Insulin sensitivity and secretion in healthy elderly human subjects with 'abnormal' glucose tolerance.
Glucose tolerance deteriorates dramatically with advancing age. It is not known whether the underlying pathophysiology is different in older subjects. We employed a two step hyperinsulinaemic euglycaemic glucose clamp with [6(14)C] glucose infusion to compare peripheral and hepatic insulin sensitivity in eight elderly (EAGT) with eight young (YAGT) subjects with abnormal (matched) glucose tolerance and nine elderly subjects with normal glucose tolerance (ENGT). There was no difference in basal HGO (EAGT 14.5 +/- 0.9, YAGT 15.3 +/- 1.1 mumol kg-1 min-1). Glucose turnover was similar in both groups at step 1 (EAGT 13.2 +/- 0.8, YAGT 13.4 +/- 0.8 mumol kg-1 min-1) and step 2 (EAGT 25.1 +/- 3.1, YAGT 27.2 +/- 2.7 mumol kg-1 min-1). HGO was lower in the EAGT subjects at step 1 (2.3 +/- 0.4 vs. 4.3 +/- 0.6 mumol kg-1 min-1 P = 0.01). Incremental serum insulin response to oral glucose was comparable (EAGT 66.8 +/- 11.6 YAGT 57.8 +/- 12.2 mU l-1.h). Compared to the ENGT group the EAGT group was insulin resistant with a lower MCR of glucose at step 1 (2.03 +/- 0.28 vs. 3.23 +/- 0.44 ml kg-1 min-1 P = 0.04) and at step 2 (6.18 +/- 0.83 vs. 9.64 +/- 0.38 ml kg-1 min-1 P = 0.004) and had a lower early insulin response (AUC 0-30 min 5.9 +/- 1.1 vs. 9.8 +/- 1.4 mU l-1.h P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)
Broughton
D L
DL
South Cleveland Hospital, Department of Medicine for the Elderly, Middlesbrough, Cleveland, UK.
Webster
J
J
Taylor
R
R
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005080:Exercise Test; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D000078790:Insulin Secretion; D016018:Least-Squares Analysis; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D007328:Insulin; D005947:Glucose