Corrigendum: Echocardiography and extravascular lung water during 3 weeks of exposure to high altitude in otherwise healthy asthmatics.

[This corrects the article DOI: 10.3389/fphys.2023.1214887.].

Echocardiography and extravascular lung water during 3 weeks of exposure to high altitude in otherwise healthy asthmatics.

Background: Asthma rehabilitation at high altitude is common. Little is known about the acute and subacute cardiopulmonary acclimatization to high altitude in middle-aged asthmatics without other comorbidities. Methods: In this prospective study in lowlander subjects with mostly mild asthma who revealed an asthma control questionnaire score >0.75 and participated in a three-week rehabilitation program, we assessed systolic pulmonary artery pressure (sPAP), cardiac function, and extravascular lung water (EVLW) at 760 m (baseline) by Doppler-echocardiography and on the second (acute) and last day (subacute) at a high altitude clinic in Kyrgyzstan (3100 m). Results: The study included 22 patients (eight male) with a mean age of 44.3 ± 12.4 years, body mass index of 25.8 ± 4.7 kg/m2, a forced expiratory volume in 1 s of 92% ± 19% predicted (post-bronchodilator), and partially uncontrolled asthma. sPAP increased from 21.8 mmHg by mean difference by 7.5 [95% confidence interval 3.9 to 10.5] mmHg (p < 0.001) during acute exposure and by 4.8 [1.0 to 8.6] mmHg (p = 0.014) during subacute exposure. The right-ventricular-to-pulmonary-artery coupling expressed by TAPSE/sPAP decreased from 1.1 by -0.2 [-0.3 to -0.1] mm/mmHg (p < 0.001) during acute exposure and by -0.2 [-0.3 to -0.1] mm/mmHg (p = 0.002) during subacute exposure, accordingly. EVLW significantly increased from baseline (1.3 ± 1.8) to acute hypoxia (5.5 ± 3.5, p < 0.001) but showed no difference after 3 weeks (2.0 ± 1.8). Conclusion: In otherwise healthy asthmatics, acute exposure to hypoxia at high altitude increases pulmonary artery pressure (PAP) and EVLW. During subacute exposure, PAP remains increased, but EVLW returns to baseline values, suggesting compensatory mechanisms that contribute to EVLW homeostasis during acclimatization.

Sleep apnea in school-age children living at high altitude.

INTRODUCTION: Among adults, sleep apnea is more common in highlanders than in lowlanders. We evaluated the sleep apnea prevalence in children living at high altitude compared to age-matched low-altitude controls. METHODS: Healthy children, 7-14 y of age, living at 2500-3800m in the Tien Shan mountains, Kyrgyzstan, were prospectively studied in a health post at 3250m. Healthy controls of similar age living at 700-800m were studied in a University Hospital at 760m in Bishkek. Assessments included respiratory sleep studies scored according to pediatric standards, clinical examination, medical history, and the pediatric sleep questionnaire (PSQ, range 0 to 1 with increasing symptoms). RESULTS: In children living at high altitude (n = 37, 17 girls, median [quartiles] age 10.8y [9.6;13.0]), sleep studies revealed: mean nocturnal pulse oximetry 90% (89;91), oxygen desaturation index (ODI, >3% dips in pulse oximetry) 4.3/h (2.5;6.7), apnea/hypopnea index (AHI) total 1.7/h (1.0;3.6), central 1.6/h (1.0;3.3), PSQ 0.27 (0.18;0.45). In low-altitude controls (n=41, 17 girls, age 11.6y [9.5;13.0], between-groups comparison of age P=0.69) sleep studies revealed: pulse oximetry 97% (96;97), ODI 0.7/h (0.2;1.2), AHI total 0.4/h (0.1;1.0), central 0.3/h (0.1;0.7), PSQ 0.18 (0.14;0.31); P<0.05, all corresponding between-group comparisons. CONCLUSIONS: In school-age children living at high altitude, nocturnal oxygen saturation was lower, and the total and central AHI were higher compared to children living at low altitude. The greater score of sleep symptoms in children residing at high altitude suggests a potential clinical relevance of the nocturnal hypoxemia and subtle sleep-related breathing disturbances.

Effect of 5 weeks of oral acetazolamide on patients with pulmonary vascular disease: A randomized, double-blind, cross-over trial.

BACKGROUND: The carbonic anhydrase inhibitor acetazolamide stimulates ventilation through metabolic acidosis mediated by renal bicarbonate excretion. In animal models, acetazolamide attenuates acute hypoxia-induced pulmonary hypertension (PH), but its efficacy in treating patients with PH due to pulmonary vascular disease (PVD) is unknown. METHODS: 28 PVD patients (15 pulmonary arterial hypertension, 13 distal chronic thromboembolic PH), 13 women, mean±SD age 61.6±15.0 years stable on PVD medications, were randomised in a double-blind crossover protocol to 5 weeks acetazolamide (250mg b.i.d) or placebo separated by a ≥2 week washout period. Primary endpoint was the change in 6-minute walk distance (6MWD) at 5 weeks. Additional endpoints included safety, tolerability, WHO functional class, quality of life, arterial blood gases, and hemodynamics (by echocardiography). RESULTS: Acetazolamide had no effect on 6MWD compared to placebo (treatment effect: mean change [95%CI] -18 [-40 to 4]m, p=0.102) but increased arterial blood oxygenation through hyperventilation induced by metabolic acidosis. Other measures including pulmonary hemodynamics were unchanged. No severe adverse effects occurred, side effects that occurred significantly more frequently with acetazolamide vs. placebo were change in taste (22/0%), paraesthesia (37/4%) and mild dyspnea (26/4%). CONCLUSIONS: In patients with PVD, acetazolamide did not change 6MWD compared to placebo despite improved blood oxygenation. Some patients reported a tolerable increase in dyspnoea during acetazolamide treatment, related to hyperventilation, induced by the mild drug-induced metabolic acidosis. Our findings do not support the use of acetazolamide to improve exercise in patients with PVD at this dosing. GOV IDENTIFIER: NCT02755298.

Visuomotor performance at high altitude in COPD patients. Randomized placebo-controlled trial of acetazolamide.

Introduction: We evaluated whether exposure to high altitude impairs visuomotor learning in lowlanders with chronic obstructive pulmonary disease (COPD) and whether this can be prevented by acetazolamide treatment. Methods: 45 patients with COPD, living <800 m, FEV1 ≥40 to <80%predicted, were randomized to acetazolamide (375 mg/d) or placebo, administered 24h before and during a 2-day stay in a clinic at 3100 m. Visuomotor performance was evaluated with a validated, computer-assisted test (Motor-Task-Manager) at 760 m above sea level (baseline, before starting the study drug), within 4h after arrival at 3100 m and in the morning after one night at 3100 m. Main outcome was the directional error (DE) of cursor movements controlled by the participant via mouse on a computer screen during a target tracking task. Effects of high altitude and acetazolamide on DE during an adaptation phase, immediate recall and post-sleep recall were evaluated by regression analyses. www.ClinicalTrials.gov NCT03165890. Results: In 22 patients receiving placebo, DE at 3100 m increased during adaptation by mean 2.5°, 95%CI 2.2° to 2.7° (p < 0.001), during immediate recall by 5.3°, 4.6° to 6.1° (p < 0.001), and post-sleep recall by 5.8°, 5.0 to 6.7° (p < 0.001), vs. corresponding values at 760 m. In 23 participants receiving acetazolamide, corresponding DE were reduced by -0.3° (-0.6° to 0.1°, p = 0.120), -2.7° (-3.7° to -1.6°, p < 0.001) and -3.1° (-4.3° to -2.0°, p < 0.001), compared to placebo at 3100 m. Conclusion: Lowlanders with COPD travelling to 3100 m experienced altitude-induced impairments in immediate and post-sleep recall of a visuomotor task. Preventive acetazolamide treatment mitigated these undesirable effects.

Markers of cardiovascular risk and their reversibility with acute oxygen therapy in Kyrgyz highlanders with high altitude pulmonary hypertension.

BACKGROUND: High altitude pulmonary hypertension (HAPH), a chronic altitude related illness, is associated with hypoxemia, dyspnea and reduced exercise performance. We evaluated ECG and pulse wave-derived markers of cardiovascular risk in highlanders with HAPH (HAPH+) in comparison to healthy highlanders (HH) and lowlanders (LL) and the effects of hyperoxia. METHODS: We studied 34 HAPH+ and 54 HH at Aksay (3250m), and 34 LL at Bishkek (760m), Kyrgyzstan. Mean pulmonary artery pressure by echocardiography was mean±SD 34±3, 22±5, 16±4mmHg, respectively (p<0.05 all comparisons). During quiet rest, breathing room air or oxygen in randomized order, we measured heart-rate adjusted QT interval (QTc), an ECG-derived marker of increased cardiovascular mortality, and arterial stiffness index (SI), a marker of cardiovascular disease derived from pulse oximetry plethysmograms. RESULTS: Pulse oximetry in HAPH+, HH and LL was, mean±SD, 88±4, 92±2 and 95±2%, respectively (p<0.05 vs HAPH+, both comparisons). QTc in HAPH+, HH and LL was 422±24, 405±27, 400±28ms (p<0.05 HAPH+ vs. others); corresponding SI was 10.5±1.9, 8.4±2.6, 8.5±2.0m/s, heart rate was 75±8, 68±8, 70±10 bpm (p<0.05, corresponding comparisons HAPH+ vs. others). In regression analysis, HAPH+ was an independent predictor of increased QTc and SI when controlled for several confounders. Oxygen breathing increased SI in HH but not in HAPH+, and reduced QTc in all groups. CONCLUSIONS: Our data suggest that HAPH+ but not HH may be at increased risk of cardiovascular mortality and morbidity compared to LL. The lack of a further increase of the elevated SI during hyperoxia in HAPH+ may indicate dysfunctional control of vascular tone and/or remodelling.

Cerebral oxygenation in highlanders with and without high-altitude pulmonary hypertension.

NEW FINDINGS: What is the central question of this study? Cerebral hypoxia impairs cognitive function and exercise performance and may result in brain damage. Residents at high altitude, in particular those with high-altitude pulmonary hypertension, are prone to hypoxaemia due to the exposure to reduced barometric pressure and impaired pulmonary gas exchange. Whether highlanders have a reduced cerebral oxygenation has not been studied. What is the main finding and its importance? We found that despite a reduced arterial oxygen saturation, healthy highlanders and even those with pulmonary hypertension have a similar cerebral oxygenation to healthy lowlanders, suggesting that compensatory mechanisms protect long-term residents at high altitude from cerebral hypoxia. Abstract High-altitude pulmonary hypertension (HAPH), a chronic altitude-related illness, causes hypoxaemia and impaired exercise performance. We evaluated the hypothesis that haemodynamic limitation and hypoxaemia in patients with HAPH are associated with impaired cerebral tissue oxygenation (CTO) compared with healthy highlanders (HH) and lowlanders (LL). We studied 36 highlanders with HAPH and 54 HH at an altitude of 3250 m, and 34 LL at 760 m. Mean(±SD) pulmonary artery pressures were 34(±3), 22(±5) and 16(±4) mmHg, respectively (P < 0.05, all comparisons). The CTO was monitored by near-infrared spectroscopy along with pulse oximetry (peripheral arterial oxygen saturation, SpO2) during quiet breathing of room air (RA) and oxygen for 20 min each, and during hyperventilation with RA and oxygen, respectively. In HAPH, HH and LL breathing RA, SpO2 was 88(±4), 92(±2) and 95(±2)%, respectively (P < 0.001, all comparisons), and CTO was similar in the three groups, at 68(±3), 68(±4) and 69(±4)%, respectively (n.s., all comparisons). Breathing oxygen increased SpO2 and CTO significantly more in HAPH than in HH and LL. Hyperventilation (RA) did not reduce CTO in HAPH but did in HH and LL; hyperventilation (oxygen) increased CTO in HAPH only. Highlanders with and without HAPH studied at 3250 m had a similar CTO to healthy lowlanders at 760 m even though highlanders were hypoxaemic. The physiological response to hyperoxia and hypocapnia assessed by cerebral near-infrared spectroscopy suggests that healthy highlanders and even highlanders with HAPH effectively maintain an adequate CTO. This adaptation may be of particular relevance because adequate cerebral oxygenation is essential for vital brain functions.

Time-varying signal analysis to detect high-altitude periodic breathing in climbers ascending to extreme altitude.

This work investigates the performance of cardiorespiratory analysis detecting periodic breathing (PB) in chest wall recordings in mountaineers climbing to extreme altitude. The breathing patterns of 34 mountaineers were monitored unobtrusively by inductance plethysmography, ECG and pulse oximetry using a portable recorder during climbs at altitudes between 4497 and 7546 m on Mt. Muztagh Ata. The minute ventilation (VE) and heart rate (HR) signals were studied, to identify visually scored PB, applying time-varying spectral, coherence and entropy analysis. In 411 climbing periods, 30-120 min in duration, high values of mean power (MP(VE)) and slope (MSlope(VE)) of the modulation frequency band of VE, accurately identified PB, with an area under the ROC curve of 88 and 89%, respectively. Prolonged stay at altitude was associated with an increase in PB. During PB episodes, higher peak power of ventilatory (MP(VE)) and cardiac (MP(LF)(HR) ) oscillations and cardiorespiratory coherence (MP(LF)(Coher)), but reduced ventilation entropy (SampEn(VE)), was observed. Therefore, the characterization of cardiorespiratory dynamics by the analysis of VE and HR signals accurately identifies PB and effects of altitude acclimatization, providing promising tools for investigating physiologic effects of environmental exposures and diseases.

Oxigenación cerebral en habitantes de gran altura con y sin hipertensión pulmonar de altura / Cerebral oxygenation in high altitude inhabitants with and without high altitude pulmonary hypertension

La Hipertensión pulmonar de gran altura (HAPH),una enfermedad crónica relacionada con laaltura, que causa hipoxemia y un deterioro enel rendimiento del ejercicio. Se ha evaluadola hipótesis que, la limitación hemodinámicae hipoxemia en pacientes con (HAPH), estánasociados con un deterioro en la oxigenación deltejido cerebral (CTO), comparados con habitantes...

Acclimatization improves submaximal exercise economy at 5533 m.

We tested whether the better subjective exercise tolerance perceived by mountaineers after altitude acclimatization relates to enhanced exercise economy. Thirty-two mountaineers performed progressive bicycle exercise to exhaustion at 490 m and twice at 5533 m (days 6-7 and day 11), respectively, during an expedition to Mt. Muztagh Ata. Maximal work rate (W(max)) decreased from mean ± SD 356 ± 73 watts at 490 m to 191 ± 49 watts and 193 ± 45 watts at 5533 m, days 6-7 and day 11, respectively; corresponding maximal oxygen uptakes (VO2max ) were 50.7 ± 9.5, 26.3 ± 5.6, 24.7 ± 7.0 mL/min/kg (P = 0.0001 5533 m vs 490 m). On days 6-7 (5533 m), VO(2) at 75% W(max) (152 ± 37 watts) was 1.75 ± 0.45 L/min, oxygen saturation 68 ± 8%. On day 11 (5533 m), at the same submaximal work rate, VO(2) was lower (1.61 ± 0.47 L/min, P < 0.027) indicating improved net efficiency; oxygen saturation was higher (74 ± 7%, P < 0.0004) but ratios of VO(2) to work rate increments remained unchanged. On day 11, mountaineers climbed faster from 4497 m to 5533 m than on days 5-6 but perceived less effort (visual analog scale 50 ± 15 vs 57 ± 20, P = 0.006) and reduced symptoms of acute mountain sickness. We conclude that the better performance and subjective exercise tolerance after acclimatization were related to regression of acute mountain sickness and improved submaximal exercise economy because of lower metabolic demands for non-external work-performing functions.

[Amyotrophic lateral sclerosis--diagnosis and treatment]. / Amyotrophe Lateralsklerose--Abklärung und Therapie.

Amyotrophic lateral sclerosis (ALS) represents the most common motoneuron disorder in adulthood. It is characterized by selective degeneration of the motoneurons. About 10% of patients have a genetically determined ALS. Clinically, ALS is characterized by coexistence of signs of the first motoneuron, such as spasticity and hyperreflexia, as well as the second motoneuron, such as muscular atrophy and fasciculations. If such signs are present in at least three regions and if other possible causes have been excluded, a definite diagnosis of ALS can be made based on the revised El-Escorial criteria. Initial manifestations are often focalized and generalization develops during the course. The glutamate antagonist riluzole is worldwide the only approved ALS treatment. However, symptomatic treatments to ameliorate spasticity, drooling, speech and swallowing problems, and assisted ventilation to treat respiratory failure are essential.

Periodic breathing during ascent to extreme altitude quantified by spectral analysis of the respiratory volume signal.

High altitude periodic breathing (PB) shares some common pathophysiologic aspects with sleep apnea, Cheyne-Stokes respiration and PB in heart failure patients. Methods that allow quantifying instabilities of respiratory control provide valuable insights in physiologic mechanisms and help to identify therapeutic targets. Under the hypothesis that high altitude PB appears even during physical activity and can be identified in comparison to visual analysis in conditions of low SNR, this study aims to identify PB by characterizing the respiratory pattern through the respiratory volume signal. A number of spectral parameters are extracted from the power spectral density (PSD) of the volume signal, derived from respiratory inductive plethysmography and evaluated through a linear discriminant analysis. A dataset of 34 healthy mountaineers ascending to Mt. Muztagh Ata, China (7,546 m) visually labeled as PB and non periodic breathing (nPB) is analyzed. All climbing periods within all the ascents are considered (total climbing periods: 371 nPB and 40 PB). The best crossvalidated result classifying PB and nPB is obtained with Pm (power of the modulation frequency band) and R (ratio between modulation and respiration power) with an accuracy of 80.3% and area under the receiver operating characteristic curve of 84.5%. Comparing the subjects from 1(st) and 2(nd) ascents (at the same altitudes but the latter more acclimatized) the effect of acclimatization is evaluated. SaO(2) and periodic breathing cycles significantly increased with acclimatization (p-value < 0.05). Higher Pm and higher respiratory frequencies are observed at lower SaO(2), through a significant negative correlation (p-value < 0.01). Higher Pm is observed at climbing periods visually labeled as PB with > 5 periodic breathing cycles through a significant positive correlation (p-value < 0.01). Our data demonstrate that quantification of the respiratory volume signal using spectral analysis is suitable to identify effects of hypobaric hypoxia on control of breathing.

[Cardiovascular consequences of obstructive sleep apnoea syndrome]. / Kardiovaskuläre Folgen des obstruktiven Schlafapnoe-Syndroms.

The obstructive sleep apnoea syndrome (OSAS) is a highly prevalent sleep related breathing disorder associated with hypopnoea/apnoea, arousals and increased daytime sleepiness. OSAS has been shown to have damaging acute effects on the cardiovascular system and thus has been postulated to represent an independent cardiovascular risk factor. A causal relationship between OSAS and cardiovascular disease has currently only been established for hypertension and heart failure. Evidence that OSAS indeed plays a key role in the pathogenesis of heart attacks and stroke and that therapy of OSAS reduces cardiovascular morbidity and mortality is currently limited. The results of multiple ongoing international multi-centre studies investigating the effects of OSAS therapy on cardiovascular event rate and mortality are thus anxiously awaited.

Disability and survival in Duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) leads to progressive impairment of muscle function, respiratory failure and premature death. Longitudinal data on the course of physical disability and respiratory function are sparse. OBJECTIVES: To assess prospectively physical impairment and disability, respiratory function and survival in patients with DMD over several years to describe the course of the disease with current care. METHODS: In 43 patients with DMD, aged 5-35 years, yearly assessments of physical disability by the Duchenne muscular dystrophy physical Impairment and Dependence on care (DID) score, ranging from 9 (no disability) to 80 (complete dependence), and forced vital capacity (FVC), were obtained over a mean time interval of 5.4 (SD 2.1) years. RESULTS: DID scores were correlated with age according to a hyperbolic function (f = 85.3 x age/(10.05+age), R = 0.62, p<0.0001). FVC declined exponentially with age (f = 139.1 x exp(-0.08 x age), R = 0.52, p<0.0001). Mean age at which patients lost their ambulation was 9.4 (SD 2.4) years and they became dependent on an electric wheelchair at 14.6 (4.0) years. Age at the beginning of assisted ventilation was 19.8 (3.9) years, Three patients died during the observation period. The estimated probability of survival to age 30 years was 85% (median survival was 35 years). CONCLUSIONS: Our detailed observations of the progression of physical disability, dependence on care and respiratory impairment in patients with DMD from childhood to adult life is valuable for predicting the clinical course with current medical care. Compared with historical data, survival has improved considerably.

Children at high altitude have less nocturnal periodic breathing than adults.

Although children commonly travel to high altitudes, their respiratory adaptation to hypoxia remains elusive. Therefore, in the present study respiratory inductive plethysmography, pulse oximetry (S(p,O(2))) and end-tidal CO(2) tension (P(ET,CO(2))) were recorded in 20 pre-pubertal children (aged 9-12 yrs) and their fathers during 1 night in Zurich (490 m) and 2 nights at the Swiss Jungfrau-Joch research station (3,450 m) following ascent by train within <3 h. In children, mean+/-sd nocturnal S(p,O(2)) fell from 98+/-1% at 490 m to 85+/-4 and 86+/-4% at 3,450 m (nights 1 and 2, respectively); P(ET,CO(2)) decreased significantly from 37+/-6 to 32+/-3 and 33+/-4 mmHg (3,450 versus 490 m). In adults, changes in nocturnal S(p,O(2)) and P(ET,CO(2)) at 3,450 m were similar to those in children. Children spent less time in periodic breathing at 3,450 m during night 1 and 2 (8+/-11 and 9+/-13%, respectively) than adults (34+/-24 and 22+/-17%, respectively), and their apnoea threshold for CO(2) was lower compared with adults (27+/-2 and 30+/-2 mmHg, respectively, both nights). S(p,O(2)), P(ET,CO(2)) and time in periodic breathing at altitude were not correlated between children and their fathers. In conclusion, children revealed a similarly reduced nocturnal O(2) saturation and associated hyperventilation at high altitude as adults but their breathing pattern was more stable, possibly related to a lower apnoea threshold for CO(2).

Glomerular filtration rate estimates decrease during high altitude expedition but increase with Lake Louise acute mountain sickness scores.

AIM: Acute mountain sickness (AMS) can result in pulmonary and cerebral oedema with overperfusion of microvascular beds, elevated hydrostatic capillary pressure, capillary leakage and consequent oedema as pathogenetic mechanisms. Data on changes in glomerular filtration rate (GFR) at altitudes above 5000 m are very limited. METHODS: Thirty-four healthy mountaineers, who were randomized to two acclimatization protocols, undertook an expedition on Muztagh Ata Mountain (7549 m) in China. Tests were performed at five altitudes: Zurich pre-expedition (PE, 450 m), base camp (BC, 4497 m), Camp 1 (C1, 5533 m), Camp 2 (C2, 6265 m) and Camp 3 (C3, 6865 m). Cystatin C- and creatinine-based (Mayo Clinic quadratic equation) GFR estimates (eGFR) were assessed together with Lake Louise AMS score and other tests. RESULTS: eGFR significantly decreased from PE to BC (P < 0.01). However, when analysing at changes between BC and C3, only cystatin C-based estimates indicated a significant decrease in GFR (P = 0.02). There was a linear decrease in eGFR from PE to C3, with a decrease of approx. 3.1 mL min(-1) 1.73 m(-2) per 1000 m increase in altitude. No differences between eGFR of the two groups with different acclimatization protocols could be observed. There was a significant association between eGFR and haematocrit (P = 0.01), whereas no significant association between eGFR and aldosterone, renin and brain natriuretic peptide could be observed. Finally, higher AMS scores were significantly associated with higher eGFR (P = 0.01). CONCLUSIONS: Renal function declines when ascending from low to high altitude. Cystatin C-based eGFR decreases during ascent in high altitude expedition but increases with AMS scores. For individuals with eGFR <40 mL min(-1) 1.73 m(-2), caution may be necessary when planning trips to high altitude above 4500 m above sea level.

The role of the nose in the pathogenesis of obstructive sleep apnoea and snoring.

Data from observational studies suggest that nasal obstruction contributes to the pathogenesis of snoring and obstructive sleep apnoea (OSA). To define more accurately the relationship between snoring, OSA and nasal obstruction, the current authors have summarised the literature on epidemiological and physiological studies, and performed a systematic review of randomised controlled trials in which the effects of treating nasal obstruction on snoring and OSA were investigated. Searches of bibliographical databases revealed nine trials with randomised controlled design. External nasal dilators were used in five studies, topically applied steroids in one, nasal decongestants in two, and surgical treatment in one study. Data from studies using nasal dilators, intranasal steroids and decongestants to relieve nasal congestion showed beneficial effects on sleep architecture, but only minor improvement of OSA symptoms or severity. Snoring seemed to be reduced by nasal dilators. Nasal surgery also had minimal impact on OSA symptoms. In conclusion, chronic nasal obstruction seems to play a minor role in the pathogenesis of obstructive sleep apnoea, and seems to be of some relevance in the origin of snoring. The impact of treating nasal obstruction in patients with snoring and obstructive sleep apnoea on long-term outcome remains to be defined through randomised controlled trials of medical and surgical therapies.

Periodic whole body acceleration: a novel therapy for cardiovascular disease.

BACKGROUND: Periodic whole body acceleration in the spinal axis (pGz) applied by a motion platform is a novel treatment modality that induced endothelial nitric oxide release into the circulation of animals, healthy subjects and patients with inflammatory diseases during single treatment sessions in previous studies. We hypothesized that patients with advanced arteriosclerotic diseases who are not candidates for a surgical intervention would clinically benefit from repeated pGz treatments over several weeks through improvement of endothelial function. PATIENTS AND METHODS: 11 patients, 5 men (37 to 71 y) with stable ischemic heart disease, LVEF < 35%, NYHA stage > II, and 6 patients (51 to 83 y, 1 woman) with intermittent leg claudication, Fontaine stage II, were enrolled after optimization of pharmacological therapy. PGz was applied for 40 min, 5 days/week during 5 weeks. Quality of life (SF-36 questionnaire), exercise performance, and endothelial function were assessed at baseline, during the treatment period, and 4 weeks after discontinuation of pGz. RESULTS: PGz was well tolerated. In heart failure paitents, pGz therapy improved quality of life, increased 6 min walking distance by a mean +/- SE of 105 +/- 24 m, and improved postischemic skin hyperemia (p < .05 in all instances). In 4 of 6 patients with intermittent claudication, quality of life, treadmill walking distance and post-ischemic skin hyperemia improved with pGz therapy (p < .05). Four weeks after discontinuation of pGz, most therapeutic effects had vanished in both patient groups. CONCLUSIONS: In patients with severe heart failure and with leg claudication who remain symptomatic despite maximal medical therapy and who were not candidates for surgery, periodic acceleration applied over several weeks improved quality of life and exercise capacity. The clinical benefits appear to be mediated through improved endothelial function.

Screening for sleep disorders in community pharmacies--evaluation of a campaign in Switzerland.

BACKGROUND: In 2003 the Swiss federation of pharmacists organized a campaign "sleep disturbances--daytime sleepiness". The goal was to assist pharmacy clients in detecting likely causes of any sleep disturbance or daytime sleepiness through a free of charge screening, and to deliver targeted counselling. For pharmacy practice there are no screening or triage guidelines to assess the severity of sleep and wakefulness disturbances and potential causes for those disturbances. In this paper the outcome of the campaign in terms of feasibility, participation, observed response patterns, sale of over-the-counter (OTC) sleeping pills, and counselling activities is evaluated. METHODS: The Stanford sleep disorders questionnaire and the Epworth sleepiness scale served to identify patterns of symptoms suggestive of four major categories of sleep disorders. The questionnaires were posted on a web-site and the clients' data were entered online in the pharmacies. A report was automatically generated and immediately available online to the pharmacists. The pharmacists documented separately their counselling activities in a pharmacist's activity report. RESULTS: Six hundred and twenty-two (23%) of 2743 pharmacy clients had response patterns suggestive of obstructive sleep apnoea, 418 (15%) of restless-legs-syndrome, 39 (1%) of a sleep disorder potentially associated with a psychiatric condition and 79 (3%) of narcolepsy. An Epworth sleepiness score >10 points was found in 567 (21%). After screening, 2345 (86%) pharmacy clients received targeted counselling. Only 216 (8%) purchased an OTC sleeping pill and 704 (26%) were recommended to consult a physician, but of these, 446 (63%) were already under medical supervision. CONCLUSIONS: The online screening tool for sleep disorders and daytime sleepiness was successfully introduced in Swiss pharmacies. Pharmacies were able to assess the pattern of individual sleep disorders and to identify a possible cause in nearly one-third of the cases.