Diabetes 52:2748-2758, 2003
© 2003 by the American Diabetes Association, Inc.
Contribution of Elevated Free Fatty Acid Levels to the Lack of Glucose Effectiveness in Type 2 Diabetes
Meredith Hawkins,
Julia Tonelli,
Preeti Kishore,
Daniel Stein,
Enzo Ragucci,
Alon Gitig, and
Kalpana Reddy
From the Division of Endocrinology and Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York
Increased circulating free fatty acids (FFAs) inhibit both hepatic and peripheral insulin action. Because the loss of effectiveness of glucose to suppress endogenous glucose production and stimulate glucose uptake contributes importantly to fasting hyperglycemia in type 2 diabetes, we examined whether the approximate twofold elevations in FFA characteristic of poorly controlled type 2 diabetes contribute to this defect. Glucose levels were raised from 5 to 10 mmol/l while maintaining fixed hormonal conditions by infusing somatostatin with basal insulin, glucagon, and growth hormone. Each individual was studied at two FFA levels: with (NA+) and without (NA-) infusion of nicotinic acid in nine individuals with poorly controlled type 2 diabetes (HbA1c = 10.1 ± 0.7%) and with (LIP+) and without (LIP-) infusion of lipid emulsion in nine nondiabetic individuals. Elevating FFA to 500 µmol/l blunted the ability of glucose to suppress endogenous glucose production (LIP- = -48% vs. LIP+ = -28%; P < 0.01) and increased glucose uptake (LIP- = 97% vs. LIP+ = 51%; P < 0.01) in nondiabetic individuals. Raising FFA also blunted the endogenous glucose production response in 10 individuals with type 2 diabetes in good control (HbA1c = 6.3 ± 0.3%). Conversely, normalizing FFA nearly restored the endogenous glucose production (NA- = -7% vs. NA+ = -41%; P < 0.001) and glucose uptake (NA- = 26% vs. NA+ = 64%; P < 0.001) responses to hyperglycemia in individuals with poorly controlled type 2 diabetes. Thus, increased FFA levels contribute substantially to the loss of glucose effectiveness in poorly controlled type 2 diabetes.
Address correspondence and reprint requests to Meredith Hawkins, Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461. E-mail: hawkins{at}aecom.yu.edu

CiteULike Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
P. Kishore, J. Tonelli, S. Koppaka, C. Fratila, A. Bose, D.-E. Lee, K. Reddy, and M. Hawkins
Time-Dependent Effects of Free Fatty Acids on Glucose Effectiveness in Type 2 Diabetes
Diabetes,
June 1, 2006;
55(6):
1761 - 1768.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. Gennarelli, V. Rovei, R. F. Novi, J. Holte, F. Bongioanni, A. Revelli, G. Pacini, P. Cavallo-Perin, and M. Massobrio
Preserved Insulin Sensitivity and {beta}-Cell Activity, but Decreased Glucose Effectiveness in Normal-Weight Women with the Polycystic Ovary Syndrome
J. Clin. Endocrinol. Metab.,
June 1, 2005;
90(6):
3381 - 3386.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Tonelli, W. Li, P. Kishore, U. B. Pajvani, E. Kwon, C. Weaver, P. E. Scherer, and M. Hawkins
Mechanisms of Early Insulin-Sensitizing Effects of Thiazolidinediones in Type 2 Diabetes
Diabetes,
June 1, 2004;
53(6):
1621 - 1629.
[Abstract]
[Full Text]
[PDF]
|
 |
|
Copyright © 2003 by the American Diabetes Association.
|
|
| |
|