Preliminary findings reveal that phthalate exposure is associated with both subjective and objective measures of sleep in a small population of midlife women.

Phthalates are endocrine-disrupting chemicals that influence endogenous hormones. Few studies have examined the link between phthalates and menopause. A recent secondary analysis revealed that phthalates were associated with self-reported sleep measures in perimenopausal women. However, the associations between phthalate exposure and additional measures of sleep remain unknown. We recruited a population of 27 midlife women (aged 45-54) to study the relationship between phthalate exposure and both subjective and objective measures of sleep. Preliminary results indicate that women with higher phthalate exposure have reduced sleep quality, more frequent sleep disruptions, and more restless sleep compared to women with lower exposure.

Continuous Positive Airway Pressure-Mandibular Advancement Device Combination Therapy for Moderate-to-Severe Obstructive Sleep Apnea: A Preliminary Study.

OBJECTIVES: The purpose of this pilot study was to determine whether compliance to auto-adjusting positive airway pressure (APAP) improves with the addition of a mandibular advancement device (MAD). Secondary outcome measures included were APAP pressure, subjective daytime sleepiness, apnea-hypopnea index (AHI), and mask leaks. SETTING AND SAMPLE POPULATION: Participants included were diagnosed with moderate-to-severe obstructive sleep apnea (OSA) and became noncompliant to prescribed APAP. Thirteen participants with a mean age of 61.6 years were recruited for this study. MATERIALS AND METHODS: All participants were given a MAD to use with their APAP. Parameters measured included APAP pressure, AHI, mask leak reported via ResMed AirViewTM software, and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]). A paired two-sample for mean t-test was performed to determine significance. RESULTS: The mean difference of pre- and postintervention APAP compliance was 23.1%, which was statistically significant (p = 0.015). The mean APAP air pressures were unchanged. The difference between pre- and postintervention mean ESS scores was 1.4 and was statistically significant (p = 0.027). The mean difference between pre- and postintervention AHI values and mask leak showed no significant difference. CONCLUSION: This study showed that combination of APAP-MAD therapy, for patients with moderate-to-severe OSA who were noncompliant to APAP use, significantly increased compliance with APAP therapy, and significantly decreased the daytime sleepiness of participants.

Mechano-acoustic sensing of physiological processes and body motions via a soft wireless device placed at the suprasternal notch.

Skin-mounted soft electronics that incorporate high-bandwidth triaxial accelerometers can capture broad classes of physiologically relevant information, including mechano-acoustic signatures of underlying body processes (such as those measured by a stethoscope) and precision kinematics of core-body motions. Here, we describe a wireless device designed to be conformally placed on the suprasternal notch for the continuous measurement of mechano-acoustic signals, from subtle vibrations of the skin at accelerations of around 10-3 m s-2 to large motions of the entire body at about 10 m s-2, and at frequencies up to around 800 Hz. Because the measurements are a complex superposition of signals that arise from locomotion, body orientation, swallowing, respiration, cardiac activity, vocal-fold vibrations and other sources, we exploited frequency-domain analysis and machine learning to obtain-from human subjects during natural daily activities and exercise-real-time recordings of heart rate, respiration rate, energy intensity and other essential vital signs, as well as talking time and cadence, swallow counts and patterns, and other unconventional biomarkers. We also used the device in sleep laboratories and validated the measurements using polysomnography.

Battery-free, wireless sensors for full-body pressure and temperature mapping.

Thin, soft, skin-like sensors capable of precise, continuous measurements of physiological health have broad potential relevance to clinical health care. Use of sensors distributed over a wide area for full-body, spatiotemporal mapping of physiological processes would be a considerable advance for this field. We introduce materials, device designs, wireless power delivery and communication strategies, and overall system architectures for skin-like, battery-free sensors of temperature and pressure that can be used across the entire body. Combined experimental and theoretical investigations of the sensor operation and the modes for wireless addressing define the key features of these systems. Studies with human subjects in clinical sleep laboratories and in adjustable hospital beds demonstrate functionality of the sensors, with potential implications for monitoring of circadian cycles and mitigating risks for pressure-induced skin ulcers.

Depth and Distribution of Symptoms in Restless Legs Syndrome/ Willis-Ekbom Disease.

STUDY OBJECTIVES: To determine the depth and distribution of sensory discomfort in idiopathic restless legs syndrome/Willis-Ekbom disease (RLS) and RLS concurrent with other leg conditions, specifically peripheral neuropathy, sciatica, leg cramps, and arthritis. METHODS: RLS subjects (n = 122) were divided into 71 idiopathic RLS and 51 RLS-C, or Comorbid, groups. All subjects were examined by an RLS expert, answered standardized RLS questionnaires, and received a body diagram to draw the location and depth of their symptoms. RESULTS: Age was 63.04 ± 12.84 years, with 77 females and 45 males. All patients had lower limb involvement and 43/122 (35.25%) also had upper limb involvement. Of the 122 subjects, 42.62% felt that the RLS discomfort was only deep, 9.84% felt that the discomfort was only superficial, and 47.54% felt both superficial and deep discomfort. There were no defining characteristics in depth or distribution of RLS sensations that differentiated those patients with idiopathic RLS from those patients with RLS associated with other comorbid leg conditions. The sensation of arthritis was felt almost exclusively in the joints and not in the four quadrants of the leg, whereas the exact opposite was true of RLS sensations. CONCLUSIONS: Depth and distribution cannot be used as a discriminative mechanism to separate out idiopathic RLS from RLS comorbid with other leg conditions. Although seen in clinical practice, the total absence of patients with non-painful RLS only in the joints in the current study attests to the rarity of this presentation and raises the possibility of misdiagnosis under these circumstances. We recommend that such patients not be admitted to genetic or epidemiological studies.

Impact of Obstructive Sleep Apnea on Neurocognitive Function and Impact of Continuous Positive Air Pressure.

There is evidence that obstructive sleep apnea (OSA) can negatively impact attention, memory, learning, executive function, and overall intellectual function in adults and children. Imaging techniques, including MRI, MR diffusion tensor imaging, MR spectroscopy, and fMRI, have provided additional insight into the anatomic and functional underpinnings of OSA-related cognitive impairment. Both animal and human studies have looked to elucidate the separate effects of oxygen desaturation and sleep fragmentation on independent aspects of cognition. Data from animal models point to neuro-inflammation and oxidative stress as driving factors of cognitive impairment.

An electrocardiogram-based analysis evaluating sleep quality in patients with obstructive sleep apnea.

OBJECTIVE: The study compares polysomnography (PSG) and cardiopulmonary coupling (CPC) sleep quality variables in patients with (1) obstructive sleep apnea (OSA) and (2) successful and unsuccessful continuous positive airway pressure (CPAP) response. PATIENTS/METHODS: PSGs from 50 subjects (32 F/18 M; mean age 48.4 ± 12.29 years; BMI 34.28 ± 9.33) were evaluated. OSA patients were grouped by no (n = 16), mild (n = 13), and moderate to severe (n = 20) OSA (apnea-hypopnea index (AHI) ≤ 5, >5-15, >15 events/h, respectively). Outcome sleep quality variables were sleep stages in non-rapid eye movement, rapid eye movement sleep, and high (HFC), low (LFC), very low-frequency coupling (VLFC), and elevated LFC broad band (e-LFCBB). An AHI ≤ 5 events/h and HFC ≥ 50 % indicated a successful CPAP response. CPC analysis extracts heart rate variability and QRS amplitude change that corresponds to respiration. CPC-generated spectrograms represent sleep dynamics from calculated coherence product and cross-power of both time series datasets. RESULTS: T tests differentiated no and moderate to severe OSA groups by REM % (p = 0.003), HFC (p = 0.007), VLFC (p = 0.007), and LFC/HFC ratio (p = 0.038) variables. The successful CPAP therapy group (n = 16) had more HFC (p = 0.003), less LFC (p = 0.003), and e-LFCBB (p = 0.029) compared to the unsuccessful CPAP therapy group (n = 8). PSG sleep quality measures, except the higher arousal index (p = 0.038) in the unsuccessful CPAP group, did not differ between the successful and unsuccessful CPAP groups. HFC ≥ 50 % showed high sensitivity (77.8 %) and specificity (88.9 %) in identifying successful CPAP therapy. CONCLUSIONS: PSG and CPC measures differentiated no from moderate to severe OSA groups and HFC ≥ 50 % discriminated successful from unsuccessful CPAP therapy. The HFC ≥ 50 % cutoff showed clinical value in identifying sleep quality disturbance among CPAP users.

Celiac disease as a possible cause for low serum ferritin in patients with restless legs syndrome.

OBJECTIVE: To describe celiac disease (CD) as a possible cause for low serum ferritin in patients with restless legs syndrome (RLS). BACKGROUND: Low iron stores have been found to be a risk factor for RLS with serum ferritin levels less than 45-50 ng/mL associated with increased severity of RLS. It has become routine clinical practice to test serum ferritin in the initial assessment of RLS. CD is a common genetic disorder that can cause iron deficiency. METHODS: Consecutive case series of four patients with RLS and serum ferritin below 25 ng/mL, who had positive screening tests for celiac disease. RESULTS: We report four patients who had serum ferritin < 12 ng/mL and positive screening tests for CD. All had CD confirmed by duodenal biopsy and response to a gluten-free diet. RLS symptoms improved in all four, with two able to discontinue RLS medication and two responding without medication. CONCLUSIONS: In patients with RLS and low serum ferritin who do not have an obvious cause for iron deficiency, we suggest looking for CD by simple, inexpensive serologic testing. Diagnosis and treatment of CD is likely to improve the outcome for RLS, as well as identify individuals who are at risk for the significant long-term complications of CD.

Sleep medicine content of major medical textbooks continues to be underrepresented.

OBJECTIVE: Sleep-related material in medical textbooks may be the only method by which physicians educate themselves about sleep. In the last decade significant progress in sleep research has been made, but how textbooks in relevant fields reflect it has not been examined. Our purpose was to review and compare (2005 with 1998) sleep content in representative medical textbooks. METHODS: Sleep content of the latest edition of textbooks in four specialties was evaluated. Present sleep content in seven textbooks was compared with that found in 1998. Numbers of pages devoted to sleep were counted and reported for the subjects covered and for the specialty of the textbook. RESULTS: Thirty-one textbooks were examined for current content and seven textbooks for content comparison. Sleep coverage in medical textbooks uniformly received less than 2% of the text volume. Focus of topics covered varied with specialty. Compared with 1998, the proportion of pages devoted to sleep remained the same or decreased. Coverage of new topics remained minimal. CONCLUSIONS: Major medical textbooks present small amounts of sleep content and few provide a comprehensive overview of sleep medicine. In comparison to textbook editions from the 1990s, current editions still devote little attention to sleep, and the diversity of topics has not improved.