Strong association between insulin resistance in liver and skeletal muscle in non-diabetic subjects.
OBJECTIVE
To examine the association between insulin resistance in skeletal muscle and liver in non-diabetic subjects.


METHODS
A total of 182 Mexican American subjects without Type 2 diabetes underwent an oral glucose tolerance test and euglycaemic-hyperinsulinaemic clamp performed with (3)[H]glucose. Insulin sensitivity in skeletal muscle was measured as the insulin-stimulated rate of total glucose disposal during the insulin clamp divided by steady-state plasma insulin concentration (TGD/SSPI). Hepatic insulin resistance was measured as the product of basal hepatic glucose production and fasting plasma insulin concentration (HGP x FPI).


RESULTS
Hepatic insulin resistance was strongly correlated (r = 0.68, P < 0.0001) with skeletal muscle insulin resistance. Thirty-eight per cent of subjects had increased insulin resistance in both liver and skeletal muscle, while 39% were insulin sensitive in both skeletal muscle and liver. Twenty-three per cent of subjects were discordant for muscle and hepatic insulin resistance (P < 0.0001). Subjects with increased skeletal muscle insulin resistance had a higher 2-h plasma glucose concentration, greater incremental area under the plasma glucose concentration curve, lower fasting plasma insulin concentration and lower rate of basal hepatic glucose production compared with subjects with increased insulin resistance in liver.


CONCLUSIONS
In non-diabetic subjects, insulin resistance in skeletal muscle is an important determinant of the fasting and 2-h plasma glucose concentrations and strongly correlates with hepatic insulin resistance.
Abdul-Ghani
M A
MA
Division of Diabetes, University of Texas Health Science Center at San Antonio, TX 78229, USA. abdulghani@uthscsa.edu
Matsuda
M
M
DeFronzo
R A
RA
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D005215:Fasting / Q000502:physiology; D005260:Female; D015309:Glucose Clamp Technique / Q000379:methods; D005951:Glucose Tolerance Test / Q000379:methods; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D011237:Predictive Value of Tests; D012016:Reference Values
D001786:Blood Glucose; D007328:Insulin