Magnetic resonance imaging evaluation of bone marrow changes in obstructive sleep apnoea syndrome in adults

Purpose. The aim of this study was to evaluate bone marrow reconversion in patients with obstructive sleep apnoea syndrome (OSAS) by means of magnetic resonance imaging (MRI). To our knowledge, no explicit correlation between OSAS and such parameter has been documented in the literature. Materials and methods. During a 35-month period, 33 patients with a clinical diagnosis of OSAS, obese but without restrictive or obstructive ventilatory defects, were evaluated with MRI during wakefulness in all patients with T1-, PD- and T2-weighted sequences in the sagittal and axial plane within 1 week after polysomnography. Results. MRI showed bone marrow reconversion in 33.3% of patients. Patients with bone marrow reconversion showed higher mean haematocrit (HT) values, lower mean nocturnal oxyhaemoglobin saturation, higher percentage of sleep time with oxygen saturation (SaO2) <90%, lower nadir, as well as greater neck adiposity and soft-palate lengthening compared with patients without bone marrow reconversion. Furthermore, in patients with bone marrow reconversion, haematocrit (HT) was negatively correlated with daytime arterial oxygen partial pressure (PaO2) and positively with arterial carbon dioxide partial pressure (PaCO2). Conclusions. In patients with OSAS, bone marrow reconversion is probably correlated with the severity of nocturnal desaturation. As bone marrow reconversion is, for unknown reasons, greater in adults younger than 40 years, MRI evidence of bone marrow reconversion could be useful in young individuals for the early diagnosis of sleep-disordered breathing and prevention of associated cardiovascular diseases.