Persistence of low HDL-C levels after weight reduction in older men with small LDL particles.

LDL subclass pattern B is characterized by a predominance of small LDL particles (LDL peak particle size < or = 255 A) and is associated with increased plasma triglyceride (TG) and reduced HDL cholesterol (HDL-C) concentrations. This study compared the effect of weight loss on lipoprotein and glucose metabolism in 15 healthy, obese (body mass index [BMI], 30.9 +/- 2.4 kg/m2), older (60 +/- 9 years) men with LDL pattern B and in 25 men of comparable age and BMI with LDL pattern A (LDL peak particle size > or = 260 A). At baseline, men with LDL pattern B had higher TG and lower apolipoprotein (apo) A-I, HDL-C, and HDL2-C levels (P < .001) than men with LDL pattern A, while the total cholesterol and LDL cholesterol levels and fasting and 2-hour postprandial glucose and insulin levels did not differ between groups. With weight loss (10.1 +/- 3.6 kg) there were significant decreases in 2-hour postprandial glucose and insulin levels in men with LDL patterns B and A (P < .05). However, the change in plasma TG, HDL-C, HDL2-C, and apoA-I levels with weight loss differed between groups. In men with LDL pattern A, plasma TG levels decreased by 15% (P < .001) compared with a 34% (P < .001) decrease in LDL pattern B (two-factor ANOVA, P < .01). Plasma HDL-C concentrations increased by 0.16 mmol/L (P < .001) in the men with LDL pattern A but by only 0.07 mmol/L in the men with LDL pattern B (two-factor ANOVA, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)