Early cardiac abnormalities and increased C-reactive protein levels in a cohort of children with sleep disordered breathing

This study aims to evaluate left ventricular (LV) structure and function and inflammation in a paediatric population with sleep disordered breathing (SDB) and in control subjects. Forty-nine children with SDB and 21 healthy, age-matched subjects were enrolled. The diagnosis of obstructive sleep apnoea syndrome (OSAS) was confirmed by the laboratory polysomnography, showing an obstructive apnoea/hypopnoea index of more than one per hour, according to the criteria of the American Academy of Sleep Medicine and modified for paediatric population. Fasting blood samples for the biochemical evaluation (including high-sensitivity C-reactive protein (hsCRP) were drawn in the morning, after the polysomnographic examination in all patients with SDB and in the control group. All children underwent a two-dimensional colour Doppler cardiac examination with LV mass assessment and systolic and diastolic function evaluation. Higher hsCRP levels were observed in subjects with OSAS than in children with primary snoring and in controls (0.8 +/- 0.7 vs 0.3 +/- 0.1 ng/dl, p = 0.001, and 0.4 +/- 0.2 ng/dl, p = 0.01, respectively). The LV diastolic dysfunction was significantly more frequent in patients with severe OSAS and higher hsCRP levels than in control group. This study shows that OSAS in children is associated with higher LV mass, early LV diastolic dysfunction and a pro-inflammatory state (high CRP levels). These findings might help to explain the higher incidence of cardiovascular morbidity in patients with OSAS.