Adiponectin mediates he effects of cardiometabolic risk profile on the coronary microcirculation in patients with idiopathic LV systolic dysfunction.

Purpose. Adiponectin (ADN), a biologically active protein produced

by the adipose
tissue, has protective vascular effects. Accordingly,

ADN plasma levels are reduced in
patients with coronary artery

disease (CAD) while in heart failure ADN tends to
increase.

We hypothesized that ADN plasma levels could mediate the effects

of
atherogenic risk profile on the coronary microcirculation

of patients with early LV
systolic dysfunction (ILVDys) not

secondary to established CAD.
Methods. Plasma ADN was measured in 55 patients (age 59±1

yrs, 36 males, BMI
26.9±0.49 Kg/m
2
, mean±sem)

with angiographically normal coronary arteries, LV
systolic

dysfunction (LVEF 39.8±1.3 % range 22-54 %) but

without overt heart failure
(NYHA class I-II) and in 40

age- and BMI-matched healthy controls by using a
specific Elisa

(Linco Res). BMI, cholesterol and glucose profiles were assessed

in all.
In a subset of 25 patients coronary microvascular function

was studied by PET and
13
N-Ammonia as a flow tracer. Myocardial

blood flow (MBF) was measured at rest
and during i.v. dipyridamole

(Dip) (0.56 mg/Kg in 4 min).
Results. ADN was 6.6±0.34 µg/ml in controls and

10.9±0.85 in ILVDys patients
(p<0.001). In patients

ADN levels were inversely related with BMI (p=0.009) and
directly

related with age (p=0.007), HDL Cholesterol (p=0.003) and MBF

Dip (0.020).
Patients showing more severe coronary microvascular

dysfunction (MBF Dip<1.42
ml/min/g, median value in patients)

had significantly depressed ADN (9.7±2.3 vs
13.7±1.6,

p=0.021) as compared with the remaining patients.
Conclusions. This is the first study which associates adiponectin

plasma levels with
atherogenic risk profile and coronary microvascular

function in patients with idiopathic
LV dysfunction. These results

suggest that adiponectin signal is strongly involved in
mediating

coronary vascular function independently of the presence of

overt CAD or
heart failure.