This Article Full Text Full Text (PDF) All Versions of this Article: 49/1/27    most recent 01.HYP.0000251679.87348.05v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shibao, C. Articles by Biaggioni, I. Search for Related Content PubMed PubMed Citation Articles by Shibao, C. Articles by Biaggioni, I. Related Collections Obesity Related Article

(Hypertension. 2007;49:27.)
© 2007 American Heart Association, Inc.

Original Articles

Autonomic Contribution to Blood Pressure and Metabolism in Obesity

Cyndya Shibao; Alfredo Gamboa; Andre Diedrich; Andrew C. Ertl; Kong Y. Chen; Daniel W. Byrne; Ginnie Farley; Sachin Y. Paranjape; Stephen N. Davis; Italo Biaggioni

From the Division of Clinical Pharmacology and the Autonomic Dysfunction Center (C.S., A.G., A.D., G.F., S.Y.P., I.B.) and Divisions of Gastroenterology (K.Y.C.) and Diabetes, Endocrinology, and Metabolism (A.C.E., S.N.D.), Department of Medicine, and the Department of Biostatistics and the General Clinical Research Center (D.W.B.), Vanderbilt University School of Medicine, Nashville, Tenn.

Correspondence to Italo Biaggioni, 1500 21st Ave South, Suite 3500, Clinical Trials Center, Vanderbilt University, Nashville, TN 37212. E-mail Italo.biaggioni{at}vanderbilt.edu

Obesity is associated with alterations in the autonomic nervous system that may contribute to the increase in blood pressure and resting energy expenditure present in this condition. To test this hypothesis, we induced autonomic withdrawal with the ganglionic blocker trimethaphan in 10 lean (32±3 years) and 10 obese (35±3 years) subjects. Systolic blood pressure fell more in obese compared with lean subjects (–17±3 versus –11±1 mm Hg; P=0.019) because of a greater decrease in total peripheral resistance (–310±41 versus 33±78 dynes/sec/cm^–5; P=0.002). In contrast, resting energy expenditure decreased less in obese than in lean subjects, (–26±21 versus –86±15 kcal per day adjusted by fat-free mass; P=0.035). We confirmed that the autonomic contribution to blood pressure was greater in obesity after including additional subjects with a wider range of blood pressures. Systolic blood pressure decreased –28±4 mm Hg (95% CI: –38 to –18.0; n=8) in obese hypertensive subjects compared with lean (–9±1 mm Hg; 95% CI: –11 to –6; n=22) or obese normotensive subjects (–14±2 mm Hg; 95% CI: –18 to –10; n=20). After removal of autonomic influences, systolic blood pressure remained higher in obese hypertensive subjects (109±3 versus 98±2 mm Hg in lean and 103±2 mm Hg in obese normotensive subjects; P=0.004) suggesting a role for additional factors in obesity-associated hypertension. In conclusion, sympathetic activation induced by obesity is an important determinant to the blood pressure elevation associated with this condition but is not effective in increasing resting energy expenditure. These results suggest that the sympathetic nervous system could be targeted in the treatment of obesity-associated hypertension.

Key Words: obesity • hypertension • autonomic nervous system • sympathetic nervous system • vascular resistance • metabolism

Related Article:

Adrenergic Overdrive as the Link Among Hypertension, Obesity, and Impaired Thermogenesis: Lights and Shadows

Guido Grassi
Hypertension 2007 49: 5-6. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

				T. E. Lohmeier, D. A. Hildebrandt, T. M. Dwyer, R. Iliescu, E. D. Irwin, A. W. Cates, and M. A. Rossing Prolonged Activation of the Baroreflex Decreases Arterial Pressure Even During Chronic Adrenergic Blockade Hypertension, May 1, 2009; 53(5): 833 - 838. [Abstract] [Full Text] [PDF]

				L. E. Okamoto, A. Gamboa, C. Shibao, B. K. Black, A. Diedrich, S. R. Raj, D. Robertson, and I. Biaggioni Nocturnal Blood Pressure Dipping in the Hypertension of Autonomic Failure Hypertension, February 1, 2009; 53(2): 363 - 369. [Abstract] [Full Text] [PDF]

				A. V. Agapitov, M. L. d. G. Correia, C. A. Sinkey, and W. G. Haynes Dissociation Between Sympathetic Nerve Traffic and Sympathetically Mediated Vascular Tone in Normotensive Human Obesity Hypertension, October 1, 2008; 52(4): 687 - 695. [Abstract] [Full Text] [PDF]

				M. J. Joyner, N. Charkoudian, and B. G. Wallin A sympathetic view of the sympathetic nervous system and human blood pressure regulation Exp Physiol, June 1, 2008; 93(6): 715 - 724. [Abstract] [Full Text] [PDF]

				I. Biaggioni Should We Target the Sympathetic Nervous System in the Treatment of Obesity-Associated Hypertension? Hypertension, February 1, 2008; 51(2): 168 - 171. [Full Text] [PDF]

				T. E. Lohmeier, T. M. Dwyer, E. D. Irwin, M. A. Rossing, and R. S. Kieval Prolonged Activation of the Baroreflex Abolishes Obesity-Induced Hypertension Hypertension, June 1, 2007; 49(6): 1307 - 1314. [Abstract] [Full Text] [PDF]

				A. Gamboa and I. Biaggioni Response to Contribution of Endothelial Nitric Oxide to Blood Pressure in Humans Hypertension, May 1, 2007; 49(5): e30 - e30. [Full Text] [PDF]

				G. Grassi Adrenergic Overdrive as the Link Among Hypertension, Obesity, and Impaired Thermogenesis: Lights and Shadows Hypertension, January 1, 2007; 49(1): 5 - 6. [Full Text] [PDF]