Effect of atorvastatin on plasma levels of asymmetric dimethylarginine in patients with non-ischaemic heart failure

BACKGROUND: Elevated plasma levels of asymmetric dimethylarginine (ADMA), an endothelial nitric oxide synthase (eNOS) inhibitor, may contribute to endothelial dysfunction in chronic heart failure (CHF). Since statins upregulate eNOS and ameliorate endothelial dysfunction in non-ischaemic CHF, we hypothesized that this may be in part through modification of ADMA. AIM: To evaluate the effect of atorvastatin on the relationship between ADMA and endothelial function in non-ischaemic CHF. METHODS: Twenty-four patients with CHF (ejection fraction <40%, New York Heart Association Functional Classes II and III) were randomised to atorvastatin treatment (40 mg) or placebo once daily for 6 weeks in a double-blinded, placebo-controlled crossover study. Plasma ADMA and l-arginine levels were measured by HPLC. Endothelial function was assessed by flow-mediated dilatation and invasive forearm plethysmography. RESULTS: Post-statin therapy, endothelial function was improved (p<0.05) independent of LDL-cholesterol reductions, but no changes were observed in ADMA levels or the l-arginine to ADMA ratio. There was a trend for ADMA to inversely correlate with endothelial function at baseline. CONCLUSIONS: Short-term atorvastatin treatment in non-ischaemic CHF improves endothelial function but has no effect on ADMA or the l-arginine to ADMA ratio. Our finding suggests that the observed statin-induced improvements in endothelial function are likely mediated via alternative pathways.     

Dietary composition as a determinant of plasma asymmetric dimethylarginine in subjects with mild hypercholesterolemia

Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide synthase inhibitor that participates in the regulation of vasodilatory function and is also linked to hypertension, whereas its stereoisomere, symmetric dimethylarginine (SDMA), is biologically inactive. Dietary components influence vascular functions and a high-fat meal seems to increase postprandial plasma ADMA levels. However, it has not been published whether diet influences plasma ADMA levels. In this study, we investigated the impact of diet on plasma ADMA and SDMA levels. Thirty-four mildly hypercholesterolemic, otherwise healthy women (n = 14) and men (n = 20) with a mean age of 46.2 years (range, 35 to 62 years) participated in the study. The subjects were examined twice at intervals of 2 months. Seven-day food records were used to analyze diet and alcohol intake. ADMA was measured by using high-performance liquid chromatography (HPLC)-tandem mass spectrometry. In a multivariate analysis (R2 = 0.20, P < .002), low amount of energy received from carbohydrates (r = -0.31, P = .009) and high plasma triglycerides (r = 0.30, P = .01) were predictors of high ADMA plasma levels. Alcohol drinkers had higher plasma ADMA concentrations than abstainers (0.50 +/- 0.13 v 0.42 +/- 0.11 micromol/L, P = .04). Plasma ADMA correlated with systolic (r = 0.60, P = .005) and diastolic blood pressure (r = 0.53, P = .02) in abstainers but not in alcohol drinkers. Plasma SDMA was not associated with any dietary components or with blood pressure. In conclusion, a high amount of dietary carbohydrates is strongly associated with low levels of plasma ADMA. Concentration of ADMA in plasma seems to be higher in alcohol drinkers than in abstainers.     

Serum asymmetric dimethylarginine levels in diabetic patients with neuropathy

Objective

The goal of our study was to evaluate the role of asymmetric dimethylarginine (ADMA) in patients with diabetic neuropathy.

Materials and methods

In this study, 58 diabetic patients and 26 healthy volunteers were included. In both groups ADMA measurements were performed together with other biochemical examinations. Nerve conduction studies and Neuropathy Symptom Score (NSS) were administered to the diabetic patients.

Results

ADMA levels were found significantly higher in diabetic patients compared to the control group (p = 0.0001). However, ADMA levels were not statistically significant between diabetic patients with neuropathy and without neuropathy (p = 0.86 and p = 0.47).

Conclusion

These results demonstrate that there is not any significant relationship between ADMA and diabetic neuropathy.     

Effect of rosuvastatin on low-density lipoprotein cholesterol in patients with hypercholesterolemia

Rosuvastatin is a new, synthetic, orally active statin, with marked low-density lipoprotein (LDL) cholesterol-lowering activity. We conducted 2 dose-ranging studies. In the first study, after a 6-week dietary run-in, 142 moderately hypercholesterolemic patients were randomized equally to receive double-blind placebo or rosuvastatin 1, 2.5, 5, 10, 20, or 40 mg or open-label atorvastatin 10 or 80 mg once daily for 6 weeks; in the second study, conducted to extend the rosuvastatin dose range, 64 patients were randomized to double-blind, once-daily placebo or rosuvastatin 40 or 80 mg (1:1:2 ratio) for 6 weeks. Data from both studies were combined for analysis of lipid effects. No statistical comparison of atorvastatin arms with placebo or rosuvastatin was performed. Rosuvastatin was associated with highly significant dose-dependent reductions in LDL cholesterol compared with placebo (p <0.001); decreases ranged from 34% (1 mg) to 65% (80 mg). Linear regression analysis indicated an additional 4.5% LDL cholesterol reduction for each doubling of the rosuvastatin dose. Across the dose range, approximately 90% of LDL cholesterol reduction occurred within the first 2 weeks of treatment. Significant, dose-dependent reductions in total cholesterol and apolipoprotein B with rosuvastatin were also observed (p <0.001). High-density lipoprotein cholesterol increases and triglyceride reductions were consistently observed and statistically significant at some dose levels. All lipid ratios were significantly reduced at all rosuvastatin dose levels (p <0.001). Adverse events were similar across placebo and active treatments. No significant increases in alanine aminotransferase or creatine kinase were seen in any patient. Over 6 weeks, rosuvastatin produced large, rapid, dose-dependent LDL cholesterol reductions and was well tolerated in hypercholesterolemic patients.     

Elevated levels of plasma homocyst(e)ine and asymmetric dimethylarginine in elderly patients with stroke

Menopause is accompanied by changes in lipoprotein particles that include an increase in density of low density lipoproteins (LDL) and high density lipoproteins (HDL) particles. The effect of 3 months of oral hormone replacement therapy (HRT) on lipoprotein particle size in postmenopausal women who were randomized to (1) estrogen replacement therapy (ERT) alone (either 17beta-estradiol (1 mg) or conjugated equine estrogens (CEE) (0.625 mg); (2) combination therapy (17beta-estradiol plus medroxyprogesterone acetate (MPA) or CEE plus MPA); and (3) placebo were examined. Lipoprotein subclass concentrations and particle size were quantified by nuclear magnetic resonance spectroscopy (NMR). Combination HRT resulted in significant (P=0.002) increases in HDL particle size as compared with those on placebo formulations or ERT alone. Women assigned to combined HRT had lower concentrations of smaller HDL particles after 3 months (P=0.005) and higher concentrations of larger HDL particles (P=0.02), whereas women assigned to ERT or placebo experienced non-significant changes. In summary, combined HRT increases HDL particle size by altering concentrations of the smallest and largest HDL subspecies.     

Asymmetric dimethylarginine plasma concentrations and L-arginine/asymmetric dimethylarginine ratio in patients with slow coronary flow

OBJECTIVE: Elevated levels of nitric oxide synthase inhibitor, asymmetric dimethylarginine (ADMA) is considered to be a marker of endothelial dysfunction and increased risk of cardiovascular disease. Recent reports have implicated endothelial dysfunction as an underlying pathophysiological mechanism of slow coronary flow (SCF) phenomenon. Accordingly, we investigated plasma L-arginine, ADMA concentrations and L-arginine/ADMA ratio in patients with SCF in comparison with participants having normal coronary flow. METHODS: We measured plasma levels of L-arginine and ADMA by high-performance liquid chromatography in 31 participants with SCF and 31 age and sex matched control participants with normal coronary flow. Coronary flow was quantified using the thrombolysis in myocardial infarction (TIMI) frame count method. RESULTS: The patients with SCF were detected to have significantly higher concentrations of plasma ADMA (P=0.006) and lower L-arginine/ADMA ratio compared with participants with normal coronary flow (P=0.002). In addition, both ADMA and L-arginine/ADMA ratio were significantly correlated with mean TIMI frame count and TIMI frame count for each coronary artery in patients with SCF and multivariate regression analysis identified plasma ADMA as an independent predictor for SCF. In the receiver operator characteristics curve analysis, patients with SCF were detected by plasma ADMA level with a sensitivity, specificity of 64.5%, 74.2%, at a cut-off of >2.4 micromol/l and L-arginine/ADMA ratio with a sensitivity, specificity of 77.4%, 67.7% at a cut-off of <36.6. CONCLUSION: Our findings provide evidence to support the hypothesis that endothelial dysfunction may be an important factor in the pathogenesis of SCF.     

瑞舒伐他汀在高龄老年高胆固醇血症患者的应用

目的:评价瑞舒伐他汀治疗老年人高胆固醇血症的疗效及安全性。方法:对62例老年高胆固醇血症患者使用瑞舒伐他汀治疗,比较治疗前后血脂、肝功、肌酸磷酸肌酶、肌酐等的变化。结果:老年高胆固醇血症患者使用瑞舒伐他汀治疗2周后,总胆固醇[TC(5.58±1.11)mmol/L:(6.39±1.10)mmol/L]、低密度脂蛋白胆固醇水平[LDL-C(3.12±0.87)mmol/L:(4.22±0.91)mmol/L]较治疗前明显下降(P均0.05);12周后,TC[(4.59±0.99)mmol/L:(6.39±1.10)mmol/L]、甘油三酯[(1.76±0.70)mmol/L:(2.20±0.78)mmol/L]、LDL-C水平[(2.30±0.78)mmol/L:(4.22±0.91)mmol/L]较治疗前明显下降(P均0.05~0.01),高密度脂蛋白胆固醇较治疗前明显升高[(1.28±0.25)mmol/L:(1.09±0.21)mmol/L,P0.01]。所有患者对瑞舒伐他汀有良好耐受及很好的服药依从性,未发现药物相关的严重不良反应。结论:瑞舒伐他汀能全面改善老年高胆固醇血症患者血脂水平,并有良好的安全性。     

Plasma asymmetric dimethylarginine and L-arginine levels in patients with cardiac syndrome X

BACKGROUND: Endothelial dysfunction and subsequently impaired microvascular circulation are the leading mechanisms in the development of cardiac syndrome X (CSX). The study evaluated the plasma asymmetric dimethylarginine (ADMA) and L-arginine levels of the patients with CSX and the control group and aimed to determine any relationship between these parameters and epicardial coronary blood flow and myocardial tissue perfusion. METHODS: The study group consisted of 32 patients (mean age: 52.6+/-9.4 years, 14 men) with typical exertional angina, positive exercise test, and normal coronary arteries diagnosed as CSX. Plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio were compared with the values of the control group, which consisted of 17 age-matched and sex-matched individuals. Concentrations of L-arginine and ADMA were measured by high-performance liquid chromatography. In all the coronary territories, epicardial coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method, and tissue level perfusion, by myocardial blush grade (MBG) method. A MBG score less than 3 was considered an impaired myocardial perfusion, and a MBG score of '3' in all the coronary territories, a normal myocardial perfusion. RESULTS: The plasma ADMA levels of the study group were higher than those of the control group (0.83+/-0.38 vs. 0.55+/-0.44 micromol/l, P=0.03), whereas plasma L-arginine levels were similar in both groups (70.25+/-21.89 vs. 76.09+/-18.22 micromol/l, P=0.36), resulting in a diminished L-arginine/ADMA ratio in the patients with CSX [82.3 (60.2-128.8) vs. 242.2 (76.7-386.4), P=0.003]. In CSX group, the patients with abnormal myocardial tissue perfusion had increased plasma ADMA levels compared with those with normal tissue perfusion (0.99+/-0.37 vs. 0.69+/-0.34 micromol/l, P=0.02), whereas plasma L-arginine levels were similar in both groups. No correlations were observed between TFC values and plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio. Plasma ADMA levels, however, were negatively correlated with MBG scores (r=-0.349, P=0.014). CONCLUSION: We have shown for the first time that in the patients with CSX, increased plasma ADMA levels might be associated with impaired myocardial tissue perfusion when assessed by MBG.     

Plasma levels of asymmetric dimethylarginine in patients with biopsy-proven nonalcoholic fatty liver disease

Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) are produced by breakdown of proteins that have been methylated posttranslationally at an arginine residue. Plasma levels of ADMA are elevated in insulin resistance states. Nonalcoholic fatty liver disease (NAFLD) is associated with insulin resistance and varying degrees of hepatic dysfunction. Because ADMA is metabolized in the liver, we hypothesized that ADMA levels will be high in patients with NAFLD as a consequence of hepatic dysfunction and insulin resistance. Plasma levels of ADMA, SDMA, total homocysteine, glucose, and insulin were measured in nondiabetic patients with biopsy-proven NAFLD (11 steatosis and 24 nonalcoholic steatohepatitis) and 25 healthy subjects. Plasma ADMA levels were significantly higher (P = .029) in patients with biopsy-proven NAFLD (0.43 ± 0.21 μmol/L) compared with controls (0.34 ± 0.10 μmol/L). However, when adjusted for insulin resistance (homeostasis model assessment), the difference between 2 groups was not evident. Plasma SDMA levels were similar in all 3 groups. Plasma levels of ADMA were positively correlated with plasma total homocysteine levels (P = .003). Plasma levels of SDMA were negatively correlated with estimated glomerular filtration rate (P = .016) and positively correlated with plasma total homocysteine levels (P = .003). The ratio of ADMA/SDMA was positively correlated with body mass index (P = .027). Elevated plasma concentrations of ADMA in biopsy-proven NAFLD were primarily related to insulin resistance. Hepatic dysfunction in NAFLD does not appear to make significant contribution to changes in plasma methylarginine levels.     

非对称性二甲基精氨酸和胱氨酸蛋白酶抑制剂C与冠心病

目的 探讨冠状动脉疾病中血浆非对称性二甲基精氨酸(ADMA)与胱氨酸蛋白酶抑制剂C(Cystatin C)之间的关系.方法 选取冠心病患者87例(其中急性心肌梗死39例,不稳定性心绞痛48例),健康对照组51例;同时,依据Cystatin C水平将冠心病患者分为Cystatin C升高组(51例)与无Cystatin C升高组(36例),采用高效液相色谱法测定血浆中ADMA、对称性二甲基精氨酸(SDMA)、左旋精氨酸(L-Arg)的含量,采用德国BNProSpec全自动速率散色比浊仪测定血浆Cystatin C的含量.结果 冠心病患者血浆ADMA[(0.47±0.15)μmol/L比(0.37±0.15)μmol/L]、SDMA[(0.39±0.19)μmol/L比(0.28±0.12)μmol/L]和Cystatin C浓度[(1.16±0.32)mg/L比(0.73±0.16)mg/L]均高于正常对照组(P均<0.05),L-Arg浓度低于正常对照组[(59.4±19.4)μmol/L比(83.7±19.6)μmol/L,P<0.05];对冠心病组的亚组分析显示血浆ADMA、L-Arg和Cystatin C浓度在心肌梗死组较心绞痛组差异无统计学意义.在Cystatin C<1 mg/L的冠心病患者中血浆ADMA与正常对照组比较,差异无统计学意义;而在Cystatin C>1 mg/L的冠心病患者血浆ADMA高于正常对照组[(0.50±0.17)μmol/L比(0.39±0.15)μmol/L,P<0.05].结论 只有在血浆Cystatin C水平升高的冠心病患者血浆ADMA水平才明显升高,提示冠心病患者血浆ADMA水平的升高并不与冠心病直接相关,可能与冠心病患者伴随轻微肾损害有关.     

Effect of chronic elevated asymmetric dimethylarginine (ADMA) levels on granulopoiesis

The endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) is elevated in both animal models of chronic inflammatory disorders as well as in patients with chronic inflammatory disease. In vivo data suggest that ADMA can increase the number of circulating monocytes and possibly affect their adhesion potential in vitro. The aim of our study was to evaluate possible effects of chronically elevated levels of ADMA on white blood cell count (WBC), leukocyte subsets, and WBC distribution pattern using a model of chronic exogenous ADMA infusion. Male Sprague–Dawley rats (n?=?20, 10 weeks of age) were randomized to receive either (1) isotonic saline or (2) ADMA applied by osmotic mini pumps. After 28 days of infusion, all animals were sacrificed for blood and tissue sampling. WBC count, flow cytometry for subtype assessment, and histological assessment were performed. Over a time period of 28 days, continuous ADMA infusion significantly increased mean plasma levels (1.26?±?0.07 μmol/l) as compared to saline infusion (0.57?±?0.02 μmol/l). Clinical side effects were not observed. Despite a physiologically relevant rise in ADMA plasma levels, measured by decrease of the l-arginine/AMDA ratio—a surrogate parameter of NO production capacity—there was no effect on WBC count or pattern of leukocyte subsets. Numbers and morphology of peripheral blood cells as well as number of NK-cells leveling liver and spleen were not affected by chronic ADMA infusion. Chronically elevated ADMA levels in otherwise healthy rats did not affect WBC counts or leukocyte subsets. Furthermore, anemia frequently found in patients with progressive renal failure and elevated ADMA levels, was not observed. In a chronic inflammatory state, elevated ADMA levels themselves are rather the result than the cause of the underlying inflammatory process.     

Effect of telmisartan on forearm postischemic hyperemia and serum asymmetric dimethylarginine levels

BACKGROUND: Although telmisartan may be more beneficial for glucose metabolism than other angiotensin II receptor blockers (ARBs), it has not been determined whether telmisartan exerts more favorable effects on biological and functional parameters related to endothelial function than other ARBs. METHODS: A study with a crossover design was conducted in 40 hypertensive patients (61 +/- 10 years old, mean +/- SD) who had previously been treated with ARBs other than telmisartan or valsartan (ie, ARBs were switched to either telmisartan 40 mg/day or valsartan 80 mg/day, administered alternately for 12 weeks each). Blood examinations were conducted, and the mean reactive hyperemia ratio (mRHR) was measured by plethysmography for each treatment regimen. RESULTS: There were no significant differences in either blood pressure or plasma levels of monocyte chemoattractant protein-1, C-reactive protein, 3-nitrotyrosine, or vascular cell adhesion molecule-1 between the two treatment regimens. The mRHR (2.7 +/- 1.0 v 2.4 +/- 1.0, mean +/- SD) was larger (P < .05), and the plasma levels of asymmetric dimethylarginine (ADMA) (0.45 +/- 0.08 v 0.50 +/- 0.17 micromol/L, mean +/- SD) and the homeostasis model assessment index of insulin resistance (HOMA-IR) (2.3 +/- 1.6 v 2.8 +/- 2.1, mean +/- SD) were lower (P < .05) in telmisartan-treated patients than in valsartan treated patients. The percent change in ADMA, but not in HOMA-IR, correlated significantly with that in the mRHR (beta = -0.33, t value = -2.00, P = .04). CONCLUSIONS: At doses producing equivalent hypotensive effects, telmisartan apparently had a more favorable effect on functional parameters related to endothelial function than did valsartan. The reduction in plasma ADMA levels may contribute to this more favorable effect of telmisartan.     

Short term fluvastatin treatment lowers serum asymmetric dimethylarginine levels in patients with metabolic syndrome

Elevated concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, are associated with endothelial dysfunction. Metabolic syndrome (MetS) is also a condition associated with impaired endothelial function. To test the hypothesis that lipid lowering treatment with a statin lowers ADMA levels, we investigated the effect of fluvastatin treatment on serum ADMA levels in patients with MetS. A total of 85 hypercholesterolemic MetS patients (53 females, 32 males; mean age, 55.8+/-9.1 years) were included in this prospective, randomized, controlled study. Patients were randomly assigned to either the treatment (n=42) or control group (n=43). Recommendations for lifestyle modification were provided to both groups. In addition, the patients in the treatment group received fluvastatin, extended release tablets, 80 mg/day, orally for 6 weeks. Serum levels of ADMA and lipids were assessed at baseline and at the completion of treatment. High performance liquid chromatography was used to measure serum ADMA concentrations. In the fluvastatin group, there was a significant reduction in serum ADMA levels compared to baseline (from 1.57+/-1.07 micromol/L to 1.17+/-1.41 micromol/L, P<0.05), whereas in the control group no significant change was observed (from 1.06+/-0.46 micromol/L to 1.24+/-1.38 micromol/L, P>0.05). There was a statistically significant difference between the groups in terms of mean percent change from baseline (P=0.047). Fluvastatin treatment for hypercholesterolemia in patients with MetS is associated with a decrease in serum ADMA levels at 6 weeks. This finding is consistent with known beneficial effects of statin treatment on endothelial function in hypercholesterolemic patients.     

Randomized dose-response study of rosuvastatin in Japanese patients with hypercholesterolemia

Rosuvastatin is a novel statin that has been shown to produce large dose-dependent reductions in low-density lipoprotein cholesterol (LDL-C) in Western hypercholesterolemic patients. Rosuvastatin dose response was assessed in a randomized, double-blind phase II trial in which 112 Japanese patients with fasting LDL-C > 160 and < 220 mg/dl and triglycerides < 300 mg/dl received placebo or rosuvastatin 1, 2.5, 5, 10, 20, or 40 mg once daily for 6 weeks. LDL-C change from baseline showed a linear dose response (p < 0.0001 for slope of regression line) over the rosuvastatin dose range, with each doubling of dose producing an additional 5.12% reduction. Mean reductions (least-squares mean percentage change from baseline from ANOVA) in LDL-C were 35.8% to 66.0% and significantly different from placebo at all doses (p < 0.0001). Linear dose response was also observed for total cholesterol (TC) and apolipoprotein (apo) B, but not for triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), or apo A-I or A-II. Mean changes at 6 weeks were - 25.5 to - 45.1% for TC, - 16.0 to - 26.2% for TG, + 7.5 to + 12.8% for HDL-C, - 31.9 to - 57.8% for apo B, + 5.5 to + 10.0% for apo A-I, and + 0.4 to + 8.1% for apo A-II. Rosuvastatin was well tolerated. Although there was some suggestion of increased frequency of treatment-related adverse events at higher doses, there were no clear dose relationships in safety parameters. Only one patient withdrew from the study because of a treatment-related adverse event. No patients had clinically significant elevations in liver transaminases or creatine kinase. Rosuvastatin produces good dose-related reductions in LDL-C and beneficial changes in other lipid fractions in Japanese hypercholesterolemic patients and is well tolerated.