Background/Purpose: Adipokines
exert pleiotropic actions, including immunoregulatory
and matrix degrading effects. There is evidence of adipokine involvement in the
pathogenesis of cardiovascular (CV) disease as well as inflammatory rheumatic
disease (IRD). It is well known, in the general population, that increased
circulating leptin is associated with CV risk while adiponectin has a cardioprotective effect. Altered circulating adiponectin
and leptin levels may contribute to the accelerated atherosclerosis in IRD. The
aim of this study was to compare plasma levels of leptin and adiponectin in
coronary artery disease (CAD) patients with and without rheumatoid arthritis (RA),
patients with RA without CAD and healthy controls (HC).

Methods: Leptin
and adiponectin were measured in plasma by ELISA in four groups of patients
from the Feiring Heart Biopsy Study: 1) RA patients referred to coronary artery
bypass grafting (CABG) (CAD+RA group, n=22); 2) Patients without RA, referred
to CABG (CAD non-RA group, n=52); 3) RA patients without CAD (RA non-CAD group,
n=17); and 4) HC (n=29).

Results: Adiponectin
was significantly lower in CAD+RA than in RA without CAD (Figure 1A). The mean leptin
was significantly lower in HC than in CAD non-RA, CAD+RA and RA without CAD (Figure
1B). Leptin/adiponectin-ratio was significantly lower in HC than in CAD non-RA and
CAD+RA (Figure 1C). In linear regression analyses, CAD was related to lower adiponectin
levels, and this relationship was independent of age, sex, RA, triglycerides, HDL
and ESR (Table 1). CAD was associated with higher leptin and
leptin/adiponectin-ratio, and these associations were independent of age, sex
and RA (Table 2 and 3). There were no significant associations between
adiponectin, leptin or leptin/adiponectin-ratio and RA disease activity score
28 (DAS28).

Image/graph:

Conclusion: CAD
was related to higher circulating levels of leptin and leptin/adiponectin ratio,
but to lower circulating levels of adiponectin. The relationship between adiponectin
and CAD was independent of age, sex, triglycerides, HDL and ESR. As previously described
for non-RA patients, increased circulating adiponectin may also provide a cardioprotective effect in RA patients.