Author + information
- Received July 14, 2009
- Revision received October 30, 2009
- Accepted January 6, 2010
- Published online May 11, 2010.
- Andreas Tomaschitz, MD*,
- Winfried Maerz, MD†∥,
- Stefan Pilz, MD*,
- Eberhard Ritz, MD‡,
- Hubert Scharnagl, PhD†,
- Wilfried Renner, PhD†,
- Bernhard O. Boehm, MD§,
- Astrid Fahrleitner-Pammer, MD*,
- Gisela Weihrauch, MSc† and
- Harald Dobnig, MD*,* ()
- ↵*Reprint requests and correspondence:
Dr. Harald Dobnig, Professor of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, A-8036 Graz, Austria
Objectives With the present analysis we intended to investigate the magnitude of the effect of relative aldosterone excess in predicting peripheral as well as aortic blood pressure levels in a well-characterized cohort of patients undergoing coronary angiography.
Background The discussion on the relationship between aldosterone concentration and blood pressure has recently gone beyond the role of primary aldosteronism in the genesis of arterial hypertension.
Methods Plasma aldosterone (pg/ml) and plasma renin concentration (pg/ml) were determined in 3,056 Caucasian patients (age 62.5 ± 11 years; 31.9% women) scheduled for coronary angiography in a single tertiary care center. We formed sex-specific deciles (D) according to plasma aldosterone/renin concentration ratio (ARR) (pg/ml/pg/ml).
Results Mean peripheral systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the entire cohort were 141 ± 24 mm Hg and 81 ± 11 mm Hg, respectively. Mean ARR was 10.2 ± 15.7 in men and 14.4 ± 19.9 in women (p < 0.0001). Median SBP and aortic SBP increased steadily and significantly from ARR D1 (126.8 mm Hg and 130.0 mm Hg, respectively) to D10 (151.0 mm Hg and 149.6 mm Hg, respectively; p < 0.0001 for both) after multivariate adjustment for age, sex, body mass index, renal function, antihypertensive medications, and various parameters potentially influencing BP. Adjusted median DBP and aortic DBP also increased significantly from 74.3 mm Hg and 66.5 mm Hg (D1) to 86.9 mm Hg and 76.7 mm Hg, respectively (D10) (p < 0.001 for both). In a multivariate stepwise regression model, ARR emerged as the second most significant independent predictor (after age) of mean SBP and as the most important predictor of mean DBP in this patient cohort.
Conclusions Our results: 1) underline that the ARR affects BP well below a cutoff used for screening for primary aldosteronism; and 2) illustrate the importance of the ARR in modulating BP over a much wider range than is currently appreciated.
Aldosterone plays a key role in homeostatic control and maintenance of blood pressure (BP) by regulation of extracellular volume, vascular tone, and cardiac output.
Recent evidence has been interpreted to suggest that increased aldosterone concentrations might be a more common cause of elevated BP than previously thought. It has been claimed that approximately 10% to 23% of patients with resistant hypertension and 2% to 13% of unselected hypertensive patients have primary aldosteronism (1–3). However, the true prevalence of primary aldosteronism in the setting of arterial hypertension has been the subject of controversy (4–6).
There is an ongoing discussion whether these cases are true primary aldosteronism or the upper end of a continuum exceeding an arbitrary threshold beyond which the diagnosis of primary aldosteronism is made (5). Definite support for a major role of the renin-angiotensin-aldosterone system in the modulation of BP is the observation that two-thirds of patients with refractory hypertension have a low renin status and can be treated effectively with an aldosterone antagonist (7). Numerous patients who have an elevated aldosterone/renin concentration ratio (ARR) but not necessarily primary aldosteronism might thus respond to blockade of the mineralocorticoid receptor.
A key finding was that in normotensive individuals the plasma aldosterone concentration (PAC) is predictive for the subsequent development of sustained hypertension (8). Recently, Meneton et al. (9) showed that in addition to high plasma aldosterone low renin levels precede the occurrence of hypertension in middle-aged Caucasians. Moreover, a significant positive association between ARR and both risk and progression of incident hypertension was reported in normotensive subjects (10). In a community-based sample a recent study further found a positive correlation between the ARR and various measures of arterial stiffness (11). Toward this, the ARR was positively associated with pulse wave velocity in young normotensive healthy adults, indicating that relative aldosterone excess might affect arterial remodeling and precede BP rise as a result of increased vascular stiffness (12). Furthermore, Lim et al. (13) demonstrated a correlation between the ARR and exercise, office, and 24-h ambulatory BP in 119 individuals adverting to a reduced peripheral vascular compliance due to inappropriate aldosterone activity.
Low-renin essential hypertension and idiopathic hyperaldosteronism were proposed to represent 2 ends of a continuum with a relative excess of aldosterone for a given level of renin (14,15). Important limitations in our understanding include the difficulties of identifying a renin level as “low” and of comprehending the mechanisms that drive the activation of the adrenal or extra-adrenal renin-angiotensin-aldosterone system. At present, the relative importance for adrenal aldosterone production of circulating angiotensin II concentrations or other factors remains elusive (16). Finally, there is currently no agreement on the true cutoff value that suggests a diagnosis of primary aldosteronism.
The aim of the present study in a large cross-sectional cohort of patients was to evaluate the impact of a relative aldosterone excess, expressed by an elevated ARR on peripheral and central BP measurements in an effort to better understand the role of the renin-angiotensin-aldosterone system in determining the level of BP.
The LUdwigshafen RIsk and Cardiovascular Health Study is an ongoing prospective cohort study of Caucasians, with and without cardiovascular disease at baseline, investigating risk factors for coronary artery disease and mortality. The design and selection criteria of the LUdwigshafen RIsk and Cardiovascular Health Study have been described previously (17). The study was approved by the Ethics Committee at the Ärztekammer Rheinland-Pfalz, Germany. Informed written consent was obtained from each of the participants.
All individuals enrolled underwent coronary angiography in a tertiary care medical center and had to present in a stable clinical condition with the exception of acute coronary artery syndrome. Individuals with major concomitant noncardiovascular diseases or a history of malignancy were excluded.
After exclusion of 29 patients (0.95%) taking mineralocorticoid receptor blocker or the diuretic amiloride and another 49 patients for whom aortic pressure values were not available, 3,056 individuals (mean age 62.5 years; 31.9% women) remained in the analysis.
According to the JNC VII report (Seventh Report of the Joint National Committee for Prevention, Detection, Evaluation, and Treatment of Hypertension) (BP <140/90 mm Hg and without antihypertensive medication), 173 (5.7%) participants were classified as normotensive, 2,219 (72.8%) were found to have elevated BP (>140/90 mm Hg irrespective of antihypertensive medication), and 2,037 of this group (91.8%) took at least 1 antihypertensive drug (18). Resistant hypertension, which was present in 32.8% of the subjects, was defined as BP >140/90 mm Hg or as >130/80 mm Hg in patients with diabetes or chronic kidney disease when 3 or more antihypertensive drugs, including a diuretic, were taken and/or participants with normal BP required 4 or more antihypertensive medications (2,18). Secondary causes of hypertension were considered on the basis of clinical aspects, blood electrolytes, free plasma catecholamines, cortisol, and cystatin C levels as a parameter of renal function. All patients were on a normal Western (sodium) diet. Assessment of daily physical activity was based on a “patient-friendly” questionnaire that classified the average daily life activities of study participants as follows: score 1 (bed rest), score 2 (mostly supine), scores 3 to 5 (not very active), scores 6 to 8 (normal domestic activities), scores 9 to 10 (physically demanding work or sports), score 11 (extremely athletic) (17).
Determination of BP
Brachial artery pressure values were measured with an automated oscillometric device (Omron MX4, Omron Health Care GmbH, Hamburg, Germany) after the patient had rested in the supine position for 10 min (17). At least 3 consecutive systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements were taken with a minimum interval of 30 s. Finally, only measurements conforming to the reproducibility criteria were entered into the database.
In addition, aortic pressure values (systolic and diastolic aortic pressure) were measured invasively during coronary angiography/cardiac catheterization.
Biomarker selection and clinical covariates
The standard laboratory methods used have been described previously (17). After an overnight fast, venous blood was sampled in the morning before coronary angiography between 8:00 amand 11:00 am, with the participants in supine position for 5 to 10 min before phlebotomy.
We measured 9 biomarkers (PAC, plasma renin concentration [PRC], angiotensin 2, C-reactive protein, cystatin C, plasma norepinephrine, plasminogen activator inhibitor-1 antigens, plasma cortisol, and N-terminal pro-brain natriuretic peptide [NT-pBNP]) representing key systems implicated in various pathogenetic aspects of hypertension (19,20).
Plasma aldosterone concentration (pg/ml; conversion to pmol/l: pg/ml × 2.774) was measured by radioimmunoassay (Active aldosterone/Diagnostic Systems Laboratories, Sinsheim, Germany). Overall correlation between the radioimmunoassay used and other commercially available assays ranges between 0.74 and 0.98 (21). The reference interval is given as 30 to 160 pg/ml (supine position).
Plasma renin concentration was determined by immunoradiometric assay (Active renin, Nichols Institute Diagnostics, San Juan, Capistrano, California). The conversion factor for PRC is based on a publication by Trenkel et al. (22) and is as follows: 1.67 μU/ml (= mU/l) renin equals 1 pg/ml (= ng/l) renin. The normal range is given as 4.2 to 45.6 pg/ml in upright position and as 3 to 28 pg/ml in supine position.
With regard to the intra-assay and interassay coefficients of variation of these assays we refer to a previous publication (17).
The following additional covariates with an impact on BP were included in our analysis models: mean heart rate, average daily physical activity, history of myocardial infarction, current smoking status, and body mass index. Finally, oral glucose tolerance test was performed in all subjects, and type 2 diabetes mellitus was diagnosed if plasma glucose was >1.25 g/l in the fasting state or >2.00 g/l 2 h after the glucose load or if participants were already receiving oral antidiabetic drugs or insulin.
The ARR was calculated as the PAC/PRC ratio (pg/ml/pg/ml) according to Trenkel et al. (22). An ARR >50 pg/ml/pg/ml was regarded as suggestive of primary aldosteronism, yielding a sensitivity and specificity of ARR of 89% and 96%, respectively (22). The ARR was modeled as a continuous ratio (with log-transformed values).
Because of the significant ARR sex difference, baseline characteristics for clinical and biochemical parameters are presented in sex-specific ARR quartiles (QUs). Categorical data are given as percentages, and continuous variables are given as medians with interquartile range. Skewed variables were log-transformed to achieve normal distribution and rechecked for normality with the Kolmogorov-Smirnov Test. Only these log-transformed variables were used in all of the following analyses.
Comparisons between ARR groups were performed with either the chi-square test for categorical data or analysis of variance (ANOVA) for continuous data. To better illustrate possible BP effects of ARR values over a broader range of data, we also categorized patients into deciles of ARR and again adjusted for important clinical confounders.
One-way ANOVA followed by Bonferroni post hoc test was used to compare mean systolic and diastolic peripheral as well as aortic BP values across deciles of ARR. The basic ANOVA model was adjusted for age and sex. In a second extended model we additionally adjusted for the following covariates: body mass index, current smoking status, antihypertensive medications (angiotensin-converting enzyme [ACE] inhibitors, angiotensin-2 receptor blockers (ARBs), beta blockers, calcium-channel blockers, diuretics, and nitrates), aspirin/nonsteroidal antirheumatic agent treatment, type 2 diabetes mellitus, history of myocardial infarction, mean heart rate, average daily physical activity, cystatin C, C-reactive protein, plasma norepinephrine, plasminogen activator inhibitor-1 antigens, plasma cortisol, and NT-pBNP levels.
Overall influence of a specific antihypertensive medication on ARR was calculated by 1-way ANOVA adjusted for age, sex, body mass index, use of other specific antihypertensive drugs, use of aspirin/nonsteroidal antirheumatic agent, SBP, sodium/potassium concentrations, and the other aforementioned risk factors and biomarkers.
Differences in mean PAC, PRC, angiotensin 2, plasma cortisol, norepinephrine, and NT-pBNP levels across sex-specific ARR deciles were calculated by multivariate adjusted 1-way ANOVA. Finally, multivariable stepwise regression analysis (backward elimination) was performed to identify important predictors of BP.
A 2-sided p value of <0.05 was considered statistically significant. Statistical analysis was performed with SPSS software version 16.0 (SPSS, Inc., Chicago, Illinois).
Overall, 98 participants (3.2% of the entire cohort, and 4.4% of the hypertensive subjects) demonstrated an ARR ≥50 pg/ml/pg/ml (accounting for 12.8% of patients in ARR QU4), a threshold value above which a screening test for primary aldosteronism was considered positive according to a study using the same renin assay system as in the present study (22). The PAC doubled from QU1 to QU4, whereas PRC increased by a factor of 10 from QU4 to QU1. Both peripheral median sBP and dBP increased by 14.7 mm Hg and 8.3 mm Hg with increasing QUs of ARR. Patients in the lowest ARR QU1 had a higher prevalence of comorbidities (as expressed by a higher Charlson comorbidity index), presence of cardiovascular disease, and type 2 diabetes mellitus and belonged on average to higher New York Heart Association functional classes than patients in other QUs. Patients in the high-renin ARR QU1 had higher angiotensin 2, NT-pBNP, and plasma norepinephrine and slightly lower plasma cortisol concentrations, whereas serum electrolytes were only marginally different between the respective groups.
In an attempt to better illustrate the effects of aldosterone levels and ARR on BP indexes, sex-adjusted deciles of aldosterone and ARR were formed comprising between 299 and 309 patients in each decile (Figs. 1Aand 1B). With regard to aldosterone deciles, there were only small but significant differences in both SBP and DBP values over a wide range of different multivariate adjusted absolute aldosterone concentrations. When aldosterone concentration was expressed relative to renin levels, however, mean SBP and DBP values were progressively higher across increasing ARR deciles.
In Table 3,2 different models illustrate the effects of a higher ARR on mean peripheral and aortic BP values. The inclusion of various clinical and functional data as well as data on various medications influencing BP did not appreciably alter the overall correlations. The absolute mean difference in peripheral SBP and DBP between ARR D1 and D10 was 24.2 mm Hg and 12.6 mm Hg, respectively. Exclusion of the 98 patients with an ARR ≥50 yielded a similar difference of 21.8 mm Hg and 11.6 mm Hg, respectively. A separate analysis included only patients without treatment with an ACE inhibitor and/or ARB (total n = 1713). Here, peripheral mean SBP and DBP values were higher by 19.5 mm Hg and 9.1 mm Hg, respectively, between the lowest and highest ARR category and were very similar to the findings for the overall cohort. Additional adjustments for serum sodium and potassium concentration in the respective models did not influence these results materially.
Figures 2Aand 2B demonstrate that the absolute concentration of PAC does not add to the information provided by the ARR. For every given QU of absolute PAC, the median BP was higher by a similar degree with rising ARR QU.
Patients were further categorized according to key indicators of renal (QU of cystatin C) and cardiac (QU of NT-pBNP levels) function, and there was the same relationship between ARR and both SBP as well as DBP. A similarly strong association between ARR and mean BP values was found in a subgroup analysis of 959 diabetic patients (data not shown).
Univariate correlation coefficients were highly significant for log PRC versus log angiotensin-2 (r = 0.553, p < 0.001), log PRC versus log PAC (r = 0.236, p < 0.001), and log angiotensin-2 versus log PAC (r = 0.233, p < 0.001). Again, exclusion of patients with ACE inhibitors as well as diuretics yielded similar results for all aforementioned correlation analyses. In general, patients taking diuretics had significantly higher PRC and PAC levels resulting in overall lower ARR values. The 5 most important predictors of log PAC in a multivariate adjusted model with the same confounders as in Figure 3(total R2of 21.8) were plasma cortisol, PRC, age, plasma norepinephrine levels, and SBP. Likewise, the 5 most important predictors of log renin levels (total R2value of 38.0) were SBP, NT-pBNP, ACE inhibitors, diuretics, and PAC (data not shown).
Stepwise multivariate linear regression analysis was performed to identify predictors of peripheral and central BP (Table 4).Age and ARR emerged as the strongest predictors for peripheral and aortic SBP, whereas for DBP, ARR was of greatest influence.
In Figure 3, relevant key elements of the renin-angiotensin-aldosterone system are superimposed graphically, together with changes seen in peripheral SBP values. One can appreciate that increasing ARR categories are accompanied by higher values of PAC and that marked increases in PRC are a major characteristic of lower ARR categories. The concentrations for PRC and PAC as well as angiotensin 2 are given as multivariate adjusted absolute levels.
The results of this study demonstrate that, across a broad range of ARR values, inappropriately elevated aldosterone levels exert a strong effect on BP values and constitute the most important and second-most important predictor of DBP and SBP, respectively. Because all patients underwent coronary angiography we also had the opportunity to measure central (aortic) BP indexes that reflect loading conditions on the myocardium and perfusion pressures of coronary arteries, renal arteries, and cerebral vasculature better than brachial BP. A similar relationship was found, as with peripheral BP, between ARR and central BP values. The size of the study population allowed us to form multiple categories of ARR. The results clearly illustrated that increasingly higher ARR values across deciles are paralleled by steadily and gradually higher values of peripheral mean BP, ranging from 127 to 151 mm Hg SBP and 74 to 87 mm Hg DBP, respectively. These data provide evidence that higher ARR values are paralleled by continuously and progressively higher BP values across a range from a high-renin to a low-renin state. We emphasize that no evidence of a BP plateau was found. With respect to the first and last ARR decile, however, the BP difference to the adjacent deciles was greater than for other interdecile BP differences. A potential reason for the greater BP difference between ARR deciles 9 and 10 might be the inclusion of some patients with primary aldosteronism. At the lower end of ARR categories, a potential reason might be inclusion of patients whose (very) high renin and low aldosterone levels might reflect strong aldosterone and renin responses to ACE inhibition and low BP values. However, excluding all patients who were taking ACE inhibitor and ARB treatment from the analysis did not change the relation between ARR and BP values. Patients without ACE inhibition had on average slightly lower BP levels, also suggesting that patients with higher BP were more likely to receive an ACE inhibitor.
At a given ARR, the level of absolute PAC was of comparably smaller relevance to BP values, indicating that patients at different absolute PAC concentrations could modulate PRC in a similar way. A raised ARR, by contrast, also often went along with PAC levels in the normal range. The multivariate adjusted relationship between PAC and BP was significant but could be markedly improved when PRC was included to form the ARR with PAC. Thus, an increase in sodium and water retention, leading to a volume-dependent BP increase and consequently increased renal perfusion and tubular sodium load, seems to decrease PRC at different individual levels of PAC. Patients with low renin levels could be found in both “low” as well as “high” PAC categories, and overall the data indicate that PRC is a BP “feedback-sensor” and a better indicator of individual aldosterone sensitivity than absolute PAC itself. Of note is yet another finding showing that, irrespective of renal and cardiac function (categories formed by cystatin C and NT-pBNP levels), the correlation between ARR and BP was maintained at all stages but with the limitation that the results can only be generalized to patients belonging to Kidney Disease Outcome Quality Initiative and New York Heart Association functional classes I to III, due to only a few patients belonging to higher categories. It seems important in this context to stress that, regardless of whether unadjusted or multivariate adjusted models for calculation of the effects of ARR on BP were used, very similar relationships could be obtained; this suggests that the association between relative mineralocorticoid excess and BP is important. We cannot make a valid statement regarding effects of ARR on BP within a normotensive cohort, but an ARR–DBP relationship was evident over a range of ARR ratios below values of 80 mm Hg, indicating that such an effect is at work and reaches well into the normotensive BP range.
Of note, at the lower end of the ARR categories, the marked increase in PRC was paralleled by a rise in circulating angiotensin 2 levels but not, however, by a corresponding increase in PAC. There might be several explanations for the 10-fold higher PRC of ARR decile 1 compared with decile 10; these include an elevated sympathetic outflow as well as numerous different systemic and intrarenal factors that often accompany severe illness (23). In line with this explanation is the observation that patients belonging to the high renin group also had higher plasma norepinephrine levels compared with patients in higher ARR categories. It seems interesting that a significant elevation of renin leads to a respective rise in angiotensin 2 but does not translate into increased PAC. We can exclude antihypertensive medications and cardiac or renal dysfunction as likely causes, because controlling for these did not change the relationship substantially. The data suggest that, with marked increases in PRC, the adrenal cortex becomes less responsive toward angiotensin 2 stimulation.
There is little knowledge on possible mechanisms leading to a relative excess of aldosterone secretion. Regulation of adrenal aldosterone synthesis is complex and depends on a variety of intra- and extra-adrenal stimulatory and inhibitory factors (24,25).
In animal models a modest increased expression of the aldosterone synthase, the enzyme that catalyzes the last step of aldosterone synthesis, makes BP more sensitive to salt (26). Therefore, an inherited increased aldosterone synthase expression might contribute to hypertension in humans with chronic dietary salt-loading independent of the renin-angiotensin system. Newton-Cheh et al. (10) recently reported in more than 3,300 individuals from the Framingham cohort that ARR was heritable (h2= 40) and that genome-wide genotyping might further identify variants that influence ARR. It was also suggested that aldosterone secretion is increased due to higher sensitivity toward angiotensin 2. Data of the present study, however, argue against that because with increasing ARR deciles not only renin but also angiotensin 2 levels declined, thus suggesting that the negative feedback loop between aldosterone and renin was intact. Whether aldosterone excess is primarily due to autonomous secretion or due to other stimulatory factors must remain subject to future research. We noticed a significant increase of plasma cortisol across ARR categories, and patients belonging to the highest plasma cortisol QU had a multivariate adjusted PAC that was 61% above that of QU1 (p < 0.001). Chronic adrenal stimulation by adrenal corticotropic hormone, also reflected by elevated plasma cortisol levels, was implicated as playing a critical role in maintenance and modulation of aldosterone synthesis (27). Connell et al. (27) reported that chronically elevated plasma cortisol levels are able to alter ARR by acting as an adrenal cortex growth factor, leading to adrenal hyperplasia and an increased sensitivity to potassium and angiotensin-2.
Study limitations and strengths
This study has some limitations. Because our patient cohort was composed exclusively of elderly Caucasian participants, generalization to other ethnicities and younger individuals is not possible. The impact of various classes of antihypertensive medications on ARR in our cohort was presumably small, although it might have interfered to some degree with the interpretation of our results. Previous studies, however, proved that ARR is an effective screening tool even in patients receiving antihypertensive treatment (28,29). We only had a single measurement of ARR and 3 to 5 BP measurements available. Another limitation is that ARR was measured on a random and not on a standardized sodium diet. Finally, the cross-sectional design of our observational study precludes conclusions with respect to causality.
Strengths of the study include its large size and the high degree of clinical and biochemical characterization of the patients. We had multiple key pathological parameters at hand that could be included in multivariate models. Furthermore, with respect to the measurement of renin and aldosterone levels, there is great controversy on different assay techniques, laboratory conditions, and influence of confounding variables. We chose the direct determination of PRC, an approach that provides advantages in comparison with more commonly used assays measuring plasma renin activity (29). Plasma renin concentration exhibits better diagnostic accuracy, provides interlaboratory reproducibility, requires fewer pre-analytical prerequisites, and is known to correlate well with plasma renin activity measured by enzyme kinetic assays (22,29–31).
Clinical Implications and Conclusions
The results of the present study suggest that overproduction of aldosterone and its associated effects on sodium and water retention as well as alterations of vascular function and structure are a major determinant of peripheral and—so far not appreciated—central BP. Because aldosterone has been shown to promote vascular reactivity, inflammation, oxidative stress, tissue remodelling, and endothelial dysfunction, it is plausible to assume that inappropriate aldosterone concentrations have implications far beyond BP (32). The association between BP and the ARR is evident even at borderline hypertensive BP values, and implies that a varying degree of relative hyperaldosteronism is common among hypertensive patients. One important consequence of the present study might be that relative hyperaldosteronism provides a rationale for wider use of mineralocorticoid receptor blockade, especially when other antihypertensive drugs are insufficient for the control of BP. Finally, more research is needed to better understand the mechanisms controlling aldosterone secretion and to make mineralocorticoid blockade a safe treatment option.
The authors thank the participants of the LUdwigshafen RIsk and Cardiovascular Health Study, the study team and the laboratory staff at the Ludwigshafen General Hospital, and the Universities of Freiburg and Ulm, Germany. The authors also thank the German registration offices and local public health departments for their assistance. The authors also thank Eugenia Lamont for her critical review of the manuscript.
The LUdwigshafen RIsk and Cardiovascular Health Study has received unrestricted grants from Sanofi-Aventis, Roche, Dade Behring, and AstraZeneca.
- Abbreviations and Acronyms
- angiotensin-converting enzyme
- analysis of variance
- angiotensin-2 receptor blocker
- aldosterone/renin concentration ratio
- blood pressure
- diastolic blood pressure
- N-terminal pro-brain natriuretic peptide
- plasma aldosterone concentration
- plasma renin concentration
- systolic blood pressure
- Received July 14, 2009.
- Revision received October 30, 2009.
- Accepted January 6, 2010.
- American College of Cardiology Foundation
- Lieb W.,
- Larson M.G.,
- Benjamin E.J.,
- et al.
- Fisher N.D.,
- Hurwitz S.,
- Ferri C.,
- Jeunemaitre X.,
- Hollenberg N.K.,
- Williams G.H.
- Ehrhart-Bornstein M.,
- Lamounier-Zepter V.,
- Schraven A.,
- et al.
- Kathiresan S.,
- Gona P.,
- Larson M.G.,
- et al.
- Schirpenbach C.,
- Seiler L.,
- Maser-Gluth C.,
- Beuschlein F.,
- Reincke M.,
- Bidlingmaier M.
- Volpe M.,
- Savoia C.,
- De Paolis P.,
- Ostrowska B.,
- Tarasi D.,
- Rubattu S.
- Spat A.,
- Hunyady L.
- Schwartz G.L.,
- Turner S.T.
- Perschel F.H.,
- Schemer R.,
- Seiler L.,
- et al.
- Unger N.,
- Lopez Schmidt I.,
- Pitt C.,
- et al.