Positive airway pressure (PAP) treatment reduces glycated hemoglobin (HbA1c) levels in obstructive sleep apnea patients with concomitant weight loss: Longitudinal data from the ESADA

Patients with obstructive sleep apnea (OSA) are at increased risk of developing metabolic disease such as diabetes. The effects of positive airway pressure on glycemic control are contradictory. We therefore evaluated the change in glycated hemoglobin (HbA1c) in a large cohort of OSA patients after long-term treatment with positive airway pressure. HbA1c levels were assessed in a subsample of the European Sleep Apnea Database [n=1608] at baseline and at long-term follow up with positive airway pressure therapy (mean 378.9±423.0 days). In a regression analysis, treatment response was controlled for important confounders. Overall, HbA1c decreased from 5.98±1.01% to 5.93±0.98% (p=0.001). Patient subgroups with a more pronounced HbA1c response included patients with diabetes (−0.15±1.02, p=0.019), those with severe OSA baseline (−0.10±0.68, p=0.005), those with morbid obesity (−0.20±0.81, p<0.001). The strongest HbA1c reduction was observed in patients with a concomitant weight reduction >5 kilos (−0.38±0.99, p<0.001). In robust regression analysis, severe OSA (p=0.038) and morbid obesity (p=0.005) at baseline, and weight reduction >5 kilos (p<0.001) during follow up were independently associated with a reduction of HbA1c following PAP treatment. In contrast, PAP treatment alone without weight reduction was not associated with significant Hb1Ac reduction. In conclusion, positive airway pressure therapy is associated with HbA1c reduction in patients with severe OSA, in morbidly obese patients. and most obviously in those with significant weight lost during the follow-up. Our study underlines the importance to combine positive airway pressure use with adjustments in lifestyle to substantially modify metabolic complications in OSA

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

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.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Long-Term Memory for Environmental Spaces: the Case of Orientation Specificity

This study examined orientation specificity in human long-term memory for environmental spaces, and was designed to disambiguate between three theories concerning the organisation of memory: reference direction theory [e.g., 1], view dependent theory [e.g., 2] and a theory assuming orientation-independency [e.g., 3]. Participants learned an immersive virtual environment by walking in one direction. The environment consisted of seven corridors within which target objects were located. In the testing phase, participants were teleported to different locations in the environment and were asked to identify their location and heading and then to point towards previously learned targets. In experiment 1 eighteen participants could see the whole corridor and were able to turn their head during the testing phase, whereas in experiment 2 visibility was limited and the twenty participants were asked to not turn their heads during pointing. Reference direction theory assumes a global reference direction underlying the memory of the whole layout and would predict better performance when oriented in the global reference direction. However, no support was found for the reference direction theory. Instead, as predicted by view-dependent theories, participants pointed more accurately when oriented in the direction in which they originally learned each corridor, even when visibility was limited to one meter for all orientations (all results p<.05). When the whole corridor was visible, participants also self-localised faster when oriented in the learned direction. In direct comparison participants pointed more accurately when facing the learned direction instead of the global reference direction. With the corridors visible they also self-localised faster. No support was found for an exclusive orientation-independent memory as performance was orientation-dependent with respect to the learned orientation. We propose a ‘network of reference frames’ theory which extends the view-dependent theory by stating how locations learned from different views are connected within a spatial network. This theory is able to integrate elements of the different theoretical positions

Orientation biases in memory for vista and environmental spaces

This experiment tested whether vista spaces such as rooms or plazas are encoded differently in memory compared to environmental spaces such as buildings or cities. Participants learned an immersive virtual environment by walking through it in one direction. The environment consisted of seven corridors forming a labyrinth within which target objects were located. The participants either learned this environmental space alone, or distant mountains provided additional compass information. In a third condition, this labyrinth was located within a big hall (i.e., a vista space) which allowed self-localisation with respect to the vista space of the hall. In the testing phase, participants were teleported to different locations in the environment and were asked to identify their location and heading first, and then to point towards previously learned targets. In general, participants self localized faster when oriented in the direction in which they originally learned each corridor. However, a subset of participants showed a different orientation specificity in their pointing performance originating more from the orientation of the mountains or the hall. These participants were identified in catch trials after the experiment. The results are first hints for a difference in memory for vista and environmental spaces

Place naming: examining the influence of language on wayfinding

We asked the question how language influences a presumably embodied system such as human wayfinding. To test this, participants walked along a route in a virtual environment. They were asked to remember half of the intersections by what they saw. At the other 50 of intersections they heard an arbitrary name which they also had to remember. In the test phase they were teleported to different intersections and had to indicate the direction the route went on. At intersections without a name they performed faster and more accurately. In a second experiment meaningful names were used instead. Participants now performed better at named intersection. The results indicate an interaction between language and the presumably embodied wayfinding system. This interaction cannot be explained by a limited common resource, depth of processing, overshadowing, or linguistic scaffolding. However, it is consistent with dual coding

Sleep apnoea management in Europe during the COVID-19 pandemic – Data from the European Sleep Apnoea Database (ESADA)

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