Insulin resistance is associated with
dyslipoproteinemia characterized by increased serum
triglycerides, reduced
high-density lipoprotein 2 (
HDL2) cholesterol, and increased small, dense
low-density lipoprotein (
LDL) subfraction particles. Physical activity and
weight reduction are known to improve
insulin resistance and
dyslipoproteinemia, but their influence on
LDL subfractions in diabetic patients is unknown. Therefore, we investigated the effect of a 4-week intervention program of exercise (2,200 kcal/wk) and diet (1,000 kcal/d: 50%
carbohydrate, 25%
protein, and 25% fat; polyunsaturated/saturated fat ratio, 1.0) on
glycemic control and HDL and
LDL subfractions in 34 obese patients with non-
insulin-dependent diabetes (age, 49 +/- 9 years; body mass index [BMI], 33.1 +/- 5.1 kg/m2). Reductions in
body weight (P < .001) and improvements in fasting
blood glucose,
insulin,
fructosamine (P < .001), and
free fatty acids (P < .01) by intervention were associated with reductions in serum
cholesterol and
apolipoprotein B (
apo B) concentrations in
very-low-density lipoprotein (VLDL) (P < .01),
intermediate-density lipoprotein (IDL), and small, dense (>1.040 g/mL)
LDL particles (P < .001). These data underlie the positive influence of
weight reduction induced by exercise and diet on
insulin resistance and
lipoprotein metabolism in obese diabetic patients, particularly showing improvements of the
LDL subfraction profile with a decrease of small, dense
LDL particles. This is of particular importance, as these particles have been shown to be associated with
coronary artery disease.