Abstract 17296: Autonomic Dysfunction in Metabolic Syndrome With Normal Blood Pressure is Associated With Exacerbate Response of Blood Pressure During Maximal Exercise
Introduction: Hypertensive patients presented impairment in the blood pressure (BP) response during maximal exercise test. Sympathetic hyperactivation and decreased baroreflex sensitivity (BRS) are involved in the progression of metabolic syndrome (MetS) in cardiovascular disease.
Hypothesis: (1) MetS patients with normal level of clinical BP show exaggerate peak and recovery systolic BP in response to maximal exercise; (2) Muscle sympathetic nerve activity (MSNA) and BRS are associated with these impairments.
Methods: We selected MetS (ATP III) patients with normal BP (ASH/ISH criteria; MetS= 27, 46±1 y) and a healthy control group without MetS (C= 19, 48±2 y). We evaluated MSNA(microneurography), BRS (spontaneous BP and HR fluctuations) and auscultatory BP measures at pretest, peak, 1st, 2nd, 4th min of recovery during cardiopulmonary exercise test.
Results: Compared to C, MetS had higher BMI and impairment in all MetS risk factors. MetS had higher BP at pretest, peak, 1st, 2nd, 4th min of recovery (P<0.05). Interestingly, we found that even MetS patients with normal BP had lower spontaneous BRS for decreases (9.38+0.7 vs. 12.33+1.25 msec/mmHg, P=0.03) and higher levels of MSNA (27+1 vs. 18+1 bursts/min, P<0.001) compared to C. Further analyses showed association between BRS for decreases with peak BP (r=-.32; P=0.04). Moreover, the MSNA had association with peak BP (r=.40; P=0.03) and BP at 1st min of recovery (r=.48; P=0.01). Fascinatingly, a subgroup of MetS patients with normal BP but exaggerate peak BP (systolic BP >190 mmHg for women and >210 mmHg for men) showed strong association between BRS for decreases with peak BP (r=-.70; P<0.02) and BRS for decreases with BP at 1st min of recovery (r=-.73; P<0.04).
Conclusion: MetS patients even with normal BP, already show sympathetic hyperactivity and decreased baroreflex sensitivity which could explain, at least in part, the exacerbated BP response during maximal exercise.
- baroreflex sensitivity
- sympathetic nerve activity
- cardiopulmonary exercise test
- exacerbated blood pressure
- blood pressure recovery
Author Disclosures: A.C. Dutra-Marques: None. F.X. Cepeda: None. S. Rodrigues: None. J.C. Carvalho: None. E. Toschi-Dias: None. C. Jordão: None. M.U. Rondon: None. M.J. Alves: None. I.C. Trombetta: None.
- © 2015 by American Heart Association, Inc.