Influence of 4 weeks' intervention by exercise and diet on low-density lipoprotein subfractions in obese men with type 2 diabetes

Insulin resistance is associated with dyslipoproteinemia characterized by i ncreased serum triglycerides, reduced high-density lipoprotein 2 (HDL2) cho lesterol, and increased small, dense low-density lipoprotein (LDL) subfract ion particles. Physical activity and weight reduction are known to improve insulin resistance and dyslipoproteinemia, but their influence on LDL subfr actions in diabetic patients is unknown. Therefore, we investigated the eff ect 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/s aturated fat ratio, 1.0) on glycemic control and HDL and LDL subfractions i n 34 obese patients with non-insulin-dependent diabetes (age, 49 +/- 9 year s; body mass index [BMI], 33.1 +/- 5.1 kg/m(2)). 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) concentr ations in very-low-density lipoprotein (VLDL) (P < .01), intermediate-densi ty lipoprotein (IDL), and small, dense (>1.040 g/mL) LDL particles (P < .00 1). These data underlie the positive influence of weight reduction induced by exercise and diet on insulin resistance and lipoprotein metabolism in ob ese diabetic patients, particularly showing improvements of the LDL subfrac tion profile with a decrease of small, dense LDL particles. This is of part icular importance, as these particles have been shown to be associated with coronary artery disease. Copyright (C) 1999 by W.B. Saunders Company.