Impact of Ezetimibe Alone or in Addition to a Statin on Plasma PCSK9 Concentrations in Patients with Type 2 Diabetes and Hypercholesterolemia: A Pilot Study

Background and Aim: The increase in proprotein convertase subtilisin/kexin type 9 (PCSK9) leads to low-density lipoprotein (LDL) receptor degradation. Statins significantly reduce LDL-cholesterol levels, but upregulate PCSK9. This study evaluated the effect of ezetimibe monotherapy or ezetimibe in combination with a statin on serum levels of PCSK9 in patients with type 2 diabetes and hypercholesterolemia. Methods: Ezetimibe treatment was given to ten patients with diabetes without statin therapy and ten patients with statin therapy. Plasma levels of PCSK9 were examined at baseline and 24 weeks after treatment. Results: At baseline, PCSK9 concentrations in patients with statin therapy were significantly higher than those in patients without statin use and in control subjects [median (25th–75th percentile) 411 (272–467) and 382 (356–453) ng/mL, respectively, p < 0.01]. After ezetimibe treatment for 24 weeks, LDL-cholesterol, triglyceride and remnant-like lipoprotein cholesterol were significantly decreased in both groups. However, PCSK9 concentration did not change compared with baseline measurements in both groups. The percentage change in LDL-cholesterol after ezetimibe therapy for 24 weeks was not correlated with the percentage change in PCSK9 concentration. Conclusion: Ezetimibe may reduce LDL-cholesterol levels without affecting PCSK9 in patients with type 2 diabetes and hypercholesterolemia.