Metformin in Gestational Diabetes The Offspring Follow Up (MiGTOFU): Associations between maternal characteristics and size and adiposity of boys and girls at nine years.

Data from 98 women recruited in the Metformin in Gestational Diabetes trial and dual-energy X-ray absorptiometry studies of their children at nine years were analysed to investigate associations between maternal measures during pregnancy and their children's size and adiposity. Mothers of boys (n = 56) and girls (n = 42) had been randomised to metformin or insulin treatment at 30.1 ± 2.8 and 29.3 ± 4.1 weeks gestation, respectively. In boys, fat-free mass indexed to height squared was associated with maternal weight, body mass index, maternal glycaemia and metformin treatment. In boys and girls, fat mass indexed to height squared was associated with maternal glycaemia measures before gestational diabetes treatment.

Maternal Glycaemic and Insulinemic Status and Newborn DNA Methylation: Findings in Women With Overweight and Obesity.

CONTEXT: Maternal dysglycaemia and prepregnancy obesity are associated with adverse offspring outcomes. Epigenetic mechanisms such as DNA methylation (DNAm) could contribute. OBJECTIVE: To examine relationships between maternal glycaemia, insulinemic status, and dietary glycemic indices during pregnancy and an antenatal behavioral-lifestyle intervention with newborn DNAm. METHODS: We investigated 172 women from a randomized controlled trial of a lifestyle intervention in pregnant women who were overweight or obese. Fasting glucose and insulin concentrations and derived indices of insulin resistance (HOMA-IR), ß-cell function (HOMA-%B), and insulin sensitivity were determined at baseline (15) and 28 weeks' gestation. Dietary glycemic load (GL) and index (GI) were calculated from 3-day food diaries. Newborn cord blood DNAm levels of 850K CpG sites were measured using the Illumina Infinium HumanMethylationEPIC array. Associations of each biomarker, dietary index and intervention with DNAm were examined. RESULTS: Early pregnancy HOMA-IR and HOMA-%B were associated with lower DNAm at CpG sites cg03158092 and cg05985988, respectively. Early pregnancy insulin sensitivity was associated with higher DNAm at cg04976151. Higher late pregnancy insulin concentrations and GL scores were positively associated with DNAm at CpGs cg12082129 and cg11955198 and changes in maternal GI with lower DNAm at CpG cg03403995 (Bonferroni corrected P < 5.99 × 10-8). These later associations were located at genes previously implicated in growth or regulation of insulin processes. No effects of the intervention on cord blood DNAm were observed. None of our findings were replicated in previous studies. CONCLUSION: Among women who were overweight or obese, maternal pregnancy dietary glycemic indices, glucose, and insulin homeostasis were associated with modest changes in their newborn methylome. TRIAL REGISTRATION: ISRCTN29316280.

Maternal rates of lipolysis and glucose production in late pregnancy are independently related to foetal weight.

OBJECTIVE: Associations between maternal glucose levels and increased foetal growth are well established, and independent relationships with maternal weight, weight gain and insulin resistance are also observed. The relative roles of lipolysis and glucose production in the determination of these observations remain unclear. DESIGN: We examined, through detailed physiological studies, the relationship between maternal late gestational energy substrate production (glucose and glycerol), maternal weight and weight gain, and estimated foetal size in the third trimester. PATIENTS: Twenty-one nulliparous pregnant women, without gestational diabetes (GDM) assessed at 28 weeks with oral glucose tolerance test, were recruited. MEASUREMENTS: Rates of hepatic glucose production (GPR) and rates of glycerol production (reflecting lipolysis) using [13 C6 ]-glucose and [2 H5 ]-glycerol were measured at 34-36 weeks of gestation. Respiratory quotient was assessed by indirect calorimetry and body composition by measurements of total body water (TBW; H218 O) and body density (BODPOD). Foetal weight was estimated from ultrasound measures of biparietal diameter, femoral length and abdominal circumference. RESULTS: At 34-36 weeks, bivariate analyses showed that GPR and lipolysis correlated with estimated foetal weight (r=.71 and .72, respectively) as well as with maternal weight, fat mass and fat-free mass, but not maternal weight gain. In multivariate analyses, rates of both glucose production (r=.42) and lipolysis (r=.47) were independently associated with foetal size explaining 63% of the variance. CONCLUSIONS: Both maternal rates of lipolysis and hepatic glucose production in late gestation are strongly related to estimated foetal weight.

Evaluation of point-of-care maternal glucose measurements for the diagnosis of gestational diabetes mellitus.

OBJECTIVE: Using updated laboratory standards as the reference, we aimed to compare point-of-care (POC) maternal capillary glucose testing with the diagnostic accuracy of reference and customary venous samples. DESIGN, SETTING, POPULATION: Women screened selectively with a one-step 75-g oral glucose tolerance test (OGTT) at 24-28 weeks' gestation were conveniently recruited to this prospective observational study. METHODS: Two venous samples and one capillary sample were taken at each OGTT time point. Venous sample one was a fluoride-EDTA (FE) tube placed on an ice-slurry until cell separation and analysis within 30 minutes (reference standard). Venous sample two was transported in a tube containing FE (without ice) (customary practice). A capillary sample was used for POC testing. Various cut-off points for the POC sample were examined to evaluate diagnostic accuracy. MAIN OUTCOME MEASURES: The sensitivity, specificity, positive and negative predictive values and accuracy of POC capillary glucose for the diagnosis of GDM. RESULTS: Of 108 women, GDM was detected in 47.2% (n = 51), 17.6% (n = 19) and 24.1% (n = 26) using the reference standard, customary practices and POC, respectively (P < 0.001). However, based on adjustment of the POC fasting diagnostic threshold from ≥5.1 to ≥4.8 mol/l (aPOC), sensitivity, specificity, PPV, NPV and accuracy improved to 92.5, 76.5, 69.8, 94.5 and 94.5%, respectively. CONCLUSIONS: POC capillary maternal glucose tests were superior to customary laboratory practices for diagnosing GDM. This has considerable potential, particularly in healthcare settings where facilities for phlebotomy are distant from the laboratory or pre-analytical sample handling is substandard. TWEETABLE ABSTRACT: Adjusted point-of-care glucose measurements have potential in the diagnosis of gestational diabetes mellitus.