COPD compared with controls. Keywords: chronic obstructive pulmonary disease, sleep, polysomnography, quality of sleep, se

Relationship of fish and cod oil intake with adult asthma

To access publisher full text version of this article. Please click on the hyperlink in Additional Link fieldBackground A diet rich in fish or cod oil might possibly reduce the risk for asthma and atopic diseases. However, previous studies show conflicting results and no studies have assessed the potential long-term effects of childhood fish intake on adult asthma. Objective To investigate whether childhood and adult fish and cod oil intake was related to adult asthma. Methods In a large population-based study, Respiratory Health in Northern Europe (RHINE), 16 187 subjects aged 23-54 years answered a postal questionnaire. The relations of fish and cod oil intake with asthma symptoms and asthma were analysed using multiple logistic and Cox regression analyses, with adjustment for gender, adult hayfever, smoking, age, body mass index, household size, dwelling, parental education and centre, and for maternal smoking and family history of hayfever and asthma in a subsample (n=2459). Results Subjects from Iceland and Norway reported much more frequent intake of fish both in childhood and adulthood as compared with subjects from Sweden, Estonia and Denmark. Current fish intake less than weekly in adults was associated with more asthma symptoms, while more frequent fish intake did not appear to decrease the risk further. No dose-response association was found between childhood fish intake and adult asthma, but those who never ate fish in childhood had an increased risk for asthma and earlier asthma onset. Adult consumption of cod oil had a u-shaped association with asthma, with the highest risks in those taking cod oil never and daily. Conclusion A minimum level of weekly fish intake in adulthood was associated with protection against asthma symptoms in this large North-European multi-centre study. Subjects who never ate fish in childhood were at an increased risk for asthma. Both indicate a possible threshold effect of fish on asthma