The association of plasma peroxiredoxin 3 with insulin in pregnant women

A comparison of meal tolerance test and oral glucose tolerance test for predicting insulin therapy in patients with gestational diabetes

AIMS

To identify factors predicting a need for insulin therapy in gestational diabetes mellitus (GDM) by comparing plasma glucose (PG) levels in a 75-g oral glucose tolerance test (75-g OGTT) with those in a 500-kcal meal tolerance test (MTT) containing 75 g of carbohydrate.

SUBJECTS AND METHODS

The MTT was performed in 61 patients who diagnosed with GDM by a 75-g OGTT (age, 33.2 ± 4.5 years; prepregnancy body mass index, 22.6 ± 4.7 kg/m2; number of gestational weeks, 25.1 ± 6.4 weeks). PG and serum insulin levels were measured before the meal and up to 180 min after the meal. The insulin secretion capacity and resistance index were calculated.

RESULTS

PG levels increased from 86.8 ± 8.8 mg/dL at fasting to 132.7 ± 20.1 mg/dL at 30 min, and 137.8 ± 27.7 mg/dL at 60 min after MTT in the 35 patients with needed insulin therapy; these levels were significantly higher than those in the 26 patients, who only needed diet therapy. The patients with needed insulin therapy had significantly higher fasting PG levels in the 75-g OGTT, PG levels at fasting and 30 min after the MTT, and homeostasis model assessment of insulin resistance (HOMA-IR), and a significantly lower disposition index (DI) and insulin index than patients treated by diet alone. Receiver operating characteristic curve analysis was performed for factors involved in insulin therapy, with the following cutoff values: fasting PG in the 75-g OGTT, 92 mg/dL; PG 30 min after MTT, 129 mg/dL; HOMA-IR, 1.51; DI, 3.9; HbA1c, 5.4%. Multivariate analysis revealed that the 30-min PG level after MTT and HOMA-IR predicted insulin therapy.

CONCLUSION

PG levels at 30 min after MTT may be useful for identifying patients with GDM, who need insulin therapy.

Mitochondrial dysfunction in the fetoplacental unit in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a disease of pregnancy that is associated with d-glucose intolerance and foeto-placental vascular dysfunction. GMD causes mitochondrial dysfunction in the placental endothelium and trophoblast. Additionally, GDM is associated with reduced placental oxidative phosphorylation due to diminished activity of the mitochondrial F₀F₁-ATP synthase (complex V). This phenomenon may result from a higher generation of reactive superoxide anion and nitric oxide. Placental mitochondrial biogenesis and mitophagy work in concert to maintain cell homeostasis and are vital mechanisms securing the efficient generation of ATP, whose demand is higher in pregnancy, ensuring foetal growth and development. Additional factors disturbing placental ATP synthase activity in GDM include pre-gestational maternal obesity or overweight, intracellular pH, miRNAs, fatty acid oxidation, and foetal (and 'placental') sex. GDM is also associated with maternal and foetal hyperinsulinaemia, altered circulating levels of adiponectin and leptin, and the accumulation of extracellular adenosine. Here, we reviewed the potential interplay between these molecules or metabolic conditions on the mechanisms of mitochondrial dysfunction in the foeto-placental unit in GDM pregnancies.