Effect of Atorvastatin on Glycemic Control in Prediabetic Patients

Diabetes is a growing public health problem throughout the world, threatening global health and economic prosperity. Currently, approximately 171 to 194 million people in the world have diabetes, the majority of the cases being Type II. This number is expected to increase to more than 330 million by the year 2025-a record doubling within a single generation. India with 62.2 million diabetic patients is fast becoming the diabetes capital of the world with possibility of the number of diabetic patients reaching the 80 million mark by 2030. Every sixth diabetic in the world is an Indian. China with 43.2 million patients comes second, followed by the US where 26.8 million people suffer from the disease.

This spectacular increase in the frequency of Type II diabetes is being paralleled by a similarly alarming increase in obesity, which is one of the major risk factors for Type II diabetes. Because of the close linkage of these two conditions, Ziv and Shafrir have suggested the term "diabesity" to describe this association. This dual epidemic which was largely ignored by the public health community until recently has come as a great surprise involving enormous economic burden as well as in terms of health. Disorders of glucose metabolism are associated with increased risk for cardiovascular disease (CVD) complications, including coronary, peripheral and cerebral arterial disease, that account for the majority of morbidity and mortality among patients with diabetes mellitus (DM).

Type II diabetes is commonly associated with dyslipidaemia, which represents a synergistic risk factor for cardiovascular disease. The National Cholesterol Education Program Adult Treatment Panel III (ATP III) listed diabetes as a coronary heart disease (CHD) risk equivalent for setting therapeutic goals for LDL cholesterol. A goal for LDL cholesterol of <100 mg/dl was recommended for patients with CHD and CHD risk equivalents. For the majority of patients with diabetes, this LDL cholesterol goal would evoke the use of cholesterol-lowering drugs, particularly statins. Some Interventional studies emphasized that statin treatment leads to a reduction in cardiovascular events independent of lipid reduction with possible benefits for patients with Type II diabetes. Statins could also contribute to diabetes prevention owing to lipid-lowering and so-called pleiotropic action. Statins improve endothelial function, inhibit smooth muscle cell proliferation, and reduce oxidative stress and inflammation. Thus, with recent FDA approved indications for statins being widened, statins are currently amongst the most widely used drugs in patients with or without diabetes.

Although statin therapy reduces cardiovascular risk, its relationship with the development of diabetes is controversial. Retrospective analysis of the West of Scotland Coronary Prevention Study (WOSCOPS) revealed that 5 years of treatment with pravastatin reduced diabetes incidence by 30%. The authors suggested that although lowering of triglyceride levels could influence diabetes incidence, other mechanisms such as anti-inflammatory action may be involved. On the contrary, pravastatin did not decrease diabetes incidence in another trial including glucose-intolerant humans, suggesting that early inception of statin therapy may be required for effective diabetes prevention. Likewise, simvastatin did not affect diabetes incidence in patients with atherosclerosis in the Heart Protection Study. In contrast, atorvastatin marginally increased diabetes incidence in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT-LLA), which could be explained by statistical variation.

A recent review of 13 studies by Naveed Sattar, et al. published in The Lancet in 2010, on statins and their side-effects including a total of more than 91,140 participants suggested that use of statins is associated with increased risk of Type II diabetes by 9%.