Lack of correlation between microalbuminuria and endothelial function in essential hypertensive patients.
OBJECTIVE
To evaluate whether microalbuminuria, defined as urinary albumin excretion between 30 and 300 mg/24 h, is associated with endothelial dysfunction in essential hypertensive patients.


METHODS
We correlated urinary albumin excretion with vasodilatation in response to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) agonists in the forearm vascular bed in essential hypertensive patients with (n = 13) and without (n = 23) microalbuminuria and matched normotensive controls (n = 21).


METHODS
We studied forearm vascular responses (strain-gauge plethysmography) to intrabrachial infusion of acetylcholine (0.15, 0.45, 1.5, 4.5 and 15 ng/100 ml forearm tissue/min) and of sodium nitroprusside (1, 2, 4ng/100 ml forearm tissue per min). Minimal forearm vascular resistances (the ratio between mean arterial pressure and maximal forearm vasodilation induced by 13 min of ischaemia + 1 min of exercise) were also evaluated.


RESULTS
Responses to acetylcholine, but not to sodium nitroprusside, were significantly blunted and minimal forearm vascular resistances were increased in hypertensive patients compared with controls. However, no correlation was found between urinary albumin excretion and vasodilatation in response to acetylcholine or to sodium nitroprusside or between urinary albumin excretion and minimal forearm vascular resistances.


CONCLUSIONS
In hypertensive patients, increased urinary albumin excretion is associated neither with functional nor with structural dysfunction in the forearm vasculature.
Taddei
S
S
I Clinica Medica, Cattedra di Medicina Interna, University of Pisa, Italy.
Virdis
A
A
Mattei
P
P
Ghiadoni
L
L
Sudano
I
I
Arrighi
P
P
Salvetti
A
A
D000109:Acetylcholine / Q000494:pharmacology; D000419:Albuminuria / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D001794:Blood Pressure; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D005542:Forearm / Q000098:blood supply; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D007261:Infusions, Intra-Arterial; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D014655:Vascular Resistance; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine