Statin Therapy in Patients with Diabetes Mellitus
Patients with diabetes mellitus should continue statin therapy as it significantly reduces cardiovascular morbidity and mortality, with benefits clearly outweighing risks. 1
Benefits of Statin Therapy in Diabetes
- Statin therapy provides substantial cardiovascular protection for patients with diabetes, with meta-analyses demonstrating a 9% reduction in all-cause mortality and 13% reduction in vascular mortality for each 1.0 mmol/L (39 mg/dL) reduction in LDL cholesterol 1, 2
- The cardiovascular benefit is linearly related to LDL cholesterol reduction without a low threshold beyond which there is no benefit observed 1
- Statin therapy significantly reduces major vascular events by 21% per mmol/L reduction in LDL cholesterol in people with diabetes 2
- Benefits include reductions in myocardial infarction, coronary death, coronary revascularization, and stroke 2
Recommendations Based on Age and Risk Profile
- For patients with diabetes aged 40-75 years without atherosclerotic cardiovascular disease (ASCVD), moderate-intensity statin therapy is recommended in addition to lifestyle therapy 1
- For patients with diabetes aged 40-75 years at higher cardiovascular risk (with additional ASCVD risk factors), high-intensity statin therapy is recommended to reduce LDL cholesterol by ≥50% and achieve an LDL cholesterol goal of <70 mg/dL (<1.8 mmol/L) 1
- For patients of all ages with diabetes and established ASCVD, high-intensity statin therapy should be added to lifestyle therapy 1
- In adults with diabetes aged >75 years already on statin therapy, it is reasonable to continue statin treatment 1, 3
Statin Intensity and Dosing
- High-intensity statin therapy (atorvastatin 40-80 mg, rosuvastatin 20-40 mg) achieves approximately 50% reduction in LDL cholesterol 1
- Moderate-intensity statin therapy (atorvastatin 10-20 mg, rosuvastatin 5-10 mg, simvastatin 20-40 mg, pravastatin 40-80 mg) achieves 30-49% reductions in LDL cholesterol 1
- For patients who do not tolerate the intended intensity, the maximally tolerated statin dose should be used 1
- There is evidence for benefit from even extremely low, less-than-daily statin doses for patients who cannot tolerate standard dosing 1
Combination Therapy
- If LDL cholesterol target is not reached with maximally tolerated statin therapy, combination with ezetimibe is recommended 1
- For patients at very high cardiovascular risk with persistent high LDL cholesterol despite treatment with maximally tolerated statin dose in combination with ezetimibe, a PCSK9 inhibitor is recommended 1
Monitoring Recommendations
- Obtain a lipid profile at initiation of statin therapy, 4-12 weeks after initiation or dose change, and annually thereafter to monitor response and inform medication adherence 1
- Monitor for potential adverse effects, particularly myopathy 3
- For patients with diabetes and statin therapy, monitor glycemic control as some statins may have modest effects on glycemic parameters 4
Special Considerations
- Different statins may have varying effects on glycemic control - moderate-intensity pitavastatin may improve glycemic control while high-intensity atorvastatin may worsen it in patients with type 2 diabetes 4
- Despite potential modest effects on glycemic parameters, the cardiovascular benefits of statin therapy clearly outweigh any small risk of worsening glycemic control 2, 5
- Statin therapy is contraindicated in pregnancy 1
Potential Pitfalls and Caveats
- Low-dose statin therapy is generally not recommended in patients with diabetes but may be the only dose tolerated by some patients 1
- Statin discontinuation in patients with diabetes can lead to increased cardiovascular events, so efforts should be made to maintain therapy 6, 5
- The modest risk of new-onset diabetes with statin therapy does not apply to patients who already have diabetes and should not influence treatment decisions 5
- Drug interactions should be carefully monitored, especially in older adults taking multiple medications 3