Enhanced secretion of insulin plays a role in the development of atherosclerosis and restenosis of coronary arteries: elective percutaneous transluminal coronary angioplasty in patients with effort angina.

Abstract

We investigated the relation between insulin and coronary atherosclerosis and restenosis of the coronary arteries, by performing elective percutaneous transluminal coronary angioplasty (PTCA). Insulin is known to promote atherosclerosis of the arteries and has been implicated in the development of restenosis after PTCA. Of 210 angina patients who underwent PTCA, newly detected lesions in 35 consecutive nondiabetic subjects without previous intervention on the same main coronary arteries were analyzed after a 75-g oral glucose tolerance test (OGTT) and follow-up coronary angiography. Atherosclerotic lesions were evaluated by pattern, severity and extent. Restenosis was defined as loss of gain, the percentage of loss of the initial gain in the coronary diameter achieved by PTCA > or = 50%. Patients with restenosis had a significantly higher extent index (a marker of atherosclerosis), insulin area, ratio of insulin area to glucose area, insulinogenic index and minimal lumen diameter after PTCA than those without restenosis (p=0.001, 0.011, 0.002, 0.016 and 0.041, respectively). Simple regression analysis revealed that only the ratio of insulin area to glucose area (a relative marker of enhanced insulin secretion) significantly correlated with the extent index (p=0.035). Extent index, insulin area, the ratio of insulin area to glucose area and insulinogenic index significantly correlated with loss of gain (p=0.001, 0.010, 0.002 and 0.032, respectively). Stepwise multiple regression analyses revealed that extent index and the ratio of insulin area to glucose area significantly correlated with loss of gain. Enhanced secretion of insulin during the OGTT might be useful as a predictor of coronary atherosclerosis and of restenosis after elective PTCA in nondiabetic patients with effort angina.