Abstract
BACKGROUND: Reports about the relationships between specific insulin concentration and coronary heart disease risk are controversial. HYPOTHESIS: The objective of this study was to examine the association between insulin level and the severity of coronary atherosclerosis. METHODS: The study population consisted of 507 consecutive patients (376 men and 131 women) who underwent coronary angiography for suspected or known coronary atherosclerosis. The patients' habits of smoking and drinking were investigated, and anthropometric measurements including body mass index, systolic and diastolic blood pressures, as well as plasma measurements including lipids and blood glucose were taken. The true insulin level was measured using a highly sensitive two-site sandwich ELISA. The severity of coronary atherosclerosis was defined by the Gensini score system. The statistical methods including Kruskal-Wallis test, chi-square analysis, Spearman correlation analysis, and multivariate stepwise linear regression analysis were employed to explore the relationship between specific insulin level and coronary atherosclerosis. RESULTS: When the Gensini score was examined as a categorical variable classified by tertile values, subjects with a high Gensini score had significantly higher values of fasting plasma specific insulin level (p = 0.022). The Spearman correlation analysis suggest that the Gensini score correlated significantly with true insulin (mIU/l) (r = 0.095, p = 0.033). However, the results from the multivariate stepwise linear regression analysis show that the association between specific insulin level and severity of coronary atherosclerosis lost its significance. CONCLUSIONS: The level of plasma fasting specific insulin was associated significantly with the severity of coronary atherosclerosis, as measured by Gensini score, but hyperinsulinemia showed no association with the severity of coronary atherosclerosis in multivariate analyses.