Wellness Check: Sleep

Ketogenic diet therapy may improve sleep symptoms in migraine patients

1. In this prospective study, preventative therapy with the ketogenic diet (KD) was associated with sleep improvements in migraine patients, including a decrease in patients with insomnia and a reduction in excessive daytime sleepiness (EDS).

2. Furthermore, KD therapy was associated with improvements in migraine symptoms, including reduced frequency and lower intensity headaches.

Evidence Rating Level: 2 (Good)

Migraines are one of the leading causes of disability worldwide and are associated with impaired quality life. Among the many symptoms of migraines, poor sleep is a common complaint of affected individuals. The ketogenic diet (KD), which consists of low carbohydrate intake and increased lipid intake, has been suggested as a possible method for treating migraine symptoms. However, further research is needed to explore this potential therapy. Therefore, the objective of the present study was to investigate the effects of KD on sleep symptoms in migraine patients.

Patients (n = 70) were enrolled from January 2020 to July 2022 from a nutritional outpatient clinic in Italy. Patients were included if they were treated with KD as a preventative therapy for migraine control. Due to the impact of many migraine drugs on sleep, patients who were introduced to migraine medication <3 months before KD therapy, or who had a change in drug dosage during the study period, were excluded. The Pittsburgh Sleep Quality Index was used to assess sleep quality, and the Epworth Sleepiness Scale was used to evaluate Excessive Daytime Sleepiness (EDS). Patients also completed a headache diary throughout the study period. Information on migraine characteristics and sleep quality was collected prior to KD therapy and 3 months after beginning treatment. The primary outcome was the change in sleep symptoms following KD therapy.

The results demonstrated that KD therapy was associated with improvements in several sleep symptoms in migraine patients. This included a reduction in the number of patients affected by poor sleep, a reduction in EDS, and significant improvements in rates of insomnia among the study participants. KD was also associated with significant improvements in migraine symptoms, including lower intensity migraines, fewer headaches per month, and reduced headache-related disability. However, the study was limited by the small sample size, which may have affected the power and generalizability of the results. Nonetheless, the study demonstrated the potential utility of KD in improving sleep factors and overall headache symptoms in migraine patients.

Substance use impacts various sleep characteristics in young adults

1. In this systematic review, substance use impacted various sleep characteristics in young adults, but the impact was dependent on the substance. For example, both caffeine and nicotine use were associated with higher odds of sleep disturbance, while nicotine alone was associated with poor sleep satisfaction.

2. Furthermore, evening chronotype, the preference to conduct activities in the evening, was associated with alcohol, caffeine, and nicotine use.

Evidence Rating Level: 1 (Excellent)

Young adults have high reports of both sleep difficulties and substance use. Although it is known that sleep difficulties and substance use exhibit a bi-directional relationship, no systematic review to date has assessed the effects of various substances on the many dimensions of sleep health in this population. Therefore, the purpose of the present study was to evaluate the association between substance use and various sleep dimensions in young adults and assess the bi-directional relationship between these domains.

Of 20,755 identified records, 46 studies were included from 3 databases (PubMed, PsychINFO, and Scopus), including 36 cross-sectional, 4 case-control, and 6 prospective studies. Studies that included participants aged 18 to 30 years and had substance use and various sleep-wake dimensions as the outcome and exposure, or vice-versa, were included. Studies that recruited participants from a special population, such as veterans or pregnant individuals, were excluded. The review was conducted in accordance with PRISMA guidelines. The odds ratios were calculated to estimate the effect of the association between substance use and various sleep dimensions. The primary outcome was the bi-directional association between substance use and several sleep characteristics.

The results demonstrated that substance use impacted several sleep characteristics, but the impact depended on the substance in question. For example, caffeine and nicotine use were associated with higher odds of sleep disturbance, but nicotine alone was associated with poor sleep satisfaction. Meanwhile, alcohol and caffeine were associated with daytime dysfunction. It was found that sleep also impacted substance use, as evening chronotype was associated with the use of alcohol, caffeine, and nicotine. Despite these results, the review was limited by the fact that most of the included studies were conducted on college students, which limited the generalizability of the results to other young adult populations. Nonetheless, the study demonstrated that the use of various substances, including alcohol, caffeine, and nicotine, may negatively impact sleep in young adults.

Respiratory muscle training may improve some symptoms of obstructive sleep apnea

1. In this systematic review and meta-analysis, it was found that in patients with obstructive sleep apnea (OSA), inspiratory muscle training likely had a positive impact on systolic blood pressure and sleepiness, but demonstrated no improvements in apnea-hypopnea index, forced vital capacity, sleep quality, and quality of life, compared to controls.

2. Meanwhile, expiratory muscle training showed some improvements in expiratory muscle strength and sleep quality compared to controls, but no improvements in sleepiness.

Evidence Rating Level: 1 (Excellent)

Obstructive sleep apnea (OSA) is a very common sleep disorder that is associated with several debilitating symptoms which can have a significant effect on quality of life. Previous studies have suggested that respiratory muscle training (RMT) may be an effective way to improve lung function and reduce symptom burden in patients with OSA. However, no systematic review to date has synthesized the findings to determine the overall impact of RMT on OSA symptoms. Therefore, the aim of the present study was to review the evidence regarding the safety and effectiveness of RMT in patients with OSA.

Of 8,931 identified records, 13 studies (n = 432 participants) were included from various sources from database inception to July 1, 2022. Studies were included if they were randomized-controlled trials investigating RMT as a treatment for OSA patients older than 18 years of age. Studies that included patients with unstable disorders, spinal cord injury, or neuromuscular disease were excluded. The review was conducted in accordance with PRISMA guidelines. The certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (Grade) System. The primary outcome was the impact of RMT on various OSA symptoms.

The results demonstrated that, compared to controls, inspiratory muscle training had a positive impact on factors including systolic blood pressure and sleepiness in OSA patients. However, there was no impact on apnea-hypopnea index, forced vital capacity, sleep quality, and quality of life. Expiratory muscle training exhibited improvements in muscle strength and sleep quality compared to controls, but no improvements in sleepiness. Despite these results, the review was limited by the small sample sizes and short intervention periods of the included studies, which may have impacted the results. Nonetheless, the present study demonstrated that RMT may be beneficial in improving some symptoms experienced by OSA patients.

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