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Arterial plasma norepinephrine correlates to blood pressure in middle-aged men with sustained essential hypertension
S E Kjeldsen1, N J Schork, P Leren
1Department of Internal Medicine, Ullevaal University Hospital, Oslo, Norway.
Insights
In middle-aged men with hypertension, arterial plasma norepinephrine levels, reflecting sympathetic nervous system activity, were elevated and linked to higher blood pressure. This suggests norepinephrine is a key factor in developing hypertension in this age group.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Hypertension Research
Background:
- Plasma catecholamine differences between hypertensive and normotensive individuals are less clear in older adults.
- Arterial catecholamine measurements may offer greater sensitivity for detecting hypertension-related differences.
Purpose of the Study:
- To compare venous and arterial plasma catecholamines in middle-aged hypertensive and normotensive men.
- To investigate the relationship between plasma catecholamines and blood pressure in established hypertension.
Main Methods:
- Measured arterial and venous plasma catecholamines (epinephrine, norepinephrine) in 50-year-old white men.
- Included never-treated essential hypertension (n=61) and normotensive (n=51) groups.
- Utilized stepwise multiple regression analysis to identify independent predictors of blood pressure.
Main Results:
- Hypertensive men showed elevated arterial and venous plasma epinephrine, heart rate, and body weight.
- Arterial plasma norepinephrine was significantly higher in hypertensive subjects.
- Arterial norepinephrine independently predicted higher blood pressure in the hypertensive group.
Conclusions:
- Arterial plasma norepinephrine, a marker of sympathetic tone, may be a crucial factor in the pathogenesis of hypertension in middle-aged men.
- Measurement of arterial catecholamines provides valuable insights into hypertension mechanisms.
Abstract:
Increased plasma catecholamine levels assessed from the venous blood have been found in a number of studies of younger patients with essential hypertension, but hypertensive-normotensive differences could not easily be demonstrated in subjects above 40 years of age. For several reasons, measurement of arterial plasma catecholamines may be a more sensitive tool for the detection of hypertensive-normotensive differences. The present study therefore aimed at examining both venous and arterial plasma catecholamines in a group of white men, all 50 years of age, with never-treated, established essential hypertension (n = 61, blood pressure 165 +/- 2/112 +/- 1 mm Hg, means +/- SE) and comparing them with a similar group of normotensive men (n = 51, blood pressure 128 +/- 1/85 +/- 1 mm Hg). Arterial and venous plasma epinephrine, heart rate, and body weight were significantly elevated in the hypertensive group. Plasma norepinephrine was similar between the groups in the venous blood, whereas in the arterial blood the values in hypertensive subjects were moderately, but significantly increased (p less than 0.03). However, stepwise multiple regression analysis suggested arterial plasma norepinephrine was the only significant independent explanatory variable of raised blood pressure in the hypertensive group (r = 0.51, t = 4.05, p = 0.0002). Such a relationship was not found in the normotensive group. Thus based on measurements in arterial blood, we conclude that plasma norepinephrine, representing sympathetic tone, may be an important pathogenetic factor for high blood pressure in middle-aged men with established hypertension.