Xue-Ming Wu

Adrenalectomy improves increased carotid intima-media thickness and arterial stiffness in patients with aldosterone producing adenoma.

CONTEXT Primary aldosteronism (PA) is the most frequent cause of secondary hypertension, and is associated with more prominent vascular stiffness and atherosclerosis. However, the effect of adrenalectomy on reversibility of vascular damage is unclear. OBJECTIVE Our objective was to investigate the vascular changes and possibility of reversibility after adrenalectomy in PA patients. METHODS We prospectively analyzed 20 patients with aldosterone producing adenoma (APA) that received adrenalectomy from October 2006 to December 2008 and 21 patients with essential hypertension (EH) were enrolled as the control group. Carotid intima media thickness (CIMT) measurement by B-mode ultrasound of the right common carotid arteries and pulse wave velocity (PWV) measurement including brachial-ankle PWV (baPWV) and heart-ankle PWV (haPWV) were performed in both groups. The follow-up measurements were performed one-year after adrenalectomy in APA group. RESULTS APA patients had significantly higher diastolic blood pressure, plasma aldosterone concentration (PAC) and aldosterone-renin ratio (ARR), but lower serum potassium level and plasma renin activity (PRA) than EH patients. APA patients had significantly higher CIMT (0.64±0.13 vs. 0.53±0.10 mm, p=0.006), higher baPWV (1589±296 vs. 1405±187 cm/s, p=0.024) and haPWV (1095±150 vs. 987±114 cm/s, p=0.013) comparing with EH patients. One-year after adrenalectomy, CIMT reduced significantly from 0.64±0.13 mm to 0.59±0.14 mm (p=0.014), and baPWV and haPWV also showed significant reduction (baPWV, 1589±296 to 1463±188 cm/s, p=0.035; haPWV, 1095±150 to 1017±109 cm/s, p=0.019). CONCLUSION APA patients have higher degree of early atherosclerosis and vascular stiffness. Adrenalectomy not only corrects the high blood pressure and biochemical parameters but also reverse adverse vascular change in APA patients.

Adrenalectomy reverses myocardial fibrosis in patients with primary aldosteronism.

Objective: Primary aldosteronism is the most frequent cause of secondary hypertension and is associated with more prominent left ventricular hypertrophy and increased myocardial fibrosis. However, the reversibility of cardiac fibrosis is still unclear. Our objective was to investigate myocardial fibrosis in primary aldosteronism patients and its change after surgery. Method: We prospectively analyzed 20 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from December 2006 to October 2008 and 20 patients with essential hypertension were enrolled as the control group. Plasma carboxy-terminal propeptide of procollagen type I (PICP) determination and echocardiography including ultrasonic tissue characterization by cyclic variation of integrated backscatter (CVIBS) were performed in both groups and 1 year after operation in the APA group. Results: APA patients had significantly higher SBP and DBP, higher plasma aldosterone concentration (PAC), higher aldosterone–renin ratio (ARR), lower serum potassium levels, and lower plasma renin activity (PRA) than patients with essential hypertension. In echocardiography, APA patients had a higher left ventricular mass index than essential hypertension patients. APA patients had significantly lower CVIBS (6.2 ± 1.5 vs. 8.7 ± 2.0 dB, P < 0.001) and higher plasma PICP levels (107 ± 27 vs. 85 ± 24 &mgr;g/l, P = 0.009) than essential hypertension patients. In the correlation study, CVIBS is correlated with log-transformed PRA and log-transformed ARR and PICP is correlated with log-transformed PRA, log-transformed PAC, and log-transformed ARR. One year after adrenalectomy, CVIBS increased significantly (6.2 ± 1.5 to 7.3 ± 1.7 dB, P = 0.033) and plasma PICP levels decreased (107 ± 27 vs. 84 ± 28 &mgr;g/l, P = 0.026). Conclusion: Increases in collagen content in the myocardium of APA patients may be reversed by adrenalectomy.

A propensity score-based case-control study of renin-angiotensin system gene polymorphisms and diastolic heart failure

Angiotensin II plays an important role in diastolic heart failure (DHF). However, genetic studies of DHF are scarce in the literature. We hypothesized that RAS genes might be the susceptible genes for DHF and conducted a propensity score-based case-control study to prove this hypothesis. A total of 666 subjects (285 diagnosed with DHF confirmed by echocardiography and 381 without diastolic dysfunction) were recruited. Genotyped were: the angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism; the T174M, M235T, G-6A, A-20C, G-152A and G-217A polymorphisms of the angiotensinogen (AGT) gene; and the A1166C polymorphisms of the angiotensin II type I receptor (AT1R) gene. Propensity scores (PS) were used to find patients with and without DHF with equalized characteristics. We also assembled another set of PS matched groups for all characteristics except left ventricular mass (LVM) to detect the genetic association with DHF through the effect of left ventricular hypertrophy. PS matched 210 patients with DHF to 210 without. In a single-locus analysis, the odds ratios (ORs) for DHF were significant with the ACE DD genotype (OR=1.30, 95% CI=1.13-1.49, permuted P=0.003) and the AT1R 1166 CC genotype (OR=2.61, 95% CI=1.52-4.45, permuted P<0.001). Significant gene-gene interaction between the two genes was also detected. However, the ACE gene effect was diminished if LVM was not controlled in the propensity scores. We concluded that genetic variants in the RAS genes may determine individual risk to develop DHF through different pathways. Concomitant presence of ACE DD and AT1R 1166 CC genotypes synergistically increased the predisposition to DHF.

Aldosterone induced galectin-3 secretion in vitro and in vivo: from cells to humans.

Context Patients with primary aldosteronism are associated with increased myocardial fibrosis. Galectin-3 is one of the most important mediators between macrophage activation and myocardial fibrosis. Objective To investigate whether aldosterone induces galectin-3 secretion in vitro and in vivo. Methods and Results We investigated the possible molecular mechanism of aldosterone-induced galectin-3 secretion in macrophage cell lines (THP-1 and RAW 264.7 cells). Aldosterone induced galectin-3 secretion through mineralocorticoid receptors via the PI3K/Akt and NF-κB transcription signaling pathways. In addition, aldosterone-induced galectin-3 expression enhanced fibrosis-related factor expression in fibroblasts. We observed that galectin-3 mRNA from peripheral blood mononuclear cells and serum galectin-3 levels were both significantly increased in mice implanted with aldosterone pellets on days 7 and 14. We then conducted a prospective preliminary clinical study to investigate the association between aldosterone and galectin-3. Patients with aldosterone-producing adenoma had a significantly higher plasma galectin-3 level than patients with essential hypertension. One year after adrenalectomy, the plasma galectin-3 level had decreased significantly in the patients with aldosterone-producing adenoma. Conclusion This study demonstrated that aldosterone could induce galectin-3 secretion in vitro and in vivo.

Reversible heart rhythm complexity impairment in patients with primary aldosteronism

Excess aldosterone secretion in patients with primary aldosteronism (PA) impairs their cardiovascular system. Heart rhythm complexity analysis, derived from heart rate variability (HRV), is a powerful tool to quantify the complex regulatory dynamics of human physiology. We prospectively analyzed 20 patients with aldosterone producing adenoma (APA) that underwent adrenalectomy and 25 patients with essential hypertension (EH). The heart rate data were analyzed by conventional HRV and heart rhythm complexity analysis including detrended fluctuation analysis (DFA) and multiscale entropy (MSE). We found APA patients had significantly decreased DFAα2 on DFA analysis and decreased area 1–5, area 6–15, and area 6–20 on MSE analysis (all p < 0.05). Area 1–5, area 6–15, area 6–20 in the MSE study correlated significantly with log-transformed renin activity and log-transformed aldosterone-renin ratio (all p < = 0.01). The conventional HRV parameters were comparable between PA and EH patients. After adrenalectomy, all the altered DFA and MSE parameters improved significantly (all p < 0.05). The conventional HRV parameters did not change. Our result suggested that heart rhythm complexity is impaired in APA patients and this is at least partially reversed by adrenalectomy.

Comparison the prognostic value of galectin-3 and serum markers of cardiac extracellular matrix turnover in patients with chronic systolic heart failure.

Background: Galectin-3 (Gal-3) shows the ability of survival prediction in heart failure (HF) patients. However, Gal-3 is strongly associated with serum markers of cardiac extracellular matrix (ECM) turnover. The aim of this study is to compare the impact of Gal-3 and serum markers of cardiac ECM turnover on prognostic prediction of chronic systolic HF patients. Methods: Serum Gal-3, brain natriuretic peptide (BNP), extracellular matrix including type I and III aminoterminal propeptide of procollagen (PINP and PIIINP), matrix metalloproteinase-2, 9 (MMP-2, 9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were analyzed. Cox regression analysis was used for survival analysis. Results: A total of 105 (81 male) patients were enrolled. During 980±346 days follow-up, 17 patients died and 36 episodes of HF admission happened. Mortality of these patients was significantly associated with the log PIIINP (β= 15.380; P=0.042), log TIMP-1(β= 44.530; P=0.003), log MMP-2 (β= 554.336; P<0.001), log BNP (β= 28.273; P=0.034). Log Gal-3 (β= 7.484; P=0.066) is borderline associated with mortality. Mortality or first HF admission of these patients was significantly associated with the log TIMP-1(β= 16.496; P=0.006), log MMP-2 (β= 221.864; P<0.001), log BNP (β= 5.999; P=0.034). Log Gal-3 (β= 4.486; P=0.095) only showed borderline significance. In several models adjusting clinical parameters, log MMP-2 was significantly associated with clinical outcome. In contrast, log Gal-3 was not. Conclusion: The prognostic strength of MMP-2 to clinical outcome prediction in HF patients is stronger than Gal-3.

Circulating tissue inhibitor of matrix metalloproteinase-1 is associated with aldosterone-induced diastolic dysfunction.

Objective: To test if collagen markers are associated with aldosterone-induced diastolic dysfunction. Background: Although primary aldosteronism is associated with more prominent cardiac remodeling and diastolic dysfunction, the reversibility of diastolic function is unclear. In addition, there is no known biomarker associated with aldosterone-induced diastolic dysfunction. Methods: We enrolled 27 patients with aldosterone-producing adenoma (APA) preparing for adrenalectomy, and 27 patients with essential hypertension prospectively from October 2006 to March 2010 at a tertiary referral center. Plasma matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were measured, and echocardiography including tissue Doppler images was performed in both groups and 1 year after receiving adrenalectomy in the APA group. Results: The baseline plasma TIMP-1 level (88.4 ± 38.7 vs. 63.6 ± 32.5 ng/ml; P = 0.014), left ventricular mass index (LVMI), and E/E’ ratio (11.5 ± 2.9 vs. 9.0 ± 2.1; P < 0.001) were significantly higher in the APA group. The baseline plasma TIMP-1 level significantly correlated with the E/E’ ratio, LVMI, interventricular septum, and left atrial diameter. The plasma MMP-2 level did not correlate with the left ventricular structure parameters, except for interventricular septum thickness. After adrenalectomy, LVMI and E/E’ ratio improved significantly. The postadrenalectomy plasma TIMP-1 levels, but not MMP-2 levels, also decreased. The change of plasma TIMP-1 levels was negatively associated with the postadrenalectomy E/E’ ratio after adjustment for age, sex, BMI, and mean blood pressure (&bgr;-coefficient = − 3.6, P = 0.004). Conclusion: Excess of aldosterone induces cardiac diastolic dysfunction, which is reversible by adrenalectomy. TIMP-1 is associated with the aldosterone-induced diastolic dysfunction.

Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation: From Clinical to Bench Studies

Aldosterone induces myocardial fibrosis. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a key factor of myocardial fibrosis. This study tested the hypothesis that aldosterone induces TIMP-1 expression and contributes to the fibrotic process. We prospectively enrolled 54 patients with primary aldosteronism, and measured plasma TIMP-1 and echocardiographic parameters. In the cell study, we investigated the possible molecular mechanism by which aldosterone induces TIMP-1 secretion and the effects on collagen accumulation. In the animal study, we measured serum TIMP-1 levels, cardiac TIMP-1 levels, and cardiac structure in an aldosterone infusion mouse model using implantation of aldosterone pellets. In patients with primary aldosteronism, plasma TIMP-1 was correlated with 24-hour urinary aldosterone, left ventricular mass, and impairment of left ventricular diastolic function. In human cardiac fibroblasts, TIMP-1 protein and mRNA expressions were significantly increased by aldosterone through the glucocorticoid receptor/PI3K/Akt/nuclear factor-&kgr;B pathway. TIMP-1 small-interfering RNA significantly reduced aldosterone-induced collagen accumulation, and aldosterone did not alter the levels of collagen1a1 or matrix metalloproteinase-1 mRNA. The aldosterone-induced TIMP-1 expression was inversely related to matrix metalloproteinase-1 activity. Furthermore, in the animal model, the serum and cardiac levels of TIMP-1 were significantly elevated in the mice that received aldosterone infusion. This elevation was blocked by RU-486 but not by eplerenone, suggesting that the effect was through glucocorticoid receptors. In a long-term aldosterone infusion model, serum TIMP-1 was associated with serum aldosterone level, cardiac structure, and fibrosis. In conclusion, aldosterone induced TIMP-1 expression in vivo and in vitro. This increased TIMP-1 expression resulted in enhanced collagen accumulation via the suppression of matrix metalloproteinase-1 activity.

The relation among aldosterone, galectin-3, and myocardial fibrosis: a prospective clinical pilot follow-up study.

Primary aldosteronism has been associated with myocardial fibrosis, and is the most common cause of secondary hypertension. We previously showed that aldosterone can induce the secretion of galectin-3. The aim of this study was to investigate the association between myocardial fibrosis and plasma galectin-3 level in patients with primary aldosteronism. We prospectively analyzed 11 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from December 2006 to October 2008, and 17 patients with essential hypertension as controls. Levels of plasma galectin-3 were determined in both groups, and both groups underwent echocardiography with cyclic variations of integrated backscatter (CVIBS) to characterize tissue initially and 1 year after surgery in the APA group. Diastolic blood pressure, concentration of plasma aldosterone and aldosterone-renin ratio were significantly higher, and serum potassium level and plasma renin activity significantly lower in the APA group compared to the controls. In addition, left ventricular mass index was significantly higher and CVIBS significantly lower in the APA group (7.3±2.0 vs 9.2±1.7 dB, p=0.015). Furthermore, the concentration of plasma galectin-3 was significantly higher in the APA group (2.1±0.9 vs 1.1±0.6 ng/mL, p=0.005) compared to the controls. CVIBS was correlated to plasma galectin-3 level. In the APA group, CVIBS increased significantly (7.3±2.0 to 9.2±2.4 dB, p=0.032) and plasma galectin-3 decreased (2.1±0.9 to 1.2±0.6, p=0.049) 1 year postadrenalectomy. The patients with APA had increased myocardial fibrosis, and this was associated with a higher plasma galectin-3 level. Both increased myocardial fibrosis and plasma galectin-3 level recovered at least partially after adrenalectomy. Trial registration number 200611031R; Results.

Aldosterone Impairs Vascular Smooth Muscle Function: From Clinical to Bench Research

CONTEXT The effect of aldosterone on vascular smooth muscle cell function is still unclear. One method to measure vascular smooth muscle cell function is endothelial-independent vascular dilation, for which the key factor is sarcoplasmic reticulum calcium adenosine triphosphatase (SERCA). OBJECTIVE Our objective was to investigate the effect of aldosterone on vascular smooth muscle cell function and SERCA regulation. DESIGN We prospectively analyzed 35 patients with primary aldosteronism (PA; 32 patients with aldosterone-producing adenoma and three patients with idiopathic hyperaldosteronism) and 30 patients with essential hypertension (EH) who were enrolled as the control group. Flow and nitrate-mediated dilation were performed in both groups and 1 year after adrenalectomy in the patients with aldosterone-producing adenoma. In addition, we investigated the effect of aldosterone on SERCA regulation in human aortic smooth muscle cells. SETTING This study took place in an academic clinical research center. PARTICIPANTS Participants included 35 patients with PA and 30 patients with EH. INTERVENTIONS Adrenalectomy was undertaken in patients with aldosterone-producing adenoma. RESULTS The PA patients had significantly lower flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) values than the patients with EH (FMD: 13 ± 6 vs 16 ± 4; NMD: 16 ± 6 vs 19 ± 5; both P < .05). FMD/NMD were significantly correlated with log 24 hour-urine aldosterone (FMD: r = -0.287, P = .048; NMD: r = -0.402, P = .005) but not blood pressure. The impaired FMD and NMD values were significantly restored 1 year after adrenalectomy (FMD: 11 ± 4 to 19 ± 7; NMD: 15 ± 6 to 21 ± 6; both P < .01). Under confocal microscopy, aldosterone was shown to suppress the expression of SERCA2a of human aortic smooth muscle cells. Aldosterone significantly suppressed the expression of SERCA2a from 10(-8) M in mRNA and protein levels. This suppression was through down-regulation of mineralocorticoid receptor dependent mitochondrial transcription factors A and B2. CONCLUSIONS Aldosterone impairs vascular smooth muscle cell function and suppresses SERCA 2a expression.