Relationship between sleep-disordered breathing and renal dysfunction in acute coronary syndrome

Two Adult Siblings With Myotonic Dystrophy Type 1 With Different Phenotypes Presenting With Chronic Respiratory Insufficiency and Sleep Apnea Syndrome

Myotonic dystrophy type 1 (DM1) is an autosomal dominant disease characterized by progressive muscle weakness and myotonia along with multiple organ system involvements. Overall, DM1 patients show reduced life expectancy, mainly due to respiratory or cardiac abnormalities. Chronic respiratory impairment is associated with increased morbidity in DM1. The main ventilatory dysfunction etiology in DM1 is complex, consisting of both peripheral respiratory dysfunction and central respiratory drive dysfunction as well as upper airway muscle dysfunction leading to obstructive sleep apnea syndrome (SAS) and aspiration. Advancements in early diagnosis of DM1 and management with non-invasive therapeutic tools have improved life expectancy for DM1 patients. We present herein two siblings with DM1, a thin elder brother and an obese younger sister with visceral fat accumulation. Although neither had voluntary symptoms related to respiratory dysfunction, their apnea-hypopnea indices revealed severe SAS and subsequent arterial blood gases studies showed hypercapnia as well as hypoxia, suggesting central nervous system involvement with peripheral respiratory dysfunction. Non-invasive positive pressure ventilation during sleep was started following pulmonary assessment. Respiratory function should be assessed in DM1 patients, even those free of respiratory symptoms, because respiratory muscle weakness occurs in a high percentage of these patients and will shorten their lives.

Effects of suvorexant on sleep apnea in patients with heart failure: A protocol of crossover pilot trial

BACKGROUND

Suvorexant, an orexin receptor antagonist, is known as a safe and effective sleep medication. Many patients with heart failure (HF) have sleep-disordered breathing (SDB) and are short sleepers, and it is unknown whether suvorexant is effective in HF patients and can improve insomnia safely. The aim of this study is to examine the effect of suvorexant on SDB in patients with HF.

METHODS

The Heart Failure with Insomnia and Suvorexant trial of Juntendo University Hospital and Juntendo Shizuoka Hospital (J-FLAVOR trial) is a multicenter trial with a randomized double crossover design. We will enroll a total of 30 HF patients treated in the Juntendo University Hospital and Juntendo Shizuoka Hospital. Eligible patients will undergo portable sleep monitoring twice with or without oral administration of suvorexant in a randomly assigned order. Before the study night, patients in the suvorexant first group will receive suvorexant for 4 consecutive days. There are at least 3 wash-out days between the study nights with and without suvorexant. Primary outcome measures of the non-inferiority trial of suvorexant include the apnea-hypopnea index and the severity of SDB, and the results will be compared between the study nights with and without suvorexant.

CONCLUSION

The present study can determine whether suvorexant can be used in HF patients without affecting their SDB. This is a pilot study to primarily assess whether suvorexant affects the severity of SDB in patients with HF. Therefore, further study is warranted to investigate whether suvorexant alters short- and long-term clinical outcomes by providing longer and better sleep in patients with HF.