We appreciate the interest of Dr Mirrakhimov in our recent study in CHEST investigating the role of rostral fluid shift in the pathogenesis of obstructive sleep apnea (OSA).1 We enrolled 135 patients who had been referred for sleep-disordered breathing. However, we only included those who had a rostral fluid shift with increased neck circumference in the study population. The OSA group consisted of typical patients with OSA with a mean age of 52.5 years, marked obesity with a BMI of 36.2 kg/m2, and wide ranging OSA severity. Hypertension and heart failure were present in 47% and 9%, respectively, of the patients with OSA. Despite significant fluid shift into the neck in both patients with OSA and control subjects without OSA, there was no increase in the apnea-hypopnea index or the breathing disturbance index (which, in addition to apnea and hypopnea, includes respiratory effort-associated arousals). We did not specifically examine the influence of rostral fluid shift in subjects with a gross edematous state. As we mentioned in our article,1 we cannot exclude some contribution of fluid shift in a worsening of OSA in this population. But this is far from suggesting rostral fluid shift as a significant mechanism in the pathogenesis of OSA in the majority of these patients.