Biomedical subjects

Victor Hoffstein

Publications and source records attributed to Victor Hoffstein.

4 recordsLinked to original sources

PubMed2007

Review of oral appliances for treatment of sleep-disordered breathing.

Between 1982 and 2006, there were 89 distinct publications dealing with oral appliance therapy involving a total of 3,027 patients, which reported results of sleep studies performed with and without the appliance. These studies, which constitute a very heterogeneous group in terms of methodology and patient population, are reviewed and the results summarized. This review focused on the following outcomes: sleep apnea (i.e. reduction in the apnea/hypopnea index or respiratory disturbance index), ability of oral appliances to reduce snoring, effect of oral appliances on daytime function, comparison of oral appliances with other treatments (continuous positive airway pressure and surgery), side effects, dental changes (overbite and overjet), and long-term compliance. We found that the success rate, defined as the ability of the oral appliances to reduce apnea/hypopnea index to less than 10, is 54%. The response rate, defined as at least 50% reduction in the initial apnea/hypopnea index (although it still remained above 10), is 21%. When only the results of randomized, crossover, placebo-controlled studies are considered, the success and response rates are 50% and 14%, respectively. Snoring was reduced by 45%. In the studies comparing oral appliances to continuous positive airway pressure (CPAP) or to uvulopalatopharyngoplasty (UPPP), an appliance reduced initial AHI by 42%, CPAP reduced it by 75%, and UPPP by 30%. The majority of patients prefer using oral appliance than CPAP. Use of oral appliances improves daytime function somewhat; the Epworth sleepiness score (ESS) dropped from 11.2 to 7.8 in 854 patients. A summary of the follow-up compliance data shows that at 30 months, 56-68% of patients continue to use oral appliance. Side effects are relatively minor but frequent. The most common ones are excessive salivation and teeth discomfort. Efficacy and side effects depend on the type of appliance, degree of protrusion, vertical opening, and other settings. We conclude that oral appliances, although not as effective as CPAP in reducing sleep apnea, snoring, and improving daytime function, have a definite role in the treatment of snoring and sleep apnea.

Continuous Positive Airway Pressure↗

PubMed2004

Acidification of distal esophagus and sleep-related breathing disturbances.

STUDY OBJECTIVES: To investigate whether distal esophageal acidification occurs during sleep in patients suspected of sleep-disordered breathing, and whether such acidification is related to respiratory abnormalities. DESIGN AND PATIENTS: Fourteen middle-aged, snoring men all complaining of daytime sleepiness and suspected of having obstructive sleep apnea. SETTING: Sleep laboratory, Pulmonary Department, Landspitali University Hospital, Reykjavik, Iceland. MEASUREMENTS AND RESULTS: Each patient underwent full nocturnal polysomnography testing, which included continuous monitoring of esophageal pressure (Pes) and pH. We identified all pH events, which were defined as a reduction in esophageal pH of >/= 1.0. During each pH event, the respiratory recordings where examined for the presence of apneas or hypopneas, and Pes was recorded. The data were analyzed to determine the possible relationships between pH events and respiratory events, and between changes in pH and changes in Pes. We found that there were more respiratory events than pH events. The mean (+/- SD) number of apneas and hypopneas per hour of sleep was 33 +/- 22, whereas the mean number of pH events per hour of sleep was 7 +/- 6. Overall, 81% of all pH events were associated with respiratory events. Correlation analysis did not reveal any significant relationship between pH events and the magnitude of Pes or apnea-hypopnea index. CONCLUSIONS: Episodes of esophageal acidification are common in patients with sleep apnea, and are usually associated with respiratory and pressure events. However, changes in pH were independent of the magnitude of the Pes.

Adult↗

PubMed2003

Pulmonary function and sleep apnea.

The purpose of this study was to determine whether there is a relationship between pulmonary function measured during wakefulness and sleep apnea. We prospectively studied 1296 patients, who were free of any lung disease, referred to our sleep clinic for evaluation of possible sleep apnea. All patients had in-hospital nocturnal polysomnography and pulmonary function measurements, which included flow-volume curve, body plethysmography, and single-breath diffusing capacity for carbon monoxide. The results were analyzed by comparing pulmonary function data between four groups of patients, grouped according to apnea severity as reflected by their apnea/hypopnea index: nonapneics (apnea-hypopnea index </= 10), mild apnea (10 < apnea-hypopnea index </= 30), moderate apnea (30 < apnea-hypopnea index </= 50), and severe apnea (apnea-hypopnea index > 50). Analysis of covariance demonstrated no difference in any of the pulmonary function parameters between the four groups, after adjusting for age, body mass index, or weight as the covariate. We conclude that in nonsmoking patients without lung disease, sleep apnea is unrelated to pulmonary function measured during wakefulness.

Anthropometry↗

PubMed2003

Gender differences in sleep apnea: the role of neck circumference.

STUDY OBJECTIVES: To determine whether differences in sleep apnea severity between men and women referred to a sleep clinic are related to the differences in neck circumference (NC). STUDY DESIGN: Case series. SETTING: University hospital sleep disorders clinic. PARTICIPANTS: A total of 3,942 patients (2,753 men and 1,189 women) referred to the sleep clinic. MEASUREMENTS AND RESULTS: All patients underwent nocturnal polysomnography. NC was used as a surrogate measure of upper airway obesity. We found that sleep apnea, defined an the apnea/hypopnea index (AHI) > 10/h, was significantly more frequent (60% vs 32%, chi(2) < 0.0001) and severe (mean +/- SE, 25 +/- 26/h vs 12 +/- 19/h, p < 0.0001) in men than in women. Men had significantly larger NC than women, but the difference became much less pronounced when we normalized NC to body height (0.24 +/- 0.02 vs 0.23 +/- 0.03, p < 0.0001). Men had significantly higher AHI than women even after controlling for age, body mass index (BMI), and neck/height ratio (NHR); analysis of covariance showed that mean AHI was 24.4 +/- 0.4 in men vs 14.8 +/- 0.7 in women (p < 0.0001). This difference persisted even when we matched men and women for NHR and BMI. Finally, multiple regression analysis revealed the following: (1) NHR was the most significant predictor of AHI, accounting for 19% of the variability; and (2) the slope of AHI vs NHR was significantly higher in men than in women. CONCLUSIONS: We conclude the following: (1) the frequency and severity of sleep apnea in the sleep clinic population is greater in men than women, and (2) factors other than NC, age, and BMI must contribute to these gender differences.

Anthropometry↗