Relationship between Overnight Rostral Fluid Shift and Obstructive Sleep Apnea in Nonobese Men

• DOI: 10.1164/rccm.200807-1076oc
• Publication Date: 2008-11-15T02:09:52Z
• Authors: Stefania Redolfi; Dai Yumino; Pimon Ruttanaumpawan; Brian Yau; Mao-Chang Su; Jennifer Lam; T. Douglas Bradley
• Keywords: Sitting; Apnea–hypopnea index

The cause of increased pharyngeal collapsibility in patients with obstructive sleep apnea is incompletely understood. In awake healthy subjects, we showed that fluid displacement from the legs into neck induced by lower body positive pressure reduces upper airway size and increases its collapsibility. Prolonged sitting leads to dependent accumulation legs.To test hypotheses apnea-hypopnea index (AHI) during will be related amount spontaneously displaced overnight, this will, turn, time spent previous day.In 23 nonobese men referred for studies suspected apnea, assessed changes leg volume circumference beginning end night, day.The overnight change correlated strongly AHI (r = -0.773, P < 0.001), -0.792, -0.588, 0.003). Multivariate analysis only significant independent correlates were circumference, which together explained 68% variability among subjects.These novel findings suggest rostral legs, prolonged sitting, may play a previously unrecognized role pathogenesis weight.