Blunted heart rate recovery is improved following exercise training in overweight adults with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) predisposes individuals to cardiovascular morbidity, and cardiopulmonary exercise test (CPET) markers prognostic for cardiovascular disease have been found to be abnormal in adults with OSA. Due to the persistence of OSA and its cardiovascular consequences, whether the cardiovascular adaptations normally conferred by exercise are blunted in adults not utilizing established OSA treatment is unknown. The aims of this study were to document whether OSA participants have abnormal CPET responses and determine whether exercise modifies these CPET markers in individuals with OSA. METHODS: The CPET responses of 43 sedentary, overweight adults (body mass index [BMI]>25) with untreated OSA (apnea-hypopnea index [AHI]≥ 15) were compared against matched non-OSA controls (n=9). OSA participants were then randomized to a 12-week exercise training (n=27) or stretching control treatment (n=16), followed by a post-intervention CPET. Measures of resting, exercise, and post-exercise recovery heart rate (HRR), blood pressure, and ventilation, as well as peak oxygen consumption (VO(2peak)), were obtained. RESULTS: OSA participants had blunted HRR compared to non-OSA controls at 1 (P=.03), 3 (P=.02), and 5-min post-exercise (P=.03). For OSA participants, exercise training improved VO2 peak (P=.04) and HRR at 1 (P=.03), 3 (P<.01), and 5-min post-exercise (P<.001) compared to control. AHI change was associated with change in HRR at 5-min post-exercise (r=-.30, P<.05), but no other CPET markers. CONCLUSIONS: These results suggest that individuals with OSA have autonomic dysfunction, and that exercise training, by increasing HRR and VO2 peak, may attenuate autonomic imbalance and improve functional capacity independent of OSA severity reduction.

Exercise training improves selected aspects of daytime functioning in adults with obstructive sleep apnea.

STUDY OBJECTIVES: To explore the utility of exercise training for improving daytime functioning in adults with obstructive sleep apnea (OSA). METHODS: Forty-three sedentary and overweight/obese adults aged 18-55 years with at least moderate-severity untreated OSA (apnea-hypopnea index ≥ 15) were randomized to 12 weeks of moderate-intensity aerobic and resistance exercise training (n = 27) or low-intensity stretching control treatment (n = 16). As part of a trial investigating the efficacy of exercise training on OSA severity, daytime functioning was assessed before and following the intervention. Sleepiness, functional impairment due to sleepiness, depressive symptoms, mood, and quality of life (QOL) were evaluated with validated questionnaires, and cognitive function was assessed with a neurobehavioral performance battery. OSA severity was measured with one night of laboratory polysomnography before and following the intervention. RESULTS: Compared with stretching control, exercise training resulted in significant improvements in depressive symptoms, fatigue and vigor, and aspects of QOL (p < 0.05). Sleepiness and functional impairment due to sleepiness also were improved following exercise versus control to a similar degree in terms of effect sizes (d > 0.5), though these changes were not statistically significant. No neurobehavioral performance improvements were found. Reduced fatigue following exercise training was mediated by a reduction in OSA severity, but changes in OSA severity did not significantly mediate improvement in any other measure of daytime functioning. CONCLUSIONS: These data provide preliminary evidence that exercise training may be helpful for improving aspects of daytime functioning of adults with OSA. Larger trials are needed to further verify the observed improvements.

The effect of exercise training on obstructive sleep apnea and sleep quality: a randomized controlled trial.

STUDY OBJECTIVES: To evaluate the efficacy of a 12-week exercise training program for reducing obstructive sleep apnea (OSA) severity and improving sleep quality, and to explore possible mechanisms by which exercise may reduce OSA severity. DESIGN: Randomized controlled trial. SETTING: Clinical exercise physiology center, sleep laboratory. PARTICIPANTS: Forty-three sedentary and overweight/obese adults aged 18-55 years with at least moderate-severity untreated OSA (screening apnea-hypopnea index [AHI] ≥ 15). INTERVENTIONS: Participants randomized to exercise training (n = 27) met 4 times/week for 12 weeks and performed 150 min/week of moderate-intensity aerobic activity, followed by resistance training twice/week. Participants randomized to a stretching control (n = 16) met twice weekly for 12 weeks to perform low-intensity exercises designed to increase whole-body flexibility. MEASUREMENTS AND RESULTS: OSA severity was assessed with one night of laboratory polysomnography (PSG) before and following the 12-week intervention. Measures of sleep quality included PSG, actigraphy (7-10 days), and the Pittsburgh Sleep Quality Index. Compared with stretching, exercise resulted in a significant AHI reduction (exercise: 32.2 ± 5.6 to 24.6 ± 4.4, stretching: 24.4 ± 5.6 to 28.9 ± 6.4; P < 0.01) as well as significant changes in oxygen desaturation index (ODI; P = 0.03) and stage N3 sleep (P = 0.03). Reductions in AHI and ODI were achieved without a significant decrease in body weight. Improvements in actigraphic sleep and subjective sleep quality were also noted following exercise compared with stretching. CONCLUSIONS: Exercise training had moderate treatment efficacy for the reduction of AHI in sedentary overweight/obese adults, which suggests that exercise may be beneficial for the management of OSA beyond simply facilitating weight loss. TRIAL REGISTRATION: Clinicaltrials.gov identification number NCT00956423.

A uHPLC-MS mathematical modeling approach to dry powder inhaler single agglomerate analysis.

Demonstration of content uniformity (CU) is critical toward the successful development of dry powder inhalers (DPIs). Methods for unit dose CU determination for DPI products are well-established within the field of respiratory science. Recent advances in the area include a uHPLC-MS method for high-throughput uniformity analysis, which allows for a greater understanding of blending operations as the industry transitions to a quality-by-design approach to development. Further enhancements to this uHPLC-MS method now enable it to determine CU and sample weight at the single agglomerate level, which is roughly 50× smaller than a unit dose. When coupled with optical microscopy-based agglomerate sizing, the enhanced uHPLC-MS method can also predict the density and porosity of individual agglomerates. Expanding analytical capabilities to the single agglomerate level provides greater insights and confidence in the DPI manufacturing process.

Raman spectroscopy for the process analysis of the manufacturing of a suspension metered dose inhaler.

The purpose of this research was to demonstrate the utility of Raman spectroscopy for process analysis of a suspension metered dose inhaler manufacturing process. Chemometric models were constructed for the quantification of ethanol and active pharmaceutical ingredient such that both could be monitored in real-time during the compounding and filling operations via tank measurements and recirculation line flow-cell measurements. Different spectral preprocessing techniques were used to delineate the effects of mixing speed and temperature changes from actual concentration effects. Raman spectroscopy offers advantages in time savings and quality of information over the standard methods of analysis for respiratory formulations, such as a drug content assay via HPLC and ethanol testing via GC. The successful implementation of this work will allow formulation scientists to quantitatively assess both the formulation (e.g., the concentration of active pharmaceutical ingredient (API) and ethanol), as well as the manufacturing process (e.g., determination of mixing endpoints) in real-time.

Rheological characterization of petrolatum using a controlled stress rheometer.

The current study focuses on characterizing the rheological characteristics of different petrolatum grades using a controlled stress rheometer. Both steady-state flow and dynamic oscillatory tests were conducted on the petrolatums. The thermorheological scans were found to be the most informative and reproducible for this study. Significant differences in the structure were observed between the petrolatum grades. The structural differences were found to be most significant in the temperature range 25-35 degrees C. The findings from this study will help in identifying the critical parameters (for e.g., temperature, mixing) during the processing and handling of such materials, which can have a direct impact on the product rheology and performance.

Effects of 'local' clutter on human target detection.

In theory, properties of clutter can be defined globally or locally. However, in the literature, the distinction between local and global clutter is arbitrary, where the standard approach of setting the local domain to twice the expected target size, in applying local clutter metrics, is adopted without any justification. This paper addresses this problem and considers the implications for the application of clutter metrics. It was found that the size of the local clutter region around a target has a strong effect on the probability of detection of that target and that this is affected by regions much larger than twice the target size. It was also discovered that this effect was much stronger for targets subtending less than 0.8 degrees of visual angle than for larger targets. In the case of the former, the fall-off in human visual performance with clutter region size was approximately quadratic, compared to a slight linear fall-off for larger targets. A simple model is presented explaining these phenomena, indicating that the auto-covariance function characterising the clutter is the main determinant of the size of the region of local clutter.

Evaluation of a cardiovascular health program for participants with mental retardation and normal learners.

An evaluation was conducted to compare the impact of an 8-week cardiovascular disease risk reduction group teaching program for 92 individuals with mental retardation (MR; IQ less than 70) and 97 normal learners. The curriculum emphasized exercise, nutritional choices, and stress reduction. Body Mass Index (BMI; weight in kilograms, divided by height in meters, squared), knowledge of healthy eating choices, self-report of fruit and vegetable intake, and exercise were measured before and after the intervention. The mean BMI decreased by .89 for normal learners and not at all for the group with MR. However, BMI decreased by at least .75 units (or approximately 5 pounds) for 18.5% of individuals with MR and 44.3% of normal learners.

Role and experience determine decision support interface requirements in a neonatal intensive care environment.

The aim of this paper is to describe a novel approach to the analysis of data obtained from card-sorting experiments. These experiments were performed as a part of the initial phase of a project, called NEONATE. One of the aims of the project is to develop decision support tools for the neonatal intensive care environment. Physical card-sorts were performed using clinical "action" and patient "descriptor" words. Thirty-two staff (eight junior nurses, eight senior nurses, eight junior doctors, and eight senior doctors) participated in the actions card-sorts and the same number of staff participated in separate descriptors card-sorting experiments. To check for consistency, the card-sorts were replicated for nurses during the action card-sorts. The card-sort data were analysed using hierarchical cluster analysis to produce tree-diagrams or dendrograms. Differences were shown in the way various classes of staff with different levels of experience mentally map clinical concepts. Clinical actions were grouped more loosely by nurses and by those with less experience, with a polarisation between senior doctors and junior nurses. Descriptors were classed more definitively and similarly by nurses and senior doctors but in a less structured way and quite differently by junior doctors. This paper presents a summary of the differences in the card-sort data for the various staff categories. It is shown that concepts are used differently by various staff groups in a neonatal unit and that this may diminish the effectiveness of computerised decision aids unless it is explored during their development.

Mismatched concepts in a neonatal intensive care unit (NICU): further issues for computer decision support?

BACKGROUND: Common concepts and definitions are important for the effective practice of medicine. In an intensive care unit clear understanding of terminology and communication between different staff groups may be critical for optimal care. If computerised decision support tools are to be successfully deployed in these high intensity environments, all staff must understand the concepts and information that is to be portrayed. OBJECTIVE: To examine the similarity of language and concepts related to newborn infants and their care in staff groups with different experience. METHODS: An experimental study in a tertiary regional neonatal intensive care unit involved 32 staff in 4 groups with varying experience (junior and senior / nurses and doctors). A psychologist developed a lexicon of clinical actions and a second lexicon of possible patient descriptors applicable to newborn infants receiving all degrees of neonatal care by conducting interviews with staff on the unit. Card sorting experiments were performed on the terms in the action and descriptor lexicons, the staff being asked to group words that were related to the same or similar concepts. The card sort data were analysed using conventional cluster analysis to produce tree-diagrams or dendrograms and then by distance matrix analysis to give cumulative probability plots. RESULTS: Differences were shown in the way various classes of staff and staff with different experience mentally map clinical concepts. Clinical actions were grouped more randomly by nurses and by those with less experience with a polarisation between senior doctors and junior nurses. Descriptors were classed more definitively and similarly by junior and senior nurses and senior doctors but more randomly and quite differently by junior doctors. Thus there were differences seen between nurses and doctors with different roles within the unit and differences related to experience. CONCLUSIONS: Concepts are used differently by various staff groups in a neonatal unit: this may have an impact on the effectiveness of computerised decision aids unless it is taken into account during their development.