['Although heart failure (HF) is characterized by increased proinflammatory cytokines, natriuretic peptide levels and impaired exercise capacity, the effect of concomitant diastolic dysfunction on those parameters has not been adequately studied.', 'We analyzed circulating levels of IL-1, IL-6, TNF-alpha and its soluble receptors, sTNFRI and sTNFRII, Nt-ANP and Nt-BNP natriuretic peptides in 81 patients, aged 56+/-12 years, with non-ischemic dilated cardiomyopathy (NIDC), LVEF 29.7+/-7.75% and functional NYHA class II-III. An echocardiographic study and cardiopulmonary exercise test (CPE) were performed in all patients.', 'Patients were divided into restrictive (24 patients, group I) and non-restrictive (57 patients, group II) groups, according to their transmitral-filling pattern. No differences in LV dimensions or LVEF were found between the two groups. Group I showed increased levels of IL-6 (P=0.006), TNF-alpha (P=0.05), sTNFRII (P=0.02), Nt-ANP (P<0.001) and Nt-BNP (P<0.001) and decreased exercise duration (P<0.001) and PVO(2) (P<0.001) compared to group II. The strongest independent predictors for restrictive filling pattern were Nt-ANP and IL-6 levels, while Nt-BNP levels were the strongest PVO(2) predictor.'] Is restrictive filling pattern associated with increased humoral activation and impaired exercise capacity in dilated cardiomyopathy?