Cardiovascular disease in type 2 diabetes mellitus: current management guidelines

Cardiovascular disease is the most prevalent and detrimental complication of diabetes mellitus. The incidence of cardiovascular mortality in diabetic subjects without a clinical history of previous cardiac events is as high as the incidence in nondiabetic subjects with a history of myocardial infarction. This inordinate increase in the risk of coronary events in diabetic patients is attributed to multiple factors, including glycation and oxidation of proteins and increased prevalence of classic risk factors of coronary disease, such as hypertension, obesity, and dyslipidemia. Despite advances in the management of cardiovascular disease, a large proportion of diabetic subjects continue to have uncontrolled hyperglycemia, hypertension, and dyslipidemia. In addition, certain medical interventions with established efficacy in the general population do not appear to be appropriate for diabetic subjects. Recently published clinical trials of managing coronary risk factors indicate that more stringent goals of therapy should be set for diabetic patients. In this communication, some of these landmark studies are reviewed and some practical guidelines of management are suggested.

[Feeding and assessment of nutritional status of spanish adolescents (AVENA study). Evaluation of risks and interventional proposal. I.Methodology]

BACKGROUND

Adolescence is a decisive period in human life due to the multiple physiological and psychological changes that take place. These changes will condition both nutritional requirements and eating/physical activity behavior. It has been demonstrated that these "adolescence" factors are of significant influence in health status during adult life. Due to its importance and adequate development the project has been granted by the Fondo de Investigación Sanitaria of the Institute of Health Carlos III.

OBJECTIVE

To develop a methodology to evaluate the health and nutritional status of a representative population of Spanish adolescents. Specific attention is paid to three specific health problems: obesity, anorexia nervosa/bulimia, dislipidemia.

METHODOLOGY

The following magnitudes will be studied: 1) dietary intake, food habits and nutrition knowledge; 2) daily physical activity and personal approach; 3) physical condition; 4) anthropometry and body composition; 5) hematobiochemical study: plasma lipid phenotypic and metabolic profile, blood cell counts; 6) genotipic profile of cardiovascular risk lipid factors; 7) immune function profile related to nutritional status; 8) psychological profile.

CONCLUSION

This project includes the co-ordinate activity of five Spanish centers of five different cities (Granada, Madrid, Murcia, Santander, Zaragoza). Each center is specialized in a specific area and will be responsible for the corresponding part of the study. From the data obtained, we will elaborate a specific intervention program in order to improve nutrition and neutralize the risk for nutritional related problems in adolescence. By this, we will contribute to improve the health status of the Spanish population in the new millennium.

Hepatoprotective and antihyperliposis activities of in vitro cultured Anoectochilus formosanus

The pharmacological effects of an aqueous extract of the whole plants of in vitro cultured Anoectochilus formosanus were investigated experimentally for hepatoprotective and antihyperliposis activities. The extract showed significant antihepatotoxic activity against carbon tetrachloride induced cytotoxicity in primary cultured rat hepatocytes. In an assay for antihyperliposis using aurothioglucose-induced obese mice, the extract suppressed significantly the increase in the weights of body and liver, ameliorated triglyceride levels in the liver and serum, and also significantly reduced the deposition of adipose tissue.

[Oxidative stress and endothelial dysfunction]

Growing numbers of morbidity and mortality due to the Coronary Heart Disease (CHD) is recognized as the more increasing challenge in the world. The initial stage of atherosclerosis, early diagnosis and treatment of CHD are the main objectives of current research. Endothelium dysfunction, the earliest expression of the atherosclerotic process is associated with subtle biochemical changes that gradually are transformed into the structural changes of the arterial wall. The theory of free radicals is the most common among the atherosclerosis explanations. Overproduction or impaired neutralization of the free radicals accounts for oxidative stress that is causing substantial damage to the low density lipoproteins, nitric oxyde (NO), endothelium cells, tissue cells and finally leads to the endothelium dysfuction. Pathophysiology of oxidative stress and its role in the endothelium dysfunction are discussed in this paper. Positive role of various medications (statins, angiotensin converting enzym inhibitors, aldosteron antagonists, estrogens, antioxidants, b-blockers with vasodilatative properties) to the oxidative stress and consequently to the endothelium dysfuction are discussed as well.

Statin therapy in people with diabetes and high-risk patients

Lipid lowering forms part of the treatment of atherosclerosis. Primary prevention is dependent on identification and treatment of patients at high risk of which patients with diabetes are the clearest example. This article reviews the role of lipid lowering in high-risk individuals.

Exercise considerations in hypertension, obesity, and dyslipidemia

Sports medicine practitioners who care for a wide array of athletes and active individuals will consistently face issues regarding chronic cardiovascular diseases and their associated risk factors. Among these, hypertension, obesity, and dyslipidemia are common clinical conditions that may be encountered even amongst elite caliber athletes. Consequently, those entrusted with the care of this active population must recognize the presence of these disorders and feel comfortable with their management in the face of continued sports or exercise participation. This article reviews the pathophysiology of these conditions as they relate to athletes and outlines the value of continued exercise in the management of each of these entities while addressing the specific and unique treatment needs of active individuals.

[Effect of cyclosporin and tacrolimus on lipoprotein oxidation after renal transplantation]

BACKGROUND

Cyclosporin A is a lipogenic immunosuppressor that can induce posttransplant hyperlipidaemia. Oxidation of low-density lipoprotein (LDL) has been recognized as a major atherogenic factor. Tacrolimus seems to be less lipogenic with an apparently better cardiovascular profile than CsA.

METHODS

We have studied the lipidic profile and the oxidation of HDL and LDL in 20 renal transplant patients, 12 male and 8 female, mean age 45 +/- 10 year, who where switched from CsA to tacrolimus due to CsA adverse effects. LDL were determined by ultracentrifugation. Oxidation study before and 6 months after conversion to tacrolimus was performed by adding CuSO4.

RESULTS

After conversion, systolic blood pressure (BP) decreased from 154 +/- 21 to 133 +/- 21 mm Hg (p = 0.008), diastolic BP from 97 +/- 13 to 77 +/- 15 mm Hg (p = 0.016), total cholesterol from 6.08 +/- 0.9 to 5.68 +/- 1.1 mmol/l (p = 0.02), LDL-chol from 3.29 +/- 1.01 to 2.96 +/- 0.3 mmol/l (p = 0.04) and apo-B lipoprotein from 1.42 +/- 0.28 to 1.15 +/- 0.34 mg/dl (p = 0.003). The oxidation of LDL improved after conversion: the initial dienic compounds decreased from 95 +/- 20 to 63 +/- 12 umol/g and the final DC from 207 +/- 56 to 107 +/- 35 umol/g. Lag-phase increased from 33 +/- 21 to 45 +/- 17 min (p < 0.05).

CONCLUSION

Tacrolimus has improved hyperlipidaemia in our cyclosporin previously treated patients and increased the resistance to oxidation of high and low-density lipoproteins.

Managing dyslipidemia in Turkey: suggested guidelines for a population characterized by low levels of high density lipoprotein cholesterol

Based on data from the Turkish Society of Cardiology and others, it is established that Turks have a high prevalence of coronary heart disease (CHD). Several risk factors are prominent in Turks: dyslipidemia, cigarette smoking, and hypertension. The dyslipidemia is unique in that very low levels of HDL-C and typically "normal" LDL-C levels characterize the Turkish population. The low HDL-C levels appear to be genetic in origin and are largely independent of high triglyceride levels (73% of Turkish men and 94% of women with HDL-C <40 mg/dl have triglyceride levels <150 mg/dl; only 15% of men and 3% of women with HDL-C <40 mg/dl have triglyceride levels >200 mg/dl). HDL-C levels are 10-15% mg/dl lower in Turks than seen in the United States or western Europe. Low HDL-C is a major risk factor; CHD risk increases 2-4% for every 1 mg/dl decrease in HDL-C levels. Existing treatment guidelines focus on plasma LDL-C levels and fail to take into account the continuous increase in CHD risk that occurs as HDL-C levels decrease. However, several studies show that patients with CHD or free of CHD but with multiple risk factors, who have low HDL-C and near optimal LDL-C, benefit very significantly from lipid-lowering therapy. Many of these patients with low HDL-C levels do not qualify for drug therapy based on existing guidelines. Therefore, we believe that unique guidelines must be developed to guide the treatment of low HDL-C Turkish patients. We suggest that treatment based on both the LDL-C level and the total cholesterol/HDL-C (TC/HDL-C) ratio is the best way to address treatment of patients with low HDL-C levels. The most effective drug treatment available presently in Turkey relies on lowering LDL-C levels to optimize the TC/HDL-C ratio.

Sopungsungi-won (SP) prevents the onset of hyperglycemia and hyperlipidemia in Zucker diabetic fatty rats

Sopungsungi-won (SP) is a known formula for senile constipation and diabetes mellitus, based on traditional Korean medicine. The preventive effect of SP on the development of overt diabetes in Zucker diabetic fatty (ZDF) rats was evaluated. When administered orally through a diet for 8 weeks, diabetic conditions such as hyperglycemia, polydipsia and hypertriglyceridemia were all ameliorated in SP-treated rats. In parallel with the onset and progression of hyperglycemia in the ZDF control rats; there was a marked decline in plasma insulin concentrations from 26.1 microU/ml, at age 7 weeks, to 14.8 microU/ml at age 15 weeks. In the SP-treated rats, however, the plasma insulin concentrations did not decline, and SP at a dose of 5 g/kg significantly increased the insulin levels to 31.9 microU/ml. Early normalization of plasma insulin and a retained ability to subsequently increase plasma insulin were indicative of a pancreatic beta cell protective action by the SP formula. In addition, expressions of an insulin-responsive gene and corresponding protein, glucose transporter 4 (GLUT4), in skeletal muscle, were also determined in SP- and rosiglitazone-treated ZDF rats. mRNA and protein levels of GLUT4 in SP-treated rats were upregulated in a dose dependent manner. Furthermore, when ZDF rats were treated with 2 g/kg of the SP formula, the activity of glucose-6-phosphatase was decreased by 49%, whereas the activity of glucokinase was increased by 196%, compared to the ZDF control rats. Taken together, these data provide evidence that the SP formula markedly lowered the plasma glucose levels, probably through an effect not only on improvement of insulin action, but through a combined stimulation of glycolysis and an inhibition of gluconeogenesis in the liver, and also suggest the validity of SP's clinical use in the treatment of type 2 diabetes mellitus following further toxicological investigation.

Glycemic control in the prevention of diabetic complications

The relationship between abnormal circulating glucose levels and the development of long-term diabetic complications became apparent soon after the introduction of insulin 70 years ago and the avoidance of early death due to ketoacidosis. Classic observational studies by Pirart described the relationship between increased glycosuria and the ultimate development of diabetic retinopathy, nephropathy, and neuropathy. Nonetheless, it required the findings of randomized, controlled clinical trials to finally and definitively establish the relationship between glucose control and microvascular diabetic complications. With the publication of the Diabetes Control and Complications Trial, the Kumomoto Trial, and the United Kingdom Prospective Diabetes Study, the impact of glycemic control in the development of microvascular complications was confirmed. Our understanding of the pathophysiology of diabetes--particularly, the dysmetabolic changes seen in type 2 diabetes--includes abnormalities in lipid metabolism, fuel flux, and endothelial function. Diabetes control, therefore, can no longer be viewed exclusively as glucose management. Rather, a more global approach is necessary to minimize risks of both microvascular and macrovascular complications. This article explores data supporting a variety of interventions that have been shown to reduce morbidity and mortality associated with long-standing diabetes mellitus. In addition to acknowledging the relationship between complications and diabetic metabolic abnormalities, this article presents a health economics perspective by examining the cost-effectiveness and health utility of these interventions.

Molecular approaches for the treatment of atherosclerosis

Advances in vascular biology and the study of molecular pathophysiology have enabled the design and initial testing of therapeutic principles for cardiovascular intervention at the level of gene expression. This approach can offer an avenue to greatly impact the onset and progression of vascular disease at its roots. Early translations of basic research into human clinical protocols might provide novel alternatives for patients without traditional therapeutic options and might provide means of improving and prolonging the success of standard therapies. As the understanding of the genetic basis of vascular disease continues to grow and the tools for in vivo genetic manipulation continue to improve, vascular gene therapies might someday become a part of routine patient care.

Lipid lowering: another method of reducing blood pressure?

Modern management of cardiovascular risk depends on assessment of cardiovascular risk factors. Hypertension and hyperlipidaemia are synergistic risk factors for cardiovascular events. Both show a degree of cross-correlation through sharing mechanisms of pathogenesis including insulin resistance and endothelial dysfunction. This article reviews the common pathways leading to dyslipidaemia and hypertension and the effects diet and lipid-lowering drug therapies have had on correcting blood pressure in patients with essential hypertension. Both statins and fibrates have shown a capability to lower blood pressure by up to 8/5 and 15/10 mmHg respectively, in some small-scale clinical trials and have effects on arterial wall structure and hence pulse wave velocity. This blood pressure action may account for some of the clinical effects of lipid-lowering drugs on cardiovascular risk. Thus, lipid lowering may provide an additional method of correcting hypertension in some high-risk patients. However, data from large-scale intervention trials are either absent or ambiguous. Definitive large-scale trials to investigate the antihypertensive effects of lipid-lowering drugs are required, although end point studies examining the interaction of lipid-lowering and antihypertensive drugs to determine optimum combinations are already under way.

The physiology of lipoproteins

The seminal studies of Brown and Goldstein (Science 1986;232:34-47) coupled with the findings of the Framingham study revolutionized our understanding of the metabolic basis for vascular disease. These studies led to the widespread use of the coronary risk lipid profile, which uses the total cholesterol/high-density lipoprotein (HDL) ratio (or low-density lipoprotein [LDL]/HDL ratio) in predicting risk for vascular disease and as a tool for therapeutic management of patients at risk for vascular disease. However, although these methods are predictive of coronary artery disease (CAD) in general, it is also well known that the extent of occlusive disease and CAD varies greatly between individuals with similar cholesterol and HDL lipid profiles. For this reason, the National Cholesterol Education Program Expert Panel revised these guidelines and now recommends monitoring LDL and HDL cholesterol in the context of coronary heart disease risk factors and "risk equivalents." In addition, more recent findings indicate that specific alterations in individual lipoprotein subclasses may account for the variations in CAD in subjects with similar lipid profiles. For example, a preponderance of small, dense LDL particles correlates with a marked increase in risk for myocardial infarction independent of LDL levels. In particular, the association of small, dense LDL with elevated triglycerides (large, less dense VLDL) and reduced HDL has been defined as the atherogenic lipoprotein profile, and the key metabolic defect driving this profile may be elevated levels of triglycerides, specifically large, less dense VLDL. In an attempt to explain the physiologic basis for lipoprotein variations, this review describes the basic metabolic scheme underlying the traditional view of lipoprotein metabolism and physiology. It then examines the identity and role of the various lipoprotein subfractions in an attempt to distill a working model of how lipoprotein abnormalities might account for vascular disease in general and the metabolic syndrome in particular.

[Immunological factors for chronic rejection and the methods for the prevention of chronic allograft nephropathy]

For the prevention of the immunological chronic rejection, HLA-DRB1 allele matching, enough immunosuppression in the induction phase and pathological diagnosis by non-episode and protocol biopsy are the effective methods. For the prevention of the non-immunological chronic rejection, treatments for hypertension, hyperlipidemia and hyperfiltration are the effective treatments.

Serum lipid profile and timolol gel

Topical use of timolol eye drops in the management of glaucoma is associated with various systemic side effects including alteration of lipid profile with increase in cardiovascular risk factors. Change over to timolol gel altered results in normalisation of altered lipid profile with decrease in cardiovascular risk factors. The decrease seen is attributable to lack of systemic absorption of timolol gel.

Are we negating the benefits of CABG by forgetting secondary prevention?

The objective of the study was to examine medically managed secondary prevention at one year after coronary artery bypass grafting (CABG). In all, 214 consecutive patients undergoing isolated elective CABG seen four weeks preoperatively and one year post-operatively. Preoperative systolic blood pressure averaged 135+/-20 mmHg, which increased to 148+/-25 mmHg (P<0.0001) as did diastolic pressure (81+/-12 to 87+/-13 mmHg; P<0.0001). Anginal symptoms were reported by 45.1% (P<0.0001) although median severity scored lower (4.0 [3.0-5.4] vs 0 [0-2.0]; P<0.0001). Breathlessness decreased from 93% to 64% (P<0.0001) and was scored less severely (4.0 [2.0-5.0] vs 2.0 [0-4.0]; P<0.0001. In all, 88% with postoperative angina reported dyspnoea against 44% of those without (P<0.0001). Calcium antagonist use was more common in patients with angina (27.2% vs 5.1%; P<0.0001), but not nitrates (P=0.8695), diuretics (P=0.4218), digoxin (P=0.2565), beta-blockers (P=0.0820), or ACE inhibitors (P=0.7256). Preoperatively 166 patients (80.2%) took aspirin vs 69.2% afterwards (P=0.0131). Twelve patients (6.5%) received warfarin after operation vs none preoperatively. Two took digoxin (0.97%) preoperatively and 14 (7.7%) postoperatively (P=0.001) for chronic atrial fibrillation. One of these took warfarin. Long-acting nitrate use fell from 63.4% to 15.8% (P <0.0001). Short-acting nitrate use fell similarly (P<0.0001). Preoperatively 37 patients (17.9%) took ACE inhibitors vs 44 postoperatively (24.2%); 39 had not received them before. Preoperatively 48 (23.2%) took diuretics vs 30 (16.5%) postoperatively (P=0.127); 24 had not previously taken diuretics. More patients took HMGCoA inhibitors postoperatively (P=0.0068) and total cholesterol was significantly reduced with a concomitant increase in HDL fraction. Smoking habit was virtually unchanged from 17.8% to 15.1% (P=0.5023).

IN CONCLUSION

angina was common. Apart from statin prescribing, postoperative secondary prevention measures were poorly applied, less widespread and less effective than preoperatively. The implications are disturbing.

Inflammatory bio-markers and cardiovascular risk prediction

Inflammatory processes are now recognized to play a central role in the pathogenesis of atherosclerosis and its complications. Plasma levels of several markers of inflammation have been found to be associated with future cardiovascular risk in a variety of clinical settings. These markers include cell adhesion molecules, cytokines, pro-atherogenic enzymes and C-reactive protein (CRP). Initially thought of as an inactive downstream marker of the inflammatory cascade, emerging evidence suggests that CRP may be directly involved in atherogenesis, and that arterial plaque can produce CRP, independent of traditional hepatic pathways. In addition to being a strong predictor of future cardiovascular risk amongst patients presenting with acute coronary syndromes, numerous studies have found that baseline levels of CRP are associated with risk of future myocardial infarction, stroke, peripheral vascular disease and cardiovascular death amongst apparently healthy populations. The combination of measurement of a marker of inflammation with lipid testing may improve upon risk stratification based on lipid testing alone, and intensification of programmes for exercise, weight loss, and smoking cessation is recommended for those with elevated CRP levels. Further trials are needed to confirm the potential benefits of statins amongst individuals with elevated CRP levels.

Thiazolidinediones in the treatment of managed care patients with type 2 diabetes

Insulin resistance and progressive beta-cell failure are fundamental defects in type 2 diabetes. Treatments that improve insulin sensitivity and beta-cell function can improve these defects and improve glycemic control. The thiazolidinediones (TZDs) improve insulin sensitivity, fasting and postprandial plasma glucose levels, and glycosylated hemoglobin (HbA1c) levels. These agents can be used as monotherapy, and they have been successfully combined with other antidiabetic therapies. The TZDs have also been associated with improvements in various cardiovascular risk factors, including hypertension, the dyslipidemic profile often observed in patients with diabetes or insulin resistance, aspects of endothelial dysfunction, abnormal hemostasis, and levels of several inflammatory markers. Studies are currently under way to evaluate the effects of TZDs on cardiovascular event rates. Accumulating evidence suggests that TZDs may enhance or preserve beta-cell function and thus may have a more durable therapeutic effect than some of the other oral antidiabetic agents. Using TZDs as monotherapy or as a component of combination therapy will contribute to improved glycemic control and should reduce the risk of diabetic complications. A number of studies have shown that a strategy of aggressive use of pharmacologic agents to achieve glycemic control is associated with cost benefits.