Abstract 21403: Favorable Impact on LDL Particle Size in Response to Treatment with Pioglitazone is Associated with Less Progression of Coronary Atherosclerosis in Patients with Type 2 Diabetes
Background: While conventional lipid parameters correlate with progression of coronary atherosclerosis, the impact of measures of LDL particle size and concentration are unknown.
Methods: PERISCOPE evaluated plaque progression with intravascular ultrasound in 360 diabetic patients treated with pioglitazone or glimepiride. The relationship between changes in LDL particle size and number determined by NMR spectroscopy and plaque burden was characterized.
Results: Pioglitazone was associated with increases in large LDL particle number (+61.2±4.4 v +15.7±4.2%, p<0.001) and mean LDL particle size (3.6±0.2 v 0.7±0.2%, p<0.001) and decreases in small LDL particle (-37.5±3.9 v -2.8±3.7%, p<0.001) and total LDL particle number (-15.1±1.8% v -1.5±1.7%, p<0.001). Progression of percent atheroma volume (PAV) was associated with increases in small LDL particles (r=0.18, p<0.001) and the total number of LDL particles (r=0.12, p=0.03). However, increases in large LDL particle number (r=-0.17, p=0.002) and mean LDL particle size (r=-0.21, p<0.001) were associated with less disease progression. Substantial regression was associated with a greater increase in LDL particle size compared with progression (3.3±0.4% v 1.7±0.4%, p=0.006). The highest tertile of increase in large LDL number (p=0.02) and mean LDL size (p<0.001) and decrease in small LDL number (p<0.001) were each associated with plaque regression. In patients with intensive lowering of LDL-C <=70 mg/dL, a greater increase in mean LDL particle size remained associated with less progression of PAV (-0.89±0.48% vs. 1.01±0.44%, p=0.004). Furthermore, in patients whose LDL-C decreased, greater disease progression of PAV was observed when the number of large LDL particles decreased (0.69±0.30 vs. -0.13±0.29%, p=0.05) and number of small LDL particles increased (0.85±0.43 vs. 0.09±0.24%, p=0.12). Multivariable analysis revealed that the change in LDL mean particle size independently predicted disease progression (p=0.003).
Conclusion: Measures of LDL particle size and number predict plaque in diabetic patients, even in patients whose LDL-C appears to be well controlled. These measures may highlight patients who require more intensive risk modification strategies.
- © 2010 by American Heart Association, Inc.