ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Endocrine Abstracts (2008) 16 P9

How does aldosterone renin ratio impact blood pressure levels? A Cross-Sectional Study of 3252 Normo- and hypertensive patients referred to coronary angiography

Andreas J Tomaschitz1,4,5,7, Winfried Maerz3, Stefan Pilz2, Hubert Scharnagl3, Wilfried Renner3, Bernhard O Boehm6, Astrid Fahrleitner-Pammer1 & Harald Dobnig1

1Division of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University of Graz, Austria, Graz, Austria; 2Department of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty, University of Heidelberg, Germany, Mannheim/Heidelberg, Germany; 3Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria, Graz, Austria; 4LURIC Study non-profit LLC, Freiburg, Germany; 5Synlab Center of Laboratory Diagnostics Stuttgart, Leinfelden-Echterdingen, Germany; 6Division of Endocrinology and Diabetes, Department of Internal Medicine, University of Ulm, Ulm, Germany; 7Synlab Center of Laboratory Diagnostics Heidelberg, Eppelheim, Germany.

Background: The renin-angiotensin-aldosterone-system (RAAS) is a major regulator of blood pressure, however, there are no studies available addressing its characterization in a large clinical setting. Therefore, the aim of the present study was to describe the relationship between parameters of the RAAS and actual blood pressure results in a large cohort of patients with and without essential hypertension.

Methods: We investigated 3253 patients (ages 63.2±10 years) who were scheduled for coronary angiography in a single tertiary centre. We formed quartiles (QU) according to aldosterone/renin ratio (ARR; pg/ml).

Results: Sixty-nine percentage of the patients were hypertensive (s/dBP ≥140/90 mmHg) and mean systolic (sBP) and diastolic (dBP) blood pressure was 141±23 and 80±11 mmHg in the entire cohort. ARR in men was 10.1±15.6 and in women 14.1±19.7 (P<0.005). In a multivariate model, adjusting for age, sex, BMI, diabetes mellitus, NT-pro-BNP, daily activity, cystatin C, CRP, specific antihypertensive therapy mean sBP of ARR QU1 was 130.9 and increased to 147.2 mmHg in QU4. Diastolic BP increased significantly from 75.7 (QU1) to 85.1 mmHg (QU4), all P values <0.001. The overall influence of antihypertensive medication on ARR was rather small: ACE inhibitors decreased ARR to 9.8 (without ACE: 13.3), as well as diuretics (ARR 9.5 vs 12.2), whereas beta blockers increased ARR to 12.7 (vs 9.3) as did calcium channel blockers (13.9 vs 11.0). In a multivariate stepwise regression model overall predictable variance of sysBP was 28% (R2) and of dBP 22.6%. Here, the ARR was the single and second most important predictor of systolic and diastolic BP values.

Conclusions: ARR accounts for a large part of the variation in BP values and is also an important modulator of BP values in normotensive subjects.