Small dense LDL cholesterol is a robust therapeutic marker of statin treatment in patients with acute coronary syndrome and metabolic syndrome.

Small dense low-density lipoprotein (sd-LDL) is an atherogenic LDL subfraction and often increased in metabolic syndrome (MetS). This study aimed to determine whether sd-LDL cholesterol (sd-LDL-C) is a therapeutic marker of statin treatment in patients with acute coronary syndrome (ACS) and MetS.We examined 71 patients with ACS and 50 non-ACS subjects with normal coronary arteries (controls). The patients with ACS were treated with life-style modifications (n=36) or those plus 20mg atorvastatin daily (n=35) for 6 months. We measured sd-LDL-C by a novel detergent-based homogenous assay and calculated buoyant LDL-C (b-LDL-C).The patients with ACS had higher sd-LDL-C than did the controls (30±14 vs. 22±8 mg/dl, p<0.001). Furthermore, sd-LDL-C was higher in the patients with ACS and MetS (n=31) than in those without MetS (n=40) (35±17 vs. 27±11 mg/dl, p<0.05). Atorvastatin reduced LDL-C and sd-LDL-C by 31% (102±23 to 70±28 mg/dl, p<0.0001) and 24% (29±15 to 22±13 mg/dl, p<0.01). The reduction in sd-LDL-C by atorvastatin was 5.5-fold greater in the patients with ACS and MetS than in those without MetS (p<0.001). Contrary, that in b-LDL-C was similar between the groups.sd-LDL-C is a superior therapeutic marker of statin treatment in patients with ACS and MetS.