ABSTRACT
The purpose of this study was to explore possible calculations using oral glucose tolerance test (OGTT) values in order to develop a simple measure of insulin sensitivity. We devised a formula for an insulin sensitivity index, ISI(0,120), that uses the fasting (0 min) and 120 min post-oral glucose (OGTT) insulin and glucose concentrations. It appears to be generalizable across a spectrum of glucose tolerance and obesity. Most importantly, our data show that ISI(0,120) correlates well, when applied prospectively in comparative studies, with the insulin sensitivity index obtained from the euglycemic hyperinsulinemic clamp (r = 0.63, P < 0.001). This correlation was demonstrably superior to other indices of insulin sensitivity such as the HOMA formula presented by Matthews, and performed comparably to the computerized HOMA index. Measurement of insulin sensitivity has traditionally been possible only in research settings because of the invasiveness and expense of the methods used. Clinical investigators have therefore sought more practical methods to obtain an index of insulin sensitivity. Such an index should approximate insulin sensitivity as measured by the euglycemic hyperinsulinemic clamp (M). We present ISI(0,120), a simple yet sensitive measure of insulin sensitivity which is adaptable for use in clinical settings as well as large epidemiologic studies.
Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus/blood , Glucose Clamp Technique , Glucose Intolerance/blood , Glucose Tolerance Test , Insulin Resistance , Insulin/blood , Obesity/blood , Adolescent , Adult , Aged , Female , Humans , Infusions, Intravenous , Insulin/administration & dosage , Insulin/pharmacology , Male , Middle Aged , Models, Biological , Regression Analysis , Reproducibility of ResultsABSTRACT
This study tested predictions derived from D.C. Glass's (1977) uncontrollability model regarding the link between control-related personality attributes and the dissociation of affective and autonomic responses to stress. Pressured drive, measured by the Jenkins Activity Survey (D. S. Krantz, D. C. Glass, & M. L. Snyder, 1974), and emotional defensiveness, measured by the Marlowe-Crowne Social Desirability Scale (D. P. Crowne & D. Marlowe, 1964), were examined in relation to cardiovascular and affective responses to mental arithmetic in 31 male and 26 female college students. Pressured drive was positively associated with cardiovascular reactivity but unrelated to affect ratings. In contrast, emotional defensiveness was unrelated to cardiovascular reactivity, but high scores were associated with smaller increases in self-reported negative affect. The findings suggest that these potentially health-damaging personality attributes may influence stress response measures through independent mechanisms for maintaining environmental control and self-control.
