The sleep characteristics in symptomatic patients with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) causes serious health consequences that include impairment of the respiratory system and sleep. The aim of our study is to investigate the sleep architecture and respiratory profile during sleep of symptomatic patients with DMD without ventilatory support. We evaluated polysomnography (PSG) of boys with DMD (n = 44) and a control group (n = 79) with sleep complaints that was matched in age but without neuromuscular disease. DMD patients presented sleep impairments when compared with the control group in terms of decreased sleep efficiency (72.4 +/- 1.9 vs 80.3 +/- 1.4 %, P = 0.002) and increased apnea-hypopnea index (AHI) during nonrapid eye movement (NREM) sleep (1.6 +/- 0.3 vs 0.3 +/- 0.2/h, P = 0.003). The main changes were observed during rapid eye movement (REM) sleep: an increase in REM sleep latency (202.2 +/- 11.8 vs 152.3 +/- 8.6 min, P < 0.001), a reduced percentage of REM sleep (13.1 +/- 0.9 vs 17.9 +/- 0.7 %, P = 0.001), and exacerbation of AHI (8.7 +/- 1.5 vs 1.0 +/- 1.1 events/h, P = 0.001). There was an increase in the total number of apneas, especially obstructive apneas (6.8 +/- 1.9 vs 0.8 +/- 1.3, P = 0.013). The sleep and respiratory profile during sleep of patients with DMD are compromised. The results suggest that these changes reflect the muscle weakness inherent in DMD and are demonstrated mainly during REM sleep. Thus, the use of PSG is important to identify sleep-disordered breathing at an early stage, before deciding when to introduce noninvasive respiratory support for prevention of respiratory complications.