Chronobiological evaluation of sympathoadrenergic function in XXXX . Relationship with arterial pressure and heart rate.

@entity1 @entity82 @entity17081 @entity843 @entity1063
Intraday activity of the adrenergic system was investigated in 7 healthy controls and in cirrhotic @entity1 without @entity843 (group 1, 7 cases) and with @entity843 (group 2, 9 cases) by determining the urinary @entity1063 and @entity17081 excretions at 4-h intervals for 24 h. Mean arterial pressure and heart rate were also recorded. In controls, the statistical evaluation by the cosinor method showed a circadian rhythm of such variables, with zenith in the morning and nadir at night. Intraday changes of urinary excretion of @entity1063 were closely related to arterial pressure and heart rate in most subjects. The most important change in cirrhotic @entity1 was the achronia [no detection of a statistically significant (p greater than 0.05) rhythm] in urinary excretion of @entity1063 and arterial pressure. This occurred not only in group 2 @entity1 , who had lower arterial pressure and higher NE mesors than controls (p less than 0.05), but also in group 1 @entity1 , whose mesors were comparable to controls. The statistical significance of heart rate rhythmicity was preserved in @entity1 , but its zenith was progressively displaced toward evening (group 1) and night hours (group 2, whose mesor was increased). Changes in urinary excretion of @entity17081 roughly paralleled those of @entity1063 both in controls and @entity1 , but they did not significantly increase even in the group with @entity843 . In both groups of cirrhotic @entity1 , the correlation between urinary excretion of @entity1063 , arterial pressure, and heart rate within the same subject was lost in most cases. This chronobiological study showed that the sympathoadrenergic activity can be deranged also in the early stages of @entity82 , and suggested that an altered control of cardiovascular homeostasis is present even under steady state conditions. This alteration might blunt adrenergic responses to stress conditions.
