Switching from atorvastatin to rosuvastatin lowers small, dense low-density lipoprotein cholesterol levels in Japanese hypercholesterolemic patients with type 2 diabetes mellitus.

•Small dense LDL-cholesterol (sd LDL-C) levels without high LDL-C levels are involved in the development of arteriosclerosis due to lipid abnormalities in patients with type 2 diabetes mellitus.•129 subjects among a total of 230 outpatient subjects with T2DM who were currently receiving 10mg atorvastatin once daily for ≥24 weeks were detected sd LDL-C using the LipoPhor AS® system.•Switching from 10mg atorvastatin to 5mg rosuvastatin exhibited a statistically significant reduction from baseline of sd LDL-C levels.