Submitted on July 22, 2002
Accepted on December 31, 2002
QUICKI is a Useful Index of Insulin Sensitivity in Subjects with Hypertension
Hui Chen1, Gail Sullivan1, Lilly Q. Yue2, Arie Katz1, and Michael J. Quon1*
1 Diabetes Unit, Laboratory of Clinical Investigation, National Center for Complementary and Alternative Medicine, National Institutes of Health, Bethesda, MD, USA
2 Division of Biostatistics, U.S. Food and Drug Administration, Rockville, MD, USA
* To whom correspondence should be addressed. E-mail: quonm{at}nih.gov.
Insulin resistance may link disorders of metabolic homeostasis such as diabetes and obesity with disorders of hemodynamic homeostasis such as hypertension. Thus, it is of interest to validate simple methods for quantifying insulin sensitivity in hypertensive patients. Quantitative Insulin-sensitivity Check Index (QUICKI) is a novel mathematical transformation of fasting blood glucose and insulin levels. In obese and diabetic subjects, QUICKI has a significantly better linear correlation with glucose clamp determinations of insulin sensitivity than minimal model estimates. To determine if QUICKI is also useful in hypertensive subjects we performed glucose clamps and frequently sampled iv glucose tolerance tests (FSIVGTT) on 27 hypertensive subjects taken off of anti-hypertensive medication. Indexes of insulin sensitivity derived from glucose clamp studies (SIClamp) were compared with QUICKI, minimal model analysis of FSIVGTTs (SIMM), and HOMA. The correlation between QUICKI and SIClamp (r = 0.84) was significantly better than that between SIMM and SIClamp (r = 0.65; p < 0.028). The correlation between QUICKI and SIClamp was comparable to that between 1/HOMA and SIClamp (r = 0.82). When studies were repeated in 14 subjects who resumed anti-hypertensive medications, the percent changes in SIClamp for each of these patients were significantly correlated with percent changes in QUICKI (r = 0.61) and HOMA (r = -0.54) but not SIMM (r = -0.18). We conclude that QUICKI is a simple, robust index of insulin sensitivity that is useful for evaluating and following the insulin resistance of hypertensive subjects in both research studies and clinical practice.
