M A Weber1, J M Neutel, D H Smith. 1. State University of New York Downstate Medical Center, Brooklyn, USA. michaelwebermd@cs.com
Abstract
OBJECTIVES: We sought to test whether the differences in activity of the renin-angiotensin and sympathetic nervous systems at rest or during exercise can explain the differing cardiovascular properties and outcomes of lean and obese hypertensive patients. BACKGROUND: Although lean hypertensive patients have fewer metabolic abnormalities than obese hypertensive patients, paradoxically they appear to have a poorer cardiovascular prognosis. METHODS: To evaluate the heightened risks in lean hypertensive patients, this study compared metabolic, neuroendocrine and cardiovascular characteristics at rest and during a standardized treadmill protocol in obese (body mass index [BMI] = 32.5 +/- 0.3 kg/m2, n = 55) and lean (BMI = 24.3 +/- 0.2 kg/m2, n = 66) hypertensive patients. Normotensive obese (n = 21) and lean (n = 55) volunteers served as control subjects. RESULTS: Compared with the lean normotensive subjects, the lean and obese hypertensive patients had greater left ventricular mass index (LVMI) values, but on multivariate analysis, LVMI correlated with plasma renin activity (p < 0.001) and plasma norepinephrine (PNE) (p < 0.01) in the lean but not the obese hypertensive patients. Arterial compliance (stroke volume/pulse pressure ratio) was reduced in the lean hypertensive patients, in whom it correlated (p = 0.033) with PNE. The PNE rose less (22%) in the obese than in the lean (55%) hypertensive patients in response to standing (p < 0.05). Likewise, during treadmill exercise, there were lesser increases in renin (65% vs. 145%, p < 0.01) and epinephrine (200% vs. 500%, p < 0.05) in the obese hypertensive patients. These changes were also less in obese patients than in lean control subjects, indicating attenuated neurohormonal responses to stress in obesity. CONCLUSIONS: Compared with obese hypertensive patients, cardiovascular properties in lean hypertensive patients are more dependent on catecholamines and the renin system. The different neuroendocrine responses to dynamic stimuli in lean and obese patients also might help to explain the disparity in their cardiovascular outcomes.
OBJECTIVES: We sought to test whether the differences in activity of the renin-angiotensin and sympathetic nervous systems at rest or during exercise can explain the differing cardiovascular properties and outcomes of lean and obese hypertensivepatients. BACKGROUND: Although lean hypertensivepatients have fewer metabolic abnormalities than obese hypertensivepatients, paradoxically they appear to have a poorer cardiovascular prognosis. METHODS: To evaluate the heightened risks in lean hypertensivepatients, this study compared metabolic, neuroendocrine and cardiovascular characteristics at rest and during a standardized treadmill protocol in obese (body mass index [BMI] = 32.5 +/- 0.3 kg/m2, n = 55) and lean (BMI = 24.3 +/- 0.2 kg/m2, n = 66) hypertensivepatients. Normotensive obese (n = 21) and lean (n = 55) volunteers served as control subjects. RESULTS: Compared with the lean normotensive subjects, the lean and obese hypertensivepatients had greater left ventricular mass index (LVMI) values, but on multivariate analysis, LVMI correlated with plasma renin activity (p < 0.001) and plasma norepinephrine (PNE) (p < 0.01) in the lean but not the obese hypertensivepatients. Arterial compliance (stroke volume/pulse pressure ratio) was reduced in the lean hypertensivepatients, in whom it correlated (p = 0.033) with PNE. The PNE rose less (22%) in the obese than in the lean (55%) hypertensivepatients in response to standing (p < 0.05). Likewise, during treadmill exercise, there were lesser increases in renin (65% vs. 145%, p < 0.01) and epinephrine (200% vs. 500%, p < 0.05) in the obese hypertensivepatients. These changes were also less in obesepatients than in lean control subjects, indicating attenuated neurohormonal responses to stress in obesity. CONCLUSIONS: Compared with obese hypertensivepatients, cardiovascular properties in lean hypertensivepatients are more dependent on catecholamines and the renin system. The different neuroendocrine responses to dynamic stimuli in lean and obesepatients also might help to explain the disparity in their cardiovascular outcomes.
Authors: Timothy P Fitzgibbons; Olga T Hardy; Darleen Lessard; Joel M Gore; Jorge Yarzebski; Robert J Goldberg Journal: Coron Artery Dis Date: 2009-12 Impact factor: 1.439
Authors: M Z Molnar; E Streja; C P Kovesdy; S Bunnapradist; M S Sampaio; J Jing; M Krishnan; A R Nissenson; G M Danovitch; K Kalantar-Zadeh Journal: Am J Transplant Date: 2011-04 Impact factor: 8.086
Authors: Joni Ricks; Miklos Z Molnar; Csaba P Kovesdy; Joel D Kopple; Keith C Norris; Rajnish Mehrotra; Allen R Nissenson; Onyebuchi A Arah; Sander Greenland; Kamyar Kalantar-Zadeh Journal: Am J Kidney Dis Date: 2011-06-12 Impact factor: 8.860