Muscle Metaboreflex Control of Sympathetic Activity in Obstructive Sleep Apnea

Purpose: Previous studies report abnormal muscle metaboreflex control of muscle sympathetic nerve activity (MSNA) in obesity, hypertension, and heart failure. We hypothesized that obstructive sleep apnea (OSA) is associated with augmented metaboreflex control of MSNA. Methods: Thirty-one sedentary individuals with no comorbidities (age = 52 ± 1 yr, body mass index = 28 ± 1 kg·m−2) without (control, n = 14) and with OSA (n = 17) defined by polysomnography, underwent echocardiography. HR, blood pressure (BP), MSNA (microneurography), and forearm blood flow measured by venous occlusion plethysmography were continuously measured 4 min at baseline, during 3 min of 30% handgrip static exercise, and during 2 min of post-handgrip muscle ischemia (PHMI). Results: Control and OSA groups were similar in age, body mass index, and ejection fraction. Baseline HR, BP, and forearm blood flow increased similarly during handgrip exercise. Blood pressure remained significantly elevated in relation to baseline during PHMI, but HR and forearm blood flow returned toward baseline during PHMI in both groups. Baseline MSNA was significantly higher in the OSA group than in controls (P

from Sports Medicine via xlomafota13 on Inoreader http://ift.tt/2td1pqD
via IFTTT