[Dynamic effect of the blood glucose and insulin on serum leptin concentration during oral glucose tolerance test].
OBJECTIVE
To investigate the effects of internal change of plasma glucose and serum insulin levels on serum leptin concentrations during oral glucose tolerance test (OGTT) in normal subjects and type II diabetics (DM).


METHODS
Plasma glucose, serum insulin and leptin concentrations were measured simultaneously in 50 age, sex and body mass index matched non-diabetic (non-DM) and 50 DM subjects who were undergoing OGTT.


RESULTS
The fast serum leptin concentrations were (3.88 +/- 0.64) microg/L in DM males and (8.30 +/- 1.06) microg/L in DM females. Respectively they were (5.01 +/- 0.64) microg/L and (10.48 +/- 1.30) microg/L in non-DM group. No significant difference was revealed. Comparing with the non-DM group, the glucose curve was elevated and the insulin releasing curve was characterized by a low response and a delayed peak in DM group. As for the leptin releasing curve, both groups showed a decreasing trend, which seemed to be more evident in DM group.


CONCLUSIONS
Leptin concentration does not increase with the release of insulin. On the contrary, it shows a diurnal rhythmic descending trend, suggesting that in vivo, the insulin effect on serum leptin concentration is relatively weak and not able to affect the day-time descending trend of leptin levels.
Chen
M
M
Shanghai Institute of Endocrinology, Department of Endocrinology, Ruijin Hospital, Affiliated to Shanghai Second Medical University, Shanghai 200025.
Gu
W
W
Tang
J
J
Li
F
F
Chen
C
C
Hu
R
R
Xu
M
M
Chen
J
J
D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood*; D020738:Leptin / Q000097:blood*; D008297:Male
D001786:Blood Glucose; D007328:Insulin; D020738:Leptin