Effects of short-term PAP treatment on endurance exercise performance in obstructive sleep apnea patients.

Objective: To measure the effects of 4 weeks of nasal positive airway pressure therapy (PAP) on exercise performance in obstructive sleep apnea patients (OSA).Background: Little published research is available which describes the effects of OSA on exercise tolerance or upon the potential of exercise testing to evaluate the outcomes of PAP therapy.Methods: Exercise testing was performed on an electronic cycle ergometer with continuous ramping to allow collection of numerous data points for each subject, up to a vigorous terminal intensity. Linear regression established each subject's pre-treatment scores for the dependent variables at 60% of estimated peak power (W(60%)). Responses at the pre-treatment W(60%) test were used to quantify and compare to responses at the same power output after treatment.Results: OSA by nocturnal polysomnography was moderately severe in this group; the respiratory distress index was 48+/-22 (mean+/-SD; n=9). Exercise heart rates after PAP therapy averaged 10.2 bt/min less at W(60%) (P<0.05). Other variables were lower but non-significantly so, further suggesting a lower cardiorespiratory exercise demand after treatment, i.e. oxygen consumption ( downward arrow7.6%), and Rating of Perceived Exertion ( downward arrow8.8%).Conclusion: Brief treatment with PAP therapy improves objective markers of aerobic exercise performance.

Surgical alternatives for treatment of obstructive sleep apnoea: review and case series.

Obstructive sleep apnoea (OSA) affects up to 24% of middle aged males, resulting in excessive daytime sleepiness, cognitive dysfunction, hypertension, increased risks for acute coronary events, stroke and auto accidents. At special risk are individuals with BMI greater than 29, neck circumference greater than 43 cm (17 inches), macroglossia and retrognathia. Although non-surgical nasal positive air pressure (nCPAP) and mandibular advancement oral appliances are often effective and are the most widely used therapy, they are not definitive for more severe OSA and patients show poor long-term compliance. Surgical reduction of palatal, lingual and nasal soft tissue volumes improve airway functions in approximately 40% of patients with mild to moderate OSA. Maxillary and mandibular advancement osteotomies have proven over the past decade to reverse even severe OSA at greater than the 90% efficacy levels. Surgical treatment targeted to skeletal and airway soft tissue anomalies using a multidisciplinary treatment approach can have a major impact on this widespread and high-risk disorder.

Evaluation of nasal patency by fiberoptic rhinoscopy.

A novel method of assessing anterior nasal patency by flexible fiberoptic rhinoscopy was evaluated in two centers by comparison with active anterior rhinomanometry. Rhinoscopy and rhinomanometry were performed 20 times on each of 14 subjects during 14 to 26 minutes. The procedure was videotaped, and nasal airway area was measured from a video monitor. The mean coefficients of variation for rhinoscopy and rhinomanometry were 14% and 19%, respectively. Another investigator examined five subjects by rhinoscopy 30 times in 15 minutes; the mean coefficient of variation was 9%. These means were not significantly different. Rhinoscopy and rhinomanometry were performed at 30-minute intervals for a 6-hour period in 13 subjects. Three investigators independently evaluated results for changes in nasal function characteristic of the nasal cycle. Rhinoscopy detected the nasal cycle in an average of 72% of subjects and rhinomanometry in 49%. Both methods detected the response to topically applied oxymetazoline and methacholine. Results indicate that, whereas the two procedures evaluate different aspects of nasal function, their precision is similar. Rhinoscopy additionally permits evaluation of nasal mucosal changes occurring from disease or treatment.

Linkage analysis of five pedigrees affected with typical autosomal dominant retinitis pigmentosa.

Five pedigrees (including an expanded version of a previously reported pedigree) exhibited typical autosomal dominant retinitis pigmentosa were analysed for linkage of RP to 29 genetic markers. No significant lod scores resulted. The largest lod score is +1.51 and suggests linkage between RP and Rh blood group at an estimated recombination fraction of 20% in males and 40% in females. Further studies are needed to confirm or refute this suggested linkage.

Possible assignment of a dominant retinitis pigmentosa gene to chromosome 1.

A genetic linkage study, performed on a large family with autosomal dominant retinitis pigmentosa (RP), demonstrated that the RP gene may be linked to the Rh locus, known to be on the short arm of human chromosome 1. Linkage studies on RP along with other studies, can help to more accurately classify these disease entities. Localizing the RP gene locus has the potential for allowing the early diagnosis of individuals at risk.

Probable genetic linkage between autosomal dominant retinitis pigmentosa (RP) and amylase (AMY2): evidence of an RP locus on chromosome 1.

A linkage analysis is reported for three branches of a single family segregating for autosomal dominant retinitis pigmentosa. A statistically significant lod score of 3.9 is obtained for the RP locus and AMY2 at a recombination frequency of 1%. This linkage indicates that the RP locus is on the no. 1 chromosome since the AMY2 locus has been placed on the short arm of 1. Lod scores are reported for four other loci on chromosome 1; none of these achieve statistical significance. Analyses are reported for 23 additional autosomal markers and close linkage with RP can be excluded for a number of these.