Effect of atorvastatin on C-reactive protein and benefits for cardiovascular disease in patients with type 2 diabetes: analyses from the Collaborative Atorvastatin Diabetes Trial.

AIMS/HYPOTHESIS: We investigated whether atorvastatin 10 mg daily lowered C-reactive protein (CRP) and whether the effects of atorvastatin on cardiovascular disease (CVD) varied by achieved levels of CRP and LDL-cholesterol. METHODS: CRP levels were measured at baseline and 1 year after randomisation to atorvastatin in 2,322 patients with type 2 diabetes (40-75 years, 69% males) in a secondary analysis of the Collaborative Atorvastatin Diabetes Study, a randomised placebo-controlled trial. We used Cox regression models to test the effects on subsequent CVD events (n = 147) of CRP and LDL-cholesterol lowering at 1 year. RESULTS: After 1 year, the atorvastatin arm showed a net CRP lowering of 32% (95% CI -40%, -22%) compared with placebo. The CRP response was highly variable, with 45% of those on atorvastatin having no decrease in CRP (median [interquartile range, IQR] per cent change -9.8% [-57%, 115%]). The LDL-cholesterol response was less variable, with a median (IQR) within-person per cent change of -41% (-51%, -31%). Baseline CRP did not predict CVD over 3.8 years of follow-up (HRper SD log 0.89 [95% CI 0.75, 1.06]), whereas baseline LDL-cholesterol predicted CVD (HRper SD 1.21 [95% CI 1.02, 1.44]), as did on-treatment LDL-cholesterol. There was no significant difference in the reduction in CVD by atorvastatin, with above median (HR 0.57) or below median (HR 0.52) change in CRP or change in LDL-cholesterol (HR 0.61 vs 0.50). CONCLUSIONS/INTERPRETATION: CRP was not a strong predictor of CVD. Statin efficacy did not vary with achieved CRP despite considerable variability in CRP response. The use of CRP as an indicator of efficacy of statin therapy on CVD risk in patients with type 2 diabetes is not supported by these data. Trial registration NCT00327418.

Small dense LDL is more susceptible to glycation than more buoyant LDL in Type 2 diabetes.

Glycation of apoB (apolipoprotein B) of LDL (low-density lipoprotein) increases its atherogenicity. Concentrations of both serum glyc-apoB (glycated apoB) and SD-LDL (small dense LDL) (syn LDL3; D=1.044-1.063 g/ml) are increased in diabetes and are closely correlated. We studied whether SD-LDL is more susceptible to glycation in vitro than more buoyant LDL in statin- and non-statin-treated Type 2 diabetes mellitus. Serum SD-LDL apoB and glyc-apoB on statins was 20±2 (means±S.D.) and 3.6±0.41 compared with 47±3 and 5.89±0.68 mg/dl in those not receiving statins (P<0.001 and <0.01, respectively). There was a dose-dependent increase in glycation on incubation of LDL subfractions with glucose, which was accompanied by an increase in LPO (lipid peroxide) and electrophoretic mobility and a decrease in free amino groups. SD-LDL was more susceptible to these changes than more buoyant LDL. Both SD-LDL and more buoyant LDL from statin-treated patients were less susceptible to glycation. There were fewer free amino groups on LDL subfractions from statin-treated patients, which may contribute to this resistance. In conclusion, greater susceptibility of SD-LDL to glycation is likely to contribute to the raised levels of circulating glyc-apoB in diabetes. Statins are associated with lower levels of both SD-LDL and glyc-apoB.

Genome-wide association study of genetic determinants of LDL-c response to atorvastatin therapy: importance of Lp(a).

We carried out a genome-wide association study (GWAS) of LDL-c response to statin using data from participants in the Collaborative Atorvastatin Diabetes Study (CARDS; n = 1,156), the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT; n = 895), and the observational phase of ASCOT (n = 651), all of whom were prescribed atorvastatin 10 mg. Following genome-wide imputation, we combined data from the three studies in a meta-analysis. We found associations of LDL-c response to atorvastatin that reached genome-wide significance at rs10455872 (P = 6.13 × 10(-9)) within the LPA gene and at two single nucleotide polymorphisms (SNP) within the APOE region (rs445925; P = 2.22 × 10(-16) and rs4420638; P = 1.01 × 10(-11)) that are proxies for the ε2 and ε4 variants, respectively, in APOE. The novel association with the LPA SNP was replicated in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) trial (P = 0.009). Using CARDS data, we further showed that atorvastatin therapy did not alter lipoprotein(a) [Lp(a)] and that Lp(a) levels accounted for all of the associations of SNPs in the LPA gene and the apparent LDL-c response levels. However, statin therapy had a similar effect in reducing cardiovascular disease (CVD) in patients in the top quartile for serum Lp(a) levels (HR = 0.60) compared with those in the lower three quartiles (HR = 0.66; P = 0.8 for interaction). The data emphasize that high Lp(a) levels affect the measurement of LDL-c and the clinical estimation of LDL-c response. Therefore, an apparently lower LDL-c response to statin therapy may indicate a need for measurement of Lp(a). However, statin therapy seems beneficial even in those with high Lp(a).

Postreceptor insulin resistance contributes to human dyslipidemia and hepatic steatosis.

Metabolic dyslipidemia is characterized by high circulating triglyceride (TG) and low HDL cholesterol levels and is frequently accompanied by hepatic steatosis. Increased hepatic lipogenesis contributes to both of these problems. Because insulin fails to suppress gluconeogenesis but continues to stimulate lipogenesis in both obese and lipodystrophic insulin-resistant mice, it has been proposed that a selective postreceptor defect in hepatic insulin action is central to the pathogenesis of fatty liver and hypertriglyceridemia in these mice. Here we show that humans with generalized insulin resistance caused by either mutations in the insulin receptor gene or inhibitory antibodies specific for the insulin receptor uniformly exhibited low serum TG and normal HDL cholesterol levels. This was due at least in part to surprisingly low rates of de novo lipogenesis and was associated with low liver fat content and the production of TG-depleted VLDL cholesterol particles. In contrast, humans with a selective postreceptor defect in AKT2 manifest increased lipogenesis, elevated liver fat content, TG-enriched VLDL, hypertriglyceridemia, and low HDL cholesterol levels. People with lipodystrophy, a disorder characterized by particularly severe insulin resistance and dyslipidemia, demonstrated similar abnormalities. Collectively these data from humans with molecularly characterized forms of insulin resistance suggest that partial postreceptor hepatic insulin resistance is a key element in the development of metabolic dyslipidemia and hepatic steatosis.

Decorin GAG synthesis and TGF-ß signaling mediate Ox-LDL-induced mineralization of human vascular smooth muscle cells.

OBJECTIVE: Decorin and oxidized low-density lipoprotein (Ox-LDL) independently induce osteogenic differentiation of vascular smooth muscle cells (VSMCs). We aimed to determine whether decorin glycosaminoglycan (GAG) chain synthesis contributes to Ox-LDL-induced differentiation and calcification of human VSMCs in vitro. METHODS AND RESULTS: Human VSMCs treated with Ox-LDL to induce oxidative stress showed increased alkaline phosphatase (ALP) activity, accelerated mineralization, and a difference in both decorin GAG chain biosynthesis and CS/DS structure compared with untreated controls. Ox-LDL increased mRNA abundance of both xylosyltransferase (XT)-I, the key enzyme responsible for GAG chain biosynthesis and Msx2, a marker of osteogenic differentiation. Furthermore, downregulation of XT-I expression using small interfering RNA blocked Ox-LDL-induced VSMC mineralization. Adenoviral-mediated overexpression of decorin, but not a mutated unglycanated form, accelerated mineralization of VSMCs, suggesting GAG chain addition on decorin is crucial for the process of differentiation. The decorin-induced VSMC osteogenic differentiation involved activation of the transforming growth factor (TGF)-ß pathway, because it was attenuated by blocking of TGF-ß receptor signaling and because decorin overexpression potentiated phosphorylation of the downstream signaling molecule smad2. CONCLUSIONS: These studies provide direct evidence that oxidative stress-mediated decorin GAG chain synthesis triggers TGF-ß signaling and mineralization of VSMCs in vitro.

Variation in paraoxonase-1 activity and atherosclerosis.

PURPOSE OF REVIEW: Paraoxonase-1 (PON1) is an HDL-associated protein of 354 amino acids with a molecular mass of 43 000 Da. It is synthesized in the liver, and in serum it is almost exclusively associated with HDL. PON1 has been reported to be an important contributor to the antioxidant and anti-inflammatory activities of HDL. PON1 impedes oxidative modification of LDL. PON1 serum activity is related to systemic lipid peroxidation stress and prospective cardiovascular risk. In this review, we discuss the relationship between PON1 activity and atherosclerotic diseases and various factors modulating PON1 activity including genes, age, lifestyle factors and medical conditions. Finally, evidence that pharmacological agents may affect PON1 activity is summarized. RECENT FINDINGS: There is increasing evidence from both animal and human studies linking low PON1 activity to an increased likelihood of cardiovascular diseases. Two prospective studies reported a significantly lower incidence of major cardiovascular events in participants with the highest systemic PON1 activity, compared with those with the lowest activity. SUMMARY: PON1 is a potentially antiatherogenic HDL-associated enzyme that protects LDL from oxidative modification. Enhancing PON1 activity could be an important target for future pharmacological agents aimed at decreasing cardiovascular risk.

Targets of statin therapy: LDL cholesterol, non-HDL cholesterol, and apolipoprotein B in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS).

BACKGROUND: LDL can vary considerably in its cholesterol content; thus, lowering LDL cholesterol (LDLC) as a goal of statin treatment implies the existence of considerable variation in the extent to which statin treatment removes circulating LDL particles. This consideration is particularly applicable in diabetes mellitus, in which LDL is frequently depleted of cholesterol. METHODS: Type 2 diabetes patients randomly allocated to 10 mg/day atorvastatin (n = 1154) or to placebo (n = 1196) for 1 year were studied to compare spontaneous and statin-induced apolipoprotein B (apo B) concentrations (a measure of LDL particle concentration) at LDLC and non-HDL cholesterol (non-HDLC) concentrations proposed as statin targets in type 2 diabetes. RESULTS: Patients treated with atorvastatin produced lower serum apo B concentrations at any given LDLC concentration than patients on placebo. An LDLC concentration of 1.8 mmol/L (70 mg/dL) during atorvastatin treatment was equivalent to a non-HDLC concentration of 2.59 mmol/L (100 mg/dL) or an apo B concentration of 0.8 g/L. At the more conservative LDLC targets of 2.59 mmol/L (100 mg/dL) and 3.37 mmol/L (130 mg/dL) for non-HDLC, however, the apo B concentration exceeded the 0.9-g/L value anticipated in the recent Consensus Statement from the American Diabetes Association and the American College of Cardiology. CONCLUSIONS: The apo B concentration provides a more consistent goal for statin treatment than the LDLC or non-HDLC concentration.

Effects of atorvastatin on kidney outcomes and cardiovascular disease in patients with diabetes: an analysis from the Collaborative Atorvastatin Diabetes Study (CARDS).

BACKGROUND: We examined whether atorvastatin affects diabetic kidney disease and whether the effect of atorvastatin on cardiovascular disease (CVD) varies by kidney status in patients with diabetes. STUDY DESIGN: The Collaborative Atorvastatin Diabetes Study (CARDS) randomized placebo-controlled trial. SETTING & PARTICIPANTS: Patients with type 2 diabetes and no prior CVD (n = 2,838). INTERVENTION: Random allocation to atorvastatin, 10 mg/d, or placebo, with a median follow-up of 3.9 years. OUTCOMES: Estimated glomerular filtration rate (eGFR), albuminuria, CVD. MEASUREMENTS: Baseline and follow-up GFRs were estimated by using the Modification of Diet in Renal Disease Study equation. Urinary albumin-creatinine ratio was measured on spot urine samples. RESULTS: At baseline, 34% of patients had an eGFR of 30 to 60 mL/min/1.73 m(2). Atorvastatin treatment was associated with a modest improvement in annual change in eGFR (net, 0.18 mL/min/1.73 m(2)/y; 95% confidence interval [CI], 0.04 to 0.32; P = 0.01) that was most apparent in those with albuminuria (net improvement, 0.38 mL/min/1.73 m(2)/y; P = 0.03). At baseline, 21.5% of patients had albuminuria and an additional 6.8% developed albuminuria during follow-up. Atorvastatin did not influence the incidence of albuminuria (hazard ratio, 1.49; 95% CI, 0.73 to 3.04; P = 0.3) or regression to normoalbuminuria (hazard ratio, 1.19; 95% CI, 0.57 to 2.49; P = 0.6). In 970 patients with a moderately decreased eGFR of 30 to 60 mL/min/1.73 m(2), there was a 42% reduction in major CVD events with treatment, including a 61% reduction in stroke. This treatment effect was similar to the 37% (95% CI, 17 to 52; P < 0.001) reduction in CVD observed in the study overall (P = 0.4 for the eGFR-treatment interaction). LIMITATIONS: Low incidence rates of albuminuria and transition to more severe kidney status limit power to detect treatment effects. CONCLUSIONS: A modest beneficial effect of atorvastatin on eGFR, particularly in those with albuminuria, was observed. Atorvastatin did not influence albuminuria incidence. Atorvastatin was effective at decreasing CVD in those with and without a moderately decreased eGFR and achieved a high absolute benefit.

Increased C-reactive protein levels in overweight and obese women taking exogenous hormones: the United Kingdom Women's Heart Study (UKWHS).

OBJECTIVE: Women's cardiovascular risk factors, including inflammatory markers such as C-reactive protein (CRP) which is emerging as a major association with cardiovascular disease (CVD) risk, can be influenced by the oral contraceptive (OC) pill in premenopausal and hormone replacement (HR) in postmenopausal women and by central adiposity which is associated with a heightened inflammatory state. The interaction between central obesity and different hormone use in both pre and postmenopausal women has not previously been reported in a study spanning the whole age range associated with hormone use. DESIGN: Observational, cross-sectional study. PATIENTS: Only healthy women were included in this study. MEASUREMENTS: A total of 21,310 women aged 30-64 employed by Marks & Spencer participated. They completed a health questionnaire and were screened for CVD risk factors including blood pressure, weight, height, waist and hip circumference, lipids and lipoproteins, CRP and fibrinogen. RESULTS: Compared with non-users, women who took the OC or HR had significantly higher CRP levels. This was more marked than effects on other CVD risk factors. It was further compounded by the independent effect of increased waist circumference. The CRP increase was greatest (more than twice that of nonhormone users) in premenopausal women with the highest quartile of waist circumference who took the combined contraceptive pill. CONCLUSIONS: Women who received first the combined OC and then HR may be exposed over much of their life to high CRP levels aggravated by central obesity. The health consequences of this require further investigation.

Squalene synthase inhibitors : clinical pharmacology and cholesterol-lowering potential.

HMG-CoA reductase inhibitors (statins) reduce cardiovascular disease morbidity and mortality with a high level of safety. Nonetheless, there are substantial numbers of people who either do not tolerate statins or whose low-density lipoprotein (LDL) levels are not lowered adequately. For these reasons, there is a need to develop other cholesterol-lowering drugs. A target for these new agents is provided by the enzymes distal to HMG-CoA reductase in the cholesterol biosynthesis pathway. Two classes of drugs have been developed: (i) squalene synthase inhibitors, which act at the first committed step in cholesterol biosynthesis, distal to the mevalonate-farnesyl diphosphate pathway; and (ii) oxidosqualene cyclase inhibitors, which act distal to the squalene intermediate. Of these, squalene synthase inhibitors have received more attention and are the subject of this review. Squalene synthase inhibitors decrease circulating LDL-cholesterol by the induction of hepatic LDL receptors in a similar manner to statins. They have fewer secondary effects mediated by a decrease in non-cholesterol products of mevalonate metabolism distal to HMG-CoA reductase, but have the potential to increase intermediates proximal to squalene. Squalene synthase inhibitors are just now entering clinical trials and data on how effectively they lower LDL-cholesterol and how they compliment the actions of statins and other agents is awaited with considerable interest.

The robustness of the Roche 2nd generation homogenous HDL cholesterol (PEGME) method: assessment of the effect of serum sample storage for up to 8 years at -80 degrees C.

BACKGROUND: Low HDL-cholesterol (HDL-C) is a strong and independent cardiovascular risk factor. Clinical trials often necessitate storage of samples before assay. Results are lacking for longer-term storage with quantification of HDL-C using different methods before and after storage. METHODS: Serum samples (n=2936) from the Collaborative Atorvastatin Diabetes Study in which HDL-C had been determined on 'fresh' samples using the MnCl(2)/heparin method before freezing and storage for up to 8 years at -80 degrees C were thawed and HDL-C was determined using the Roche direct method. We participated in the Riqas QC programme and results obtained for the control serum samples using a CDC-approved method were used to generate a regression equation and thus to adjust both original results, obtained after precipitation and also to align the direct HDL-C results. RESULTS: CDC-aligned HDL-C results for stored samples were lower than CDC-aligned HDL-C results before storage (mean [S.E.M.]: 1.41 [0.01] vs. 1.43 [0.01] mmol/L; P<0.0001, n=2936). Although results after storage tended to be lower, there was no significant time-dependent change in the ratio of original to stored results for HDL-C. CONCLUSIONS: The study establishes that the Roche 2nd generation PEGME method is robust and eminently suitable for determinations of HDL-C in stored serum samples.

Adiponectin in umbilical cord blood is inversely related to low-density lipoprotein cholesterol but not ethnicity.

CONTEXT: Adiponectin is a recognized protective risk marker for cardiovascular disease in adults and is associated with an optimal lipid profile. The role of adiponectin at birth is not well understood, and its relationship with the neonatal lipid profile is unknown. Because ethnic disparities in cardiovascular risk have been attributed to low adiponectin and its associated low high-density lipoprotein cholesterol (HDL-C), investigation at birth may help determine the etiology of these risk patterns. OBJECTIVE: Our objective was to investigate the relationship between neonatal adiponectin and lipid profile at birth in two ethnic groups in cord blood. DESIGN, SETTING, AND PARTICIPANTS: Seventy-four healthy mothers and their newborns of South Asian and White European origin were studied in this cross-sectional study at St. Mary's Hospital, Manchester, United Kingdom. MAIN OUTCOME MEASURES: Serum adiponectin, total cholesterol, HDL-C, low-density lipoprotein cholesterol (LDL-C), and triglyceride levels were measured in umbilical venous blood at birth and in maternal blood collected at 28 wk gestation. RESULTS: Cord adiponectin was significantly inversely associated with cord LDL-C (r = -0.32; P = 0.005) but not HDL-C. In a multiple regression analysis, cord LDL-C remained the most significant association of cord adiponectin (beta = -0.13; P < 0.001). We did not find any significant ethnic differences in cord adiponectin or lipids with the exception of triglycerides, which were significantly lower in South Asian newborns (P < 0.05). CONCLUSION: This is the first report of an inverse relationship between cord adiponectin and LDL-C at birth. In contrast to adult studies, we found no significant association between adiponectin and HDL-C in cord blood. Our results and the strong independent association between adiponectin and HDL-C observed in adult studies suggest a role for adiponectin in lipid metabolism. Ethnic differences in adiponectin may arise after birth.

Effects of dydrogesterone and norethisterone, in combination with oestradiol, on lipoproteins and inflammatory markers in postmenopausal women.

OBJECTIVE: The lack of cardiovascular benefit from postmenopausal hormone replacement therapy (HRT) in randomised controlled trials is not readily explained. The androgenic properties of progestogens could be crucial in understanding the results of these studies, all of which employed medroxyprogesterone. We have previously reported that medroxyprogesterone has some androgenic effects intermediate between those of the more androgenic norethisterone and the less androgenic desogestrel. To examine the androgenicity of progestogens further, we compared the effects of dydrogesterone (DGT) that is even less androgenic than desogestrel, and norethisterone (NET), on lipoproteins and inflammatory markers while maintaining the same oestrogen dose. METHOD: In a crossover trial, 25 non-hysterectomised postmenopausal women were randomised to two preparations of HRT each for three 28-day treatment cycles. Both HRT regimens comprised oestradiol (1mg). One also included DGT (10mg) and the other NET (1mg). Oestradiol was taken continuously and the progestogens sequentially. Measurements were made at baseline and on the last day of the oestradiol phase and the last day of the progestogen phase in the third treatment cycle of each regimen. RESULTS: NET was more effective than DGT in significantly reducing lipoprotein (a) (p < 0.05). NET was, however, associated with significantly lower levels of high-density lipoprotein (HDL) cholesterol (p = 0.001) and triglycerides (p < 0.05). NET was less effective in opposing the oestrogen-related increase in C-reactive protein (CRP). Interleukin-6 levels did not change with either progestogen. CONCLUSION: The effect of androgenic progestogens on cardiovascular risk factors may not be as deleterious as previously assumed, especially if the lower HDL levels result from more efficient reverse cholesterol transport. The hormone related rise in C-reactive protein, without a corresponding increase in interleukin-6, may not represent a systemic inflammatory response.

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.

High-density lipoprotein impedes glycation of low-density lipoprotein.

Glycation of low-density lipoprotein (LDL) increases its atherogenicity, but whether high-density lipoprotein (HDL) can protect LDL against glycation is not known. LDL and HDL were isolated from 32 volunteers with serum HDL cholesterol concentrations ranging from 0.76 to 2.01 (mean = 1.36) mmol/L. Glycation of LDL was induced by incubation with 0-80 mmol/L glucose for 7 days at 37°C under nitrogen in the presence of and absence of human HDL. Glycation of LDL apolipoprotein B (apoB) doubled at glucose 50 and 80 mmol/L (both p < 0.001), and this increase was ameliorated by HDL. In the absence of glucose, 0.11 (0.01) [mean (standard error, SE)] mg apoB/mg LDL protein was glycated increasing to 0.22 (0.02) mg/mg at glucose 80 mmol/L in the absence of HDL, but remaining at 0.13 (0.01) mg/mg when autologous HDL was present. Heterologous HDL from a further study of 12 healthy participants was similarly effective in impeding LDL apoB glycation. HDL impeded not only glycation but also the lipid peroxidation, free amino group consumption and increased electrophoretic mobility of LDL which accompanied glycation. HDL from participants with higher serum paraoxonase1 (PON1) was more effective in impeding glycation and the related processes. In conclusion, HDL can impede the glucose-induced glycoxidation of LDL. PON1 may be important for this function of HDL.

Serum sphingolipids level as a novel potential marker for early detection of human myocardial ischaemic injury.

BACKGROUND: Ventricular tachyarrhythmias are the most common and often the first manifestation of coronary heart disease and lead to sudden cardiac death (SCD). Early detection/identification of acute myocardial ischaemic injury at risk for malignant ventricular arrhythmias in patients remains an unmet medical need. In the present study, we examined the sphingolipids level after transient cardiac ischaemia following temporary coronary artery occlusion during percutaneous coronary intervention (PCI) in patients and determined the role of sphingolipids level as a novel marker for early detection of human myocardial ischaemic injury. METHODS AND RESULTS: Venous samples were collected from either the coronary sinus (n = 7) or femoral vein (n = 24) from 31 patients aged 40-73 years-old at 1, 5 min, and 12 h, following elective PCI. Plasma sphingolipids levels were assessed by HPLC. At 1 min coronary sinus levels of sphingosine 1-phosphate (S1P), sphingosine (SPH), and sphinganine (SA) were increased by 314, 115, and 614%, respectively (n = 7), while peripheral blood levels increased by 79, 68, and 272% (n = 24). By 5 min, coronary sinus S1P and SPH levels increased further (720%, 117%), as did peripheral levels of S1P alone (792%). Where troponin T was detectable at 12 h (10 of 31), a strong correlation was found with peak S1P (R (2) = 0.818; P < 0.0001). CONCLUSION: For the first time, we demonstrate the behavior of plasma sphingolipids following transient cardiac ischaemia in humans. The observation supports the important role of sphingolipids level as a potential novel marker of transient or prolonged myocardial ischaemia.

Apolipoprotein B100 is a better treatment target than calculated LDL and non-HDL cholesterol in statin-treated patients.

INTRODUCTION: Clinical trials have shown that apolipoprotein B100 (apoB) is better than calculated low-density lipoprotein cholesterol (c-LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) as a target for statin treatment. However, there are no published reports of how well these targets are reached in patients with more severe hyperlipidaemias than represented in trials, as seen in lipid clinics. METHODS: We audited 195 patients attending a tertiary centre lipid clinic, who had been treated with a statin for more than one year. We measured total cholesterol, HDL-cholesterol (HDL-C) and triglyceride and from these calculated LDL-cholesterol (LDL-C) and non-HDL-C. We determined the average measured apoB values, at critical target values of LDL-C and non-HDL-C, by linear regression and compared them with values of apoB considered equivalent to these cholesterol indexes by expert groups. We also assessed the number of patients, both before and after treatment, in whom c-LDL-C and non-HDL-C could not be calculated due to hypertriglyceridaemia. RESULTS: At the LDL-C target of 2.6 mmol L(-1) and the non-HDL-C target of 3.4 mmol L(-1), the measured apoB values were significantly higher than consensus apoB target values. The difference was most marked for c-LDL-C in hypertriglyceridaemic subjects and for non-HDL-C in patients without hypertriglyceridaemia. A similar pattern was seen using centile-derived consensus values but the differences were accentuated because this approach generates lower equivalent consensus apoB values. CONCLUSION: ApoB offers a more consistent treatment target independent of hypertriglyceridaemia and would obviate technical problems related to high triglycerides.

Adiponectin and lipid profiles compared with insulins in relation to early growth of British South Asian and European children: the Manchester children's growth and vascular health study.

CONTEXT: Adiponectin, high-density lipoprotein cholesterol (HDL-C) and insulin concentrations may be important in the pathophysiology of cardiovascular disease. OBJECTIVE: We tested the hypothesis that serum adiponectin rather than insulin differs from early life, between South Asians and Europeans, with a potentially key role in excess cardiovascular risk characteristic of adult South Asians. DESIGN AND PARTICIPANTS: We conducted a longitudinal study of 215 British-born children of European (n = 138) and South Asian (n = 77) origin, from birth to 3 yr. MAIN OUTCOME MEASURE: Serum adiponectin, insulin, proinsulin and HDL-C concentrations were assessed in relation to ethnic group and growth in anthropometric variables from 0-3 yr of age. RESULTS: Serum adiponectin was lower in South Asian children, despite their smaller size, notable at age 3-6 months (9.5 vs. 11.8 mg/liter; P = 0.04), with no ethnic differences in serum lipids or insulin or proinsulin. In mixed-effects longitudinal models for HDL-C, determinants were adiponectin (P = 0.034), age (P < 0.001), and body mass index (P < 0.001) but not ethnicity. None of these or growth variables affected either insulin or proinsulin. In a fully adjusted mixed-effects longitudinal model including age, sex, insulin, and proinsulin, the independent determinants of serum adiponectin were height [21.3 (95% confidence interval = 31.7-10.8 cm lower, for every 1 mmol/liter increase in adiponectin, P < 0.001], HDL-C [2.8 (1.3-4.2) mmol/liter higher, P < 0.0001], body mass index (lower, P = 0.03), and South Asian ethnicity (lower, P = 0.01). CONCLUSIONS: These British South Asian-origin infants have lower serum adiponectin but no differences in HDL-C or insulin molecules. In South Asians, factors affecting adiponectin metabolism in early life, rather than insulin resistance, likely determine later excess cardiovascular risk.

Total soluble and endogenous secretory receptor for advanced glycation end products as predictive biomarkers of coronary heart disease risk in patients with type 2 diabetes: an analysis from the CARDS trial.

OBJECTIVE: Circulating levels of soluble receptor for advanced glycation end products (sRAGE) likely comprise both a secreted isoform (esRAGE) and wild-type RAGE cleaved from the cell membrane. Both sRAGE and esRAGE have been proposed as biomarkers of cardiovascular disease (CVD), but prospective data are limited. We examined the relationship of sRAGE and esRAGE to incident coronary heart disease (CHD) and stroke in type 2 diabetic patients followed for 3.9 years in a trial of atorvastatin: the Collaborative Atorvastatin Diabetes Study (CARDS). RESEARCH DESIGN AND METHODS: We used a nested case-control design sampling all incident cases of CVD with available plasma and randomly selecting three control subjects, who were free of CVD throughout follow-up, per case. Analysis was by Cox regression with adjustment for treatment allocation and relevant covariates. RESULTS: sRAGE and esRAGE were strongly correlated (ρ = 0.88) and were both higher in those with lower BMI (P < 0.001), higher adiponectin (P < 0.001), lower estimated glomerular filtration rate (P = 0.009), and white ethnicity (P < 0.001). Both sRAGE and esRAGE were associated with incident CHD events, independently of treatment allocation and the above factors; hazard ratio (HR) = 1.74 (95% CI 1.25-2.41; P = 0.002) for a doubling of the sRAGE level; HR = 1.45 (1.11-1.89; P = 0.006) for a doubling of the esRAGE level. There was no significant association with stroke; HR for sRAGE = 0.66 (0.38-1.14). Atorvastatin, 10 mg daily, did not alter sRAGE. CONCLUSIONS: Higher levels of sRAGE and esRAGE are associated with incident CHD but not stroke in type 2 diabetes.

Small-dense LDL and LDL glycation in metabolic syndrome and in statin-treated and non-statin-treated type 2 diabetes.

Small-dense LDL (SD-LDL) has been particularly implicated in atherosclerosis. It has previously been reported that in non-diabetic people SD-LDL is preferentially glycated. The distribution of glycated apolipoprotein B (glyc-apoB) in lipoproteins in metabolic syndrome (MS) and in type 2 diabetes has not previously been studied. Plasma apoB and glyc-apoB were determined in different apoB-containing lipoproteins including buoyant and SD-LDL in MS (n=18) and type 2 diabetes (DM) [n=48; 12 statin-untreated (DM-S) and 36 statin-treated (DM+S)]. Plasma glyc-apoB was 5.6 ± 0.9, 3.5 ± 0.5 and 4.0 ± 0.2 mg/dl in DM-S, DM+S and MS, respectively. The glycated proportion of SD-LDL-apoB was greater than buoyant LDL in all groups. SD-LDL contributed most to plasma glyc-apoB in DM-S, because SD-LDL-apoB was higher in DM-S than in MS and DM+S (p < 0.001). Plasma glyc-apoB correlated with SD-LDL-apoB (r=0.74, p < 0.0001 in diabetes and r=0.53, p < 0.001 in MS), but not with HbA(1c). SD-LDL is preferentially glycated in type 2 diabetes and MS. Its concentration is a stronger determinant of plasma glycapoB than glycaemia. Statin-induced changes in its level may be important in decreasing apoB glycation in diabetes. These findings may explain the small effect of improving glycaemia relative to statin treatment in reducing atherosclerosis risk in type 2 diabetes and the increased risk in MS even before the onset of type 2 diabetes.