Paraoxonase-1 status in patients with hereditary hemochromatosis.

Hereditary hemochromatosis (HH) is characterized by accumulation of iron, oxidative stress, inflammation, and fibrogenesis in liver tissue. In this setting, research on the protection afforded by intracellular antioxidants is of clinical relevance. Paraoxonase-1 (PON1) is an enzyme that degrades lipid peroxides. This study investigates the alterations in serum PON1 status, PON1 gene polymorphisms, and PON1 hepatic expression in patients with HH. We performed a case-control study in 77 patients with HH (80.5% men, 22-70 years of age) and 408 healthy individuals (43.1% men, 26-74 years of age). Serum PON1 activities against different substrates and PON1192 and PON155 polymorphisms were analyzed. PON1 protein expression was investigated in 20 liver biopsies. HH patients had significantly lower serum PON1 activity, which was inversely correlated with ferritin (marker of iron stores) and serum 8-isoprostane concentrations (index of oxidative stress). PON1 protein expression in liver tissue was higher in patients and showed stronger staining in hepatocytes surrounding the areas of inflammation. Our study provides preliminary evidence that PON1 may play a role in protecting against iron-induced oxidative stress in hereditary hemochromatosis.

Paraoxonase-1 deficiency is associated with severe liver steatosis in mice fed a high-fat high-cholesterol diet: a metabolomic approach.

Oxidative stress is a determinant of liver steatosis and the progression to more severe forms of disease. The present study investigated the effect of paraoxonase-1 (PON1) deficiency on histological alterations and hepatic metabolism in mice fed a high-fat high-cholesterol diet. We performed nontargeted metabolomics on liver tissues from 8 male PON1-deficient mice and 8 wild-type animals fed a high-fat, high-cholesterol diet for 22 weeks. We also measured 8-oxo-20-deoxyguanosine, reduced and oxidized glutathione, malondialdehyde, 8-isoprostanes and protein carbonyl concentrations. Results indicated lipid droplets in 14.5% of the hepatocytes of wild-type mice and in 83.3% of the PON1-deficient animals (P < 0.001). The metabolomic assay included 322 biochemical compounds, 169 of which were significantly decreased and 16 increased in PON1-deficient mice. There were significant increases in lipid peroxide concentrations and oxidative stress markers. We also found decreased glycolysis and the Krebs cycle. The urea cycle was decreased, and the pyrimidine cycle had a significant increase in orotate. The pathways of triglyceride and phospholipid synthesis were significantly increased. We conclude that PON1 deficiency is associated with oxidative stress and metabolic alterations leading to steatosis in the livers of mice receiving a high-fat high-cholesterol diet.

Paraoxonase-1 inhibits oxidized low-density lipoprotein-induced metabolic alterations and apoptosis in endothelial cells: a nondirected metabolomic study.

We studied the influence of PON1 on metabolic alterations induced by oxidized LDL when incubated with endothelial cells. HUVEC cells were incubated with native LDL, oxidized LDL, oxidized LDL plus HDL from wild type mice, and oxidized LDL plus HDL from PON1-deficient mice. Results showed alterations in carbohydrate and phospholipid metabolism and increased apoptosis in cells incubated with oxidized LDL. These changes were partially prevented by wild type mouse HDL, but the effects were less effective with HDL from PON1-deficient mice. Our results suggest that PON1 may play a significant role in endothelial cell survival by protecting cells from alterations in the respiratory chain induced by oxidized LDL. These results extend current knowledge on the protective role of HDL and PON1 against oxidation and apoptosis in endothelial cells.

Serum paraoxonase-3 concentration in HIV-infected patients. Evidence for a protective role against oxidation.

We investigated the influence of the HIV infection on serum paraoxonase-3 (PON3) concentration and assessed the relationships with lipoprotein-associated abnormalities, immunological response, and accelerated atherosclerosis. We studied 207 HIV-infected patients and 385 healthy volunteers. Serum PON3 was determined by in-house ELISA, and PON3 distribution in lipoproteins was investigated by fast-performance liquid chromatography (FPLC). Polymorphisms of the PON3 promoter were analyzed by the Iplex Gold MassArray(TM) method. PON3 concentrations were increased (about three times) in HIV-infected patients with respect to controls (P < 0.001) and were inversely correlated with oxidized LDL levels (P = 0.038). Long-term use of nonnucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy was associated with a decrease of PON3 concentrations. In a multivariate linear regression analysis, these relationships were still strong when the main confounding covariates were considered. PON3 was mainly found in HDL in HIV-infected patients, but a substantial amount of the protein was detected in LDL particles. This study reports for the first time an important increase in serum PON3 concentrations in HIV-infected patients that is associated with their oxidative status and their treatment with NNRTI. Long-term, prospective studies are needed to confirm the possible influence of this enzyme on the course of this disease and its possible utility as an analytical biomarker.

Monocyte chemoattractant protein-1 and paraoxonase-1 and 3 levels in patients with sepsis treated in an intensive care unit: a preliminary report.

BACKGROUND: There is considerable interest in the research of molecules modulating the acute inflammatory response in patients with sepsis. Paraoxonases (PON) are antioxidant and anti-inflammatory enzymes that inhibit the production of the monocyte chemoattractant protein-1 (MCP-1). This preliminary study investigated changes in PON status and MCP-1 concentrations in critically ill patients with severe sepsis treated in an ICU and their relationship with the evolution of disease. METHODS: This was a longitudinal, prospective and observational study on 15 patients with sepsis, studied at baseline and on days 1, 2, 5, 7 and 10 of their stay in the ICU. In all the patients we measured serum PON1 and PON3 concentrations, PON1 paraoxonase and lactonase activities, serum MCP-1 concentrations, and several standard biochemical and haematological parameters. RESULTS: MCP-1 concentration significantly decreased with the resolution of sepsis, and this decrease was especially important during the first 5 days of hospitalisation. PON1 and PON3 tended to decrease during the first 5 days in ICU and significantly increased in days 7 and 10. Linear regression analysis showed significant and direct correlations among serum MCP-1 concentration and lactate levels at baseline. At the end of stay, PON1 paraoxonase and lactonase activities were significantly correlated with organ system function measurements. CONCLUSIONS: We observed an inverse pattern between changes in MCP-1, and PON1 and PON3 levels in patients with sepsis, this was related to the resolution of their infection after receiving treatment in an ICU.

Measurement of serum PON-3 concentration: method evaluation, reference values, and influence of genotypes in a population-based study.

Experimental studies showed that paraoxonase-3 (PON3) retards lipoprotein oxidation. Our objective was to describe a new assay to measure serum PON3 concentrations and report their reference values in a population-based study. The influence of PON3 promoter polymorphisms and their relationships with PON1 and lipid profile were also studied. We generated an anti-PON3 antibody by inoculating rabbits with a synthetic peptide specific to mature PON3. This antibody was used to develop an ELISA. The average regression line of standard plots (n = 8) was y = 0.9587 (0.3392) log(10)x + 1.9466 (0.0861) [r(2) = 0.924 (0.0131); P < 0.001]. There was no cross reaction with PON1. Detection limit was 0.24 mg/l. Imprecision was ≤ 13.2%. Reference interval (n = 356) was 1.00-2.47 mg/l. PON3 was observed in HDL particles containing apolipoprotein (apo)A-I and PON1, but not apoA-II or apoE. Serum PON3 concentrations showed a moderate influence (about 10% variation) by PON3 promoter polymorphisms. Our study describes for the first time a method to measure serum PON3 concentrations. This method offers new opportunities in the investigation of the properties and role of PON3 in cardiovascular disease, with possible implications in clinical practice.

'Dippers' flu' and its relationship to PON1 polymorphisms.

OBJECTIVES: Sheep-dippers report an acute flu-like condition (dippers' flu: DF) but the cause and relation to chronic disability are unknown. METHODS: In a case-referent study previously reported, 175 sheep dippers with chronic disability and 234 referents, sheep dippers in good health, completed an interview with information on dipping, type of pesticide used and health for each year 1970-2000 and gave blood for typing of PON1 polymorphisms. RESULTS: Reports of DF were much higher (66.3% 116/175) in the chronically unwell than in those without chronic ill-health (18.0% 42/234: OR=8.99 95% CI 5.69-14.21). No significant relation was seen between reported exposures and DF in those with chronic illness, but risk was higher with concentrate handling in those without. An R allele at position 192 on PON1 related to reports of DF both in those with chronic illness (OR=2.04 95% CI 1.08-3.87) and in those who started dipping after 1969 and were not chronically unwell (OR=2.52 95%CI 1.00-6.37). Interaction between handling diazinon concentrate and PON1 (192R) increased the risk of DF. No precipitating factor was identified in a case-crossover analysis. In the group without chronic illness those with 192R developed DF earlier (risk ratio 2.49 95%CI 1.03-6.02). CONCLUSION: 'Dippers' flu' and chronic ill-health attributed to dipping share a common polymorphism (192R). The interaction between handling diazinon concentrate and PON1 genotype supports the conclusion that organophosphates may cause DF. Sheep dippers who are still healthy but experience 'dippers' flu' may be wise to further limit exposures to organophosphates.

Paraoxonase-1 gene haplotypes are associated with metabolic disturbances, atherosclerosis, and immunologic outcome in HIV-infected patients.

BACKGROUND: Oxidative stress is associated with human immunodeficiency virus (HIV) infection. Paraoxonase-1 (PON1) is an antioxidant enzyme that is bound to high-density lipoproteins (HDLs). We evaluated whether PON1 gene haplotypes influence the metabolic disturbances, presence of subclinical atherosclerosis, and virologic outcome associated with the infection. METHODS: DNA from blood samples collected from 234 HIV-infected patients and 633 healthy control subjects had single-nucleotide polymorphisms of PON1(192), PON1(55), PON1(-162), PON1(-832), PON1(-909), PON1(-1076), and PON1(-1741) analyzed using the Iplex Gold MassArray method. Subsequently, the influence of these single-nucleotide polymorphisms on measured biochemical and clinical variables was assessed. RESULTS: We observed significant differences in the haplotype distribution between the control subjects and the HIV-infected patients. Haplotype H10 (GTCCGTC) was more prevalent in the HIV-infected patients (6.41% vs 0.64%; P < .001), and haplotype H5 (GACCGTC) was less prevalent in HIV-infected patients (27.7% vs 42.9%; P = .001). In HIV-infected patients, haplotype H7 (AATTCCT) was associated with better CD4(+) cell count recovery, higher levels of HDL cholesterol (P = .048) and apolipoprotein A-I (P = .019), lower levels of triglycerides (P = .004), and lower rates of subclinical arteriosclerosis (P < .001). CONCLUSIONS: PON1 haplotypes segregate with HIV infection, HDL metabolism, the presence of subclinical atherosclerosis, and CD4(+) cell recovery after treatment.

Paraoxonase-1 and -3 Protein Expression in the Brain of the Tg2576 Mouse Model of Alzheimer's Disease.

BACKGROUND: Brain oxidative lipid damage and inflammation are common in neurodegenerative diseases such as Alzheimer's disease (AD). Paraoxonase-1 and -3 (PON1 and PON3) protein expression was demonstrated in tissue with no PON1 or PON3 gene expression. In the present study, we examine differences in PON1 and PON3 protein expression in the brain of a mouse model of AD. METHODS: we used peroxidase- and fluorescence-based immunohistochemistry in five brain regions (olfactory bulb, forebrain, posterior midbrain, hindbrain and cerebellum) of transgenic (Tg2576) mice with the Swedish mutation (KM670/671NL) responsible for a familial form of AD and corresponding wild-type mice. RESULTS: We found intense PON1 and PON3-positive staining in star-shaped cells surrounding Aß plaques in all the studied Tg2576 mouse-brain regions. Although we could not colocalize PON1 and PON3 with astrocytes (star-shaped cells in the brain), we found some PON3 colocalization with microglia. CONCLUSIONS: These results suggest that (1) PON1 and PON3 cross the blood-brain barrier in discoidal high-density lipoproteins (HDLs) and are transferred to specific brain-cell types; and (2) PON1 and PON3 play an important role in preventing oxidative stress and lipid peroxidation in particular brain-cell types (likely to be glial cells) in AD pathology and potentially in other neurodegenerative diseases as well.

Decreased paraoxonase-1 activity is associated with alterations of high-density lipoprotein particles in chronic liver impairment.

BACKGROUND: Paraoxonase-1 (PON1), a lactonase synthesized by the liver, circulates in blood bound to high-density lipoproteins (HDL). This enzyme is thought to degrade oxidized phospholipids and play an important role in the organism's antioxidant and anti-inflammatory system. Chronic liver diseases are characterized by decreased serum PON1 activity. The aim of the present study was to investigate the compositional changes in HDL that could influence PON1 activity in liver impairment. METHODS: The study was performed in samples from five patients with advanced liver cirrhosis and with preserved renal function, chosen on the basis of having low serum PON1 activity and high serum PON1 concentration. As a control group, we accessed five healthy volunteers from among our hospital staff. Lipid and protein compositional analysis of lipoprotein particles were done by high-performance liquid chromatography, gel electrophoresis, and Western-Blot. RESULTS: HDL particles from cirrhotic patients had an increased phospholipid content that was inversely correlated to PON1 activity. The HDL particles contained high levels of PON1 that corresponded, in part, to an immunoreactive protein of high molecular weight (55 kDa) not present in control subjects. This protein was identified as glycosylated PON1 and was also present in biopsies from patients with steatosis and from rats with CCl(4)-induced hepatic impairment. These changes were associated with an increased plasma concentration of markers of oxidative stress, inflammation and fibrogenesis. CONCLUSION: Abnormalities in the composition of lipids and proteins of HDL particles, including PON1 glycosylation, are associated with the decrease in serum PON1 activity in patients with liver disease. These alterations may adversely affect the protective role of HDL against oxidative stress and inflammation in these patients.

Paraoxonase-1 is related to inflammation, fibrosis and PPAR delta in experimental liver disease.

BACKGROUND: Paraoxonase-1 (PON1) is an antioxidant enzyme synthesized by the liver. It protects against liver impairment and attenuates the production of the pro-inflammatory monocyte chemoattractant protein-1 (MCP-1). We investigated the relationships between hepatic PON1 and MCP-1 expression in rats with liver disease and explored the possible molecular mechanisms involved. METHODS: CCl4 was administered for up to 12 weeks to induce liver damage. Serum and hepatic levels of PON1 and MCP-1, their gene and protein expression, nuclear transcription factors, and histological and biochemical markers of liver impairment were measured. RESULTS: High levels of PON1 and MCP-1 expression were observed at 12th week in the hepatocytes surrounding the fibrous septa and inflammatory areas. CCl4-administered rats had an increased hepatic PON1 concentration that was related to decreased gene transcription and inhibited protein degradation. Decreased PON1 gene transcription was associated with PPARdelta expression. These changes were accompanied by increased hepatic MCP-1 concentration and gene expression. There were significant direct relationships between hepatic PON1 and MCP-1 concentrations (P = 0.005) and between PON1 and the amount of activated stellate cells (P = 0.001). CONCLUSION: Our results from this experimental model suggest a hepato-protective role for PON1 against inflammation, fibrosis and liver disease mediated by MCP-1.

Immunohistochemical analysis of paraoxonases-1, 2, and 3 expression in normal mouse tissues.

The paraoxonase (PON) enzyme family, comprising PON1, PON2, and PON3, are antioxidant enzymes that degrade oxidised phospholipids. We describe the immunohistochemical localisation of the PON proteins in the normal mouse. Antibodies were obtained by inoculating rabbits with peptides derived from specific sequences of mature PONs. PON1 and PON3 were detected in the skin external epithelium, acini of the sebaceous glands, tongue epithelium, acini of the submandibular gland, surface epithelia of the stomach and the intestine, hepatocytes, exocrine pancreas acini, fibre tracts of the encephalon and the spinal cord, skeletal and cardiac muscle, eye lens epithelium and retinal layers, adipocytes, chondrocytes, epithelial cells of the trachea and bronchiole, ovary follicular fluid, seminiferous tubules, spermatozoa, and kidney proximal tubules. PON2 expression was weaker than that of PON1 and PON3, and was absent in some of the tissues studied, such as submandibular gland, nerve cells, and adipocytes. In muscle cells, PON2 expression was restricted to the endomysium. Apolipoprotein A-I did not colocalise with PONs, suggesting local synthesis. This study provides an experimental model to investigate the role played by these enzymes as antioxidants and their relationship with the development of a variety of diseases.

Lipid external quality assessment: commutability between external quality assessment and clinical specimens.

BACKGROUND: Targets for cholesterol reduction are part of the Quality Outcomes Framework and general practitioners have to meet these targets to fulfil their remuneration package. By contrast, there are no targets for the accuracy of cholesterol or other lipid measurements and no recent surveys on performance of these assays. We have assessed the performance of lipid measurement of the available methods in the UK. METHODS: Serum samples collected from individual donors attending the national blood service were distributed after values were obtained from a secondary reference laboratory. Samples were sent to participant laboratories to assess different methods' analytical performance on single donation specimens, on routine external quality assessment pooled specimens, on specimens subjected to a range of freeze-thaw cycles and on frozen-stored specimens. RESULTS: Differences in measured cholesterol were found that were method-dependent and related to triglyceride content. HDL-cholesterol (HDL-C) showed significant positive bias in all assays. Individual donor specimens showed no significant changes with differing numbers of freeze-thaw cycles. Pooled serum was stable for up to six months. CONCLUSIONS: Most cholesterol measurements are accurate but some methods are affected by triglyceride interference. HDL-C methods show significant positive bias. Although there are potential matrix effects introduced as a result of specimen preparation, additional work is needed to show if these effects are present in fresh patient samples.

Serum paraoxonase-1 in chronic alcoholics: relationship with liver disease.

OBJECTIVES: To investigate the relationship between serum paraoxonase-1 and liver damage in chronic alcoholic patients. To assess the diagnostic accuracy of paraoxonase-1 plus standard biochemical tests in the assessment of liver damage in alcoholics. DESIGN AND METHODS: We studied 328 chronic alcoholics and 368 healthy individuals. RESULTS: Paraoxonase-1 activity was decreased and the concentration was increased in alcoholics (P<0.001). The enzyme activity was correlated with albumin (r=0.45; P<0.001) and prothrombin time (r=0.49; P<0.001). Addition of paraoxonase-1 activity measurement to a battery of biochemical tests increased the sensitivity in differentiating between patients and controls up to 96.6% but did not improve the sensitivity in differentiating between subgroups of alcoholics. CONCLUSIONS: Paraoxonase-1 was related to the severity of alcoholic liver disease. Its measurement was useful in discriminating between patients and healthy subjects, but did not add any valuable information in subgroups of alcoholics.

High C-reactive protein and low paraoxonase1 in diabetes as risk factors for coronary heart disease.

BACKGROUND: Paraoxonase1 (PON1) is an anti-inflammatory enzyme located on HDL, which protects against the development of atherosclerosis. C-reactive protein (CRP) is a marker of the inflammatory response in CHD. We hypothesised that low PON1 and high CRP found in CHD may be important markers of CHD and the CRP:PON1 ratio may be an index of the risk of developing atherosclerosis. We have, therefore, compared the levels of PON1 and CRP between control subjects, those with no diabetes and CHD, type 1 diabetes and type 2 diabetes. METHODS AND RESULTS: PON1 activity was different between the populations in the order: controls > type 1 diabetes > type 2 diabetes > CHD with no diabetes (P<0.001). CRP concentration also differed between the populations in the order: controls < type 1 diabetes < type 2 diabetes < CHD with no diabetes (P<0.001). The CRP:PON1 ratio followed the same trend as the CRP concentration (P<0.001). Both CRP and the CRP:PON1 ratio were associated with the presence of CHD. In the control population only, PON1 was a determinant of CRP concentration. Amongst the diabetics, people with CHD had higher levels of CRP (P<0.001) and in comparing the control group with the CHD group, the CHD group had a higher level of CRP (P<0.001). CONCLUSIONS: Higher levels of CRP seem to be generally associated with low levels of PON1 activity, providing a mechanistic link between inflammation and the development of atherosclerosis. However, the relationship between PON1, CRP and atherosclerosis, and the usefulness of the PON1:CRP ratio as a risk factor for CHD requires further evaluation.

Paraoxonase gene polymorphism and serum activity in progressive IgA nephropathy.

BACKGROUND: HDL-associated paraoxonase (PON1) reduces oxidation of lipids in LDL, and activity is inversely related to coronary heart disease risk with a beneficial effect on the development of atherosclerosis. Risk factors associated with atherosclerosis, such as hypertension, dyslipidemia and smoking, also promote the progression of chronic glomerulonephritides which may therefore be associated with perturbations in PON1 activity. METHODS: We performed a genetic association study in patients with IgA nephropathy (IgAN) (n=115) compared with control subjects (n=118). The aim was to test whether polymorphisms in the PON1 coding region (Q192R and L55M) and its promoter (-108C/T and -162A/G) are associated with either IgAN or with the progression. We measured serum paraoxonase activity in 60 out of 115 patients. All patients had been followed up for more than 4 years. RESULTS: There were no differences in the genotype frequency at 3 of the polymorphic sites (Q192R, L55M and -108C/T) between the patients and controls. However, the frequency distribution at -162 position (A/G) was significantly diffe-rent in IgAN (p=0.028, chi-square test) with a higher frequency of the heterozygote (0.017, Fisher exact test [FE]; odds ratio [OR] = 1.99; 95% confidence interval [95% CI], 1.14-3.47). Although there were no differences in the genotype frequency at 3 of the polymorphic sites (Q192R, L55M and -162C/T) between the patients with progressive IgA and the nonprogressive patients, we found that the frequency of the C allele for the -108C/T polymorphism was elevated in those patients with nonprogressive disease (n=85) compared with those with progressive disease (n=30) (61% vs. 47%; p=0.070, FE; OR=1.75, 95% CI, 0.97-3.18). Furthermore, PON1 activity was significantly higher in nonprogressive patients compared with progressors (206 +/- 71 vs. 136 +/- 48; p<0.001), and activity significantly correlated with 1/serum creatinine (SCr) (p<0.001; r=0.38). CONCLUSIONS: The results of this study suggest that in IgAN, lower PON1 activity may be associated with the deterioration of kidney function. This could be due to variable expression of the PON1 gene, or a functional effect of the gene product.

Low paraoxonase activity predicts coronary events in the Caerphilly Prospective Study.

BACKGROUND: The hypothesis that paraoxonase (PON1) has a role in preventing atherosclerosis is based on experimental, transgenic, and case-control studies but has not previously been tested prospectively. METHODS AND RESULTS: The Caerphilly Prospective Study is a cohort study of men aged 49 to 65 years observed for coronary heart disease (CHD) events (fatal and nonfatal myocardial infarction) over a mean period of 15 years. Serum PON1 activity toward paraoxon was measured in 1353 participants. PON1 activity was 20% lower in the 163 men who had a coronary event (P=0.039). Men in the highest quintile of PON1 activity had a decreased risk compared with those in the lowest quintile (OR 0.57 [95% CI, 0.33 to 0.96]). The inverse relationship between quintiles of serum PON1 activity and CHD risk was graded, the median change in OR across each quintile being 0.87 (0.77 to 0.98). After adjustment for all other CHD risk factors, including HDL cholesterol, this median value became 0.90 (0.78 to 1.02). PON1 was most predictive of a new CHD event in patients at highest risk by virtue of preexisting CHD (adjusted median OR for each quintile, 0.74 [0.59 to 0.93]; n=313) or the presence of other risk factors. For the highest tertile of CHD risk (n=390) calculated by the Framingham equation, adjusted median OR for each quintile was 0.84 (0.66 to 1.05); n=390. CONCLUSIONS: Low serum PON1 activity toward paraoxon is an independent risk factor for coronary events in men at high risk because of preexisting disease or other CHD risk factors.

Systemic lupus erythematosus: an independent risk factor for endothelial dysfunction in women.

BACKGROUND: Systemic lupus erythematosus (SLE) patients have a significantly increased risk of coronary heart disease (CHD) that is not fully explained by classic risk factors. Endothelial dysfunction is an early stage in the process of atherogenesis. Our aim was to determine whether endothelial dysfunction occurs in SLE and whether it is associated with the occurrence of classic Framingham risk factors. METHODS AND RESULTS: We studied 62 women with SLE (1997 revised criteria) and 38 healthy women. Demographic and risk factor data were collected. In patients, disease activity and treatment-related parameters were also assessed. Endothelial function was assessed by flow-mediated dilation (FMD) in the brachial artery in response to reactive hyperemia. Carotid intima-media thickness (IMT) and the presence of carotid plaques were also assessed in SLE patients. FMD was impaired in SLE patients (median, 3.6%; range, -6.3% to 13.7%; versus median, 6.9%; range, -6.6% to 17.8%, P<0.01). Using multiple regression analysis that included all subjects in which we retained all the classic CHD risk factors, we found that systolic blood pressure (P=0.019) and SLE (P=0.017) were significantly associated with impaired FMD. Within SLE patients, IMT showed a negative correlation with percent FMD (r=-0.37, P<0.01). In stepwise multiple regression of SLE patients only that also included SLE factors and IMT, IMT alone was independently associated with FMD (P=0.037). CONCLUSIONS: Patients with SLE have endothelial dysfunction that remained significant even after adjustment for other classic CHD risk factors. Within SLE patients, endothelial dysfunction correlates negatively with IMT, another marker of early atherosclerosis. Understanding the mechanism(s) of endothelial dysfunction in SLE may suggest novel strategies for CHD prevention in this context.

Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial.

BACKGROUND: Type 2 diabetes is associated with a substantially increased risk of cardiovascular disease, but the role of lipid-lowering therapy with statins for the primary prevention of cardiovascular disease in diabetes is inadequately defined. We aimed to assess the effectiveness of atorvastatin 10 mg daily for primary prevention of major cardiovascular events in patients with type 2 diabetes without high concentrations of LDL-cholesterol. METHODS: 2838 patients aged 40-75 years in 132 centres in the UK and Ireland were randomised to placebo (n=1410) or atorvastatin 10 mg daily (n=1428). Study entrants had no documented previous history of cardiovascular disease, an LDL-cholesterol concentration of 4.14 mmol/L or lower, a fasting triglyceride amount of 6.78 mmol/L or less, and at least one of the following: retinopathy, albuminuria, current smoking, or hypertension. The primary endpoint was time to first occurrence of the following: acute coronary heart disease events, coronary revascularisation, or stroke. Analysis was by intention to treat. FINDINGS: The trial was terminated 2 years earlier than expected because the prespecified early stopping rule for efficacy had been met. Median duration of follow-up was 3.9 years (IQR 3.0-4.7). 127 patients allocated placebo (2.46 per 100 person-years at risk) and 83 allocated atorvastatin (1.54 per 100 person-years at risk) had at least one major cardiovascular event (rate reduction 37% [95% CI -52 to -17], p=0.001). Treatment would be expected to prevent at least 37 major vascular events per 1000 such people treated for 4 years. Assessed separately, acute coronary heart disease events were reduced by 36% (-55 to -9), coronary revascularisations by 31% (-59 to 16), and rate of stroke by 48% (-69 to -11). Atorvastatin reduced the death rate by 27% (-48 to 1, p=0.059). No excess of adverse events was noted in the atorvastatin group. INTERPRETATION: Atorvastatin 10 mg daily is safe and efficacious in reducing the risk of first cardiovascular disease events, including stroke, in patients with type 2 diabetes without high LDL-cholesterol. No justification is available for having a particular threshold level of LDL-cholesterol as the sole arbiter of which patients with type 2 diabetes should receive statins. The debate about whether all people with this disorder warrant statin treatment should now focus on whether any patients are at sufficiently low risk for this treatment to be withheld.