Directly Measured Insulin Resistance and the Assessment of Clustered Cardiovascular Risks in Hypertension

BACKGROUND: The purpose of the study was to use factor analysis to investigate the contribution of a directly measured insulin sensitivity index, steady-state plasma glucose (SSPG) from insulin suppression test (IST), to a clustering of cardiovascular risk factors in hypertensive subjects. METHODS: A total of 204 nondiabetic hypertensive patients who received IST for SSPG were included for current analysis. Factor analysis was performed to explore the contribution of SSPG as additional information to a clustering of risk factors in these subjects. RESULTS: In factor analysis, SSPG aggregated with metabolic variables in an obesity-hyperinsulinemia domain that included two factors: one with positive loadings for SSPG, 2-h glucose, and Log 2-h insulin; and the other with positive loadings for body mass index, waist circumference, and fasting glucose. Fasting insulin linked the two factors together and explained 38.3% of the total variance. Systolic and diastolic blood pressures were loaded on a blood pressure domain separately. The third domain consisted of two factors: one with positive loadings for Log triglycerides and negative loading for high-density lipoprotein cholesterol; and the other with positive loadings for Log triglycerides and non-high-density lipoprotein cholesterol. The model loaded without SSPG explained a proportion of the total variance (78.5%) similar to that achieved with the model loaded with SSPG (77.1%). CONCLUSIONS: Directly measured insulin sensitivity index SSPG clustered with 2-h glucose and Log 2-h insulin in factor analysis in a cohort consisting entirely of hypertensive subjects. However, the contribution of SSPG as additional information to explain the total variance seems to be insignificant.