[Plasma levels of basal beta-endorphin and after effort in patients with severe left ventricular dysfunction and heart failure].
BACKGROUND
Purpose of the study was to evaluate beta-endorphin plasma levels at rest and after exercise, and the beta-endorphin release, in relation to exercise capacity, in patients with severe left ventricular dysfunction and heart failure.


METHODS
Beta-endorphin plasma levels were assayed by radio-immunoassay before and after cardiopulmonary exercise testing in 28 heart failure patients with radionuclide ejection fraction < 35%, left ventricular end-dyastolic dimension > 60 mm and heart failure, and in 9 age-matched normal subjects. According to Weber's classification, 10 patients were in class A, 9 in class B, and 9 in class C.


RESULTS
Beta-endorphin plasma levels at rest were respectively 3.52 +/- 2.31 pmol/L in patients, and 1.77 +/- 0.84 pmol/L (p < 0.05) in normals. In patients, baseline beta-endorphin correlated to VO2max (r = -0.76), peak rate-pressure product (r = -0.60) and exercise time (r = -0.56), then progressively increasing from class A to C. After exercise, beta-endorphin plasma levels increased respectively to 6.42 +/- 3.44 pmol/L (p < 0.001 vs baseline) in patients, and to 5.46 +/- 2.14 pmol/L (p < 0.001 vs baseline and NS vs patients) in normals. In patients, the release during exercise of beta-endorphin (exercise - baseline/baseline x 100) correlated to VO2max (r = 0.82), peak rate-pressure product (r = 0.64) and exercise time (r = 0.55), then progressively decreasing from class A to C. At multivariate analysis beta-endorphin release showed the greater correlation to exercise capacity parameters.


CONCLUSIONS
In heart failure patients, beta-endorphin plasma levels are elevated at rest and its release during exercise is reduced in relation to functional impairment.
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Casa Sollievo Della Sofferenza, IRCCS, San Giovanni Rotondo, FG.
Modoni
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Stanislao
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de Luca
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Fanelli
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Loperfido
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D000328:Adult; D000368:Aged; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000097:blood*; D006352:Heart Ventricles; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D001615:beta-Endorphin / Q000097:blood*
D001615:beta-Endorphin
Livelli plasmatici di beta-endorfina basali e dopo sforzo in pazienti con disfunzione ventricolare sinistra severa e scompenso cardiaco.