Relative hypoleptinaemia in women with mild gestational diabetes mellitus.
OBJECTIVE
There is increasing evidence suggesting that leptin plays a major role in the regulation of energy homeostasis, as well as in the neuroendocrine and reproductive systems. Leptin is synthesized in the human placenta. The aim of this study was to relate serum leptin levels during pregnancy to glucose tolerance, body mass index (BMI) and specific metabolic variables, such as specific insulin and proinsulin.


METHODS
A 2-h 75 g oral glucose tolerance test was performed in 221 pregnant women at 22-29 weeks of gestation (median 25th week). Serum leptin was measured using a radioimmunoassay. In 49 women, sequential leptin measurements were performed (during pregnancy and post partum (median 5 months)).


RESULTS
During pregnancy serum leptin was significantly related to body weight (r = 0.49), BMI (r = 0.51), fasting immunoreactive insulin (r = 0.46), specific insulin (r = 0.43) and proinsulin (r = 0.29) (all P-values <0.0001). In women with mild gestational diabetes (GDM, n = 55), leptin levels were lower compared to women with normal glucose tolerance (n = 166) after adjusting for BMI and fasting insulin (26.9 vs. 19.4 ng/ml, P = 0.0001). Leptin was significantly higher during pregnancy compared to post partum (mean +/- SE: 24.3+/-1.5 vs. 19.6+/-1.6 ng/ml, P = 0.0003), even after adjustment for changes in BMI and changes in fasting insulin (P = 0.013).


CONCLUSIONS
Leptin levels are elevated in pregnancy. Women with mild GDM presented with relative hypoleptinaemia compared to women with normal glucose tolerance.
Festa
A
A
Department of Medicine, University of Texas Health Science Center at San Antonio, 78284-7873, USA. festa@uthscsa.edu
Shnawa
N
N
Krugluger
W
W
Hopmeier
P
P
Schernthaner
G
G
Haffner
S M
SM
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016640:Diabetes, Gestational / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin; D010920:Placenta / Q000378:metabolism; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy / Q000097:blood*; D011506:Proteins / Q000378:metabolism*; D012016:Reference Values
D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D011506:Proteins