Do adiponectin, TNFalpha, leptin and CRP relate to insulin resistance in pregnancy? Studies in women with and without gestational diabetes, during and after pregnancy.
BACKGROUND
The role of adiponectin, tumour necrosis factor alpha (TNFalpha), leptin and C-reactive protein in the insulin resistance of pregnancy is not clear. We measured their levels in women with gestational diabetes (GDM) and in controls, during and after pregnancy, and related them to insulin secretion and action.


METHODS
Nineteen women with GDM and 19 BMI-matched healthy pregnant women underwent intravenous glucose tolerance tests in the third trimester of pregnancy and 4 months postpartum to determine insulin sensitivity (SI) and insulin secretion. Adiponectin, TNFalpha, leptin and high sensitivity CRP (hsCRP) were measured in fasted blood.


RESULTS
Of the circulating factors, only leptin (r = -0.41, p = 0.01) correlated with SI in pregnancy. Leptin and hsCRP levels were elevated in pregnancy compared to postpartum (leptin (mean +/- SEM): 27.8 +/- 2.4 vs 19.3 +/- 2.1 ng/mL, p < 0.001; hsCRP: 5.2 +/- 0.7 vs 3.2 +/- 0.6 mg/L, p < 0.001). Adiponectin levels did not change from pregnancy to postpartum, despite a marked increase in SI. All four factors correlated with SI postpartum (adiponectin: r = 0.38, p = 0.01; TNFalpha: r = -0.48, p = 0.002; Leptin: r = -0.61, p = 0.001; hsCRP: r = -0.48, p = 0.002). TNFalpha correlated inversely with insulin secretion in pregnancy (r = -0.35, p = 0.03) and was significantly higher in the GDM group (2.62 +/- 0.3 vs 1.88 +/- 0.3 pg/mL, p = 0.01) in pregnancy.


CONCLUSIONS
In our study, the influence of adiponectin, TNFalpha and hsCRP upon SI is overwhelmed by other factors in pregnancy. While leptin and SI correlated in pregnancy, it is unclear whether this represents cause or effect. Finally, TNFalpha may exert an inhibitory effect on insulin secretion in GDM, contributing to the associated hyperglycaemia.
McLachlan
Kylie A
KA
Department of Endocrinology, St Vincents Hospital, Victoria, Australia. jane.ford@svhm.org.au
O'Neal
David
D
Jenkins
Alicia
A
Alford
Frank P
FP
D052242:Adiponectin / Q000097:blood*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D049628:Body Size; D002097:C-Reactive Protein / Q000378:metabolism*; D016640:Diabetes, Gestational / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D012016:Reference Values; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D052242:Adiponectin; D001786:Blood Glucose; D020738:Leptin; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein