HYPERINSULINISM IN PATIENTS WITH CORONARY-ARTERY DISEASE

Aim: To assess the clinical impact of hyperinsulinism and major corona ry risk factors in patients with angiographically documented or exclud ed coronary artery disease (CAD), a clinical study was carried out in 268 men admitted for left heart catheterization. Methods: Fasting immu noreactive insulin (IRI) levels were correlated to all major cardiovas cular risk factors and to the presence and degree of CAD. Results: IRI levels were correlated significantly with the degree of CAD (one-vess el disease: mean IRI 9.45 mu U/ml+/-0.43 SEM; two-vessel disease: mean IRI 10.4 mu U/ml+/- 0.71 SEM; three-vessel disease: mean IRI 11.88 mu U/ml+/-0.98 SEM) and inversely to the high-density lipoprotein level (P<0.05). In patients with arterial hypertension, IRI levels were elev ated, without a significant difference between those with and those wi thout CAD, whereas the IRI levels of non-hypertensive men with CAD (n= 81; mean IRI 9.85 mu U/ml+/-0.51 SEM) differed significantly (P<0.05) from those of non-hypertensive men without CAD (n=59; mean IRI 7.76 mu U/ml+/-0.43 SEM). IRI levels were significantly higher (P<0.05) in ob ese patients (n=65; mean IRI 11.68 mu U/ml+/-0.70 SEM versus n=203; me an IRI 9.32 mu U/ml+/-0.34 SEM), in patients with elevated triglycerid es (n=58 mean IRI 11.59 mu U/ml+/-0.81 SEM versus n=210; mean IRI 9.42 mu U/ml+/-0.33 SEM), and in patients with lowered HDL cholesterol (n= 178; mean IRI 11.06 mu U/ml+/-0.63 SEM versus n=90; mean IRI 9.29 mu U /ml+/-0.34 SEM). Diabetic patients on angiotensin converting enzyme in hibitor therapy (n=11; mean IRI 7.91 mu U/ml+/-0.91 SEM) had significa ntly (P<0.05) lower IRI levels than those not treated with ACE inhibit ors (n=25; mean IRI 12.96 mu U/ml+/-1.47 SEM). IRI levels exceeding 8 mu U/ml were associated with a 1.98-fold risk for CAD compared with IR I levels below 8 mu U/ml. Stepwise logistic regression showed that ins ulin was an independent determinant of CAD. Conclusion: Knowledge of t he fasting insulin level is an important contribution to the identific ation of patients with, or at risk of, CAD.