Statin therapy reduces the risk of major vascular events* in a wide range of individuals with diabetes, irrespective of whether they already have cardiovascular disease, and regardless of age, sex, and other clinical characteristics. As such, most people with diabetes should now be considered for statin therapy, according to an Article in this week’s issue of The Lancet.
At least 170 million people worldwide are estimated to have diabetes mellitus, and this number is predicted to more than double by 2030. Since both types of diabetes are associated with increased risk of cardiovascular disease the identification of treatments for the prevention of major vascular events is a public-health priority. Although previous studies** have shown that statin therapy is effective for the prevention of major vascular events in patients with diabetes, there has been uncertainty about the size of any benefits on major coronary events (ie, heart attack or death from coronary heart disease), on stroke, and on coronary revascularisation (the need for an operation to bypass or unblock the coronary arteries). Moreover, there are unanswered questions about whether statin therapy is as effective in patients with diabetes as in those without diabetes, and whether statins are beneficial in people with diabetes who do not have a history of vascular disease.
To answer these questions, the Cholesterol Treatment Trialists’ (CTT) Collaborators (Clinical Trial Service Unit and Epidemiological Studies Unit, Oxford, UK and National Health and Medical Research Council Clinical Trial Centre, Sydney, Australia) did a meta-analysis of 18 686 individuals with diabetes and a further 71 370 without diabetes in 14 randomised trials to explore the effects of lowering LDL cholesterol with statin therapy.
During a mean follow-up of 4.3 years, there were 3247 vascular events in people with diabetes. The researchers found a 9% proportional reduction in all-cause mortality per mmol/L reduction in LDL cholesterol in participants with diabetes, which was similar to the 13% reduction in those without diabetes. There was a significant one-fifth proportional reduction in major vascular events per mmol/L reduction in LDL cholesterol in people with diabetes, which was similar to the effect observed in those without diabetes. The authors note that this relative-risk reduction was similar irrespective of previous history of vascular disease, age, sex, and other baseline characteristics. After 5 years, 42 fewer people with diabetes had major vascular events per 1000 allocated statin therapy.
The authors say: “This meta-analysis shows convincingly that the proportional benefits of statin therapy on major vascular events were similar in a wide range of individuals with diabetes, including those with no previous history of vascular disease, and benefits were similar to those observed in people without diabetes.”
They conclude: “Most people with diabetes should now be considered for statin therapy, unless their risk is low (eg, as in children) or statin therapy has been shown to be unsuitable for them (eg, as in pregnancy.”***
In an accompanying Comment, Professor Bernard Cheung (University of Birmingham, UK) says that statins are among the most notable triumphs of modern medicine and adds: “Apart from drug treatment, one must not forget the importance of lifestyle changes, such as cessation of smoking, healthy diet, and regular exercise.”
Medical Research Council press office, London, UK. T) 020 7670 5139 or out of hours 07818 428 297 press.office@headoffice.mrc.ac.uk
Comment Professor Bernard Cheung, University of Birmingham, UK. T) +44 (0)121 414 47548 b.cheung@bham.ac.uk
Notes to Editors
*ie, heart attack, stroke, or coronary revascularisation (the need for an operation to bypass or unblock the coronary arteries).
**The authors have previously reported the results of a collaborative meta-analysis of 14 randomised trials of statin therapy (the Cholesterol Treatment Trialists [CTT] Collaboration). The results showed that lowering LDL cholesterol by 1 mmol/L reduces the risk of major vascular events by about a fifth in a wide range of high-risk participants, largely irrespective of baseline lipid profile or other presenting characteristics, including diabetes.
*** Quote directly from author and cannot be found in text of article.
Journal
The Lancet