Low-renin (volume dependent) mild-hypertensive patients have impaired flow-mediated and glyceryl-trinitrate stimulated vascular reactivity.
BACKGROUND
Low-renin (volume-dependent) hypertension represents 25-30% of all cases of primary hypertension. Endothelial dysfunction and vascular remodeling are associated with hypertension but their relevance to volume-dependent hypertension (VDH) is not yet known. To evaluate this, flow-mediated dilation (FMD) of the brachial artery and the carotid intima-media thickness in the distal common carotid artery were measured and compared between renin-dependent mild-hypertensive patients (RDH) and controls.


RESULTS
The study group comprised 40 mild-hypertensive patients and 25 controls. Plasma renin activity (PRA), plasma aldosterone concentration, angiotensin II and nitrite/nitrate plasma levels were measured. According to PRA, subjects were classified as VDH (<0.6 ng . ml (-1) . h(-1)), or RDH (>0.6 ng . ml(-1) . h (-1)). Vascular function was evaluated by FMD before and after reactive hyperemia (RH) and glyceryl-trinitrate (GTN) administration. FMD in response to RH and GTN in the VDH group when compared with RDH group was 10.2+/-2.8% vs 13.3+/-3.6% (p=0.01); and 16.0+/-3.5% vs 19.9+/-4.5% (p=0.01), respectively.


CONCLUSIONS
This study showed impaired FMD and reduced GTN response in mildly hypertensive patients with low-renin plasma levels.
Yugar-Toledo
Juan Carlos
JC
Cardiovascular Pharmacology and Hypertension Section, Clinical Hospital of Campinas & Faculty of Medical Sciences, State University of Campinas (UNICAMP), Brazil.
Bonalume Tácito
Lúcia Helena
LH
Ferreira-Melo
Sílvia Elaine
SE
Sousa
Walnéia
W
Consolin-Colombo
Fernanda
F
Irigoyen
Maria Cláudia
MC
Franchini
Kléber
K
Coelho
Otávio Rizzi
OR
Moreno
Heitor
H
D000328:Adult; D001916:Brachial Artery / Q000473:pathology / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage*; D012083:Renin / Q000097:blood*; D017539:Tunica Intima / Q000473:pathology / Q000503:physiopathology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage*
D014665:Vasodilator Agents; D012083:Renin; D005996:Nitroglycerin