Leptin, a novel predictor of lung function in heart failure

Background: Leptin is a protein hormone produced by adipose tissue. Leptin has proinflammatory properties and is usually elevated in patients with chronic heart failure. We assessed if serum leptin relates to the loss in lung function in noncachectic patients with chronic heart failure. Materials and methods: One hundred thirty-five consecutively eligible non-Hispanic white subjects (age, 24 to 79 years; 85 men and 50 women) with a diagnosis of stable systolic heart failure were recruited prospectively, along with 106 matched control subjects. FVC, FEV₁, and single-breath diffusing capacity of the lung for carbon monoxide (DLCO) were measured by spirometry. Plasma leptin was measured by radioimmunoassay. Multiple linear regression was applied. Results: The relationships of FEV₁, FVC, and DLCO with leptin differed significantly between heart failure and control subjects after controlling for age, sex, percentage of body fat, and ejection fraction. In heart failure, leptin was as an independent predictor of FVC values (additional R² = 0.05, p < 0.0001), FEV₁ values (additional R² = 0.05, p < 0.0001), and DLCO values (additional R² = 0.14, p < 0.0001). In a final multiple regression model predicting lung function in heart failure, the independent effect of leptin was significant after further adjustments. Conclusions: The predictive information provided by leptin is additive to that provided by measures of body fat in heart failure patients, especially for DLCO. Leptin may play a role in the impairment of lung function in subjects with heart failure.