Patient-reported experience with hypoglossal nerve stimulation in the treatment of obstructive sleep apnea.

BACKGROUND: Breathing-synchronized hypoglossal nerve stimulation (HNS) is routinely used as an alternative treatment for patients with obstructive sleep apnea (OSA). Significant and clinically relevant improvements in disease severity and OSA symptoms such as daytime sleepiness as well as overall quality of life have been reported in randomized-controlled trials and large real-world cohort studies. However, so far, few data exist on patient-reported experience with the treatment. METHODS: A structured survey with 22 questions was constructed using five-level Likert scales (1 = no agreement, 5 = complete agreement) to evaluate patient experience with HNS and perception of the treatment in the domains "Overall experience with therapy," "Experience with treatment process," and "Side-effects from treatment." Additional data were collected on current symptom status, measured with Epworth sleepiness scale (ESS) questionnaire, and OSA disease history. Multiple linear regression analysis was conducted to test associations of medical variables and response behavior. Correlations between variables and domains, as well as individual items, were assessed using Spearman rank test. RESULTS: A total of 75 patients from Germany who were treated with breathing-synchronized HNS were enrolled (mean age 57.3 years, 78% male), and 71 questionnaires with complete data were included for analysis. Two-thirds of participants (67%) had a history of OSA history for 5 years or longer. Of all patients, 76% had normalized OSA symptoms at time of the study (ESS: 6.4 ± 5.0) and 98% reported using stimulation therapy every night. Regression analysis revealed an association of current symptoms measured with ESS and response behavior. Hence, patients with normalized daytime sleepiness reported significantly more positive experience across all domains assessed, compared to patients with residual daytime sleepiness. Overall, only 2% of participants reported side effects that made them reduce or discontinue stimulation therapy. The rate of reported side effects was associated with current symptom control under therapy. CONCLUSIONS: Overall patient-reported experience with breathing-synchronized HNS therapy was positive and high satisfaction with the treatment process was observed. Side effects occurred, but rarely affected subjective use of the therapy or satisfaction. Subjective experience and perception are influenced by residual daytime sleepiness with stimulation therapy.

Stated patient preferences for overnight at-home diagnostic assessment of sleep disorders.

PURPOSE: The diagnostic workup for assessment of sleep disorders commonly involves overnight testing to assess sleep patterns and pathological events. So far, little is known about preferences for provision of home sleep tests to patients with sleep disorders. This study aims to close this gap by eliciting preferences for home sleep testing using a discrete choice experiment (DCE). METHODS: A DCE with seven attributes of at-home sleep testing and three levels per attribute was developed using a fractional factorial design. Patients with and without previous sleep testing experience were recruited from two large sleep centers in Germany. Coefficients for attribute levels were calculated using a conditional logit model to estimate their influence on choice decisions and calculate the relative importance of each attribute. RESULTS: 305 patients (54.5 ± 13,1 years, 65.3% male) were enrolled, and 288 surveys with complete data included for analysis. Attributes with greatest relevance were Waiting time to discuss sleep study results; Waiting time to conduct sleep study, and Sleep quality during measurement. Of lowest importance was Diagnostic accuracy of sleep study, followed by Effort to apply sleep study device. Significant heterogeneity in choice behavior was found, including differences by gender, willingness-to-pay for sleep studies, and previous experience with sleep studies. Preferred location for conducting sleep testing was at-home in 50.7% and in-lab in 46.9%. CONCLUSIONS: Preferences and relative importance of home sleep test attributes vary among different subgroups. Considering those preferences can be important for clinicians and policymakers when designing care pathways and planning of testing policies for sleep disorders.

Lessons learned from microsatellite development for nonmodel organisms using 454 pyrosequencing.

Microsatellites, also known as simple sequence repeats (SSRs), are among the most commonly used marker types in evolutionary and ecological studies. Next Generation Sequencing techniques such as 454 pyrosequencing allow the rapid development of microsatellite markers in nonmodel organisms. 454 pyrosequencing is a straightforward approach to develop a high number of microsatellite markers. Therefore, developing microsatellites using 454 pyrosequencing has become the method of choice for marker development. Here, we describe a user friendly way of microsatellite development from 454 pyrosequencing data and analyse data sets of 17 nonmodel species (plants, fungi, invertebrates, birds and a mammal) for microsatellite repeats and flanking regions suitable for primer development. We then compare the numbers of successfully lab-tested microsatellite markers for the various species and furthermore describe diverse challenges that might arise in different study species, for example, large genome size or nonpure extraction of genomic DNA. Successful primer identification was feasible for all species. We found that in species for which large repeat numbers are uncommon, such as fungi, polymorphic markers can nevertheless be developed from 454 pyrosequencing reads containing small repeat numbers (five to six repeats). Furthermore, the development of microsatellite markers for species with large genomes was also with Next Generation Sequencing techniques more cost and time-consuming than for species with smaller genomes. In this study, we showed that depending on the species, a different amount of 454 pyrosequencing data might be required for successful identification of a sufficient number of microsatellite markers for ecological genetic studies.

Higher parasite resistance in Daphnia populations with recent epidemics.

Natural populations often show genetic variation in parasite resistance, forming the basis for evolutionary response to selection imposed by parasitism. We investigated whether previous epidemics selected for higher resistance to novel parasite isolates in a Daphnia galeata-microparasite system by comparing susceptibility of host clones from populations with varying epidemic history. We manipulated resource availability to evaluate whether diet influences Daphnia susceptibility as epidemics are common in nutrient-rich lakes. Exposing clones from 10 lakes under two food treatments to an allopatric protozoan parasite, we found that Daphnia originating from lakes (mainly nutrient rich) with previous epidemics better resist infection. Despite this result, there was a tendency of higher susceptibility in the low food treatment, suggesting that higher resistance of clones from populations with epidemic background is not directly caused by lake nutrient level. Rather, our results imply that host populations respond to parasite-mediated selection by evolving higher parasite resistance.

Effects of optimized heart failure medication on central sleep apnea with Cheyne-Stokes respiration pattern in chronic heart failure with reduced left-ventricular ejection fraction.

Central Sleep Apnea with Cheyne Stokes Respiration (CSA-CSR) is often diagnosed in patients with chronic heart failure (CHF). CSA-CSR displays a periodic breathing pattern with a typical waxing and waning breathing with central sleep apnea phases in between. Optimization of heart failure medication with Angiotensin receptor neprilysin inhibition (ARNi) can effect phenotypic traits of CSA-CSR indicating improvements of both, hemodynamic parameters and central chemosensitivity.

Diabetes mellitus is no independent risk factor for perioperative mortality following hepatic resection.

For patients with concomitant diabetes mellitus an increased perioperative mortality and morbidity in hepatic resections has repeatedly been described. Other studies, however, demonstrated equal outcome data in diabetic and non-diabetic patients. As patient populations were selected for underlying disease, conflicting results may reflect patient selection criteria rather than impact of diabetes mellitus on outcome measures. Therefore, a multivariate analysis in a largely unselected patient population has been performed to determine the independent prognostic value of diabetes mellitus in liver surgery. From a prospective database 633 adult patients undergoing hepatic resection without preceding major abdominal surgery or chemotherapy have been identified. Besides diabetes mellitus, demographic data, variables expressing the functional reserve of the liver, and parameters of surgical technique were analyzed for their impact on mortality and morbidity. 75 patients were diabetic (11.8 %) and 96 hepatic resections (15.2 %) were performed in cirrhotic patients. In the univariate analysis, concomitant diabetes was associated with an increased mortality compared to all non-diabetic patients (10.7 % vs. 5.3 %, p = 0.047). Diabetic patients, however, were also significantly older and presented a higher prevalence of liver cirrhosis. Multivariate modeling finally identified only age, albumin, cirrhosis, extent of surgery, and era of surgery as independent variables with an impact on perioperative mortality. Overall, complications were detected in diabetic and non-diabetic patients with a comparable frequency (44 % vs. 36 %, p = 0.179). Also, the length of in-hospital stay did not significantly differ between both groups (18.5 +/- 1.7 vs. 17.7 +/- 1.0 days, p = 0.119). Rates of postoperative renal impairment, prolonged ascites or pneumonia, however, were higher in diabetics than in other patients. Following established cardiopulmonary and surgical selection criteria, diabetes mellitus is not an independent risk-factor for perioperative mortality in hepatic resections. Although the overall postoperative morbidity was not different in diabetic and non-diabetic patients, a specific pattern of complications has been identified, mandating particular attention in the postoperative course of diabetic patients.