Effect of ezetimibe add-on therapy over 52 weeks extension analysis of prospective randomized trial (RESEARCH study) in type 2 diabetes subjects

BACKGROUND

Lowering cholesterol levels decreases the risk of atherosclerotic diseases. Effective ways to stably reduce LDL-C level are warranted in type 2 diabetic patients, a high-risk population for CVD, with various anti-diabetic therapeutic background. The RESEARCH study focuses on LDL-C reduction in this population along with modifications of the lipid profiles. We evaluated long-term ezetimibe add-on therapy in T2DM patients with hypercholesterolemia.

METHODS

In a randomized, multicenter, open-label, prospective study, a total of 109 T2DM patients not attaining LDL-C target value despite first-line dose statin (10 mg of atorvastatin or 1 mg of pitavastatin) therapy in Japan were recruited. We investigated the difference in cholesterol lowering effect between ezetimibe (10 mg) add-on statin (EAT) group and double-dose statin (DST) group. Changes of parameters related to atherosclerotic event risks were assessed.

RESULTS

The reduction of LDL-C was larger in the EAT group (28.3%) than in the DST group (9.2%) at 52 weeks as well as the primary endpoint of 12 weeks. EAT achieved significant lower levels of TC and apo B, respectively. Both treatments attained significant reduction in sd-LDL-C or hsCRP on this long-term basis. Notably, sd-LDL-C in EAT reduced as low as 36.1 ± 14.9 mg/dl to reach near the threshold (35.0 mg/dl) for atherosclerosis with significantly higher achievement rate (55.6%) than DST treatment. Simultaneously, hsCRP reduction by EAT attained as low value as 0.52 ± 0.43 mg/l.

CONCLUSIONS

In the present 52-week long-term period, ezetimibe add-on therapy showed a robust advantage in lowering LDL-C and in attaining target LDL-C values compared with the doubling of statin dose. Moreover, it's meaningful that sd-LDL, powerfully atherogenic lipoprotein, exhibited prominent decrease consistently prominently by ezetimibe add-on therapy. DM patients with hypercholesterolemia are at high risk for CAD, and adding ezetimibe onto usual-dose statin treatment in Japan has been suggested as the first-line therapy for those DM patients who failed to attain the target LDL-C value (UMIN000002593).

Effect of Ezetimibe on LDL-C Lowering and Atherogenic Lipoprotein Profiles in Type 2 Diabetic Patients Poorly Controlled by Statins

Background

There exists a subpopulation of T2DM in whom first-line doses of statin are insufficient for optimally reducing LDL-C, representing a major risk of CVD. The RESEARCH study focuses on LDL-C reduction in this population along with modifications of the lipid profiles leading to residual risks.

Methods

Lipid changes were assessed in a randomized, multicenter, 12-week, open-label study comparing a high-potency statin (10mg of atorvastatin or 1mg of pitavastatin) plus ezetimibe (EAT: n = 53) with a double dose of statin (20mg of atorvastatin or 2mg of pitavastatin) (DST: n = 56) in DM subjects who had failed to achieve the optimal LDL-C targets. Lipid variables were compared with a primary focus on LDL-C and with secondary focuses on the percentage of patients who reached the LDL-C targets and changes in the levels of RLP-C (remnant like particle cholesterol) and sd-LDL-C, two characteristic atherogenic risks of DM.

Results

The reduction of LDL-C (%), the primary endpoint, differed significantly between the two groups (-24.6 in EAT vs. -10.9 in DST). In the analyses of the secondary endpoints, EAT treatment brought about significantly larger reductions in sd-LDL-C (-20.5 vs. -3.7) and RLP-C (-19.7 vs. +5.5). In total, 89.4% of the patients receiving EAT reached the optimized treatment goal compared to 51.0% of the patients receiving DST. The changes in TC (-16.3 vs. -6.3) and non-HDL-C (-20.7 vs. -8.3) differed significantly between the two groups.

Conclusion

Ezetimibe added to high-potency statin (10 mg of atorvastatin or 1 mg of pitavastatin) was more effective than the intensified-dose statin (20 mg of atorvastatin or 2 mg of pitavastatin) treatment not only in helping T2DM patients attain more LDL-C reduction, but also in improving their atherogenic lipid profiles, including their levels of sd-LDL-C and RLP-C.

We thus recommend the addition of ezetimibe to high-potency statin as a first line strategy for T2DM patients with insufficient statin response.

Trial Registration

The UMIN Clinical Trials Registry UMIN000002593