Wellness Check: Sleep

Symptom severity is associated with discrepancies between subjective and objective sleep measures in patients with non-seasonal depression

1. This randomized controlled trial found that patients with more severe depressive symptoms exhibited more significant underestimation of total sleep time and discordance between diary-based and actigraphic sleep parameters.

2. However, those who received bright light therapy showed greater improvements in diary-based time to fall asleep and rise time than those in the control group.

Evidence Rating Level: 1 (Excellent)

Depression is a common mental health disorder often associated with sleep disturbances, and those with an eveningness chronotype are particularly susceptible to these effects. Subjective sleep data is obtained from self-reported measures, such as a sleep diary, while polysomnography is used for objective measures of sleep parameters. Prior studies have demonstrated significant discrepancies between subjective and objective sleep measures, which mental health disorders may influence. Furthermore, bright light therapy (BLT) is known to help treat sleep disturbances in non-seasonal depression. This study aimed to investigate the discrepancies between subjective and objective sleep parameters in people with non-seasonal depression and eveningness and evaluate the impact of BLT on these parameters.

This randomized controlled trial included 93 adult patients diagnosed with non-seasonal major depressive disorder. Participants were included if they were aged 18-65, met the diagnostic criteria for major depressive disorder, scored at least 14 on the 17-item Hamilton Depression Score (17-HDS), and scored 41 or less on the Morningness Eveningness Questionnaire, indicating an eveningness chronotype. Participants were excluded if they had seasonal depression, a current substance abuse disorder, significant suicidal risk, a history of light-induced migraine or epilepsy, were on photosensitizing medication, engaged in shift work, or were on any treatments that could interfere with circadian rhythm. Participants were randomized to the treatment group, which received five weeks of 10,000lux BLT for 30 minutes a day, or the control group, which received 50lux dim red light therapy (DRL). Participants completed a daily sleep diary. At weekly follow-ups, patients completed the 17-HDS for depressive symptoms, the Insomnia Severity Index (ISI), and the 36-item Short-form Survey (SF-36) to assess daytime functioning. Participants wore an actiwatch for actigraphic measurements for seven days at baseline and during the last week of treatment. The primary outcomes were the difference in subjective and objective sleep measurements and the impact of BLT on these findings.

The results demonstrated that patients with more severe depressive symptoms had more significant discrepancies between diary-based and actigraphic measures of total sleep time. Those who received BLT exhibited improvements in subjective time to fall asleep and rise time compared to the DRL group. However, both groups demonstrated comparable improvements in other subjective measures of sleep, including wake after sleep onset, total sleep time, and sleep efficiency. Furthermore, the two groups exhibited no significant difference in actigraphic sleep measures following treatment. However, the study was limited by looking exclusively at patients with eveningness chronotype, which limited the generalizability of the findings to other patients with major depressive disorder. Nonetheless, the present study demonstrated that symptom severity in depression is associated with discrepancies in subjective and objective sleep measures.

Nasal ventilation function is associated with the etiology and treatment of obstructive sleep apnea syndrome in children

1. This randomized controlled trial found that children with obstructive sleep apnea syndrome (OSAS) had significantly higher nasal resistance than those without OSAS.

2. However, in participants who were effectively treated with intranasal corticosteroids and oral montelukast, there were improvements in nasal resistance, nasal minimal cross-sectional area, and nasal cavity volume.

Evidence Rating Level: 1 (Excellent)

Obstructive sleep apnea syndrome (OSAS) is a common condition in children that can have detrimental effects on overall health and quality of life. Given that tonsil and adenoid hypertrophy are associated with the development of OSAS, removing these tissues is the standard treatment for children. However, prior research has found that children can experience a complete resolution of their OSAS symptoms without experiencing changes in the size of their tonsils or adenoids. Thus, other factors are being investigated for playing a role in the etiology of OSAS, including nasal ventilation function (NVF). This study aimed to examine the role of NVF in children with OSAS and evaluate the impact of NVF on the efficacy of drug treatments in this population.

This randomized controlled trial included 109 patients with OSAS and 116 without, forming the control group. Participants in the OSAS group were included if they were diagnosed with OSAS based on polysomnography, their symptoms persisted for at least 12 months, and they had no history of tonsillectomy and/or adenoidectomy. Patients were excluded if they had a history of nasal disease, nasal anatomic anomalies, cranial and facial deformity, immunodeficiency, cardiovascular disease, or had recently undergone corticosteroid treatment. The control group consisted of healthy participants who underwent physical examination at the same hospital during the same time period. Patients underwent overnight polysomnography (PSG) monitoring and acoustic rhinometry (AR) to assess various measurements of the nasal cavity. The OSAS group then received 12 weeks of treatment with intranasal corticosteroids and oral montelukast and underwent PSG and AR measurements again at the end of treatment. The primary outcomes were the different measures of NVR, including nasal resistance (NR), nasal minimal cross-sectional area (NMCA), nasal cavity volume (NCV), and nasopharyngeal volume (NPV).

The results demonstrated that OSAS patients had significantly higher NR and smaller NMCA, NCV, and NPV than those in the control group. The OSAS participants who were effectively treated with intranasal corticosteroids and oral montelukast demonstrated significant improvements in NR, NMCA, and NCV but not NPV. However, the study was limited by its small sample size, which may have impacted the results. Nonetheless, the present study demonstrated the importance of NVF in the etiology and treatment of OSAS in children.

Poor sleep efficiency is associated with improvements in episodic memory in older adults following a moderate-intensity exercise intervention

1. In this randomized controlled trial, improvements in episodic memory in older adults who underwent a moderate-intensity exercise program were mediated by baseline sleep efficiency—those with lower sleep efficiency demonstrated greater improvements in episodic memory following the treatment.

2. However, there were no differences in sleep parameters, including duration, sleep efficiency, and sleep onset latency, in participants who completed a medium- or high-intensity exercise program from baseline to post-intervention.

Evidence Rating Level: 1 (Excellent)

Exercise is known to provide several benefits on cognition. However, there is significant variation in these results. There are likely many moderating factors that influence the role of exercise in improving cognitive function. Sleep is associated with cognition, and exercise interventions are often associated with improved sleep quality. Thus, sleep may be an important mediating factor in this relationship between exercise and cognition. Although observational research has pointed to this link, no clinical trials have investigated sleep’s mediating role on cognition. This study aimed to assess the role of baseline sleep on the relationship between exercise and cognition in older adults.

This randomized controlled trial included 99 cognitively unimpaired participants aged 60-80. Participants were excluded if they were unable to engage in cycling-based exercise due to physical limitations, had a history of schizophrenia, schizoaffective disorder, or bipolar disorder, had untreated obstructive sleep apnea, a recent history of alcohol abuse, a history of cancer, significant medical conditions, uncontrolled diabetes, or hypertension, or had contraindications to magnetic resonance imaging. Participants were randomized to 6 months of either high-intensity exercise, moderate-intensity exercise, or an inactive control group. Participants exercised on a cycle ergometer twice a week for six months. The Pittsburgh Sleep Quality Index (PSQI) and a number of cognitive tests were administered at baseline and at the end of the intervention to investigate sleep quality and cognition, respectively. The primary outcomes were the PSQI and cognitive test scores.

The results demonstrated an improvement in episodic memory and global cognition in the moderate-intensity exercise group following the intervention. However, those in the moderate-intensity group with a lower sleep efficiency of <75% at baseline demonstrated improvements in episodic memory, while those with a higher sleep efficiency did not. Similarly, everyone in the moderate-intensity group showed improvements in cognition, except for those with a sleep efficiency in the 75-84% range. There were no differences in sleep variables in any of the groups following the exercise intervention. However, the study was limited by the self-reported nature of sleep variables, which may have introduced bias. Nonetheless, the present study demonstrated that those with poor sleep efficiency may have the greatest cognitive benefit from exercise interventions.

Image: PD

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