The Use of Statin in Diabetic Patients Not Known to Have Atherosclerotic Cardiovascular Disease

Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by hyperglycemia due to insulin resistance resulting in vascular complications. It accounts for approximately 75% of all atherosclerosis-related events.

Moreover, 65% of patients with diabetes die from any type of cardiovascular disease or stroke. Currently, lipid-lowering statin therapy is recommended for the primary prevention of atherosclerotic cardiovascular diseases, as well as for secondary prevention in DM patients with established cardiovascular disease.

The cardiovascular effects of statins extend beyond their effects on lipid fractions and include atherosclerotic plaque stabilization, anti-inflammatory effects, inhibition of vascular smooth muscle cell proliferation, inhibition of platelet function, and improved vascular endothelial function.

Diabetes mellitus (DM) increases cardiovascular disease (CVD) incidence and mortality. While guidelines endorse statin use in type 2 DM (T2DM) to mitigate cardiovascular risks and mortality, challenges like statin initiation and prompt treatment adjustments affect patient outcomes.

According to the ADA and ACC/AHA guidelines, moderate-intensity statin and lifestyle modifcations are recommended for all diabetic patients aged 40-75 without contraindication to statin therapy to achieve an LDL goal of less than 100 mg/dL. Furthermore, high-intensity statin therapy is recommended for patients with cardiovascular risk factors or overt cardiovascular disease to achieve the LDL goal of less than 70 mg/day.

Even though statins should be prescribed for diabetic patients (\> 40) regardless of their LDL laboratory values, monitoring their LDL is needed because some patients may have high LDL values even though they are using statins. It is imperative to consider this because high LDL values build up fatty deposits in the arteries, which reduce blood flow, leading to an increased risk of heart attack.

For primary prevention, moderate-dose statin therapy is recommended for those aged $40 years although high-intensity therapy should be considered in the context of additional ASCVD risk factors. The evidence is strong for people with diabetes aged 40-75 years, an age-group well represented in statin trials showing benefit. Since cardiovascular risk is enhanced in people with diabetes, as noted above, individuals who also have multiple other coronary risk factors have increased risk, equivalent to that of those with ASCVD. Therefore, current guidelines recommend that in people with diabetes who are at higher cardiovascular risk, especially those with one or more ASCVD risk factors, high intensity statin therapy should be prescribed to reduce LDL cholesterol by $50% from baseline and to target an LDL cholesterol of \<70 mg/dL (\<1.8 mmol/L) Five categories for reasons for statin nonuse were finalized after manual annotation: statin-associated side effects/contraindication, guideline discordant clinician practice, clinical inertia, statin hesitancy, and nonspecific reasons. In addition to side effects attributed to prior statin use, if statins were avoided based on pre-existing comorbidities (such as liver disease) or perceived contraindications (including pregnancy) without a trial or challenge, these reasons were categorized within the side effects/contraindication category. This was done because of low individual frequencies for some of these reasons and to comply with privacy regulations that prevent the reporting of groups with fewer than 10 patients. Clinicians avoiding statin use based on lipid levels was considered guideline-discordant practice, given that statin indications for diabetes are primarily independent of lipid levels. Deferral of statin decisions to future visits despite their indications was considered clinical inertia. Statin hesitancy was noted when patients expressed a preference to avoid statins despite discussion of their indication. Nonspecific documentation was recorded when statin nonuse was documented without additional explanation.