Increased lipolysis in non-obese pregnant women studied in the third trimester.
BACKGROUND
During pregnancy, metabolic adaptation takes place in the mother to provide for the supply of substrates to the growing fetus.


OBJECTIVE
To determine rates and endocrine regulation of lipolysis and glucose production (GPR) in late pregnancy.


METHODS
Energy substrate production was measured in healthy pregnant women by use of stable isotope-labelled compounds.


METHODS
University Hospital, Uppsala, Sweden.


METHODS
Eight healthy non-obese, non-smoking women with normal pregnancies were studied at 33-36 weeks of gestation after an overnight (12-14 hours) fast.


METHODS
Rates of glycerol and glucose production were analysed by gas chromatography/mass spectrometry following constant rate infusion of [1,1,2,3,3-(2)H(5)]-glycerol and [6,6-(2)H(2)]-glucose.


METHODS
Glycerol and glucose production in the third trimester.


RESULTS
The mean rate of glycerol production, reflecting lipolysis, was 3.06 (0.66) and the mean GPR was 13.2 (1.5) micromol kg(-1) minute(-1) [2.38 (0.27) mg kg(-1) minute(-1)]. There was a correlation between rate of glycerol production and GPR (r = 0.75, P = 0.033). Fasting insulin levels correlated inversely with both the rate of glycerol production (r = -0.85, P = 0.008) and GPR (r = -0.78, P= 0.021).


CONCLUSIONS
Our results show that lipolysis is markedly increased during late pregnancy compared with reported data for non-pregnant women. The data also confirm the occurrence of an increased GPR in pregnant women. The finding of a correlation between rate of glycerol production and GPR corroborates the view that lipolysis promotes gluconeogenesis. Although late gestation is associated with insulin resistance, the results show that insulin plays a regulatory role both in lipolysis and glucose production.
Diderholm
Barbro
B
Department of Women's and Children's Health, Uppsala University, Sweden.
Stridsberg
Mats
M
Ewald
Uwe
U
Lindeberg-Nordén
Solveig
S
Gustafsson
Jan
J
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D008066:Lipolysis / Q000502:physiology*; D011247:Pregnancy / Q000378:metabolism*; D011263:Pregnancy Trimester, Third
D001786:Blood Glucose; D007328:Insulin; D005990:Glycerol