Leptin and inflammation in patients with chronic heart failure.

Background: There is an increasing interest in the role of leptin in cardiovascular pathophysiology, including proinflammatory effects. Many studies have reported elevated leptin levels in non-cachectic patients with chronic heart failure (CHF), however, the role of leptin in CHF remains unclear.

Aim: To assess the relationship between leptin levels in patients with CHF and left ventricular (LV) systolic dysfunction in relation to ventilatory response to exercise and hsCRP levels.

Methods: The study group consisted of 41 patients (mean age 50.2 ± 9.3 years) with stable CHF and LV ejection fraction < 45% and eight healthy controls (mean age 43.6 ± 14.7 years). Sixteen (39%) patients had coronary artery disease. All subjects underwent anthropometric measurements (weight, height, and waist circumference), standard echocardiography, and maximal cardiopulmonary exercise treadmill test. Biochemical analysis included the assessment of leptin and hsCRP levels as well as white blood count (WBC) and erythrocyte sedimention rate.

Results: Leptin levels, including body mass index (BMI)-adjusted leptin levels, were significantly higher in the CHF patients than in the controls (9.2 ± 7.5 vs 2.9 ± 1.25 ng/mL; p = 0.005). We found significantly higher WBC, neutrophil count, lymphocyte percentage and BNP levels in the CHF group vs controls. There were significant correlations in the CHF group between leptin levels and BMI (r = 0.55; p < 0.05), waist circumference (r = 0.49; p < 0.05), leukocyte count (r = 0.41; p < 0.05), hsCRP levels (r = 0.34; p < 0.05), and peak VO₂ (r = -0.34; p < 0.05). Multivariate step forward regression analysis showed that peak VO₂ was significantly related with leptin levels. After adding VE/VCO₂ slope to the multivariate regression analysis model, only VE/VCO₂ slope was independently associated with leptin levels.

Conclusions: There is a significant relationship between serum leptin levels and peak VO₂, VE/VCO₂ slope and levels of inflammatory markers in patients with CHF.