Consequences of Comorbid Sleep Apnea in the Metabolic Syndrome-Implications for Cardiovascular Risk

Author(s):Show less -

Trombetta, Ivani C. ^[1] ; Somers, Virend K. ^[1] ; Maki-Nunes, Cristiane ; Drager, Luciano F. ; Toschi-Dias, Edgar ; Alves, Maria Janieire N. N. ; Fraga, Raffael F. ; Rondon, Maria Urbana P. B. ; Bechara, Malta G. ; Lorenzi-Filho, Gerado ; Negrao, Carlos E. ^{[2, 3]}

Affiliation

^[1] Mayo Clin & Mayo Fdn, Dept Internal Med, Div Cardiovasc Dis, Rochester, MN - USA

^[2] Univ Sao Paulo, Sch Med, Heart Inst InCor, Unidade Reabilitacao Cardiovasc & Fisiol Exercici, BR-05403000 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Med, Sch Phys Educ & Sports, BR-05403000 Sao Paulo - Brazil

• Document type: Journal article
• Source: Sleep; v. 33, n. 9, p. 1193-1199, SEP 1 2010.
• Web of Science Citations: 46

Abstract

Study Objectives: Metabolic syndrome (MetSyn) increases overall cardiovascular risk. MetSyn is also strongly associated with obstructive sleep apnea (OSA), and these 2 conditions share similar comorbidities. Whether OSA increases cardiovascular risk in patients with the MetSyn has not been investigated. We examined how the presence of USA in patients with MetSyn affected hemodynamic and autonomic variables associated with poor cardiovascular outcome. Design: Prospective clinical study. Participants: We studied 36 patients with MetSyn (ATP-III) divided into 2 groups matched for age and sex: (1) MetSyn+OSA (n = 18) and (2) MetSyn-OSA (n = 18). Measurements: USA was defined by an apnea-hypopnea index (AHI) > 15 events/hour by polysomnography. We recorded muscle sympathetic nerve activity (MSNA - microneurography), heart rate (HR), and blood pressure (BP - Finapres). Baroreflex sensitivity (BRS) was analyzed by spontaneous BP and HR fluctuations. Results: MSNA (34 +/- 2 vs 28 +/- 1 bursts/min, P = 0.02) and mean BP (111 +/- 3 vs. 99 +/- 2 mm Hg, P = 0.003) were higher in patients with MetSyn+OSA versus patients with MetSyn-USA. Patients with MetSyn+OSA had lower spontaneous BRS for increases (7.6 +/- 0.6 vs 12.2 +/- 1.2 msec/mm Hg, P = 0.003) and decreases (7.2 +/- 0.6 vs 11.9 +/- 1.6 msec/mm Hg, P = 0.01) in BP. MSNA was correlated with AHI (r = 0.48; P = 0.009) and minimum nocturnal oxygen saturation (r = -0.38, P = 0.04). Conclusion: Patients with MetSyn and comorbid USA have higher BP, higher sympathetic drive, and diminished BRS, compared with patients with MetSyn without USA. These adverse cardiovascular and autonomic consequences of USA may be associated with poorer outcomes in these patients. Moreover, increased BP and sympathetic drive in patients with MetSyn+OSA may be linked, in part, to impairment of baroreflex gain. (AU)

• 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
• FAPESP's process: 05/59740-7 - Physical exercise and autonomic control in cardiovascular physiopathology
• Grantee: Carlos Eduardo Negrão
• Support Opportunities: Research Projects - Thematic Grants