Statins in the Treatment of Type 2 Diabetes Mellitus: A Systematic Review.

摘要

Globally, Type 2 diabetes mellitus (T2DM) continues to prove a huge challenge to patients and clinicians. Treatment of T2DM has traditionally been focused on the regulation of sugar in the blood with diet and drugs. Substantial epidemiological data has demonstrated since the 1970s that cardiovascular diseases (CVD) constitute the primary cause of morbidity and mortality in patients with diabetes. This systematic review was aimed at using clinical trials on published literature to pull out evidence - based medicine to support or discount the mortality benefits of statin therapy in T2DM patients. From the clinical trials reviewed, statin therapy in non diabetic and T2DM showed varying degrees of reduction in CHD events. Pravastatin therapy reduced the risk among all patients from 15.9 % to 12.3% (relative risk reduction (RRR) 24%). In diabetics, the RRR was 19%. Same therapy reduced the risk of stroke from 9.9% to 6.3% in diabetic group. Another study observed in their results a significant reduction in mortality (1328:12.9%) deaths among 10,269 patients in the simvastatin group versus 1507: 14.7% among 10,267 patients in the placebo group. Other studies also reported significant or near significant reduction in mortality or death rate. Artovastatin reduced acute CHD events by 36%, coronary revascularization by 31% and rate of stroke by 48%. Pravastatin on the other hand showed 25% reduction of risk of coronary events (CHD, death, non fatal myocardial Infarction (MI) and coronary artery by pass graft (CABG)). Another study showed that patients with T2DM and other risk factors of coronary artery disease or retinopathy had a 35% relative risk reduction in CVD when Atorvaststin 10mg was given daily which was similar to a 33% relative risk reduction in CVD with Simvastatin 40mg. Other clinical trials showed significant evidence that the pharmacological treatment with statins reduced mortality and morbidity associated with CVD especially those who are already at higher risk of CHD events, such as patients with T2DM while long term treatment is often necessary. Introduction Type 2 diabetes mellitus (T2DM) continues to prove a huge challenge to patients and clinicians worldwide. In the U.S alone, diabetes is the 5th leading cause of death(American Diabetic Association, 2003) with economic burden costing an estimated $174 billion in medical expenses ( American Diabetes Association, 2007) An estimated 20.8 million people (roughly 7% of U.S population) have diabetes, and with it’s relatively high mortality, T2DM accounts for about 85-90% of all diabetes cases.1 T2DM increases the risk of cardiovascular disease (CVD) 2-4 times with outcomes especially worse after myocardial infarcation (MI) or stroke. Substantial epidemiological data has demonstrated since the 1970s that Cardiovascular diseases (CVD) constitute the primary cause of morbidity and mortality in patients with diabetes. (John Buse 2003)Atherosclerosis accounts for about 80% of all mortality in patients who have diabetes, with estimates suggesting that about half of patients who have been recently diagnosed with T2DM have coronary heart disease (CHD) ( Ginsberg,2006, Haffner et al,1998) Further studies have also suggested that high risk patients who have T2DM without a history of CHD have rates of new events similar to those of non-diabetic subjects with CHD. By implication, CVD is a major cause of morbidity and mortality in patients with T2DM, and the degree of CHD risk in patients with T2DM, without a prior history of CHD is similar to that of patients without T2DM but with existing CHD (Haffner et al, 1998).Following results from studies suggesting this pattern of risk, the National Cholesterol Education Program classified T2DM as a cardiovascular disease equivalent, in its report (Stone et al, 2005). In order to reduce the risk of CVD and stroke in patients at significant risk, initiation of statin therapy is recommended.The statins (3-Hydroxy-3-methyl glutaryl Coenzyme A re