Cardiovascular outcomes among participants with diabetes in the recent large statin trials

Does Statin Therapy Reduce the Risks of Mortality and Major Adverse Cardiac and Cerebrovascular Events in Young Adults with End-Stage Renal Disease? Population-Based Cohort Study

Among hemodialysis patients aged more than 40 years old, previous large-scale studies showed statin treatment had no effect on reducing cardiovascular adverse events. However, young-adult-onset end-stage renal disease (ESRD) patients have different physicosocial factors compared to older ESRD patients. The benefit of statins in such a specific group has not been well evaluated. Through the use of Taiwan's National Health Insurance Research Database (NHIRD), young adult patients aged 20-40 with incident ESRD requiring permanent dialysis between 1 January 2003 and 31 December 2015 were identified. The enrollees were further divided into two groups depending on whether they received statin therapy for more than 90 days (statin group) or never received any statin (nonstatin group) in the first year after initiation of dialysis. Propensity score weighting (PSW) was used to balance the baseline characteristics between the two groups. After PSW, the statin group (n = 771) exhibited a higher rate of major adverse cardiac and cerebrovascular events (MACCEs) (2.65% vs. 1.44%, hazard ratio (HR): 1.87, 95% confidence interval (CI): 1.43-2.45), and acute myocardial infarction (1.51% vs. 0.30%, HR: 5.34, 95% CI: 3.40-8.39) compared to the nonstatin group (n = 1709). The risk of all-cause mortality, cardiovascular (CV) death. and stroke did not significantly differ between the two groups. Similar to older patients, this study demonstrated that statin therapy cannot offer any protective effects in reducing CV outcomes among young adult ESRD patients undergoing dialysis.

Neutrophil extracellular traps promote macrophage inflammation and impair atherosclerosis resolution in diabetic mice

Neutrophil extracellular traps (NETs) promote inflammation and atherosclerosis progression. NETs are increased in diabetes and impair the resolution of inflammation during wound healing. Atherosclerosis resolution, a process resembling wound healing, is also impaired in diabetes. Thus, we hypothesized that NETs impede atherosclerosis resolution in diabetes by increasing plaque inflammation. Indeed, transcriptomic profiling of plaque macrophages from NET+ and NET- areas in low-density lipoprotein receptor-deficient (Ldlr-/-) mice revealed inflammasome and glycolysis pathway upregulation, indicating a heightened inflammatory phenotype. We found that NETs declined during atherosclerosis resolution, which was induced by reducing hyperlipidemia in nondiabetic mice, but they persisted in diabetes, exacerbating macrophage inflammation and impairing resolution. In diabetic mice, deoxyribonuclease 1 treatment reduced plaque NET content and macrophage inflammation, promoting atherosclerosis resolution after lipid lowering. Given that humans with diabetes also exhibit impaired atherosclerosis resolution with lipid lowering, these data suggest that NETs contribute to the increased cardiovascular disease risk in this population and are a potential therapeutic target.

The SGLT-2 Inhibitor Dapagliflozin Has a Therapeutic Effect on Atherosclerosis in Diabetic ApoE-/- Mice

Background. Our study aimed to observe the effect of sodium glucose cotransporter-2 (SGLT2) inhibitor dapagliflozin on diabetic atherosclerosis and investigate the subsequent mechanism. Methods. Aortic atherosclerosis was induced in streptozotocin induced diabetic ApoE^-/- mice by feeding with high-fat diet, and dapagliflozin was administrated intragastrically for 12 weeks as treatment. Effects of dapagliflozin on indices of glucose and fat metabolism, IL-1β, IL-18, NLRP3 protein levels, and the reactive oxygen species (ROS) were measured. The atherosclerosis was evaluated by oil red O and hematoxylin-eosin staining. The effects of dapagliflozin on the IL-1β production in culturing primary macrophages of wild type and NLRP3^-/- knockout mice were investigated for mechanism analyses. Results. Dapagliflozin treatment showed favorable effects on glucose and fat metabolism, partially reversed the formation of atherosclerosis, inhibited macrophage infiltration, and enhanced the stability of lesion. Also, reduced production of IL-1β, IL-18, NLRP3 protein, and mitochondrial ROS in the aortic tissues was detected with dapagliflozin treatment. In vitro, NLRP3 inflammasome was activated by hyperglucose and hyperlipid through ROS pathway. Conclusions. Dapagliflozin may be of therapeutic potential for diabetic atherosclerosis induced by high-fat diet, and these benefits may depend on the inhibitory effect on the secretion of IL-1β by macrophages via the ROS-NLRP3-caspase-1 pathway.

Prevention of cardiovascular complications of the metabolic syndrome: focus on pharmacotherapy

The metabolic syndrome increases the risk of atherothrombotic cardiovascular disease (CVD) and diabetes. In turn, diabetes promotes the development of atheroma and is regarded as a coronary heart disease risk equivalent. A multifactorial therapeutic strategy is advocated for patients with the metabolic syndrome to improve cardiovascular risk factor profiles and to reduce the chances of developing type 2 diabetes. Individual components of the syndrome must be addressed using safe, efficacious, and cost-effective measures. There is general agreement that lifestyle modifications, including control of body weight, avoidance of central adiposity, adoption of an antiatherogenic diet, and regular physical activity, are crucial. However, as the magnitude of the individual components of the metabolic syndrome increases with time, lifestyle measures are often insufficient. An individual with metabolic syndrome will often require drug treatment for hyperglycemia, atherogenic dyslipidemia, and high blood pressure, together with antiplatelet therapy. Reducing the need for polypharmacy is an increasingly important consideration for clinicians and the pharmaceutical industry; to date, no single therapy has emerged that targets the root cause(s) of the syndrome. HMG-CoA reductase inhibitors are important agents that reduce CVD morbidity and mortality, in people with impaired fasting glucose or metabolic syndrome. Selective cannabinoid receptor antagonists appear promising because they improve or attenuate several key defects of the syndrome. Thiazolidinediones and metformin are presently licensed for treatment of type 2 diabetes but may prove to have a broader role in future. Novel insulin-sensitizing drugs are under investigation. Drugs that act to prevent or reverse endothelial dysfunction may be of particular utility in preventing cardiovascular disease, especially if initiated before tissue damage has become irreversible. Insulin therapy, which has antiinflammatory and endothelial protective properties, has been shown to reduce morbidity and mortality in high-risk nondiabetic patients during critical illness. Potential synergy between different classes of drugs with metabolic and/or cardiovascular protective properties merits further investigation.

Dysglycemia but not lipids is associated with abnormal urinary albumin excretion in diabetic kidney disease: a report from the Kidney Early Evaluation Program (KEEP)

BACKGROUND

The relationship between glycemic control and lipid abnormalities with urinary albumin-creatinine ratio (ACR) in chronic kidney disease (CKD) patients with diabetes mellitus (DM) is unknown. We sought to investigate the association of dyslipidemia and glycemic control with levels of albuminuria in the National Kidney Foundation (NKF) Kidney Early Evaluation Program (KEEP) participants with DM and CKD stage 3 or higher.

METHODS

We performed a cross-sectional study of 6639 eligible KEEP patients with DM and CKD Stage 3 to 5 from June 2008 to December 2009. Multivariate logistic regression was used to evaluate the association of lipid parameters (per 10 mg/dl change in serum level) and glycosylated hemoglobin (HbA1c) values with three degrees of albuminuria normo (<30 mg/g), micro (30 to 300 mg/g) and macro (>300 mg/g).

RESULTS

2141 KEEP participants were included. HbA1c levels were strongly associated with micro-albuminuria (compared to normo-albuminuria) and macro-albuminuria (compared to normo-albuminuria and micro-albuminuria). Each 1.0% increase in HbA1c increased the odds of micro-albuminuria by 32% (OR 1.32, 95% CI 1.23-1.42) and the odds of macro-albuminuria (vs. microalbuminuria) by 16% (OR 1.16, 95% CI 1.05-1.28). Only increases in serum HDL were associated with decreased odds of micro-albuminuria; otherwise, the association between other components of the serum lipid profile with urinary ACR did not reach statistical significance.

CONCLUSION

In this cross-sectional study of 2141 KEEP participants with DM and CKD stages 3-5, overall glycemic control but not lipids were associated with abnormal urinary albumin excretion, a marker of increased risk for progressive disease.

DPP-4 (CD26) inhibitor alogliptin inhibits atherosclerosis in diabetic apolipoprotein E-deficient mice

Dipeptidyl peptidase-4 (DPP-4 or CD26) inhibitors, a new class of antidiabetic compounds, are effective in the treatment of hyperglycemia. Because atherosclerosis-related cardiovascular diseases are the major complications of diabetes, it is important to determine the effect of DPP-4 inhibitors on atherosclerosis. In this study, nondiabetic and diabetic apolipoprotein E-deficient mice were treated with DPP-4 inhibitor alogliptin for 24 weeks, and atherosclerotic lesions in aortic origins were examined. Results showed that diabetes significantly increased atherosclerotic lesions, but alogliptin treatment reduced atherosclerotic lesions in diabetic mice. Metabolic studies showed that diabetes increased plasma glucose and that alogliptin treatment reduced glucose. Furthermore, immunohistochemistry study showed that diabetes increased interleukin-6 (IL-6) and IL-1β protein expression in atherosclerotic plaques, but alogliptin treatment attenuated diabetes-augmented IL-6 and IL-1β expression. In consistence with the observations from the mouse models, our in vitro studies showed that alogliptin-inhibited toll-like receptor 4 (TLR-4)-mediated upregulation of IL-6, IL-1β, and other proinflammatory cytokines by mononuclear cells. Taken together, our findings showed that alogliptin-inhibited atherosclerosis in diabetic apolipoprotein E-deficient mice and that the actions of alogliptin on both glucose and inflammation may contribute to the inhibition.

Statins and renal disease: friend or foe?

The role of statins in the treatment and prevention of cardiovascular diseases, such as coronary artery disease, acute coronary syndromes, diabetes, or stroke, is well established. However, there are still some questions regarding the role of statins in patients with chronic kidney disease (CKD). Dyslipidemia is a known cardiovascular risk factor in individuals without CKD. In these patients, however, the relation of dyslipidemia to cardiovascular risk is complex, and the underlying pathobiological mechanisms are complex. Statins have proven to be highly effective in patients with initial stages of CKD; however, their effects in patients with advanced-stage CKD have been neutral despite a low-density lipoprotein cholesterol-lowering effect. In this review, we summarize the findings of the recent clinical trials of statins in renal disease and make recommendations for our patients.

National Kidney Foundation consensus conference on cardiovascular and kidney diseases and diabetes risk: an integrated therapeutic approach to reduce events

Cardiovascular disease (CVD) is the most common cause of death in industrialized nations. Type 2 diabetes is a CVD risk factor that confers risk similar to a previous myocardial infarction in an individual who does not have diabetes. In addition, the most common cause of chronic kidney disease (CKD) is diabetes. Together, diabetes and hypertension account for more than two-thirds of CVD risk, and other risk factors such as dyslipidemia contribute to the remainder of CVD risk. CKD, particularly with presence of significant albuminuria, should be considered an additional cardiovascular risk factor. There is no consensus on how to assess and stratify risk for patients with kidney disease across subspecialties that commonly treat such patients. This paper summarizes the results of a consensus conference utilizing a patient case to discuss the integrated management of hypertension, kidney disease, dyslipidemia, diabetes, and heart failure across disciplines.

Lipid-lowering treatment for all could substantially reduce the burden of macrovascular complications of diabetes patients in the Netherlands

BACKGROUND

We aimed to quantify the potential health benefits of increased use of lipid-lowering treatment (LLT), according to current guidelines, for the Dutch diabetes population.

DESIGN

Simulation study.

METHODS

We compared the long-term health outcomes for a scenario in which all diabetes patients received LLT to those in a 'current practice' scenario, in which 28% received LLT. The model reflected the Dutch diabetes population 40-80 years of age, in 2003. Sensitivity analyses were performed, using more conservative assumptions.

RESULTS

Over the lifetime, LLT for all diabetes patients reduced the expected cumulative incidences of coronary heart disease (CHD) and stroke by, respectively, 6 and 9%. Average life expectancy of Dutch diabetes patients would increase by 0.33 years, ranging from 0.14 years for patients aged 70-79 years, to 0.84 years for patients aged 40-49 years at the start of the simulation. Life-long treatment for patients aged 50-59 contributed most to the life years gained (55,000 out of 146,000). With reduced effectiveness of LLT and fewer patients starting LLT, the cumulative incidences of both CHD and stroke would decrease by approximately 2%. The number needed to treat to prevent one incident case of cardiovascular disease over lifetime was 20 for CHD and 44 for stroke.

CONCLUSION

This simulation study shows that increased use of LLT can substantially reduce the expected future burden of CHD and stroke in the Dutch diabetes population.

The HMG-CoA reductase inhibitor rosuvastatin and the angiotensin receptor antagonist candesartan attenuate atherosclerosis in an apolipoprotein E-deficient mouse model of diabetes via effects on advanced glycation, oxidative stress and inflammation

AIMS/HYPOTHESIS

We evaluated the anti-atherosclerotic effect of the 3-hydroxy-3-methylglutaryl CoA reductase inhibitor, rosuvastatin, and the angiotensin II receptor blocker (ARB), candesartan, alone and in combination, in the streptozotocin-induced diabetic apolipoprotein E-deficient (Apoe (-/-)) mouse.

METHODS

Control and streptozotocin-induced diabetic Apoe (-/-) mice received rosuvastatin (5 mg kg(-1) day(-1)), candesartan (2.5 mg kg(-1) day(-1)), dual therapy or no treatment for 20 weeks. Aortic plaque deposition was assessed by Sudan IV staining and subsequent visual quantification. The abundance of proteins was measured using immunohistochemistry.

RESULTS

Diabetes was associated with a fourfold increase in total plaque area. Rosuvastatin attenuated plaque area in diabetic mice in the absence of lipid-lowering effects. The anti-atherosclerotic effect of rosuvastatin was comparable to that observed with candesartan. A similar beneficial effect was seen with dual therapy, although it was not superior to monotherapy. Rosuvastatin treatment was associated with attenuated accumulation of AGE and AGE receptor (RAGE) in plaques. Similar beneficial effects on markers of oxidative stress were seen with the ARB and statin. Candesartan was more effective at reducing macrophage accumulation and collagen I abundance in plaques compared with rosuvastatin. The combined effect of candesartan and rosuvastatin was superior in reducing macrophage infiltration, monocyte chemoattractant protein-1 level, vascular AGE accumulation and RAGE abundance in the vascular wall. Furthermore, the combination tended to be more effective in reducing smooth muscle cell infiltration and connective tissue growth factor abundance in plaques.

CONCLUSIONS/INTERPRETATION

Rosuvastatin has direct anti-atherosclerotic effects in diabetic macrovascular disease. These effects are independent of effects on lipids and comparable to the effects observed with candesartan.

The protective effect of rosuvastatin in human umbilical endothelial cells exposed to constant or intermittent high glucose

In diabetes the exposure of the vascular endothelium to high glucose levels results in increased oxidative insult and in vascular dysfunction. We have investigated the effects of rosuvastatin on oxidative stress and apoptosis induced in human umbilical vein endothelial cells (HUVECs) by constant and intermittent high glucose levels. HUVECs were incubated for 14 days in either low (5 mM) or high (20 mM) glucose concentrations, or intermittent high and low glucose on a daily basis. Constant high glucose levels increased p47-phox, p67-phox, and p22-phox expression [components of the Nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase complex]; endothelial nitric oxide synthase, nitric oxide, and O(2)(-) production; nitrotyrosine, 8-hydroxy-2'-deoxyguanosine, and caspase-3 expression; and reduced Bcl-2 expression. These effects were significantly greater under intermittent compared to constant high/low glucose conditions. The effect of rosuvastatin (1 microM) in the presence or absence of mevalonate (200 microM) was evaluated in the cells under both constant and intermittent glucose conditions. Rosuvastatin almost normalized all these parameters. These effects of rosuvastatin were prevented when mevalonate was also added, demonstrating the link to inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase. These data suggest that rosuvastatin has the potential to prevent damage to and apoptosis of HUVECs induced by high glucose exposure, by reducing oxidative stress. The action of rosuvastatin on antioxidant pathways is related to the inhibition of the overexpression of components of NAD(P)H oxidase induced by the two conditions of high glucose.

Interactions between microvascular and macrovascular disease in diabetes: pathophysiology and therapeutic implications

Convention partitions the complications of diabetes into two main subtypes. First are the diabetes-specific microvascular complications of retinopathy, nephropathy and neuropathy; second are the atherothrombotic macrovascular complications that account for the majority of premature deaths. Pathological interactions between microvascular and macrovascular complications, for example, nephropathy and macrovascular disease, are common. Similar mechanisms and shared risk factors drive the development and progression of both small and large vessel disease. This concept has therapeutic implications. Mounting evidence points to the need for multifactorial strategies to prevent vascular complications in subjects with diabetes and/or the metabolic syndrome. We advocate a combined therapeutic approach that addresses small and large vessel disease. Preferential use should be made of drug regimens that (i) maximize vascular protection, (ii) reduce the risk of iatrogenic vascular damage and (iii) minimize the increasing problem of polypharmacy.

The randomized clinical trial: An unbeatable standard in clinical research?

The purpose of this paper is to discuss whether the randomized clinical trial (RCT) is indeed the gold standard among epidemiological studies. This paper illustrates to what extent different study designs may contribute to the answer of the following therapeutic research question based on a study of Wanner et al.: 'Is the use of a statin associated to less cardiac mortality in patients with type 2 diabetes mellitus who receive hemodialysis?' If a therapeutic study is feasible, like the research question of the clinical example, the RCT is almost unbeatable: the problems that may occur in the other study designs do not exist or to a lesser extent using an RCT. The main advantage of an RCT is that the randomization procedure helps to prevent selection bias by the clinician by breaking the link between the clinician's therapy prescription and the patient's prognosis. Within observational studies, however, selection by the clinician may occur, and, even after adjustment for potential confounders in the statistical analysis, it may not be possible to make a fair comparison between the groups. Usually, results from observational studies are needed to come to a hypothesis that can subsequently be tested within an RCT. Moreover, observational data are most often more useful than RCTs for non-therapeutic studies.

Statins attenuate ischemia-reperfusion injury by inducing heme oxygenase-1 in infiltrating macrophages

Statins induce heme oxygenase-1 (HO-1) in several cell types, such as vascular smooth muscle cells, endothelial cells, and macrophages. The present study assessed the role of statin-induced HO-1 up-regulation on circulating monocytes/macrophages and their contribution in preventing renal ischemia-reperfusion (IR) injury in a rat model. Cerivastatin was administered via gavage (0.5 mg/kg) for 3 days before IR injury; controls received vehicle. Statin pretreatment reduced renal damage and attenuated renal dysfunction (P < 0.05) after IR injury. The protective statin pretreatment effect was completely abolished by cotreatment with tin protoporphyrin IX (Sn-PP), a competitive HO inhibitor. IR increased HO-1 expression at the transcript and protein level in renal tissue. This effect was significantly more evident (P < 0.05) in the statin-pretreated animals 24 hours after IR injury. We identified infiltrating macrophages as the major source of tissue HO-1 production. Moreover, in ancillary cell culture (monocyte cell line) and in in vivo experiments (isolation of circulating monocytes), we confirmed that statins regulate HO-1 expression in these cells. We conclude that statin treatment up-regulates HO-1 in circulating monocytes/macrophages in vivo and in vitro. We hypothesize that local delivery of HO-1 from infiltrating macrophages exerts anti-inflammatory effects after IR injury and thereby may reduce tissue destruction.

Low HDL-cholesterol is common in European Type 2 diabetic patients receiving treatment for dyslipidaemia: data from a pan-European survey

AIMS

To measure the prevalence of low high-density lipoprotein (HDL)-cholesterol (men < 1.03 mmol/l; women < 1.29 mmol/l) in European Type 2 diabetic patients receiving treatment for dyslipidaemia.

METHODS

The pan-European Survey of HDL-cholesterol measured lipids and other cardiovascular risk factors in 3866 patients with Type 2 diabetes and 4436 non-diabetic patients undergoing treatment for dyslipidaemia in 11 European countries.

RESULTS

Diabetic patients were more likely to be obese or hypertensive than non-diabetic patients. Most patients received lifestyle interventions (87%) and/or a statin (89%); treatment patterns were similar between groups. Diabetic patients had [means (SD)] lower HDL-cholesterol [1.22 (0.37) vs. 1.35 mmol/l (0.44) vs. non-diabetic patients, P < 0.001] and higher triglycerides [2.32 (2.10) vs. 1.85 mmol/l (1.60), P < 0.001]. More diabetic vs. non-diabetic patients had low HDL-cholesterol (45% vs. 30%), high triglycerides (> or = 1.7 mmol/l; 57% vs. 42%) or both (32% vs. 19%). HDL-cholesterol < 0.9 mmol/l was observed in 18% of diabetic and 12% of non-diabetic subjects. Differences between diabetic and non-diabetic groups were slightly greater for women. LDL- and total cholesterol were lower in the diabetic group [3.02 (1.05) vs. 3.30 mmol/l (1.14) and 5.12 (1.32) vs. 5.38 mmol/l (1.34), respectively, P < 0.001 for each].

CONCLUSIONS

Low HDL-cholesterol is common in diabetes: one in two diabetic women has low HDL-cholesterol and one diabetic man in four has very low HDL-cholesterol. Management strategies should include correction of low HDL-cholesterol to optimize cardiovascular risk in diabetes.

Extent and management of cardiovascular risk factors in patients with type 2 diabetes and serious mental illness

Cardiovascular disease is the leading cause of death in Type 2 diabetes, which commonly occurs in patients with serious mental illnesses (SMIs). We determined the extent to which patients with diabetes and SMI, relative to diabetes patients without SMI, met American Diabetes Association goals for cholesterol and blood pressure, met criteria for the metabolic syndrome, and were prescribed medications known to reduce cardiovascular events. We found that less than half of diabetes patients, both with and without SMI, met recommended goals for cholesterol levels; even fewer had adequate blood pressure control. In addition, a substantial proportion of all diabetes patients met metabolic syndrome criteria. However, diabetes patients with SMI were less likely to be prescribed cholesterol-lowering statin medications, angiotensin-converting enzyme inhibitors, and angiotensin receptor blocking agents than diabetes patients without SMI. Patients with both diabetes and SMI are treated less aggressively for high cardiovascular risk than diabetes patients without mental disorders.

Oxidative stress in insulin-resistant conditions: cardiovascular implications

The risk of cardiovascular disease (CVD) in patients with diabetes mellitus is increased more than 3-fold and is the major cause of mortality and morbidity in diabetic patients. Historically, diabetes has been considered an inadequate insulin response leading to elevated plasma glucose levels with morbidities attributable to hyperglycemia. However, diabetes represents a complex pathology that often includes hypertension, dyslipidemia, endothelial dysfunction, microalbuminuria, platelet disaggregation, abnormal fibrinolysis, and chronic inflammation. Furthermore, oxidative stress has been shown to contribute to the pathology of diabetic CVD, having implications in the development of hypertension, renal disease, and stroke. Hypertension is a common feature of diabetes and is the primary contributor to CVD, which highlights the importance of blood pressure control (<130/80 mm Hg). Recent investigations have also implicated the renin-angiotensin-aldosterone system in promoting oxidative stress-induced endothelial dysfunction, inflammation, and insulin resistance. These pathophysiologic considerations will be important in developing prevention strategies for CVD in diabetes. Further research is needed to identify antioxidant and insulin-sensitizing agents that will improve CVD outcomes in patients with diabetes.

Serum lipids and the progression of nephropathy in type 1 diabetes

OBJECTIVE

Dyslipidemia contributes to the progression of microvascular disease in diabetes. However, different lipid variables may be important at different stages of nephropathy. This study examines the pattern of dyslipidemia associated with the progression of nephropathy in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A total of 152 patients with type 1 diabetes were recruited in order to represent various phases of nephropathy. Patients were followed for 8-9 years, during which time they received standard care. Renal progression was defined a priori as a doubling in albumin excretion (in patients with normo- or microalbuminuria) or a decline in creatinine clearance (in those with macroalbuminuria). A panel of lipid variables was determined and correlated with indexes of progression.

RESULTS

In patients with normoalbuminuria (n = 66), progression was associated with male sex (P < 0.05), borderline albuminuria (P = 0.02), and LDL-free cholesterol (P = 0.02). In patients with microalbuminuria (n = 51), progression was independently associated with triglyceride content of VLDL and intermediate-density lipoprotein (both P < 0.05). In patients with macroalbuminuria (n = 36), a significant decline in the renal function (>3 ml x min(-1) x year(-1)) was independently associated with poor glycemic control, hypertension, and LDL size (P < 0.05). When all patients with progressive nephropathy were analyzed together, only LDL cholesterol was predictive on multivariate analysis (P < 0.05), which masked the importance of triglyceride enrichment in microalbuminuria.

CONCLUSIONS

Lipid variables are associated with progression of diabetic kidney disease, but the relationship is not the same at all stages. This finding has implications for the design of renoprotective strategies and the interpretation of clinical trials in type 1 diabetes.

Treating dyslipidemia in the elderly

PURPOSE OF REVIEW

The treatment of dyslipidemia has been dynamic over the past several years. Of special importance is the impact of recent clinical trial data on management strategies of dyslipidemia in the elderly. People 65 years and older are living longer and are the fastest growing subset of the US population, necessitating more attention to chronic disease conditions that manifest in this age group. This review addresses guidelines of lipid management, discusses data that support their use, and examines the benefits of lipid-lowering therapy in the elderly with attention to the chronic conditions that are common in this population.

RECENT FINDINGS

Clinical trials completed since the publication of the 2001 National Cholesterol Education Program (NCEP) Adult Treatment Panel III guidelines support the use of lipid-lowering therapy in the elderly population. Lipid-lowering therapy has not only proven to be generally safe in the elderly, but has also proven effective in helping manage the chronic disease conditions that are common in this age group.

SUMMARY

The elderly segment of our population continues to grow. Along with this growth in population is a growth in incidence of cardiovascular disease, the metabolic syndrome, chronic kidney disease, cerebrovascular disease, and diabetes mellitus. There is no known panacea for managing these chronic disease conditions; however, lipid-lowering therapy has been shown to prevent or delay the progression of these diseases and the mortality and morbidity that accompanies them.

Diabetes mellitus-associated atherosclerosis: mechanisms involved and potential for pharmacological invention

While diabetes mellitus is most often associated with hypertension, dyslipidemia, and obesity, these factors do not fully account for the increased burden of cardiovascular disease in patients with the disease. This strengthens the need for comprehensive studies investigating the underlying mechanisms mediating diabetic cardiovascular disease and, more specifically, diabetes-associated atherosclerosis. In addition to the recognized metabolic abnormalities associated with diabetes mellitus, upregulation of putative pathological pathways such as advanced glycation end products, the renin-angiotensin system, oxidative stress, and increased expression of growth factors and cytokines have been shown to play a causal role in atherosclerotic plaque formation and may explain the increased risk of macrovascular complications. This review discusses the methods used to assess the development of atherosclerosis in the clinic as well as addressing novel biomarkers of atherosclerosis, such as low-density lipoprotein receptor-1. Experimental models of diabetes-associated atherosclerosis are discussed, such as the streptozocin-induced diabetic apolipoprotein E knockout mouse. Results of major clinical trials with inhibitors of putative atherosclerotic pathways are presented. Other topics covered include the role of HMG-CoA reductase inhibitors and fibric acid derivatives with respect to their lipid-altering ability, as well as their emerging pleiotropic anti-atherogenic actions; the effect of inhibiting the renin-angiotensin system by either ACE inhibition or angiotensin II receptor antagonism; the effect of glycemic control and, in particular, the promising role of thiazolidinediones with respect to their direct anti-atherogenic actions; and newly emerging mediators of diabetes-associated atherosclerosis, such as advanced glycation end products, vascular endothelial growth factor and platelet-derived growth factor. Overall, this review aims to highlight the observation that various pathways, both independently and in concert, appear to contribute toward the pathology of diabetes-associated atherosclerosis. Furthermore, it reflects the need for combination therapy to combat this disease.

What is the most effective strategy for managing diabetic dyslipidaemia?

The dyslipidaemic profile of diabetes greatly contributes to the increased cardiovascular risk associated with the disorder, and evidence from many intervention trials using statins, fibrates, nicotinic acid or a nicotinic acid-statin combination, indicates the substantial cardiovascular risk reduction to be gained from lipid modification. Several large statin trials have demonstrated the efficacy of cholesterol-lowering in individuals with coronary heart disease and raised low-density lipoprotein-cholesterol (LDL-C) (>or=130 mg/dL; >or=3.4 mmol/L), but for the 40% of patients whose LDL-C is within recommended limits, many of whom have low high-density lipoprotein-cholesterol (HDL-C), an alternative strategy is necessary if excess risk is to be minimized. The veterans affairs high-density lipoprotein cholesterol intervention trial (VA-HIT) proved the efficacy of the fibric acid derivative, gemfibrozil, to elevate HDL-C and reduce triglycerides, with a resulting 22% relative risk reduction for cardiovascular death or non-fatal myocardial infarction, and even greater reductions in individuals with insulin resistance and diabetes. Increased HDL-C was independently predictive of reduction in coronary heart disease. In the Coronary Drug Project, individuals with diabetes or insulin resistance derived as much as 70% cardiovascular risk reduction from the HDL-C elevations achieved with nicotinic acid therapy. The effects of lowering LDL-C and raising HDL-C are additive and predictive of total cardiovascular event reduction, and by using statin-nicotinic acid combination therapy, cardiovascular risk reductions as great as 90% are possible. Such combination strategies offer patients the greatest opportunity for improved cardiovascular health and are likely to become the treatment strategy of the future.

Diabetes alters the occupancy of the hepatic 3-hydroxy-3-methylglutaryl-CoA reductase promoter

Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) protein and mRNA are substantially decreased in diabetic animals and rapidly restored by the administration of insulin. To begin to examine the underlying molecular mechanisms, measurements of transcription by nuclear run-on assays and an investigation of occupancy of the promoter were performed. The rate of transcription was substantially reduced in the diabetic rats and fully restored within 2 h after insulin treatment. In vivo footprinting revealed several areas of protein binding as shown by dimethyl sulfate protection or enhancement. The cAMP-response element was heavily protected in all conditions, including diabetes, feeding of dietary cholesterol, or statin treatment. Striking enhancements in footprints from diabetic animals were visible at -142 and at -161 (in the sterol-response element). Protections at a newly identified NF-Y site at -70/-71 were observed in normal animals and not in diabetics. This NF-Y site was found to be required for efficient HMGR transcription in luciferase assays. CREB-1 was able to bind the HMGR cAMP-response element in vitro and the promoter in vivo. This evidence supports an essential role for cAMP-response element-binding protein in transcription of hepatic HMGR and identifies at least two sites where in vivo occupancy is regulated by insulin.

Atorvastatin in patients with type 2 diabetes mellitus undergoing hemodialysis

BACKGROUND

Statins reduce the incidence of cardiovascular events in persons with type 2 diabetes mellitus. However, the benefit of statins in such patients receiving hemodialysis, who are at high risk for cardiovascular disease and death, has not been examined.

METHODS

We conducted a multicenter, randomized, double-blind, prospective study of 1255 subjects with type 2 diabetes mellitus receiving maintenance hemodialysis who were randomly assigned to receive 20 mg of atorvastatin per day or matching placebo. The primary end point was a composite of death from cardiac causes, nonfatal myocardial infarction, and stroke. Secondary end points included death from all causes and all cardiac and cerebrovascular events combined.

RESULTS

After four weeks of treatment, the median level of low-density lipoprotein cholesterol was reduced by 42 percent among patients receiving atorvastatin, and among those receiving placebo it was reduced by 1.3 percent. During a median follow-up period of four years, 469 patients (37 percent) reached the primary end point, of whom 226 were assigned to atorvastatin and 243 to placebo (relative risk, 0.92; 95 percent confidence interval, 0.77 to 1.10; P=0.37). Atorvastatin had no significant effect on the individual components of the primary end point, except that the relative risk of fatal stroke among those receiving the drug was 2.03 (95 percent confidence interval, 1.05 to 3.93; P=0.04). Atorvastatin reduced the rate of all cardiac events combined (relative risk, 0.82; 95 percent confidence interval, 0.68 to 0.99; P=0.03, nominally significant) but not all cerebrovascular events combined (relative risk, 1.12; 95 percent confidence interval, 0.81 to 1.55; P=0.49) or total mortality (relative risk, 0.93; 95 percent confidence interval, 0.79 to 1.08; P=0.33).

CONCLUSIONS

Atorvastatin had no statistically significant effect on the composite primary end point of cardiovascular death, nonfatal myocardial infarction, and stroke in patients with diabetes receiving hemodialysis.

Diabetic dyslipidaemia: insights for optimizing patient management

BACKGROUND

Lipid abnormalities in people with diabetes are likely to play an important role in the development of atherogenesis. These lipid disorders include potentially atherogenic quantitative (increased triglyceride levels and decreased high-density lipoprotein-cholesterol [HDL-C] levels) and qualitative abnormalities of lipoproteins (changes in lipoprotein size, increase in triglyceride content of low-density lipoprotein (LDL) and HDL, glycation of apoproteins and increased susceptibility of LDL to oxidation). Guidelines from the two main diabetes organizations, the International Diabetes Federation and the American Diabetes Association, recommend the aggressive management of diabetic dyslipidaemia to reduce the risk of cardiovascular disease (CVD). Statins are the first choice pharmacological therapy to address diabetic dyslipidaemia due to their effectiveness at lowering LDL-C levels in patients with diabetes. Fibrates (peroxisome proliferator-activated receptor [PPAR]alpha ligands) target another aspect of dyslipidaemia by lower ing triglycerides (to a greater extent than statins) and raising HDL-C levels, especially when baseline levels are low. The PPARgamma agonist, pioglitazone appears to affect lipid metabolism by decreasing plasma triglycerides, increasing HDL-C and decreasing the number of small, dense atherogenic LDL particles.

SCOPE

This paper provides a review of the current literature (based on searches of MEDLINE and EMBASE from 1985 to 2005, inclusive) supporting the recommendations for the management of dyslipidaemia among patients with type 2 diabetes, including new strategies involving drug combinations that achieve good glycaemic and lipidaemic control that could potentially reduce the morbidity and mortality associated with type 2 diabetes.