Sleep Patterns in Patients Affected by Lymphangioleiomiomatosis

Lymphangioleiomyomatosis (LAM) is a rare and progressive pulmonary disease of unknown etiology that almost exclusively affects women. It is characterised by cystic radiological lung pattern and by the possible presence of angiomyolipomas in other sites or organs. Functionally LAM is associated with airway obstruction or restriction and progressive hypoxemia up to chronic respiratory failure. There are no studies, so far, which have investigated whether during sleep these patients show changes in the sleep profile and gas exchange and if these changes are related to disease severity. Aim of the study, prospective and pilot, is to evaluate whether the physiological modification of respiratory mechanics during sleep is associated with polysomnographic alterations in LAM.

Lymphangioleiomiomatosis (LAM) is a rare progressive disease that affects primarily lungs with a cystic radiologic pattern and may be associated with angiomiolipomas in the kidneys or in other sites and an increased frequency of meningioma. Patients with sporadic LAM are usually female (incidence around 1/400.000 adult females). LAM associated with tuberous sclerosis may affect male, female and children. LAM patients are functionally characterized by obstructive or restrictive syndrome that leads patients to hypoxemia and chronic respiratory failure, so that quality of Life (QoL) of these patients is affected by dyspnea. Hypoxemia contributes to the development of secondary pulmonary hypertension (PH) during progression of LAM history, worsening the damage. The modifications in the neural control of ventilation during sleep in combination with anatomical disposition drive to sleep-related changes in upper airway resistance and physiologic desaturations. In healthy subjects these features are almost completely compensated but, in LAM patients, may lead to airway obstruction and/or pathologic oxygen desaturation that could be managed. So far, none have investigated the changes in sleep architecture and related blood gas exchange in patients with LAM relating these changes with disease severity. This pilot study investigate if the physiologic modifications of breathing during sleep lead to sleep disorders in LAM patients, measured through abnormalities in polysomnography (PSG) and ih sleep disorders in LAM are associated with respiratory functional abnormalities and disease severity.

Patients with confirmed diagnosis of LAM underwent a whole-night polysomnography. The presence of either acute or chronic respiratory failure or the use of long-term oxygen therapy are considered exclusion criteria

Aim of the project is to assess the presence of sleep disorders (oxygen destaruration during sleep and/or sleep apnea or hypopnea) in patients affected by LAM.

Another aim of the project is to stratify the presence of sleep-related disorders (oxygen desaturation during sleep, sleep apnea or hypopnea) according to the severity of LAM measured through functional impairment. By spirometry performed at the time of PSG the study population will be divided in: subjects with obstructive impairment; subjects with restrictive abnormality and subjects with no alterations.

correlation between sleep-related disorders and LAM severity measured by annual decline of forced-expiratory volume at the first second (FEV1)

Another aim of the project is to stratify the presence of sleep-related disorders (oxygen desaturation during sleep, sleep apnea or hypopnea) according to the severity of LAM measured by annual decline of forced-expiratory volume at the first second (FEV1), expressed in ml/year. Annual decline of FEV1 will be measured subtracting the FEV1 value (ml) at the time of PSG test to the FEV1 value (ml) at the time of diagnosis and then, dividing it by disease duration in years.

Another aim of the project is to stratify the presence of sleep-related disorders (oxygen desaturation during sleep, sleep apnea or hypopnea) according to the severity of LAM measured through arterial blood gas exchanges values: partial pressure of oxygen (PaO2 - mmHg), partial pressure of carbon dioxide (PaCO2 - mmHg), oxygen saturation (SatO2, %).

Moreover, another aim is to assess the distribution of sleep disorders (oxygen desaturation during sleep, sleep apnea or hypopnea) according to age, sex, body mass index (BMI), comorbidities in patients affected by LAM. BMI will be calculated using height (mt) and weight (Kg) at the time of PSG and expressed in Kg/m^2.

Inclusion Criteria: confirmed diagnosis of LAM according to current guidelines sign of informed consent to participate Exclusion Criteria: the presence of either acute or chronic respiratory failure the use of long-term oxygen therapy