|
|
||||||||||
|
J Am Coll Cardiol, 2002; 40:937-943 © 2002 by the American College of Cardiology Foundation |

* Department of Medicine, Stanford, California, USA
Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California, USA
Manuscript received August 27, 2001; revised manuscript received March 19, 2002, accepted June 4, 2002.
* Reprint requests and correspondence: Dr. Gerald M. Reaven, Falk CVRC Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305-5406, USA
greaven{at}cvmed.Stanford.edu
| Abstract |
|---|
|
|
|---|
BACKGROUND: The importance of obesity as a risk factor for type 2 diabetes and hypertension is well-recognized, but its role as a CHD risk factor in nondiabetic, normotensive individuals is less well established.
METHODS: Insulin resistance was quantified by determining the steady-state plasma glucose (SSPG) concentration during the last 30 min of a 180-min infusion of octreotide, glucose, and insulin. In addition, nine CHD risk factors: age, systolic blood pressure, diastolic blood pressure (DBP), total cholesterol, triglycerides (TG), high-density lipoprotein (HDL) cholesterol and low-density lipoprotein cholesterol concentrations, and glucose and insulin responses to a 75-g oral glucose load were measured in the volunteers.
RESULTS: The BMI and the SSPG concentration were significantly related (r = 0.465, p < 0.001). The BMI and SSPG were both independently associated with each of the nine risk factors. In multiple regression analysis, SSPG concentration added modest to substantial power to BMI with regard to the prediction of DBP, HDL cholesterol and TG concentrations, and the glucose and insulin responses.
CONCLUSIONS: Obesity and insulin resistance are both powerful predictors of CHD risk, and insulin resistance at any given degree of obesity accentuates the risk of CHD and type 2 diabetes.
| ||||||||||||||||||||||||
Our second goal was to clarify the relative impact of obesity, per se, as distinguished from insulin resistance, on CHD risk factors. Given the difficulty in achieving success in weight control programs (7), it would be helpful to identify a subset of obese individuals who would benefit the most from weight loss and, therefore, be given the highest priority in weight loss programs.
The present report describes the relationship between BMI and insulin resistance in 314 nondiabetic, normotensive, healthy volunteers and defines the association of conventional CHD risk factors with obesity and insulin resistance.
| Methods |
|---|
|
|
|---|
Subjects were weighed on an electronic scale to the nearest 0.01 kg in hospital garments, height was measured to the nearest 0.01 cm without shoes, and BMI was calculated by dividing weight in kilograms by the square of the height in meters. Fasting plasma glucose and insulin concentrations were measured before and 30, 60, 120, and 180 min after the ingestion of a 75-g oral glucose challenge. The total integrated glucose and insulin responses were quantified by calculating the glucose and insulin area under the curve by use of the trapezoidal method. The analytical methods used for determining plasma glucose and insulin concentrations were similar over the duration of the study, as were those used for the determination of fasting concentrations of total cholesterol, triglycerides (TG), high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol (911). Insulin-mediated glucose disposal was estimated by a modification of the insulin suppression test (12) as introduced and validated by our research group (13). After an overnight fast, an intravenous catheter was placed in each arm of the patient. One arm was used for the administration of a 180-min infusion of octreotide, insulin, and glucose, and the other arm was used for collecting blood samples. Blood was sampled every 30 min initially and then at 10-min intervals from 150 to 180 min of the infusion to determine the steady-state plasma insulin (SSPI) and glucose concentrations for each individual. Because SSPI concentrations are similar for all subjects, the steady-state plasma glucose (SSPG) concentration provides a direct measure of the ability of insulin to mediate disposal of an infused glucose load; the higher the SSPG, the more insulin-resistant is the individual.
The population was divided into three categories of BMI as proposed by the National Institutes of Health (14): normal weight (18.5 to 24.9 kg/m2); overweight (25.0 to 29.9 kg/m2); and obesity class I (30.0 to 34.9 kg/m2). When this was done, our study population closely resembled the distribution of BMI in NHANES III, containing 52.5%, 32.1%, and 15.3% of individuals defined as being normal weight, overweight, and obese (15), compared with values of 43.6%, 32.6%, and 14.3%, respectively, for the same groups in NHANES III (1,15).
Data are expressed as mean ± SE. In each of the three BMI categories, means of BMI, SSPG, and the nine CHD risk factors (age, systolic blood pressure [SBP], diastolic blood pressure [DBP], total cholesterol, TG, HDL cholesterol, LDL cholesterol, glucose response, and insulin response) were compared using one-way analysis of variance.
The relationship between BMI and SSPG concentration was depicted in the form of a scatter plot, and Pearson and Spearman correlation coefficients were calculated. Individuals were defined as insulin-sensitive and insulin-resistant if they were in the lower (SSPG <4.66 mmol/l) and upper (SSPG >8.38 mmol/l) SSPG tertiles of the sample, respectively.
Simple and partial (adjusting for sex) correlation coefficients were calculated, first between each of the nine CHD risk factors and BMI, and then between each of the nine CHD risk factors and SSPG.
Multiple regression analyses were performed to evaluate whether the prediction of each of the nine CHD risk factors from the level of BMI would be modified if the degree of insulin resistance (SSPG) and an interaction between obesity (BMI) and insulin resistance (SSPG) were known in addition to the BMI. Two regression models were employed to evaluate these relationships. In model A, each risk factor was regressed on BMI and SSPG jointly. In model B, each risk factor was regressed on BMI, SSPG, and an interaction term. The interaction term was calculated by multiplying BMI and SSPG for each individual. Furthermore, using the results of regression model B, each of the nine CHD risk factors and BMI were graphed as continuous variables, while holding SSPG constant at three levels, namely, the means of the lower (insulin-sensitive), intermediate, and upper (insulin-resistant) SSPG tertiles of the sample.
| Results |
|---|
|
|
|---|
|
= 0. 441, p < 0.001). Furthermore, SSPG values varied widely across the BMI range; obese individuals (BMI >30.0 kg/m2) were insulin-sensitive, and insulin resistance occurred in normal weight individuals (BMI <25.0 kg/m2). Indeed, approximately 25% of insulin-resistant individuals were of normal weight, and the same proportion was obese.
|
|
|
|
| Discussion |
|---|
|
|
|---|
One important caveat that must be made as to our estimate of the magnitude of the relationship between obesity and insulin-mediated glucose disposal is the use of BMI as the measure of obesity. This decision was based upon our attempt to relate our findings to the NHANES III results, but it should be noted that the conclusions of the EGIR investigators (4) was independent of the estimates of obesity used in that "neither the waist circumference, nor the waist-to-hip ratio, indices of body fat distribution, was related to insulin sensitivity after adjustment for age, gender, and BMI."
Relationship between obesity, insulin resistance, and type 2 diabetes
The results of this study provide relevant information concerning the link between obesity and insulin resistance and the development of type 2 diabetes. Several prospective studies have shown that degree of insulin resistance and/or hyperinsulinemia are strong predictors of type 2 diabetes in normal glucose tolerant individuals (2025). It is obvious from Figure 2 that, at any given BMI, the most insulin-resistant tertile had plasma insulin concentrations that were three to four times higher than those in the most insulin-sensitive tertile. It should also be noted that the individuals in the most insulin-resistant tertile were also the most glucose intolerant, a change that also increases their risk of developing type 2 diabetes (20). Based upon these considerations, it can be concluded that overweight/obese individuals are not at equal risk to develop type 2 diabetes, and those in the lowest insulin-resistant tertile are at less risk of developing type 2 diabetes than an insulin-resistant individual of any weight.
Relationship between obesity, insulin resistance, and CHD
The results presented also provide considerable insight into the relationship between obesity, insulin resistance, and CHD risk. Insulin resistance and/or compensatory hyperinsulinemia have been shown to predict CHD in nondiabetics (2630), although it is not clear if this is a direct effect or secondary to the risk factors present in these individuals (31). The metabolic abnormalities most closely related to insulin resistance are hyperinsulinemia, some degree of glucose intolerance, hypertriglyceridemia, and a low HDL cholesterol concentration (31), changes that have been shown to increase CHD risk (2634). In our study we have demonstrated that, for a given level of obesity, these metabolic abnormalities are clearly accentuated in the most insulin-resistant tertile (Table 3 and Fig. 2). Thus, whether it is insulin resistance, per se, or its most common manifestations that increase CHD risk in insulin-resistant individuals, these changes are not present in obese individuals who are insulin-sensitive.
Conclusions
The results presented have reaffirmed the fact that the greater the BMI, the more insulin-resistant the individual. At the same time our results show that overweight/obese individuals can be insulin-sensitive and that normal weight subjects can be insulin-resistant. In addition, we have differentiated between the relative impact of overweight/obesity and insulin resistance on CHD risk factors, demonstrating that insulin resistance at any given BMI accentuates the risks of both type 2 diabetes and CHD. Implications of these findings are self-evident; the most intensive efforts to reduce risk of type 2 diabetes and CHD in overweight/obese individuals should be focused on those individuals who are also insulin-resistant.
| Footnotes |
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
J.-P. Despres, I. Lemieux, J. Bergeron, P. Pibarot, P. Mathieu, E. Larose, J. Rodes-Cabau, O. F. Bertrand, and P. Poirier Abdominal Obesity and the Metabolic Syndrome: Contribution to Global Cardiometabolic Risk Arterioscler. Thromb. Vasc. Biol., June 1, 2008; 28(6): 1039 - 1049. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Langeveld, K. J. M. Ghauharali, H. P. Sauerwein, M. T. Ackermans, J. E. M. Groener, C. E. M. Hollak, J. M. Aerts, and M. J. Serlie Type I Gaucher Disease, a Glycosphingolipid Storage Disorder, Is Associated with Insulin Resistance J. Clin. Endocrinol. Metab., March 1, 2008; 93(3): 845 - 851. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-P. Despres, P. Poirier, J. Bergeron, A. Tremblay, I. Lemieux, and N. Almeras From individual risk factors and the metabolic syndrome to global cardiometabolic risk Eur. Heart J. Suppl., March 1, 2008; 10(suppl_B): B24 - B33. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kotronen and H. Yki-Jarvinen Fatty Liver: A Novel Component of the Metabolic Syndrome Arterioscler. Thromb. Vasc. Biol., January 1, 2008; 28(1): 27 - 38. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Riserus, J. Arnlov, and L. Berglund Long-Term Predictors of Insulin Resistance: Role of lifestyle and metabolic factors in middle-aged men Diabetes Care, November 1, 2007; 30(11): 2928 - 2933. [Abstract] [Full Text] [PDF] |
||||
![]() |
K.-C. Sung, S. H. Kim, and G. M. Reaven Relationship Among Alcohol, Body Weight, and Cardiovascular Risk Factors in 27,030 Korean Men Diabetes Care, October 1, 2007; 30(10): 2690 - 2694. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Park, B. I. Kim, S. H. Kim, H. J. Kim, D. I. Park, Y. K. Cho, I. K. Sung, C. I. Sohn, H. Kim, D. K. Keum, et al. Body Fat Distribution and Insulin Resistance: Beyond Obesity in Nonalcoholic Fatty Liver Disease among Overweight Men J. Am. Coll. Nutr., August 1, 2007; 26(4): 321 - 326. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. C. Sung, M. C. Ryan, B. S. Kim, Y. K. Cho, B. I. Kim, and G. M. Reaven Relationships Between Estimates of Adiposity, Insulin Resistance, and Nonalcoholic Fatty Liver Disease in a Large Group of Nondiabetic Korean Adults Diabetes Care, August 1, 2007; 30(8): 2113 - 2118. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Reaven The Individual Components of the Metabolic Syndrome: Is There a Raison d'Etre? J. Am. Coll. Nutr., June 1, 2007; 26(3): 191 - 195. [Full Text] [PDF] |
||||
![]() |
T. McLaughlin, F. Abbasi, C. Lamendola, and G. Reaven Heterogeneity in the Prevalence of Risk Factors for Cardiovascular Disease and Type 2 Diabetes Mellitus in Obese Individuals: Effect of Differences in Insulin Sensitivity Arch Intern Med, April 9, 2007; 167(7): 642 - 648. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Beaser and P. Levy A Work in Progress, but a Useful Construct Circulation, April 3, 2007; 115(13): 1812 - 1818. [Full Text] [PDF] |
||||
![]() |
E. P. Weiss and J. O. Holloszy Improvements in Body Composition, Glucose Tolerance, and Insulin Action Induced by Increasing Energy Expenditure or Decreasing Energy Intake J. Nutr., April 1, 2007; 137(4): 1087 - 1090. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. P Weiss, S. B Racette, D. T Villareal, L. Fontana, K. Steger-May, K. B Schechtman, S. Klein, J. O Holloszy, and and the Washington University School of Medicine C Improvements in glucose tolerance and insulin action induced by increasing energy expenditure or decreasing energy intake: a randomized controlled trial. Am. J. Clinical Nutrition, November 1, 2006; 84(5): 1033 - 1042. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Li, E. S. Ford, L. C. McGuire, A. H. Mokdad, R. R. Little, and G. M. Reaven Trends in hyperinsulinemia among nondiabetic adults in the u.s. Diabetes Care, November 1, 2006; 29(11): 2396 - 2402. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. R. Sinaiko, J. Steinberger, A. Moran, C.-P. Hong, R. J. Prineas, and D. R. Jacobs Jr Influence of Insulin Resistance and Body Mass Index at Age 13 on Systolic Blood Pressure, Triglycerides, and High-Density Lipoprotein Cholesterol at Age 19 Hypertension, October 1, 2006; 48(4): 730 - 736. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. B. Meigs, P. W. F. Wilson, C. S. Fox, R. S. Vasan, D. M. Nathan, L. M. Sullivan, and R. B. D'Agostino Body Mass Index, Metabolic Syndrome, and Risk of Type 2 Diabetes or Cardiovascular Disease J. Clin. Endocrinol. Metab., August 1, 2006; 91(8): 2906 - 2912. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D. Ahuja, I. K Robertson, D. P Geraghty, and M. J Ball Effects of chili consumption on postprandial glucose, insulin, and energy metabolism Am. J. Clinical Nutrition, July 1, 2006; 84(1): 63 - 69. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. von Eynatten, A. Hamann, D. Twardella, P. P. Nawroth, H. Brenner, and D. Rothenbacher Relationship of Adiponectin with Markers of Systemic Inflammation, Atherogenic Dyslipidemia, and Heart Failure in Patients with Coronary Heart Disease Clin. Chem., May 1, 2006; 52(5): 853 - 859. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Bernstein, J. Berry, S. Kim, B. Canavan, and S. K. Grinspoon Effects of Etanercept in Patients With the Metabolic Syndrome. Arch Intern Med, April 24, 2006; 166(8): 902 - 908. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. M. Farin, F. Abbasi, and G. M Reaven Body mass index and waist circumference both contribute to differences in insulin-mediated glucose disposal in nondiabetic adults Am. J. Clinical Nutrition, January 1, 2006; 83(1): 47 - 51. [Abstract] [Full Text] [PDF] |
||||
![]() |
P.H. Whincup, J.A. Gilg, A.E. Donald, M. Katterhorn, C. Oliver, D.G. Cook, and J.E. Deanfield Arterial Distensibility in Adolescents: The Influence of Adiposity, the Metabolic Syndrome, and Classic Risk Factors Circulation, September 20, 2005; 112(12): 1789 - 1797. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Caban, D. J. Lee, L. E. Fleming, O. Gomez-Marin, W. LeBlanc, and T. Pitman Obesity in US Workers: The National Health Interview Survey, 1986 to 2002 Am J Public Health, September 1, 2005; 95(9): 1614 - 1622. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Dekker, C. Girman, T. Rhodes, G. Nijpels, C. D.A. Stehouwer, L. M. Bouter, and R. J. Heine Metabolic Syndrome and 10-Year Cardiovascular Disease Risk in the Hoorn Study Circulation, August 2, 2005; 112(5): 666 - 673. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Hirschler, C. Aranda, M. d. L. Calcagno, G. Maccalini, and M. Jadzinsky Can Waist Circumference Identify Children With the Metabolic Syndrome? Arch Pediatr Adolesc Med, August 1, 2005; 159(8): 740 - 744. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Reaven Counterpoint: Just Being Alive Is Not Good Enough Clin. Chem., August 1, 2005; 51(8): 1354 - 1357. [Full Text] [PDF] |
||||
![]() |
C. A. Geluk, F. W. Asselbergs, H. L. Hillege, S. J.L. Bakker, P. E. de Jong, F. Zijlstra, and W. H. van Gilst Impact of statins in microalbuminuric subjects with the metabolic syndrome: a substudy of the PREVEND Intervention Trial Eur. Heart J., July 1, 2005; 26(13): 1314 - 1320. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. T. Bloomgarden Second World Congress on the Insulin Resistance Syndrome: Insulin resistance syndrome and nonalcoholic fatty liver disease Diabetes Care, June 1, 2005; 28(6): 1518 - 1523. [Full Text] [PDF] |
||||
![]() |
G. M. Reaven Dr. Reaven responds: Clin. Chem., June 1, 2005; 51(6): 1083 - 1084. [Full Text] [PDF] |
||||
![]() |
E. M. Allister, N. M. Borradaile, J. Y. Edwards, and M. W. Huff Inhibition of Microsomal Triglyceride Transfer Protein Expression and Apolipoprotein B100 Secretion by the Citrus Flavonoid Naringenin and by Insulin Involves Activation of the Mitogen-Activated Protein Kinase Pathway in Hepatocytes Diabetes, June 1, 2005; 54(6): 1676 - 1683. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Reaven The Metabolic Syndrome: Requiescat in Pace Clin. Chem., June 1, 2005; 51(6): 931 - 938. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Curtis, J. G. Selter, Y. Wang, S. S. Rathore, I. S. Jovin, F. Jadbabaie, M. Kosiborod, E. L. Portnay, S. I. Sokol, F. Bader, et al. The Obesity Paradox: Body Mass Index and Outcomes in Patients With Heart Failure Arch Intern Med, January 10, 2005; 165(1): 55 - 61. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M.R. Gill, A. Al-Mamari, W. R. Ferrell, S. J. Cleland, C. J. Packard, N. Sattar, J. R. Petrie, and M. J. Caslake Effects of prior moderate exercise on postprandial metabolism and vascular function in lean and centrally obese men J. Am. Coll. Cardiol., December 21, 2004; 44(12): 2375 - 2382. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. McCord, B. J. Mundy, M. P. Hudson, A. S. Maisel, J. E. Hollander, W. T. Abraham, P. G. Steg, T. Omland, C. W. Knudsen, K. R. Sandberg, et al. Relationship Between Obesity and B-Type Natriuretic Peptide Levels Arch Intern Med, November 8, 2004; 164(20): 2247 - 2252. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. S. Lim, G. Y. H. Lip, and A. D. Blann Plasma von Willebrand Factor and the Development of the Metabolic Syndrome in Patients with Hypertension J. Clin. Endocrinol. Metab., November 1, 2004; 89(11): 5377 - 5381. [Abstract] [Full Text] [PDF] |
||||