Rosiglitazone increases LDL particle size and buoyancy and decreases C-reactive protein in patients with type 2 diabetes on statin therapy

Abstract

A substantial number of individuals with type 2 diabetes mellitus (T2DM) demonstrate a predominance of small dense low-density lipoprotein (sdLDL), which is associated with an increased risk of cardiovascular disease (CVD). In some cases, sdLDL persists after treatment with a statin to reduce levels of LDL. The effect of the addition of a thiazolidinedione, rosiglitazone (RSG) (4 mg/day or 8 mg/day) to statin therapy on LDL phenotype and C reactive protein (CRP) levels was investigated in a 12-week, placebo-controlled study of 72 T2DM patients who were well controlled and on a statin, but who had persistently predominant sdLDL. Addition of RSG 8 mg to statin therapy significantly increased LDL buoyancy (relative flotation +0.014, p=0.003) and LDL particle size (+4.2Å, p=0.001) from baseline and relative to the change with placebo (+0.014 and +3.8Å; p=0.03 and p=0.04, respectively), and was associated with a non-significant decrease in sdLDL. RSG 8 mg moderately, but significantly, increased total cholesterol (by 12.2%, p=0.004), LDL-cholesterol (11.2%, p=0.02) and intermediate-density lipoprotein (IDL)-cholesterol from baseline but did not increase total or LDL apolipoprotein B. RSG 4 mg and 8 mg significantly reduced CRP compared with placebo (-44.9% and-48.0%; p=0.008 and p=0.004, respectively), and significantly reduced insulin resistance and fasting plasma glucose from baseline. Addition of RSG to statin therapy may further reduce cardiovascular risk by improving the LDL phenotype, as well as reducing insulin resistance and CRP levels. However, the increase in IDL may be proatherogenic and must be considered when assessing the benefits of rosiglitazone.