{"id":745,"date":"2012-03-20T14:43:07","date_gmt":"2012-03-20T14:43:07","guid":{"rendered":"https:\/\/www.touchendocrinology.com\/2012\/03\/20\/management-of-dyslipidemia-in-patients-with-diabetes\/"},"modified":"2012-03-20T14:43:07","modified_gmt":"2012-03-20T14:43:07","slug":"management-of-dyslipidemia-in-patients-with-diabetes","status":"publish","type":"post","link":"https:\/\/www.touchendocrinology.com\/cardiovascular-risk\/journal-articles\/management-of-dyslipidemia-in-patients-with-diabetes\/","title":{"rendered":"Management of Dyslipidemia in Patients with Diabetes"},"content":{"rendered":"

In association with the global spread of abdominal adiposity, the worldwide prevalence of type 2 diabetes continues to increase.1<\/sup> This is one of the pivotal factors underscoring the projection that cardiovascular disease will become the leading cause of mortality worldwide by 2020. Diabetes is associated with an adverse clinical outcome in individuals with and without established cardiovascular disease.2\u20134<\/sup> These observations have promoted the concept that diabetes should be considered a coronary risk equivalent in guidelines for cardiovascular prevention.
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\nIn association with the global spread of abdominal adiposity, the worldwide prevalence of type 2 diabetes continues to increase.1<\/sup> This is one of the pivotal factors underscoring the projection that cardiovascular disease will become the leading cause of mortality worldwide by 2020. Diabetes is associated with an adverse clinical outcome in individuals with and without established cardiovascular disease.2\u20134<\/sup> These observations have promoted the concept that diabetes should be considered a coronary risk equivalent in guidelines for cardiovascular prevention. They also identify individuals who are more likely to derive greater benefit from the use of more intensive preventive therapies.<\/p>\n

Considerable attention has focused on determining whether improvement of glycemic control is associated with cardiovascular benefit in patients with diabetes. The findings from recent clinical trials have, however, failed to demonstrate any reduction in macrovascular events.5\u20137<\/sup> Despite this, clinical trials have consistently reported cardiovascular protection in association with lowering levels of low-density lipoprotein cholesterol (LDL-C).8\u201312<\/sup> While LDL-C lowering has become increasingly integrated into clinical strategies for the prevention of cardiovascular disease, there remains a substantial residual risk of clinical events.<\/p>\n

It has been proposed that the presence of additional dyslipidemic features contributes to ongoing vascular risk in patients with diabetes.13\u201316<\/sup> These features include hypertriglyceridemia, low levels of high-density lipoprotein cholesterol (HDL-C) and abundant circulating levels of small, dense LDL particles. Accordingly, each of these abnormal lipid states has emerged as an attractive target for therapeutic manipulation.<\/p>\n

The Characteristics of Dyslipidemia in Patients with Diabetes<\/strong>
Despite the finding that lowering LDL-C is beneficial in patients with diabetes, LDL-C levels are typically not found to be elevated. In contrast, a number of additional lipid parameters have been found to be abnormal in patients with diabetes, including hypertriglyceridemia, low levels of HDL-C and a greater number of circulating small, dense, LDL particles.13\u201316<\/sup> Small, dense forms of LDL may be particularly atherogenic due to a greater avidity to diffusion into the artery wall and subsequent oxidation. This may reflect a level of circulating LDL that is associated with considerable vascular risk, despite having an apparently well-controlled LDL-C level. Furthermore, it may also contribute to the unequivocal benefit of LDL-C-lowering strategies in patients with type 2 diabetes. While the precise mechanisms that underscore the presence of this dyslipidemic profile in diabetes remain to be completely elucidated, insulin resistance appears to have an adverse impact on the secretion of apolipoprotein (apo) B-containing particles and lipoprotein remodeling.17,18<\/sup> In combination, these lipid abnormalities are likely to confer an adverse effect on the artery wall and increase overall cardiovascular risk. Management of Diabetic Dyslipidemia<\/strong>
Lifestyle interventions\u2014including diet, physical activity, weight loss and smoking cessation\u2014remain the cornerstone of all approaches to management of patients with diabetes. Although lifestyle intervention can improve diabetic dyslipidemia to some extent,19,20<\/sup> it remains difficult to achieve optimal goals. The addition of pharmacologic therapy will be needed in many patients. Dyslipidemia is also partially corrected by control of hyperglycemia, but abnormalities persist, partly due to the effects of insulin resistance on lipoprotein metabolism. Current management strategies in diabetes patients with atherogenic dyslipidemia focus on lowering the LDL-C level by at least 30\u201340 %, with a statin as the preferred drug, together with lifestyle intervention to reduce cardiovascular risk.21<\/sup><\/p>\n

Pharmacologic Strategies for Lipid Modification Statins<\/strong>
Pharmacologic inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) are the most important advance in the treatment of lipid disorders. Statins are considered first-line therapy for the treatment of dyslipidemia because they have significant clinical benefit in patients with and without diabetes. A post hoc analysis of the Heart Protection Study examined the effects of simvastatin 40 mg or placebo on cardiovascular events in people with diabetes.10 Simvastatin reduced the incidence of coronary events by 27 % (p<0.0001) and the incidence of any major vascular events by 24 % (p<0.0001).\n\n The Collaborative Atorvastatin Diabetes Study was the first prospective placebo-controlled trial of statin therapy in patients with type 2 diabetes and no history of cardiovascular disease.8<\/sup> The incidence of major cardiovascular events was reduced by 37 % with atorvastatin 10 mg (p=0.001). In addition to this, fatal and nonfatal strokes were reduced by 48 % and total mortality was reduced by 27 % (p=0.059). A meta-analysis of 14 randomized trials of statin therapy in patients with diabetes showed a 9 % reduction in all-cause mortality per mmol\/L reduction in LDL-C (p=0.02).22 There was also a 21 % reduction in major vascular events per mmol\/L reduction in LDL-C. The results in individuals with diabetes were comparable to those without the disease.<\/p>\n

The Treating to New Targets study assessed the efficacy and safety of lowering LDL-C <80 mg\/dL with a high-dose statin in patients with stable coronary artery disease.23<\/sup> A post hoc analysis was carried out of the patients with diabetes in this study. The analysis showed the favorable efficacies of high-dose statin (atorvastatin 80 mg) for several primary endpoint components\u2014non-procedure-related myocardial infarction (MI), fatal\/nonfatal stroke and cardiac-death\u2014compared with low-dose statin (atorvastatin 10 mg).9<\/sup> The atorvastatin 80 mg group had a 22 % relative reduction in the primary endpoint compared with the atorvastatin 10mg group (p<0.001). Significant differences favoring atorvastatin 80 mg were also found for cerebrovascular events (p=0.037) and any cardiovascular event (p=0.044). These results support the use of high-dose statins as an appropriate therapeutic option in patients with diabetes and cardiovascular disease.\n\n Overall, these statin trials confirm that LDL-C reduction in patients with diabetes will reduce major cardiovascular events, including stroke, whether or not the patients have established coronary artery disease. Thus, LDL-C is still a main target for the reduction of cardiovascular events in patients with diabetes.\n\n Lipid Modification Beyond Statins<\/strong>
Despite optimal statin therapy, a residual cardiovascular risk persists in patients with diabetes, who continue to demonstrate substantial event rates in clinical trials. The results from intravascular ultrasound trials show accelerated plaque progression within the coronary artery despite the use of medical therapies including a statin.24<\/sup><\/p>\n

While there is an ongoing search to develop additional LDL-C-lowering therapies, interventions that also target dyslipidemic states, such as low levels of HDL-C and hypertriglyceridemia, may reduce the burden of cardiovascular disease. Fibrates<\/strong>
Fibrates are agonists of peroxisome proliferator-activated receptors (PPAR-\u03b1), which regulate the expression of specific target genes that control lipid metabolism and inflammatory cascades.25<\/sup> Although fibrates have a minimal impact on LDL-C levels, they:26\u201328<\/sup><\/p>\n