Time delay of baroreflex control and oscillatory pattern of sympathetic activity in patients with metabolic syndrome and obstructive sleep apnea

Author(s)

Toschi-Dias, Edgar ^[1] ; Trombetta, Ivani C. ^[1] ; Dias da Silva, Valdo J. ^[2] ; Maki-Nunes, Cristiane ^[1] ; Cepeda, Felipe X. ^[1] ; Alves, Maria-Janieire N. N. ^[1] ; Drager, Luciano F. ^[1] ; Lorenzi-Filho, Geraldo ^[1] ; Negrao, Carlos E. ^{[1, 3]} ; Rondon, Maria Urbana P. B. ^{[1, 3]}

Affiliation

^[1] Univ Sao Paulo, Inst Heart, Sch Med, BR-05508030 Sao Paulo - Brazil

^[2] Univ Fed Triangulo Mineiro, Sch Med, Belo Horizonte, MG - Brazil

^[3] Univ Sao Paulo, Sch Phys Educ & Sports, BR-05508030 Sao Paulo - Brazil

• Document type: Journal article
• Source: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY; v. 304, n. 7, p. H1038-H1044, APR 2013.
• Web of Science Citations: 18

Abstract

Toschi-Dias E, Trombetta IC, Dias da Silva VJ, Maki-Nunes C, Cepeda FX, Alves MJ, Drager LF, Lorenzi-Filho G, Negrao CE, Rondon MU. Time delay of baroreflex control and oscillatory pattern of sympathetic activity in patients with metabolic syndrome and obstructive sleep apnea. Am J Physiol Heart Circ Physiol 304: H1038-H1044, 2013. First published January 25, 2013; doi:10.1152/ajpheart.00848.2012.-The incidence and strength of muscle sympathetic nerve activity (MSNA) depend on the magnitude (gain) and latency (time delay) of the arterial baroreflex control (ABR). However, the impact of metabolic syndrome (MetS) and obstructive sleep apnea (OSA) on oscillatory pattern of MSNA and time delay of the ABR of sympathetic activity is unknown. We tested the hypothesis that MetS and OSA would impair the oscillatory pattern of MSNA and the time delay of the ABR of sympathetic activity. Forty-three patients with MetS were allocated into two groups according to the presence of OSA (MetS + OSA, n = 21; and MetS - OSA, n = 22). Twelve aged-paired healthy controls (C) were also studied. OSA (apnea-hypopnea index > 15 events/h) was diagnosed by polysomnography. We recorded MSNA (microneurography), blood pressure (beat-to-beat basis), and heart rate (EKG). Oscillatory pattern of MSNA was evaluated by autoregressive spectral analysis and the ABR of MSNA (ABR(MSNA), sensitivity and time delay) by bivariate autoregressive analysis. Patients with MetS + OSA had decreased oscillatory pattern of MSNA compared with MetS - OSA (P < 0.01) and C (P < 0.001). The sensitivity of the ABR(MSNA) was lower and the time delay was greater in MetS + OSA compared with MetS - OSA (P < 0.001 and P < 0.01, respectively) and C (P < 0.001 and P < 0.001, respectively). Patients with MetS - OSA showed decreased oscillatory pattern of MSNA compared with C (P < 0.01). The sensitivity of the ABR(MSNA) was lower in MetS - OSA than in C group (P < 0.001). In conclusion, MetS decreases the oscillatory pattern of MSNA and the magnitude of the ABR(MSNA). OSA exacerbates these autonomic dysfunctions and further increases the time delay of the baroreflex response of MSNA. (AU)

• FAPESP's process: 11/17533-6 - Autonomic, metabolic and inflammatory aspects of metabolic syndrome associated with obstructive sleep apnea: effect of hypocaloric diet and physical training
• Grantee: Ivani Credidio Trombetta
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/03714-6 - 3D body scan to diagnose obesity and assess cardiovascular risk
• Grantee: Ivani Credidio Trombetta
• Support Opportunities: Scholarships abroad - New Frontiers