Assessing sleep architecture and cognition in older adults with depressive symptoms attending a memory clinic.

BACKGROUND: While depression is intrinsically and bidirectionally linked with both sleep disturbance and cognition, the inter-relationships between sleep, cognition, and brain integrity in older people with depression, especially those with late-onset depression are undefined. METHODS: One hundred and seventy-two older adults (mean age 64.3 ± 6.9 years, Depression: n = 66, Control: n = 106) attending a memory clinic underwent a neuropsychological battery of declarative memory, executive function tasks, cerebral magnetic resonance imaging and overnight polysomnography with quantitative electroencephalography. RESULTS: The time spent in slow-wave sleep (SWS) and rapid eye movement (REM) sleep, slow-wave activity, sleep spindles, hippocampal volume and prefrontal cortex thickness did not differ between depression and control and depression onset groups. However, sleep onset latency (p = 0.005) and REM onset latency (p = 0.02) were later in the Depression group compared to controls. Less SWS was associated with poorer memory (r = 0.31, p = 0.023) in the depression group, and less SWS was related to better memory in the control group (r = -0.20, p = 0.043; Fishers r-to-z = -3.19). LIMITATIONS: Longitudinal studies are needed to determine if changes in sleep in those with depressive symptoms predict cognitive decline and illness trajectory. CONCLUSION: Older participants with depressive symptoms had delayed sleep initiation, suggestive of delayed sleep phase. The association between SWS and memory suggests SWS may be a useful target for cognitive intervention in older adults with depression symptoms. Reduced hippocampal volumes did not mediate this relationship, indicating a broader distributed neural network may underpin these associations.

CPAP combined with oral appliance therapy reduces CPAP requirements and pharyngeal pressure swings in obstructive sleep apnea.

Oral appliance (OA) therapy is the leading alternative to continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA). It is well tolerated compared with CPAP. However, ≥50% of patients using OA therapy have incomplete resolution of their OSA. Combination therapy with CPAP and oral appliance (CPAP + OA) is a potential alternative for incomplete responders to OA therapy. This study aimed to determine the extent to which combination therapy reduces therapeutic CPAP requirements using gold-standard physiological methodology in those who have an incomplete response to OA therapy alone. Sixteen incomplete responders [residual apnea/hypopnea index (AHI) > 10 events/h] to a novel OA with a built-in oral airway were recruited (3 women:13 men, aged 31-65 yr, body mass index: 22-38 kg/m2, residual AHI range: 13-63 events/h). Participants were fitted with a nasal mask, pneumotachograph, epiglottic pressure catheter, and standard polysomnography equipment. CPAP titrations were performed during non-rapid eye movement (NREM) supine sleep in each participant during three conditions (order randomized): CPAP only, CPAP + OA (oral airway open), and CPAP + OA (oral airway closed). OSA was resolved at pressures of 4 ± 2 and 5 ± 2 cmH2O during CPAP + OA (oral airway open) and CPAP + OA (oral airway closed) conditions versus 8 ± 2 cmH2O during CPAP only (P < 0.01). Negative epiglottic pressure swings in oral airway open and closed conditions were normalized to CPAP only levels [-2.5(-3.7, -2.6) vs. -2.3(-3.2, -2.4) vs. -2.1(-2.7, -2.3) cmH2O]. Combined CPAP and OA therapy reduces therapeutic CPAP requirements by 35%-45% and minimizes epiglottic pressure swings. This combination may be a therapeutic alternative for patients with incomplete responses to OA therapy alone and those who cannot tolerate high CPAP levels.NEW & NOTEWORTHY Combined CPAP and oral appliance therapy has been suggested as an alternative for incomplete responders to oral appliance therapy. We used a novel oral appliance incorporating an oral airway together with CPAP to show that pharyngeal pressure swings were normalized at reduced CPAP levels. Our findings demonstrate that using CPAP and oral appliance together may be a beneficial alternative for incomplete responders to oral appliance therapy and intolerant CPAP users due to high-pressure requirements.

Efficacy of a novel oral appliance and the role of posture on nasal resistance in obstructive sleep apnea.

STUDY OBJECTIVES: High nasal resistance is associated with oral appliance treatment failure in obstructive sleep apnea (OSA). A novel oral appliance with a built-in oral airway has been shown to reduce pharyngeal pressure swings during sleep and may be efficacious in those with high nasal resistance. The role of posture and mandibular advancement on nasal resistance in OSA remains unclear. This study aimed to determine (1) the effects of posture and mandibular advancement on nasal resistance in OSA and (2) the efficacy of a new oral appliance device including in patients with high nasal resistance. METHODS: A total of 39 people with OSA (7 females, apnea-hypopnea index (AHI) (mean ± standard deviation) = 29 ± 21 events/h) completed split-night polysomnography with and without oral appliance (order randomized). Prior to sleep, participants were instrumented with a nasal mask, pneumotachograph, and a choanal pressure catheter for gold standard nasal resistance quantification seated, supine and lateral (with and without oral appliance, order randomized). RESULTS: Awake nasal resistance increased from seated, to supine, to lateral posture (median [interquartile range] = 1.8 [1.4, 2.7], 2.7 [1.7, 3.5], 3.4 [1.9, 4.6] cm H2O/L/s, P < .001). Corresponding measures of nasal resistance did not change with mandibular advancement (2.3 [1.4, 3.5], 2.5 [1.8, 3.6], 3.5 [1.9, 4.8] cm H2O/L/s, P = .388). The median AHI reduced by 47% with oral appliance therapy (29 ± 21 versus 18 ± 15 events/h, P = .002). Participants with high nasal resistance (> 3 cm H2O/L/s) had similar reductions in AHI versus those with normal nasal resistance (61 [-8, 82] versus 40 [-5, 62] %, P = .244). CONCLUSIONS: Nasal resistance changes with posture in people with OSA. A novel oral appliance with a built-in oral airway reduces OSA severity in people with OSA, including in those with high nasal resistance. CLINICAL TRIAL REGISTRATION: Registry: ANZCTR; Title: Combination therapy for obstructive sleep apnoea; Identifier: ACTRN12617000492358; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372279.

Combination therapy with mandibular advancement and expiratory positive airway pressure valves reduces obstructive sleep apnea severity.

STUDY OBJECTIVES: Mandibular advancement splint (MAS) therapy is a well-tolerated alternative to continuous positive airway pressure for obstructive sleep apnea (OSA). Other therapies, including nasal expiratory positive airway pressure (EPAP) valves, can also reduce OSA severity. However, >50% of patients have an incomplete or no therapeutic response with either therapy alone and thus remain at risk of adverse health outcomes. Combining these therapies may yield greater efficacy to provide a therapeutic solution for many incomplete/nonresponders to MAS therapy. Thus, this study evaluated the efficacy of combination therapy with MAS plus EPAP in incomplete/nonresponders to MAS alone. METHODS: Twenty-two people with OSA (apnea-hypopnea index [AHI] = 22 [13, 42] events/hr), who were incomplete/nonresponders (residual AHI > 5 events/hr) on an initial split-night polysomnography with a novel MAS device containing an oral airway, completed an additional split-night polysomnography with MAS + oral EPAP valve and MAS + oral and nasal EPAP valves (order randomized). RESULTS: Compared with MAS alone, MAS + oral EPAP significantly reduced the median total AHI, with further reductions with the MAS + oral/nasal EPAP combination (15 [10, 34] vs. 10 [7, 21] vs. 7 [3, 13] events/hr, p < 0.01). Larger reductions occurred in supine nonrapid eye movement AHI with MAS + oral/nasal EPAP combination therapy (ΔAHI = 23 events/hr, p < 0.01). OSA resolved (AHI < 5 events/hr) with MAS + oral/nasal EPAP in nine individuals and 13 had ≥50% reduction in AHI from no MAS. However, sleep efficiency was lower with MAS + oral/nasal EPAP versus MAS alone or MAS + oral EPAP (78 ± 19 vs. 87 ± 10 and 88 ± 10% respectively, p < 0.05). CONCLUSIONS: Combination therapy with a novel MAS device and simple oral or oro-nasal EPAP valves reduces OSA severity to therapeutic levels for a substantial proportion of incomplete/nonresponders to MAS therapy alone. CLINICAL TRIALS: Name: Targeted combination therapy: Physiological mechanistic studies to inform treatment for obstructive sleep apnea (OSA)URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372279 Registration: ACTRN12617000492358 (Part C).