Polymorphism in the C-reactive protein (CRP) gene affects CRP levels in plasma and one early marker of atherosclerosis in men: The Health 2000 Survey.

BACKGROUND: C-reactive protein (CRP) is an inflammatory protein that may play a role in the pathogenesis of cardiovascular disease (CVD). However, its status as a causal risk factor is still controversial. CRP gene single nucleotide polymorphisms (SNPs) have been shown to associate with CRP concentration, but not convincingly with early atherosclerotic changes. OBJECTIVE: We assessed whether CRP genotypes or their haplotypes associate with plasma CRP levels or carotid artery intima-media thickness (IMT) or carotid artery elasticity (CAE) in a Finnish middle-aged study population. METHODS: We genotyped CRP gene polymorphisms -717A>G (rs2794521), -286C>T>A (rs3091244), +1059G>C (rs1800947), +1444C>T (rs1130864) and +1846G>A (rs1205) and measured CRP concentration in a sub-population (N=1332, mean age 58.2 ± 8.0, women n=727 and men n=605) of a large Finnish cross-sectional health examination survey, The Health 2000 Study, carried out in 2000-2001. Results. Significant association (both sexes p<0.0001, women p=0.015 and men p=0.029) was found between CRP rs1800947 genotype and CRP concentration. Multivariate analysis showed an independent effect of the genotype on CRP concentration after adjustment for risk factors (women p=0.036 and men p=0.009). Similar associations were seen at the haplotype level in haplotype ACCCA where +1059 C-carriers had lower median CRP values than non-carriers (p=0.008). One CRP genotype (rs1130864) was associated with one CAE parameter in men but no association was observed between CRP genotypes and carotid artery IMT. CONCLUSIONS: CRP gene allelic variation is associated with CRP levels in both sexes and with one CAE parameter (SI) in men in a population-based Finnish cohort of middle-aged subjects.

Asymmetric dimethylarginine (ADMA) has a role in regulating systemic vascular tone in young healthy subjects: the cardiovascular risk in young Finns study.

BACKGROUND: This study was designed to evaluate whether plasma asymmetric dimethylarginine (ADMA) has any role in predicting hemodynamic responses in clinically healthy young subjects. ADMA, as an endogenous nitric oxide (NO) synthase inhibitor, has been demonstrated to associate with hypertension and vascular reactivity in experimental but not undoubtedly in physiological settings. METHODS: A total of 199 subjects aged 31.4 years (range 24-39 years) were studied. Plasma ADMA and symmetric dimethylarginine (SDMA) were assessed by isocratic high-pressure liquid chromatography using precolumn derivatization with o-phtaldialdehyde at baseline. Blood pressure (BP) was measured by casual measurements in the beginning of the study and after a follow-up period of 2.45 +/- 0.42 years (range, 1.86-3.19 years). Hemodynamic regulation was assessed by noninvasive methods after a follow-up. RESULTS: Plasma ADMA had a negative association with resting systemic vascular resistance index (SVRI) (r = -0.23, P < 0.01) and pulse wave velocity (PWV) (r = -0.17, P < 0.05) and positive association with cardiac index (CI) (r = 0.21, P < 0.01) after the follow-up. Plasma ADMA had also negative association with responses of SVRI (r = -0.19, P < 0.01) and positive association with CI (r = 0.25, P < 0.001) in a hemodynamic reactivity test. In a multivariate linear model (R2 = 0.20, P < 0.00001), diastolic BP (R = 0.37, P < 0.00001) and ADMA (R = -0.20, P < 0.01) were significant predictors of SVRI. CONCLUSIONS: These results suggest that plasma ADMA seems to play a role in the regulation of vascular tone in young healthy subjects.

Plasma asymmetric dimethylarginine and retinal vessel diameters in middle-aged men.

It has been suggested that asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is linked to hypertension and vascular reactivity. Retinal arteriolar narrowing has been observed to associate early with increased risk of hypertension. The objective of this study was to evaluate the role of ADMA as a biomarker for early vascular changes of retinal vessels and thus as a possible biomarker of hypertension risk. Thirty-five healthy white men aged 50.1 years (range, 45-55 years) were studied. Using digitized fundus photography, the following diameters of retinal arterioles and venules were measured 1 disc diameter from the optic disc edge: the mean arteriole width (MAW) and venule width (MVW), the sum of squares of widths of arterioles (SSWA) and venules (SSWV), and the central retinal artery equivalent (CRAE) and venous equivalent (CRVE). Arteriovenous ratio was determined using MAW/MVW, SSWA/SSWV, and CRAE/CRVE. Blood pressure was measured by 24-hour ambulatory recordings and also by resting measurements. Plasma ADMA was determined by a high-performance liquid chromatography tandem mass spectrometry. Plasma ADMA had a strong negative association with MAW, MVW, SSWA, SSWV, CRAE, and CRVE. Arteriovenous ratio measurements did not associate with plasma ADMA or with l-arginine to ADMA ratio, but arteriovenous ratios had a strong association with blood pressure. In a multivariate linear model, plasma ADMA concentration was the most significant predictor of arteriole and venule diameter measurements. These results suggest that plasma ADMA is associated with vascular phenomenon seen in early hypertension and that ADMA may be a potential biomarker candidate for development of hypertension.

Osteopontin levels are associated with cholesterol synthesis markers in mildly hypercholesterolaemic patients.

OBJECTIVE: Atherosclerotic lesions are characterized by an accumulation of inflammatory cells and lipids. Osteopontin (OPN) is a cell-binding phosphoprotein, and it seems to promote the development of atherosclerosis. The purpose of our study was to find out whether plasma levels of OPN are associated with cholesterol metabolites in plasma or tissues. METHODS AND RESULTS: Forty-three normal or mildly hypercholesterolaemic subjects, aged 31 to 69, were studied. The plasma level of OPN correlated negatively with muscle lathosterol (r = -0.52, P < 0.0001) and with the muscle lathosterol to muscle cholesterol ratio (r = -0.48, P = 0.001). Lathosterol concentrations in muscle (P = 0.003) and in relation to cholesterol (P = 0.005) were also significantly different among the OPN tertiles. OPN correlated negatively and significantly with muscle lathosterol in men (r = -0.58, P = 0.001, n = 29) but not in women (r = -0.21, P = 0.48, n = 14). Correspondingly, it also correlated negatively and significantly with the muscle lathosterol to muscle cholesterol ratio (r = -0.60, P = 0.001) in men but not in women (r = -0.13, P = 0.65). Plasma levels of OPN had a non-significant inverse correlation with plasma lathosterol and the plasma lathosterol to plasma cholesterol ratio. Plasma OPN concentrations were not related to plant sterols, cholesterol and 27-hydroxycholesterol. CONCLUSIONS: Tissue markers of cholesterol synthesis were related to plasma OPN, particularly in men. This suggests that there is interplay between OPN and cholesterol metabolism in human cells.

Genetic variant of the SREBF-1 gene is significantly related to cholesterol synthesis in man.

Sterol regulatory element binding proteins-1 and -2 (SREBPs) are transcription factors controlling lipid homeostasis in human cells. The G-allele carriers of the SREBF-1 gene C-G polymorphism in exon 18c and coding for glycine at the protein level (G952G) have shown to associate more frequently with obesity and type 2 diabetes than the C-allele carriers. However, the C-allele has suggested to be linked to dyslipidemia. Thus, our aim was to study effect of the SREBF-1 gene polymorphism (G952G) on sterol metabolism in man. Ninety-five subjects with moderate hypercholesterolemia participated in this study and 14 homozygous CC carriers of the SREBF-1 (G952G) gene were found. Plasma lathosterol concentration and lathosterol-to-cholesterol ratio, markers of endogenous cholesterol synthesis, were significantly higher in CC homozygous subject compared to others. Similarly muscle cholesterol (p=0.045) and lathosterol (p=0.054) concentrations were elevated in the CC homozygotes supporting the view that endogenous cholesterol synthesis rate is SREBF-1 genotype-dependent.

Asymmetric dimethylarginine and hemodynamic regulation in middle-aged men.

The goal of this study was to evaluate the role of asymmetric dimethylarginine (ADMA) in the regulation of hemodynamic functions in hypertensive men. It has been suggested that ADMA, as an endogenous nitric oxide synthase inhibitor, is linked to hypertension and vascular reactivity. Sixty-seven men aged 51.1 years (range, 45-55 years) were studied. Plasma ADMA and symmetric dimethylarginine were determined by high-performance liquid chromatography-tandem mass spectrometry. Blood pressure (BP) was measured by 24-hour ambulatory recordings and casual measurements. Hemodynamic regulation was assessed by noninvasive methods. The nitric oxide production was estimated based on plasma nitrate (NO(3)(-)) determination. Results showed that plasma arginine derivatives or l-arginine/ADMA ratio was not associated with BP values observed during 24-hour monitoring or in casual measurements. Systemic vascular resistance, pulse wave velocity, or cardiac output was not associated with plasma ADMA or plasma NO(3)(-) levels. No association was found between plasma ADMA and NO(3)(-) either. Interestingly, subjects on antihypertensive treatment had lower plasma ADMA concentrations than nontreated subjects (0.30+/-0.08 and 0.36+/-0.11 micromol/L, respectively, P=.04) despite higher BP values. In conclusion, these results suggest that plasma ADMA does not have a determinative role in the regulation of hemodynamic functions in Finnish middle-aged men.

High-dose statin treatment does not alter plasma marker for brain cholesterol metabolism in patients with moderately elevated plasma cholesterol levels.

Statins inhibit endogenous cholesterol synthesis, up-regulate low-density lipoprotein (LDL) receptor expression in mammalian liver cells, and thus decrease circulating LDL-cholesterol concentrations. As cholesterol seems to play a role in the development of neurodegenerative diseases, it is of interest to evaluate the effect of high dosages of statins (eg, atorvastatin or simvastatin) on brain cholesterol metabolism. Plasma samples from 44 participants (aged 30-69 years, 16 men and 18 women) of an earlier randomized, placebo-controlled, double-blind trial, who took 40 mg atorvastatin or 80 mg simvastatin daily for 2 months, were used to analyze total cholesterol, its precursor lathosterol, and its metabolites 24(S)-hydroxycholesterol and 27-hydroxycholesterol. Despite a significant decrease in absolute plasma concentrations of oxysterols, total cholesterol, and its endogenous synthesis rate, indicated by a decreased ratio of lathosterol to cholesterol, the plasma 24(S)-hydroxycholesterol to cholesterol ratio, a surrogate marker of brain cholesterol homeostasis, remained unchanged. Short-term high-dose atorvastatin and simvastatin treatment does not seem to influence brain cholesterol metabolism in patients with moderately elevated plasma cholesterol levels.

Plasma asymmetric dimethylarginine (ADMA), nitrate and the indices of low-density lipoprotein oxidation.

BACKGROUND: Oxidative modification of low-density lipoprotein (LDL) is an important contributor to atherosclerosis. Also, oxidized LDL is suspected to cause accumulation of asymmetric dimethylarginine (ADMA), an endogenous competitive nitric oxide synthase inhibitor, which is suggested to be an independent risk factor for atherosclerosis. This study was performed to evaluate how plasma ADMA is related to plasma nitric oxide production, oxidized LDL and ex vivo susceptibility of LDL to oxidation in mildly hypercholesterolemic otherwise healthy subjects. METHODS: Plasma ADMA was determined using high performance liquid chromatography tandem mass spectrometry. LDL oxidation was estimated by the lag time and rate of copper-induced LDL oxidation. The nitric oxide production in plasma was estimated based on nitrate (NO(3)(-)) determination and plasma oxidized LDL was determined by a capture ELISA. RESULTS: Low ADMA was a significant determinant for high LDL oxidation rate and concentration of plasma ADMA was associated with nitrate levels. CONCLUSIONS: There may be an interplay between LDL fatty acid oxidation rate and plasma ADMA and nitrate. We hypothesize that plasma ADMA has a bivalent role: high ADMA may have a protective role in decelerating LDL fatty acid oxidation and also a risk factor for endothelial dysfunction by decreasing availability of nitric oxide.

High-dose statins and skeletal muscle metabolism in humans: a randomized, controlled trial.

BACKGROUND: Myopathy, probably caused by 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibition in skeletal muscle, rarely occurs in patients taking statins. This study was designed to assess the effect of high-dose statin treatment on cholesterol and ubiquinone metabolism and mitochondrial function in human skeletal muscle. METHODS: Forty-eight patients with hypercholesterolemia (33 men and 15 women) were randomly assigned to receive 80 mg/d of simvastatin (n = 16), 40 mg/d of atorvastatin (n = 16), or placebo (n = 16) for 8 weeks. Plasma samples and muscle biopsy specimens were obtained at baseline and at the end of the follow-up. RESULTS: The ratio of plasma lathosterol to cholesterol, a marker of endogenous cholesterol synthesis, decreased significantly by 66% in both statin groups. Muscle campesterol concentrations increased from 21.1 +/- 7.1 nmol/g to 41.2 +/- 27.0 nmol/g in the simvastatin group and from 22.6 +/- 8.6 nmol/g to 40.0 +/- 18.7 nmol/g in the atorvastatin group (P = .005, repeated-measurements ANOVA). The muscle ubiquinone concentration was reduced significantly from 39.7 +/- 13.6 nmol/g to 26.4 +/- 7.9 nmol/g (P = .031, repeated-measurements ANOVA) in the simvastatin group, but no reduction was observed in the atorvastatin or placebo group. Respiratory chain enzyme activities were assessed in 6 patients taking simvastatin with markedly reduced muscle ubiquinone and in matched subjects selected from the atorvastatin (n = 6) and placebo (n = 6) groups. Respiratory chain enzyme and citrate synthase activities were reduced in the patients taking simvastatin. CONCLUSIONS: High-dose statin treatment leads to changes in the skeletal muscle sterol metabolism. Furthermore, aggressive statin treatment may affect mitochondrial volume.

Plasma asymmetric dimethylarginine and hyperemic myocardial blood flow in young subjects with borderline hypertension or familial hypercholesterolemia.

OBJECTIVE: The goal of this study was to examine the relationship between plasma asymmetric dimethylarginine (ADMA) level and hyperemic myocardial blood flow (MBF) in subjects with borderline hypertension (BHT) and familial hypercholesterolemia (FH). METHODS: Asymmetric dimethylarginine is an endogenous competitive inhibitor of nitric oxide synthase that may modulate vascular function. We measured plasma ADMA levels and myocardial flow in 77 young men (mean age 35 +/- 5 years), including 47 healthy controls, 16 men with BHT, and 14 men with FH. Basal and dipyridamole-induced myocardial flow was measured using positron emission tomography. Plasma ADMA levels were measured using high-pressure liquid chromatography. RESULTS: Asymmetric dimethylarginine levels were significantly elevated in the BHT group compared with controls (0.59 +/- 0.13 micromol/l vs. 0.43 +/- 0.12 micromol/l, p < 0.001), and they had significantly lower dipyridamole flow (2.85 +/- 1.20 ml/min/g vs. 3.69 +/- 1.68 ml/min/g, p < 0.05). In a multivariate regression model adjusted for the study group, dipyridamole flow was inversely associated with ADMA (p < 0.05), age (p < 0.05), and apolipoprotein B concentration (p < 0.05). CONCLUSIONS: We conclude that plasma ADMA concentration is related to dipyridamole-induced vasodilatory function in young men, independently of blood pressure elevation and hypercholesterolemia. Subjects with BHT have significantly increased plasma ADMA levels, which may partly explain the impaired hyperemic MBF in this condition.

Asymmetrical dimethylarginine (ADMA) and risk of acute coronary events. Does statin treatment influence plasma ADMA levels?

The purpose of this study was to evaluate the hypothesis that high serum levels of ADMA, an indicator of endothelial dysfunction, are associated with an elevated risk of acute coronary events in middle-aged men. To test the hypothesis that lipid lowering medication with statins lowers circulating ADMA levels, we also investigated the effect of simvastatin and atorvastatin treatment on plasma ADMA concentration. In a prospective nested case-control study in 150 middle-aged non-smoking men from Eastern Finland, those who were in the highest quartile for serum ADMA (>0.62 micromol/l) had a 3.9-fold (95% CI: 1.25-12.3, P=0.02) increase in risk of acute coronary events compared with other quartiles. In an 8-week randomised double-blind placebo-controlled trial, plasma ADMA concentrations remained unchanged in simvastatin 80 mg/day (n=16), atorvastatin 40 mg/day (n=16) and placebo (n=16) groups over the study period. Our findings indicate that high serum levels of ADMA, a potential marker for endothelial dysfunction, may increase the risk of acute coronary syndromes. However, aggressive treatment with either simvastatin or atorvastatin did not reduce plasma ADMA levels.

Plasma concentrations of asymmetric-dimethyl-arginine in type 2 diabetes associate with glycemic control and glomerular filtration rate but not with risk factors of vasculopathy.

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS). Increased plasma levels of ADMA may indicate endothelial dysfunction and increased risk of angiopathy. The relation of ADMA to diabetes, glycemic control, and renal function, especially early diabetic hyperfiltration, remains unknown. We tried to evaluate whether there is an association between ADMA and glycosylated hemoglobin (GHbA(1c)) on the one hand and glomerular filtration rate (GFR) on the other hand in diabetic subjects with normal or slightly increased GFR. We also studied whether plasma ADMA is associated with some risk factors of vasculopathy (hypercholesterolemia and hypertension). The study subjects consisted of 86 patients with type 2 diabetes and 65 control subjects. Plasma ADMA levels were measured by high-pressure liquid chromatography as o-pthalaldehyde (OPA) derivatives and GFR was determined by the plasma clearance of chromium 51-EDTA. The diabetic patients had lower plasma ADMA levels than the nondiabetic control subjects (0.29 +/- 0.15 v 0.34 +/- 0.16 micromol/L, P <.03). In the diabetic subjects, plasma ADMA concentrations were inversely correlated with GHbA(1c) (R = -0.28, P =.01). In a multivariate linear model, significant predictors of ADMA were GFR (R = -0.32, P =.008) in diabetic subjects and GHbA(1c) (R = -0.19, P =.03) and GFR (R = -0.19, P =.02) in all subjects. Plasma ADMA was not associated with risk factors of vasculopathy. We conclude that diabetic patients with a normal or slightly increased GFR have lower circulating ADMA concentrations than nondiabetic control subjects. In type 2 diabetic patients high GFR and poor glycemic control were related to low plasma ADMA concentrations.

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.

Beyond LDL-C lowering: distinct molecular sphingolipids are good indicators of proprotein convertase subtilisin/kexin type 9 (PCSK9) deficiency.

OBJECTIVES: Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) has been proposed to be a potential new therapeutic target for treatment of hypercholesterolaemia. However, little is known about the effects of PCSK9 inhibition on the lipidome. METHODS: We performed molecular lipidomic analyses of plasma samples obtained from PCSK9-deficient mice, and serum of human carriers of a loss-of-function variant in the PCSK9 gene (R46L). RESULTS: In both mouse and man, PCSK9 deficiency caused a decrease in several cholesteryl esters (CE) and short fatty acid chain containing sphingolipid species such as CE 16:0, glucosyl/galactosylceramide (Glc/GalCer) d18:1/16:0, and lactosylceramide (LacCer) d18:1/16:0. In mice, the changes in lipid concentrations were most prominent when animals were given regular chow diet. In man, a number of molecular lipid species was shown to decrease significantly even when LDL-cholesterol was non-significantly reduced by 10% only. Western diet attenuated the lipid lowering potency of PCSK9 deficiency in mice. CONCLUSIONS: Plasma molecular lipid species may be utilized for characterizing novel compounds inhibiting PCSK9 and as sensitive efficacy markers of the PCSK9 inhibition.

Levels of asymmetrical dimethylarginine are predictive of brachial artery flow-mediated dilation 6 years later. The Cardiovascular Risk in Young Finns Study.

AIM: Plasma asymmetric dimethylarginine (ADMA) is a novel risk factor for atherosclerosis and has been observed to associate with endothelial function in cross-section studies. In the present study our aim was to investigate whether plasma ADMA levels are predictive of brachial artery endothelial function in a prospective setting. METHODS AND RESULTS: Using ultrasound we measured brachial artery flow-mediated dilation (FMD) both in 2001 and 2007 in 1808 healthy subjects aged 24-39 years at baseline. Plasma methylarginines were determined by isocratic high-pressure liquid chromatography in 2001. In a multivariable model adjusted with brachial diameter and conventional cardiovascular risk factors, baseline ADMA levels had a significant inverse association with FMD measured 6 years later (ß±SE: -1.89±0.69%, P=0.006). CONCLUSIONS: We conclude that plasma ADMA can predict brachial artery FMD in subjects without prevalent atherosclerotic disease. These data suggest that plasma ADMA may have a determinative role in predicting endothelial function.

Plasma-soluble CD40 is related to cholesterol metabolism in patients with moderate hypercholesterolemia.

OBJECTIVES: CD40 is a marker of immunological activation and is expressed in the atherosclerotic lesions. We studied whether CD40 and cholesterol synthesis pathways are associated with each other. DESIGN: Forty-three subjects were randomly assigned to receive either simvastatin (n = 14), atorvastatin (n = 15), or placebo (n = 14) for eight weeks. Plasma samples were obtained before and at the end of the follow-up. sCD40 levels were measured in duplicate using an enzyme-linked immunosorbent assay. Cholesterol, its precursor lathosterol, the plant sterols campesterol and sitosterol as well as 27-hydroxycholesterol were quantified by gas-liquid chromatography-mass spectrometry. RESULTS: sCD40 was inversely correlated with the lathosterol to cholesterol ratio (r = - 0.47, p = 0.002), an indicator of cholesterol synthesis rate, as well as apolipoprotein A-I (r = - 0.38, p = 0.01) in addition to being directly correlated with 27-hydroxycholesterol (r = 0.40, p = 0.008). In multivariate linear regression analysis these three predictors explained 37% of the total variability of sCD40 levels. Simvastatin or atorvastatin treatment had no significant effect on sCD40 levels. CONCLUSION: These results indirectly suggest that sCD40 concentrations are related to cellular cholesterol levels. This may be a novel indication for the relationship between immunological processes and cholesterol metabolism.

A systems biology strategy reveals biological pathways and plasma biomarker candidates for potentially toxic statin-induced changes in muscle.

BACKGROUND: Aggressive lipid lowering with high doses of statins increases the risk of statin-induced myopathy. However, the cellular mechanisms leading to muscle damage are not known and sensitive biomarkers are needed to identify patients at risk of developing statin-induced serious side effects. METHODOLOGY: We performed bioinformatics analysis of whole genome expression profiling of muscle specimens and UPLC/MS based lipidomics analyses of plasma samples obtained in an earlier randomized trial from patients either on high dose simvastatin (80 mg), atorvastatin (40 mg), or placebo. PRINCIPAL FINDINGS: High dose simvastatin treatment resulted in 111 differentially expressed genes (1.5-fold change and p-value<0.05), while expression of only one and five genes was altered in the placebo and atorvastatin groups, respectively. The Gene Set Enrichment Analysis identified several affected pathways (23 gene lists with False Discovery Rate q-value<0.1) in muscle following high dose simvastatin, including eicosanoid synthesis and Phospholipase C pathways. Using lipidomic analysis we identified previously uncharacterized drug-specific changes in the plasma lipid profile despite similar statin-induced changes in plasma LDL-cholesterol. We also found that the plasma lipidomic changes following simvastatin treatment correlate with the muscle expression of the arachidonate 5-lipoxygenase-activating protein. CONCLUSIONS: High dose simvastatin affects multiple metabolic and signaling pathways in skeletal muscle, including the pro-inflammatory pathways. Thus, our results demonstrate that clinically used high statin dosages may lead to unexpected metabolic effects in non-hepatic tissues. The lipidomic profiles may serve as highly sensitive biomarkers of statin-induced metabolic alterations in muscle and may thus allow us to identify patients who should be treated with a lower dose to prevent a possible toxicity.

Effect of high-dose statin treatment on plasma concentrations of endogenous nitric oxide synthase inhibitors.

Asymmetric dimethylarginine (ADMA) and monomethylarginine (LMMA) are endogenous inhibitors of nitric oxide synthase. A high level of ADMA in plasma has shown to be a significant risk factor for acute coronary syndromes and elevated plasma ADMA levels are prevalent in patients with hypercholesterolemia. It was therefore hypothesized that lowering plasma cholesterol levels with statin treatment would also lower ADMA concentrations. This double-blind study addressed the effect of high-dose statin treatment on plasma levels of ADMA and LMMA. Forty-eight subjects with mild hypercholesterolemia were randomly assigned to receive simvastatin 80 mg/d, atorvastatin 40 mg/d, or placebo for 8 weeks. Both statins decreased low-density lipoprotein cholesterol effectively (simvastatin 54% and atorvastatin 49%). However, concentrations of arginine derivatives remained unchanged during statin treatment and did not correlate with cholesterol levels. This study indicates that statin treatment has no clear influence on plasma ADMA or LMMA concentrations.