[Changes in sleep and night respiration in asthma and obstructive or restrictive lung diseases]

Interactions between sleep and respiration have been noticed in several lung diseases. In COPD (chronic obstructive pulmonary disease) patients, the night sleep is delayed or shortened and deep sleep is often reduced or even absent. These disturbances are associated with hypoxaemic episodes occurring either in light slow wave sleep or in REM sleep, the former being short in duration and mild but repetitive and related to ventilatory changes, the latter prolonged, often severe, and resulting from both decrease in ventilation and alterations of ventilation-perfusion ratios. Restrictive syndrome due to interstitial pneumonia, kyphoscoliosis, neuromuscular diseases or, more commonly, to obesity or even pregnancy also alter sleep in a non-specific manner. Most of them result in hypoxia during paradoxical sleep. Unquestionably, there exists a relationship between sleep and asthma (aggravation of dyspnoea at night, reduction of peak expiratory flow when awaking, stage 2 asthmatic attacks). This relationship is probably caused by multifactorial interactions.