Altered vascular responses to circulating angiotensin II in familial combined hyperlipidemia.
OBJECTIVE
Patients with familial combined hyperlipidemia (FCHL) are at increased risk of hypertension and cardiovascular disease. We examined if patients with FCHL have altered microvascular and macrovascular responses to angiotensin II, a principal mediator of the renin-angiotensin-aldosterone system.


METHODS
Sixteen patients with FCHL and 16 healthy controls were investigated before, during and after a 3 h intravenous infusion of angiotensin II (10 ng/kg/min). Forearm skin microcirculation was studied by laser Doppler fluxmetry during rest and local heating to 44 degrees C (microvascular hyperemia).


RESULTS
Baseline systolic blood pressures were 129 +/- 13 and 123 +/- 12 mmHg in FCHL patients and controls (P = 0.11), respectively. Angiotensin II elicited a greater systolic blood pressure response in the FCHL group (+32 +/- 13 mmHg) than in the control group (+20 +/- 11 mmHg; P < 0.001). At 3 h angiotensin II infusion, microvascular hyperemia increased in the controls (P < 0.001), whereas microvascular hyperemia was unchanged in the FCHL patients (P < 0.01, between groups).


CONCLUSIONS
In healthy individuals, a 3 h intravenous infusion of angiotensin II enhances heat-induced microvascular hyperemia. In FCHL, this microvascular hyperemia is impaired and the systolic blood pressure response is increased. A reduced microvascular dilatation capacity in FCHL may contribute to the observed blood pressure elevation and promote development of micro- and macrovascular complications.
Jörneskog
Gun
G
Karolinska Institutet, Department of Clinical Sciences, Division of Medicine, Sweden, Stockholm, Sweden. gun.jorneskog@ds.se
Kahan
Thomas
T
Ekholm
Mikael
M
Bröijersén
Anders
A
Wallén
N Håkan
NH
D000328:Adult; D000804:Angiotensin II / Q000008:administration & dosage / Q000378:metabolism*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006358:Hot Temperature; D006801:Humans; D006940:Hyperemia / Q000378:metabolism / Q000503:physiopathology; D006950:Hyperlipidemia, Familial Combined / Q000378:metabolism* / Q000503:physiopathology; D007262:Infusions, Intravenous; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature; D013997:Time Factors; D014655:Vascular Resistance; D014664:Vasodilation
D000804:Angiotensin II