Figure 6.

Structural and neuromechanical defects in obstructive sleep apnea (OSA) patients: upper airway critical pressure (P_CRIT ± SD) measurements in patients with obstructive sleep apnea (closed circles) and age-, sex-, and body mass index-matched normal controls (open circles) under passive and active conditions. (A) Sleep apnea patients compared to controls demonstrated elevations in both passive P_CRIT (*) and active P_CRIT (**) compared to controls. Furthermore, under active conditions, OSA patients produced lesser reductions in P_CRIT compared to normal controls (see † vs. ‡); (B) among subjects who were matched by structural loads (passive P_CRIT), sleep apnea patients lowered the active P_CRIT less than normal asymptomatic controls [ΔP_CRIT 2.2 cmH₂O ±2.2 (ϴ) vs. 8.0±7.4 (ϴϴ), respectively]. Adapted from Patil et al. 2007 (48).