Influence of obesity, impaired glucose tolerance, and NIDDM on LDL structure and composition: possible link between hyperinsulinemia and atherosclerosis

Certain factors may increase the risk of disease of the coronary arteries, the major blood vessels supplying the heart. These risk factors were evaluated in excessively overweight women with normal blood glucose levels, impaired glucose tolerance (IGT; the inability of the body to absorb and use glucose), and non-insulin-dependent diabetes mellitus (NIDDM). The numbers of patients in the groups were 14, 8, and 14, respectively. The women were assessed before and after gastric bypass surgery, an operation to bypass the stomach. In comparison with 10 lean women of similar age, before surgery the obese women had blood lipid and apolipoprotein levels that tended to be atherogenic. (Atherogenic refers to the ability to cause atherosclerosis, the accumulation of lipids and overgrowth of cells within blood vessels, which obstructs blood flow.) The smaller and more dense low-density-lipoprotein (LDL) particles in obese women with IGT or NIDDM may also contribute to the risk for coronary heart disease (CHD). A decrease in size of LDL particles is correlated with increases in blood insulin levels. The body mass index, blood insulin levels, and triglyceride levels decreased and LDL size increased after gastric bypass surgery. In addition, high-density-lipoprotein (HDL; which is believed to have a protective effect in preventing CHD) was increased in all the women following surgery. Changes in the properties of LDL appear to be beneficial in reducing the risk of coronary heart disease in obese women with IGT or NIDDM. (Consumer Summary produced by Reliance Medical Information, Inc.)