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Biomedical subjects

Susan M Harding

Publications and source records attributed to Susan M Harding.

14 recordsLinked to original sources
PubMed2007

Three-dimensional changes in upper airways of patients with obstructive sleep apnea following maxillomandibular advancement.

PURPOSE: The purpose of this study was to analyze the morphologic changes of the airway in obstructive sleep apnea (OSA) patients by helical computed tomography (CT) scanning following maxillomandibular advancement (MMA) surgery. MATERIALS AND METHODS: Twenty consecutive OSA patients treated with MMA from 2000 to 2003 at the University of Alabama at Birmingham Hospital and diagnosed by polysomnography (PSG) were included in this study. The criteria for this study were MMA surgery, pre- and postoperative helical CT scan, and PSG. Lateral (LAT) and anterioposterior (AP) airway dimensions were measured from the level of the hard palate to the hyoid using helical CT scans. RESULTS: There was enlargement of LAT and AP diameters for all patients at all levels. LAT dimensions were enhanced greater than AP in the retroglossal region. CONCLUSION: MMA results in significant increase in both AP and LAT airway dimensions.

Adult↗
PubMed2005

Effects of esomeprazole 40 mg twice daily on asthma: a randomized placebo-controlled trial.

RATIONALE: Gastroesophageal reflux disease (GERD) is common in patients with asthma, suggesting an interaction between the two conditions. OBJECTIVES: To assess the effect of gastric acid suppression with the proton pump inhibitor esomeprazole on asthma outcomes in subjects with persistent moderate to severe asthma treated with antiinflammatory asthma medication. METHODS: In this double-blind study, subjects were randomized to receive esomeprazole 40 mg or placebo twice daily for 16 wk. According to nocturnal respiratory symptoms (NOC) and GERD, subjects were divided into three strata: GERD-/NOC+, GERD+/NOC-, and GERD+/NOC+. MEASUREMENTS AND MAIN RESULTS: A total of 770 subjects were randomized. There was no statistically significant improvement in morning peak expiratory flow (PEF) over placebo in the overall study population: 6.3 L/min (p = 0.061). Over the whole treatment period, in GERD+/NOC+ subjects (n = 350), esomeprazole provided an 8.7-L/min improvement (p = 0.03) in morning PEF, and a 10.2-L/min improvement (p = 0.012) in evening PEF over placebo. Among 307 subjects taking long-acting beta2-agonists, improvements over placebo were observed in morning PEF (12.2 L/min, p = 0.017) and in evening PEF (11.1 L/min, p = 0.024); these improvements were more pronounced in GERD+/NOC+ subjects. Esomeprazole 40 mg twice daily was well tolerated and no safety concerns were noted. CONCLUSIONS: Esomeprazole improved PEF in subjects with asthma who presented with both GERD and NOC. In subjects without both GERD and NOC, no improvement could be detected.

Administration, Oral↗
PubMed2005

Gastroesophageal reflux: a potential asthma trigger.

Gastroesophageal reflux (GER) is a potential trigger of asthma. Approximately 77% of asthmatics report heartburn. GER is a risk factor for asthma-related hospitalization and oral steroid burst use. Asthmatics may be predisposed to GER development because of a high prevalence of hiatal hernia and autonomic dysregulation and an increased pressure gradient between the abdominal cavity and the thorax, over-riding the lower esophageal sphincter pressure barrier. Asthma medications may potentiate GER. Potential mechanisms of esophageal acid-induced bronchoconstriction include a vagally mediated reflex, local axonal reflexes, heightened bronchial reactivity, and microaspiration, all resulting in neurogenic inflammation. Anti-reflux therapy improves asthma symptoms in approximately 70% of asthmatics with GER. A 3-month empiric trial of twice-daily proton pump inhibitor given 30 to 60 minutes before breakfast and dinner can identify asthmatics who have GER as a trigger of their asthma.

Asthma↗
PubMed2004

Aldosterone excretion among subjects with resistant hypertension and symptoms of sleep apnea.

OBJECTIVE: The severity of obstructive sleep apnea (OSA) correlates with the difficulty of controlling BP. The mechanism, however, by which sleep apnea contributes to the development of resistant hypertension remains obscure. Having observed a high prevalence of OSA among hypertensive subjects with primary hyperaldosteronism, we hypothesized a possible association between sleep apnea and aldosterone excretion. DESIGN: In consecutive subjects referred to a university clinic for resistant hypertension, we prospectively determined plasma renin activity (PRA), plasma aldosterone concentration (PAC), and 24-h urinary aldosterone excretion during high dietary salt ingestion. In addition, all subjects completed the Berlin Questionnaire, a survey designed to identify subjects at risk of having sleep apnea. Primary hyperaldosteronism (PA) was defined as a PRA < 1.0 ng/mL/h and 24-h urinary aldosterone excretion > 12 micro g during high urinary sodium excretion (> 200 mEq/24 h). RESULTS: Of the 114 subjects evaluated, 72 subjects had a high probability and 42 subjects had a low probability of having sleep apnea based on their responses to the Berlin Questionnaire. Subjects at high risk for sleep apnea were almost two times more likely to have PA diagnosed (36 vs 19%, p < 0.05), tended to have lower PRA (1.2 +/- 1.8 ng/mL/h vs 1.9 +/- 4.1 ng/mL/h), and had significantly greater 24-h urinary aldosterone excretion (13.6 +/- 9.6 micro g vs 9.8 +/- 7.6 micro g, p < 0.05) compared to subjects at low risk of sleep apnea. CONCLUSION: These data provide evidence of increased aldosterone excretion in subjects with resistant hypertension and symptoms of sleep apnea. While the causality of this association is unknown, it is hypothesized that sleep apnea contributes to the development of resistant hypertension by stimulating aldosterone excretion.

Aldosterone↗
PubMed2003

Recent clinical investigations examining the association of asthma and gastroesophageal reflux.

For more than a decade, investigations have examined the association between asthma and gastroesophageal reflux (GER), and have demonstrated that the presence of esophageal acid events is associated with respiratory symptoms. The most current research shows that GER is prevalent in patients with asthma, that esophageal acid may alter bronchial hyperresponsiveness, and that medical or surgical GER therapy may improve asthma outcome in selected asthma patients. Further research will build on our current knowledge base and, hopefully, enable us to better identify those patients with asthma who will most benefit from reflux therapy.

Anti-Asthmatic Agents↗
PubMed2003

Acid reflux and asthma.

The association between asthma and gastroesophageal reflux (GER) has been further delineated with recent clinical investigations. The prevalence of GER development in asthmatics is higher than in control populations. Furthermore, asthmatics with GER have a higher risk of asthma hospitalization. Asthma medications may be one of the promoting factors for GER development in asthmatics. Inhaled albuterol decreases lower esophageal sphincter (LES) pressure and esophageal contraction amplitude. Furthermore, oral prednisone results in increased esophageal acid contact times. Respiratory symptoms also correlate with esophageal acid events. The role of neurogenic inflammation in asthma-induced bronchoconstriction is also being further developed. Therapy of GER may improve asthma outcomes in selected asthmatics. Currently, there are no double-blind, placebo-controlled, multicenter trials reporting asthma outcomes with antireflux therapy.

Asthma↗
PubMed2002

Developing an action plan for integrating sleep topics into the medical school curriculum.

Sleep disorders are prevalent although they go unrecognized by clinicians, partially because of limited exposure to sleep medicine topics during medical school. Sleep topics can be integrated during both the preclinical and clinical years of the medical school curriculum by developing an integration strategy and action plan. Components of the action plan include examining the current medical school curriculum and the teaching infrastructure. Understanding curricular governance issues and how curriculum time is allocated will allow development of an effective integrative strategy. Sleep topics can be integrated into neuroscience, neuroanatomy, physiology, and behavioral science courses during the preclinical years. The sleep history and physical can be integrated into the physical diagnosis course. Sleep disorders can be introduced in clinical correlation courses. Integration strategies during the clinical years may include computer-based simulations. Careful assessment of the existing curriculum, curricular governance processes, and available educational resources will optimize the probability of successfully integrating sleep topics into the medical school curriculum.

Curriculum↗
PubMed2002

Oral corticosteroids increase esophageal acid contact times in patients with stable asthma.

STUDY OBJECTIVES: The prevalence of gastroesophageal reflux disease (GERD) is higher in people with asthma than in control populations. Predisposing factors for GERD development may include asthma medications such as prednisone. The objective of this study was to determine whether prednisone alters GERD parameters in people with asthma. DESIGN: Prospective, single-blinded, placebo-controlled, crossover study. SETTING: University medical center clinic. PARTICIPANTS: Twenty adults with stable, moderate persistent asthma with minimal esophageal reflux symptoms (less than three times a week) who were not receiving antireflux therapy. INTERVENTION: Prednisone, 60 mg/d, for 7 days. MEASUREMENTS AND RESULTS: Asthma, esophageal reflux symptoms, and spirometry were measured during baseline, placebo, and prednisone phases, each 7 days in duration. Dual-probe esophageal pH monitoring, esophageal and respiratory manometrics (20 subjects), and basal and stimulated gastric acid secretion (4 subjects) were measured after placebo and prednisone phases. There were significant increases in esophageal acid contact times at the distal and proximal pH probes during the prednisone phase. Total percentage of time that pH was < 4.0 at the distal probe was 2.5 +/- 0.4% for placebo compared with 5.9 +/- 0.9% for prednisone (p < 0.002). Total percentage of time that pH was < 4.0 at the proximal probe was 0.3 +/- 0.1% for placebo and 0.8 +/- 0.2% for prednisone (p < 0.0007). There were no significant changes in subject weight, spirometry, asthma or esophageal reflux symptoms, manometrics, or basal or stimulated gastric acid secretion. CONCLUSION: Prednisone, 60 mg/d for 7 days, increased esophageal acid contact times in this small population of people with stable asthma; however, the mechanism for this finding is unclear.

Adult↗
PubMedDate not supplied

Validation and clinical utility of a simple in-home testing tool for sleep-disordered breathing and arrhythmias in heart failure: results of the Sleep Events, Arrhythmias, and Respiratory Analysis in Congestive Heart Failure (SEARCH) study.

Fifty patients with New York Heart Association class III systolic heart failure were enrolled in this prospective multicenter study that compared the diagnostic accuracy of a home-based cardiorespiratory testing system with standard attended polysomnography. Patients underwent at least 2 nights of evaluation and were scored by blinded observers. At diagnostic cutoff points of > or =5, > or =10, and > or =15 events per hour for respiratory disturbance severity, polysomnography demonstrated a sleep-disordered breathing prevalence of 69%, 59%, and 49%, respectively. Compared with polysomnography, the cardiorespiratory testing system demonstrated predictive accuracies of 73%, 73%, and 75%, which improved to 87%, 87%, and 83%, respectively, when analysis of covariance suggested reanalysis omitting one site's data. The system accurately identified both suspected and unsuspected arrhythmias. The device was judged by 80% of patients to be easy or very easy to use, and 74% of patients expressed a preference for the in-home system. Therefore, this system represents a reasonable home testing device in these patients.

Adult↗