Effects of CPAP on nitrate and norepinephrine levels in severe and mild-moderate sleep apnea

• Autor(a) principal: Pinto, Paula
• Data de Publicação: 2013
• Outros Autores: Bárbara, Cristina, Montserrat, Josep M., Patarrão, Rita, Guarino, Maria P., Carmo, Miguel Mota, Macedo, Maria P., Martinho, C., Gomes, Maria J. M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/24268
• topic: ASSOCIATION; CHEMI-LUMINESCENCE; PLASMA-LEVELS; NITRIC-OXIDE; TRIAL; POSITIVE AIRWAY PRESSURE; BLOOD-PRESSURE; CARDIOVASCULAR-DISEASE; HYPERTENSION; URINARY CATECHOLAMINES; nitrate; noradrenalin

Background: Reduced plasma nitrate (NOx) levels and increased urinary norepinephrine (U-NE) levels have been described in severe obstructive sleep apnea (OSA), and are reverted by continuous positive airway pressure (CPAP). The effect of CPAP on these biomarkers in mild-moderate OSA is not well understood. The aim of this study was to compare NOx and U-NE levels and blood pressure (BP) between male patients with mild-moderate and severe OSA and determine the impact of 1 month of CPAP therapy on these parameters. Methods: We undertook a prospective study of 67 consecutive OSA patients (36 mild-moderate, 31 severe). Measurements of plasma NOx at 11 pm, 4 am and 7 am, 24-h U-NE and ambulatory BP were obtained at baseline and after 1 month of CPAP. Results: At baseline, NOx levels showed a significant decrease during the night in both groups (p < 0.001). U-NE level and BP were significantly higher in the severe OSA group. After 1 month of CPAP, there was a significant increase in NOx levels and a reduction in U-NE level and BP only in patients with severe OSA. Conclusions: One month of CPAP results in significant improvements in NOx levels, 24-h U-NE level and BP in patients with severe OSA, but not in patients with mild-moderate OSA.