Cytokines and thyroid hormones are involved in the biochemical changes 
associated to heart failure (HF).
AIM: Aims of the study were to investigate: plasma circulating levels of the 
cytokines Interleukine-6 (IL-6) TNF alpha and C reactive protein (CRP) in 
patients with stable HF in relation to the severity of left ventricular 
dysfunction; the relationship between these inflammatory markers and thyroid 
hormones.
METHODS: One-hundred and sixty-six patients (121 males, age 64+/-12), with 
non-ischemic cardiomyopathy, were admitted to the Institute of Clinical 
Physiology for progressive deterioration of symptoms. Forty-eight healthy 
subjects (30 males, age range 26-75 years) were also enrolled as control group 
(Group N). High sensitivity (hs)-IL-6 and hs-TNFalpha were quantified using 
solid phase sandwich ELISA kits. Hs-CRP was measured by Immulite System.
RESULTS: In the whole population (HF and N), the association between 
inflammatory markers and age resulted statistically significant only for IL-6 
serum concentration (p<0.001) but not for TNFalpha and CRP. IL-6 and TNFalpha 
were strongly higher in the HF in comparison with N (p<0.001) while CRP showed a 
less significant difference (p<0.05). Whole population showed a negative 
association between IL-6 and EF% and between CRP and EF% (respectively p<0.01, 
r=-0.23; p<0.05, r=0.19). Comparing normal subjects with two classes of 
patients, respectively with EF>35% and EF<35%, we clearly observed the 
progressive enhancement of the inflammatory markers. Considering normal 
subjects, patients without and with low T3 syndrome, IL-6 and TNFalpha increased 
progressively from normal to patients with fT3<2 pg/ml (p<0.01 and p<0.01) while 
CRP only respect to the group with low T3 syndrome (p<0.01). The inflammatory 
markers were all inversely correlated with FT3 levels.
CONCLUSION: Because low FT3 serum concentration represents a negative prognostic 
index, it is likely that impairment of T3 production and enhanced inflammation 
represent pathogenic mechanisms linked to HF progression.