RESUMO
STUDY OBJECTIVE: Studies in adults and children have shown that African American race is a risk factor for the obstructive sleep apnea syndrome (OSAS). Therefore, we hypothesized that non-obese, non-snoring African American children would have a more collapsible upper airway during sleep than age-, gender-, and size-matched Caucasians. DESIGN: Upper airway dynamic function was measured during sleep in normal African American and Caucasian children. SETTING: Sleep laboratory. PATIENTS OR PARTICIPANTS: 56 normal children between the ages of 8-18 years. INTERVENTIONS: Pressure-flow relationships were measured during NREM sleep. Nasal pressure was decreased to subatmospheric levels, using previously described techniques that resulted in an activated and relatively hypotonic upper airway. MEASUREMENTS AND RESULTS: The activated and hypotonic critical pressures (Pcrit) were -25 (-25, -3) (median, range) and -19 (-25, -3) for African Americans, and -25 (-25, -4) and -25 (-25.0, -4) cm H(2)O, respectively, for Caucasians. The slopes of the pressure-flow response (SPF) under activated and hypotonic conditions for African Americans were 10 (-9, 46) and 13 (-20, 46), and for Caucasians 9 (-9, 64) and 8 (-5, 54) mL/s/cm H(2)O, respectively. There were no significant differences between groups for Pcrit or SPF under either activated or hypotonic conditions. CONCLUSION: Upper airway collapsibility was similar in asymptomatic, non-obese African American and Caucasian children. Differences in upper airway characteristics and neuromotor function cannot explain the increased prevalence of OSAS in African American children.