PEOPLE WITH DIABETES
Statin therapy is effective among patients with diabetes mellitus and should be considered for all diabetic individuals who are at sufficiently high risk of vascular events
Previous CTT meta-analyses had shown statins to reduce the risk of occlusive vascular events in people with diabetes mellitus, but there remained uncertainty about the effects on particular outcomes and whether such effects depended on the type of diabetes, lipid profile, or other factors. The CTT Collaboration undertook a meta-analysis to help resolve these uncertainties.
Data were analyzed from approximately 18,500 individuals with diabetes (approximately 1500 with type 1 and 17,000 with type 2 diabetes) in the context of a further approximately 71,000 individuals without diabetes in 14 randomized trials of statin therapy. Mean follow-up was 4.3 years.
There was 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. This finding reflected a significant reduction in vascular mortality but no effect on non-vascular mortality in participants with diabetes.
There was a significant 21% proportional reduction in major vascular events per mmol/L reduction in LDL cholesterol in people with diabetes, which was again similar to the effect observed in those without diabetes. In diabetic participants there were also separately significant reductions of about one fifth per mmol/L reduction in LDL cholesterol in myocardial infarction or coronary death, coronary revascularization and stroke.
The reduction in major vascular events was similar among diabetic participants with pre-existing vascular disease and those with no such history. Among diabetic individuals, there was no evidence that the relative effects of statin therapy differed by diabetes type (type 1 or 2), gender, age, systolic or diastolic blood pressure, smoking, body mass index, renal function, predicted annual risk of a major vascular event, or the baseline lipid profile.
The effects on major vascular events started to emerge within the first year, but were greater in subsequent years.