Plasma noradrenaline and neuropeptide-Y may not be of primary importance in the pathophysiology of cardiac involvement in systemic sclerosis

Objective. The present study was performed to measure concentrations of plasma noradrenaline and neuropeptide-Y-like immunoreactivity in relation to cardiac function in patients with systemic sclerosis (SSc). Methods. Plasma noradrenaline was measured by high performance liquid chromatography and neuropeptide-Y by radioimmunoassay in 30 consecutive patients with SSc and 48 sex and age matched controls. Left ventricular (LV) function was evaluated by Echocardiography. Results. There were no significant differences between patients and controls in either plasma noradrenaline or plasma neuropeptide- Y. LV dysfunction and hypertrophy were common among patients. Plasma Neuropeptide-Y was related only to systolic function, while noradrenaline was related to both systolic and diastolic function as well as to LV hypertrophy. Conclusion. Patients with SSc develop different forms of myocardial dysfunction without activation of the sympathetic nervous system as evaluated by plasma noradrenaline and neuropeptide-Y; leaving vascular disease of the heart to be a main candidate.