[Maternal serum tumor necrosis factor-alpha concentration and correlation with insulin resistance in gestational diabetes].

OBJECTIVE: To investigate serum concentration of tumor necrosis factor (TNF)-alpha and its correlation with insulin resistance in pregnant women with gestational diabetes mellitus (GDM). METHODS: Enzyme-linked immunosorbent assay was used to measure the fasting serum TNF-alpha levels of 42 women with GDM (28 approximately 39 gestational weeks), and 40 cases of normal pregnant women in the third trimester. Fasting plasma glucose, insulin, C-peptide and glycosylated hemoglobin (HbA1c) were also measured at the same time. Insulin sensitive index (ISI) was calculated. RESULTS: (1) Significantly elevated serum TNF-alpha was found in the women with GDM (5.2 +/- 1.6) ng/L as compared with the healthy pregnant women in third trimester (4.5 +/- 0.5) ng/L (P < 0.01); ISI between the two groups was significantly different, (-4.3 +/- 0.5) and (...3.8 +/- 0.3) (P < 0.01). (2) fasting plasma glucose, insulin, C-peptide, HbA1c in GDM group were (5.5 +/- 0.7) mmol/L, (13.4 +/- 3.8) mU/L, (1.6 +/- 0.4) nmol/L, (5.6 +/- 0.5)%, being significantly higher than those in the normal pregnant women (P < 0.01 or P < 0.05). (3) Significant negative linear correlation was revealed between TNF-alpha and ISI (r = -0.703, P < 0.01), and positive linear correlations between TNF-alpha and plasma glucose, C-peptide, and HbA1c were found (r = 0.512, 0.629, 0.386); but no correlation between TNF-alpha and insulin was found in GDM group. In normal group the correlation between ISI and TNF-alpha was also found (r = -0.390, P < 0.05), but less significant than that in the GDM group. CONCLUSIONS: Fasting plasma TNF-alpha levels in pregnant women with GDM is significantly higher than in normal pregnant women. A negative relationship between TNF-alpha and insulin sensitivity index is found in GDM, suggesting increased TNF-alpha may contribute to insulin resistance in pregnant women with gestational diabetes.

[Maternal plasma leptin levels and their relationship to insulin and glucose in pregnant women with gestational diabetes mellitus and gestational impaired glucose tolerance].

OBJECTIVE: To investigate the changes in leptin levels and the relationship between the substance and insulin and glucose in pregnant women with gestational diabetes mellitus (GDM) and gestational impaired glucose tolerance (GIGT). METHODS: Radio immunoassay was used to measure the leptin levels at fasting and 3 h after oral glucose load (50 g) in 36 patients with GDM and GIGT, and also in 24 normal pregnant women. In each pregnant women, fasting serum insulin levels and glycosylated haemoglobin values were measured by electrochemiluminescent immunoassays and pressure liquid chromatography (LPLC) respectively, glucose levels 1 h after the administration of glucose by glucose oxidase method. RESULTS: The serum leptin levels in pregnant women with GDM and GIGT and normal pregnant women were (14.9 +/- 4.3) micro g/L and (10.0 +/- 1.8) micro g/L, respectively, suggesting the serum leptin levels were significantly higher in pregnant women with GDM and GIGT than in normal controls. The levels of fasting serum insulin, glycosylated haemoglobin values and plasma glucose levels obtained 1h after oral administration of 50 g glucose were (12.9 +/- 4.3) mU/L, (6.1 +/- 1.1)%, (11.0 +/- 1.4) mmol/L, respectively, whereas the corresponding values in normal controls were (8.6 +/- 3.2) mU/L, (4.5 +/- 1.0)%, (7.8 +/- 1.2) mmol/L. A positive correlation was found between maternal serum leptin levels and fasting serum insulin levels in pregnant women with GDM and GIGT (r = 0.835, P < 0.01). A positive correlation was also found between maternal leptin concentrations and glycosylated haemoglobin values, as well as between leptin levels and plasma glucose levels obtained 1 h after the administration of 50g glucose in women with GDM and GIGT (r = 0.758, P < 0.01; r = 0.561, P < 0.01). CONCLUSIONS: Leptin levels are elevated in pregnant women with GDM and GIGT compared with healthy pregnant women, a positive and significant correlation was found between the maternal leptin levels and fasting insulin levels, as well as between the maternal leptin levels and plasma glucose levels obtained 1 h after the administration of 50 g glucose in women with GDM and GIGT.