Reproducibility of a Standardized Actigraphy Scoring Algorithm for Sleep in a US Hispanic/Latino Population.

STUDY OBJECTIVES: While actigraphy is considered objective, the process of setting rest intervals to calculate sleep variables is subjective. We sought to evaluate the reproducibility of actigraphy-derived measures of sleep using a standardized algorithm for setting rest intervals. DESIGN: Observational study. SETTING: Community-based. PARTICIPANTS: A random sample of 50 adults aged 18-64 years free of severe sleep apnea participating in the Sueño sleep ancillary study to the Hispanic Community Health Study/Study of Latinos. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants underwent 7 days of continuous wrist actigraphy and completed daily sleep diaries. Studies were scored twice by each of two scorers. Rest intervals were set using a standardized hierarchical approach based on event marker, diary, light, and activity data. Sleep/wake status was then determined for each 30-sec epoch using a validated algorithm, and this was used to generate 11 variables: mean nightly sleep duration, nap duration, 24-h sleep duration, sleep latency, sleep maintenance efficiency, sleep fragmentation index, sleep onset time, sleep offset time, sleep midpoint time, standard deviation of sleep duration, and standard deviation of sleep midpoint. Intra-scorer intraclass correlation coefficients (ICCs) were high, ranging from 0.911 to 0.995 across all 11 variables. Similarly, inter-scorer ICCs were high, also ranging from 0.911 to 0.995, and mean inter-scorer differences were small. Bland-Altman plots did not reveal any systematic disagreement in scoring. CONCLUSIONS: With use of a standardized algorithm to set rest intervals, scoring of actigraphy for the purpose of generating a wide array of sleep variables is highly reproducible.

Interest in bariatric surgery among obese patients with obstructive sleep apnea.

BACKGROUND: Standard obstructive sleep apnea (OSA) therapies are poorly tolerated. Bariatric surgery is a potential alternative but the level of interest in this intervention among OSA patients is unknown. OBJECTIVES: Determine the proportion of OSA patients who would be interested in bariatric surgery. SETTING: Sleep clinics, United States. METHODS: Consecutive adult patients with untreated severe OSA and a body mass index of 35-45 kg/m(2) were approached. Patients at low perioperative risk and no urgent indication for OSA treatment were invited to a separate informational visit about bariatric surgery as primary treatment for OSA. RESULTS: Of 767 eligible patients, 230 (30.0%) were not at low perioperative risk, 49 (6.4%) had drowsy driving, and 16 (2.1%) had no insurance coverage for bariatric surgery. Of the remaining 482 patients, over one third (35.5%) were interested in bariatric surgery. Surgical interest was 47.2% in women versus 27.6% in men (P<0.01) and 67.3% in diabetics versus 31.0% in nondiabetics (P<0.01). In multivariable adjusted models, female gender (odds ratio 1.89, 95% CI [1.10-3.25]) and diabetes (odds ratio 3.97, 95% CI [1.97-8.01]) remained highly predictive of bariatric surgery interest. CONCLUSIONS: Nearly two thirds of obese patients with severe OSA are good candidates for bariatric surgery. Among candidates, over one third are interested in this treatment. Interest rates are highest among women and diabetics, indicating that metabolic improvements continue to be a major driver of surgery even in patients with severe OSA. Given patient interest, the role of bariatric surgery should be routinely discussed with obese OSA patients.

Treatment of obstructive sleep apnea alters cancer-associated transcriptional signatures in circulating leukocytes.

RATIONALE: Obstructive sleep apnea (OSA) has been associated with a number of chronic disorders that may improve with effective therapy. However, the molecular pathways affected by continuous positive airway pressure (CPAP) treatment are largely unknown. We sought to assess the system-wide consequences of CPAP therapy by transcriptionally profiling peripheral blood leukocytes (PBLs). METHODS: Subjects in whom severe OSA was diagnosed were treated with CPAP, and whole-genome expression measurement of PBLs was performed at baseline and following therapy. We used gene set enrichment analysis (GSEA) to identify pathways that were differentially enriched. Network analysis was then applied to highlight key drivers of processes influenced by CPAP. RESULTS: Eighteen subjects with significant OSA underwent CPAP therapy and microarray analysis of their PBLs. Treatment with CPAP improved apnea-hypopnea index (AHI), daytime sleepiness, and blood pressure, but did not affect anthropometric measures. GSEA revealed a number of enriched gene sets, many of which were involved in neoplastic processes and displayed downregulated expression patterns in response to CPAP. Network analysis identified several densely connected genes that are important modulators of cancer and tumor growth. CONCLUSIONS: Effective therapy of OSA with CPAP is associated with alterations in circulating leukocyte gene expression. Functional enrichment and network analyses highlighted transcriptional suppression in cancer-related pathways, suggesting potentially novel mechanisms linking OSA with neoplastic signatures.

Memory for the 2008 presidential election in healthy ageing and mild cognitive impairment.

The present study examined memory accuracy and confidence for personal and public event details of the 2008 presidential election in healthy older adults and those with mild cognitive impairment (MCI). Participants completed phone interviews within a week after the election and after a 10-month delay. MCI patients and healthy older adults had comparable emotional reactions to learning the outcome of the election, with most people finding it to be a positive experience. After the delay period, details about the election were better remembered by all participants than a less emotionally arousing comparison event. However, MCI patients had more difficulty than healthy older adults correctly recalling details of public information about the election, although often the MCI patients could recognise the correct details. This is the first study to show that MCI patients' memory can benefit from emotionally arousing positive events, complementing the literature demonstrating similar effects for negative events.