title: Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension.
abstract: BACKGROUND
  Hyperaldosteronism is well known cause of secondary hypertension. However, the importance of aldosterone for the much larger group of patients with primary hypertension is less clear. We hypothesized that in young subjects with primary hypertension, the rise of plasma aldosterone levels in response to head-up tilt testing as a stress stimulus is exaggerated.
  
  
  METHODS
  Hemodynamics (blood pressure (BP), heart rate (HR), cardiac index (CI), and total peripheral vascular resistance index (TPRI), all by TaskForce monitor) and hormones (plasma renin activity (PRA), angiotensin II (Ang II), aldosterone) were measured before and during 30 minutes of head-up tilt in 45 young hypertensive and 45 normotensive subjects.
  
  
  RESULTS
  BP, HR, CI, and TPRI all increased in response to head-up tilt, with no difference between groups. There was no difference in baseline PRA, Ang II, and aldosterone between groups. During head-up tilt, PRA, and Ang II levels increased similarly. However, aldosterone levels increased to a greater extent in the hypertensive vs. normotensive subjects (P = 0.0021).
  
  
  CONCLUSIONS
  Our data suggest that an increased release of aldosterone in response to orthostatic stress is a feature of early primary hypertension. The similar increase in PRA and Ang II suggests a potential role for secretagogues of aldosterone other than Ang II in this response. In addition to its established role in secondary hypertension, dysregulation of aldosterone release might contribute to the development of primary arterial hypertension.
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Reinold
authors.affiliation: Department of Internal Medicine I, Divisions of Nephrology and Intensive Care Medicine, University Hospital Würzburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Kalizki
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Raff
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schneider
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Roland E
authors.initials: RE
authors.lastname: Schmieder
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Hannover, Germany.
authors.forename: Bernhard M W
authors.initials: BMW
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D000367:Age Factors; D000450:Aldosterone / Q000097:blood*; D000804:Angiotensin II / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D001794:Blood Pressure; D016022:Case-Control Studies; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D011187:Posture; D011237:Predictive Value of Tests; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System; D018667:Tilt-Table Test / Q000379:methods*; D013997:Time Factors; D015854:Up-Regulation; D014655:Vascular Resistance; D055815:Young Adult
chemical_list: D015415:Biomarkers; D000804:Angiotensin II; D000450:Aldosterone; D012083:Renin
keywords: aldosterone; blood pressure; head-up-tilt; hypertension; primary hypertension