Mechanisms Behind Severe Insulin Resistance During Pregnancy in Women With Glucose Metabolic Disorders (SIR-MET)

Mechanisms Behind Severe Insulin Resistance During Pregnancy in Women With Glucose Metabolic Disorders (SIR-MET)

The aim of this study is to describe the metabolic changes during pregnancy in women with type 2 diabetes or gestational diabetes in order to detect the pathophysiological mechanisms behind severe insulin resistance during pregnancy as well as the short- and long term consequences for mother and child.

Included pathophysiological mechanisms potentially associated with severe insulin resistance are: Maternal hormonal, inflammatory and metabolic markers in the blood, as well as the level, content and bioactivity of exosomes and genetic variants associated with overweight and diabetes.

In addition to the analysis on maternal blood, the same analysis will be performed on umbilical cord blood in order to determine the correlation between markers associated with insulin sensitivity in maternal and umbilical blood. Furthermore, fetal metabolic changes influence on fetal growth and development will be evaluated. Postpartum, the breast milk will also be examined for metabolic active substances that could influence the newborns growth and metabolism.

Investigating one potential short-term consequence of diabetes during pregnancy, the association between insulin resistance and structural and functional changes in the placenta will be examined as well as the consequences of such changes on fetal growth and development.

Investigating one potential long-term consequence of diabetes during pregnancy, the association between treatment with high doses of insulin during pregnancy and the future risk of developing cardiovascular diseases and heart failure will be examined.

This is a prospective observational study including app. 24 pregnant women from the outpatient clinics at Department of Obstetrics and Gynecology at Aalborg and Aarhus University Hospital.

The study includes 8 healthy women without pregestational or gestational diabetes, 8 women with gestational diabetes or type 2 diabetes with a total daily insulin dose <= 75 units/day and 8 women with gestational diabetes or type 2 diabetes with a total daily insulin dose >= 100 units/day.

There are three study days: One in gestational week 28-36 (day 1), one during labour (day 2) and one 6 months postpartum (day 3).

Hormonal profiles and inflammatory markers will be measured at all three study days. During labour both maternal and umbilical blood will be collected. The blood sample analysis will include HbA1c, glukose, insulin, C-peptid, human anti-insulin antibody, lipid profile, liver enzymes, creatinine, FGF-21, TSH, Cortisol, human chorionic gonadotropin, estradiol, progesterone, SHBG, prolactin, human placental lactogen, placental growth hormone, PAPP-A, sFlt-1, PP13, IGF-1, IGF-BP's, Leptin, Adiponectin, hs-CRP, IL-6, IL-10, IL-1α, IFN-ɣ, TNF-α, ICAM1, VCAM and CD163. In addition to this, exosomes will be isolated precisely and profiling of the content of exosomes will be performed using in vitro assays. Proteomics and miRNAs sequencing will be employed. Furthermore, whole genome analysis will be applied to find genetic variants associated with overweight and diabetes (genetic analysis will not be performed on umbilical cord blood). Insulin sensitivity will be estimated using the homeostasis model assessment, IS-HOMA, based on fasting C-peptid and glucose concentrations.

In addition to the blood samples, the following examinations will be performed at day 1:

• Height, weight and bioelectrical impedance analysis
• Urine sample (Albumin-to-creatinine ratio)
• Blood pressure and 24-hour ambulatory blood pressure monitoring
• Central arterial pressure waveform analysis (SphygmoCor)
• Echocardiography
• Fetal ultrasound
• MRI scan of the placenta and heart

In addition to the blood samples, the following examinations will be performed at day 2:

• Placenta will be collected for a postpartum histopathological examination
• Breast milk (analyzed for lipid profile, leptin, adiponectin, prolactin, prolactin-binding protein, oxytocin, ghrelin, insulin, hs-CRP, IL-6, IL-10, IL-1α, IFN-ɣ, TNF-α, ICAM1, VCAM, CD163 and untargeted metabolomics)
• Skinfold measurement of the newborn with a caliper

In addition to the blood samples, the following examinations will be performed at day 3:

• Height, weight and bioelectrical impedance analysis
• Urine sample (Albumin-to-creatinine ratio)
• Blood pressure and 24-hour ambulatory blood pressure monitoring
• Central arterial pressure waveform analysis (SphygmoCor)
• Echocardiography
• Breast milk (analyzed for lipid profile, leptin, adiponectin, prolactin, prolactin-binding protein, oxytocin, ghrelin, insulin, hs-CRP, IL-6, IL-10, IL-1α, IFN-ɣ, TNF-α, ICAM1, VCAM, CD163 and untargeted metabolomics)

Inclusion Criteria:

• Pregnant women at The Department of Gynaecology and Obstetrics at Aarhus University Hospital or Aalborg University Hospital.
• Women have to be in 1 of 3 categories: Healthy without pregestational or gestational diabetes, type 2 diabetes treated with insulin or gestational diabetes treated with insulin.

Exclusion Criteria:

• Age < 18 years
• Not able to read and understand danish
• Previous bariatric surgery
• Treatment with systemic corticosteroids
• Other severe chronic diseases such as inflammatory bowel disease, cystic fibrosis and type 1 diabetes