Fetal outcome in gestational diabetes with elevated amniotic fluid insulin levels. Dietary versus insulin treatment

Aβ and Tau Regulate Microglia Metabolism via Exosomes in Alzheimer’s Disease

One of the most striking hallmarks shared by various neurodegenerative diseases, including Alzheimer’s disease (AD), is microglia-mediated neuroinflammation. The main pathological features of AD are extracellular amyloid-β (Aβ) plaques and intracellular tau-containing neurofibrillary tangles in the brain. Amyloid-β (Aβ) peptide and tau protein are the primary components of the plaques and tangles. The crosstalk between microglia and neurons helps maintain brain homeostasis, and the metabolic phenotype of microglia determines its polarizing phenotype. There are currently many research and development efforts to provide disease-modifying therapies for AD treatment. The main targets are Aβ and tau, but whether there is a causal relationship between neurodegenerative proteins, including Aβ oligomer and tau oligomer, and regulation of microglia metabolism in neuroinflammation is still controversial. Currently, the accumulation of Aβ and tau by exosomes or other means of propagation is proposed as a regulator in neurological disorders, leading to metabolic disorders of microglia that can play a key role in the regulation of immune cells. In this review, we propose that the accumulation of Aβ oligomer and tau oligomer can propagate to adjacent microglia through exosomes and change the neuroinflammatory microenvironment by microglia metabolic reprogramming. Clarifying the relationship between harmful proteins and microglia metabolism will help people to better understand the mechanism of crosstalk between neurons and microglia, and provide new ideas for the development of AD drugs.

Fetal abdominal overgrowth is already present at 20-24 gestational weeks prior to diagnosis of gestational diabetes mellitus

Fetal abdominal obesity (FAO) was detected at the time of gestational diabetes mellitus (GDM) diagnosis at 24–28 gestational weeks (GW) in older (≥ 35 years) and/or obese (≥ body mass index 25 kg/m²) women and persisted until delivery. We investigated whether FAO is already present at 20–24 GW. Medical records of 7820 singleton pregnancy including 384 GDM were reviewed. Fetal abdominal overgrowth was assessed by the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference per actual GA by the last menstruation period, biparietal diameter or femur length, respectively. FAO was defined as FAOR ≥ 90th percentile. FAORs measured at 20–24 GW in older and/or obese but not in young and non-obese GDM subjects were significantly higher than those in NGT subjects. Relative to NGT subjects without FAO at 20–24 GW, odds ratios for exhibiting FAO at GDM diagnosis and large for gestational age in GDM with FAO at 20–24 GW were 10.15 and 5.57, and their primary cesarean delivery rate was significantly higher than those in GDM without FAO (44% vs. 29%). Earlier diagnosis and active interventions of GDM well before 20–24 GW might be necessary to prevent FAO in the older and/or obese women.

Sonographic and other nonglycemic factors can predict large-for-gestational-age infants in diet-managed gestational diabetes mellitus: A retrospective cohort study

BACKGROUND

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy. Left untreated or poorly controlled, GDM results in adverse infant outcomes such as large for gestational age (LGA). This study aims to identify nonglycemic maternal and fetal factors predictive of LGA outcomes in pregnancies complicated by diet-managed GDM.

METHODS

This was a retrospective cohort study of singleton pregnancies complicated by diet-managed GDM from 2004 to 2015. Multiple logistic regression analysis was performed on maternal and perinatal factors to identify risk factors for LGA. In addition, a subset univariate analysis was conducted for pregnancies in which fetal ultrasound abdominal circumference measurements were available at gestational weeks 18 to 22, 24 to 28, and 29 to 33.

RESULTS

A total of 1064 women were included, delivering 123 LGA infants. Women with higher parity (odds ratio [OR] 1.44; CI, 1.23-1.68; P < .001) and higher prepregnancy body mass index (BMI) (OR 1.09; CI, 1.06-1.12; P < .001) were more likely to have LGA infants. Maternal smoking (OR 0.30; CI, 0.14-0.62; P = .001) and higher gestational age at birth (OR 0.91; CI, 0.84-0.99; P = .018) were associated with reduced risk. Subset univariate analysis showed that fetal abdominal circumference measurements at weeks 24 to 28 and 29 to 33 beyond the 75th percentile (OR 5.92 and 13.74, respectively) and 90th percentile (OR 4.57 and 15.89, respectively) were highly predictive of LGA.

CONCLUSIONS

Parity, smoking status, maternal BMI, gestational age, and ultrasound fetal abdominal circumference measurements were identified as useful predictors of LGA. Presence of these predictors may prompt closer monitoring of pregnancy and early therapeutic intervention to improve management and reduce the risk of adverse fetal and maternal outcomes.

Histological Changes in Severe Diabetic Fetopathy: An Autopsy Case Report

Maternal diabetes is one of the most common and dangerous risk factors during pregnancy, as often there are no generalized signs. Diabetic fetopathy is a severe, poorly defined complication of gestational diabetes or preexisting maternal diabetes mellitus, with an ill-defined histological spectrum of changes. Herein we report a case of severe diabetic fetopathy diagnosed upon autopsy of a recently miscarried fetus. On histology, the liver revealed severe generalized macrovesicular steatosis and number of small cysts. The pancreas revealed not only Langerhans isle hyperplasia, but also Langerhans amyloidosis, evident of the severity of maternal diabetes and fetal hyperglycemia. The adrenal glands revealed hyperplasia in zona glomerulosa, due to aldosterone overproduction, evident of fetal hypertension. The current case is an extreme example of an undiagnosed and untreated gestational diabetes mellitus. The severity of histological changes, in this case, is suggestive of further extension of the diagnostic criteria of diabetic fetopathy to include more subtle changes that can be observed clinically and even a combination of maternal-newborn factors.

The fetal glucose steal: an underappreciated phenomenon in diabetic pregnancy

Adverse neonatal outcomes continue to be high for mothers with type 1 and type 2 diabetes, and are far from eliminated in mothers with gestational diabetes mellitus. This is often despite seemingly satisfactory glycaemic control in the latter half of pregnancy. Here we argue that this could be a consequence of the early establishment of fetal hyperinsulinaemia, a driver that exaggerates the fetal glucose steal. Essentially, fetal hyperinsulinaemia, through its effect on lowering fetal glycaemia, will increase the glucose concentration gradient across the placenta and consequently the glucose flux to the fetus. While the steepness of this gradient and glucose flux will be greatest at times when maternal hyperglycaemia and fetal hyperinsulinaemia coexist, fetal hyperinsulinaemia will favour a persistently high glucose flux even at times when maternal blood glucose is normal. The obvious implication is that glycaemic control needs to be optimised very early in pregnancy to prevent the establishment of fetal hyperinsulinaemia, further supporting the need for pre-pregnancy planning and early establishment of maternal glycaemic control. An exaggerated glucose steal by a hyperinsulinaemic fetus could also attenuate maternal glucose levels during an OGTT, providing an explanation for why some mothers with fetuses with all the characteristics of diabetic fetopathy have 'normal' glucose tolerance.

Etiologies of obesity in children: nature and nurture

Childhood obesity is a profoundly complex problem and serves as an example of a biospsychosocial issue. Scientific inquiry has provided incredible insight into the complex etiology of weight gain but must be viewed as an interaction between a human's propensity to conserve calories for survival in a world with an abundance of it. This article provides a brief overview divided between biological (nature) and psychosocial and behavioral (nurture) factors.

Can ultrasound fetal biometry predict fetal hyperinsulinaemia at delivery in pregnancy complicated by maternal diabetes?

OBJECTIVE

The aim of this study was to determine whether there is an association between ultrasound fetal biometry and amniotic fluid insulin levels at delivery in women with pre-existing diabetes or impaired glucose tolerance in pregnancy.

STUDY DESIGN

This retrospective cohort study identified 93 women who had amniotic fluid insulin levels measured at time of delivery. Standardised estimated fetal weight and fetal growth velocity were calculated from serial third trimester fetal ultrasound measurements.

RESULTS

Women with pre-existing diabetes had significantly greater mean growth velocity [1.39 (95% CI: 0.43-2.23) versus 0.39 (95% CI: -01.7-0.95); p=0.04], significantly greater mean estimated fetal weight (EFW) Z score prior to delivery [2.36 (95% CI: 1.82-2.9) versus 1.38 (95% CI: 1.02-1.74); p=0.002] and greater mean birthweight centile [82 (95% CI: 0.74-0.89) versus 67 (95% CI: 58-76); p=0.02] than those with GDM/IGT. Amniotic fluid insulin levels demonstrated a similar significant difference between the pre-existing and GDM/IGT groups [20.5 (95% CI: 12.9-28.1) versus 8.5 (95% CI: 5.4-11.7); p=0.001]. An association between fetal growth and size and amniotic fluid insulin was observed in women with pre-existing diabetes. Positive likelihood ratios were 1.67 and 2.08, respectively, for the prediction of liquor insulin greater than the 95th centile in women with pre-existing diabetes.

CONCLUSION

Ultrasound measures of fetal size and growth used in this study are not sufficiently accurate to predict those infants likely to be at risk from the adverse effects of fetal hyperinsulinaemia.

Flexible treatment of Gestational Diabetes modulated on ultrasound evaluation of intrauterine growth: a controlled randomized clinical trial

OBJECTIVES

In order to prevent abnormalities of fetal growth still characterizing pregnancies complicated by Gestational Diabetes (GDM), in the present study we evaluated a therapeutic strategy for GDM based on ultrasound (US) measurement of fetal insulin-sensitive tissues.

METHODS

All GDM women diagnosed before 28th week immediately started diet and self-monitoring of blood glucose; after 2 weeks they were randomized to conventional (C) or modified (M) management. In C the glycemic target (GT) was fixed at 90 fasting/120 post-prandial mg/dl; in M GT varied, according to US measurement of the Abdominal Circumference (AC) centile performed every 2 weeks: 80/100 if AC > or =75th, 100/140 if AC<75th. Therapy was tailored to mean fasting (FG) and postprandial glycemia (PPG).

RESULTS

Globally, 229 women completed the study, 78 in C, 151 in M. Use of insulin was 16.7% in C, 30.4% in M (total groups), significantly more frequent in M than in C (59.7% vs 15.4%) when considering only women with AC > or =75th c. Mean metabolic data were similar in the 2 groups, but in M a tightly-optimized subgroup, resulting from the lowering of GT due to AC > or =75th, coexisted with a less-controlled one, whose higher GT was justified by AC<75th. Pregnancy outcome was better in M, with lower (p<0.05*) rate of LGA* (7.9% vs 17.9%), SGA (6.0% vs 9.0%) and Macrosomia* (3.3% vs 11.5%).

CONCLUSIONS

Our data show the value of a flexible US-based approach to the treatment of GDM. This model does not necessarily involve a generalized aggressive treatment, allowing to concentrate therapeutical efforts on a small subgroup of women showing indirect US evidence of fetal hyperinsulinization. Such a selective approach allowed to obtain a near-normalization of fetal growth, with clear advantages on global pregnancy outcome.

Can glucose tolerance test predict fetal hyperinsulinism?

OBJECTIVE

To establish cut off levels for oral glucose tolerance test in pregnancy using fetal hyperinsulinism as a clinical endpoint.

DESIGN

Capillary blood glucose levels at 0, 1, and 2 hours after the ingestion of either 1 g/kg or 75 g glucose, at 28 (SD 5) weeks of gestation were analysed in 220 women with elevated amniotic fluid insulin levels [> or =42 pmol/L (> or =7 microU/mL)] after a mean (SD) of 31 weeks (3) and in 220 nondiabetic controls.

RESULTS

In women with elevated amniotic fluid insulin levels the mean (SD) capillary blood glucose values at 0, 1, and 2 hours were 5.2 mmol/L (1.0) [94 mg/dL (18)], 10.5 mmol/L (1.4) [189 mg/dL (25)] and 8.2 mmol/L (2.0) [147 mg/dL (36)], respectively. The one-hour value had the highest sensitivity to predict elevated amniotic fluid insulin levels. The 5th centile of the one-hour blood glucose levels representing a detection rate of 95% was 8.9 mmol/L (160 mg/dL).

CONCLUSION

Glucose cut off levels in most established oral glucose tolerance test criteria are too high, to accurately predict amniotic fluid hyperinsulinism. A one-hour test may be sufficient for detecting amniotic fluid hyperinsulinism. Since different loads (1 g/kg, 75 g or 100 g) and blood fractions (venous plasma or capillary blood) have minimal impact on oral glucose tolerance test results, a single one-hour cut off of 8.9 mmol/L (160 mg/dL), independent of the sampling method, may be appropriate for the diagnosis of gestational diabetes mellitus severe enough to cause amniotic fluid hyperinsulinism.

Amniotic fluid insulin levels identify the fetus at risk of neonatal hypoglycaemia

AIMS

To investigate the use of amniotic fluid insulin (AFI) as a predictor of neonatal morbidity in the macrosomic newborn of the diabetic mother, in view of the fact that raised AFI levels are a marker for fetal hyperinsulinaemia.

METHODS

AFI was measured by radioimmunoassay in a group of pregnant diabetic women (n = 63) with normal (n = 41) or accelerated fetal growth (n = 22).

RESULTS

Using log transformed data, liquor insulin was found to be significantly higher in pregnant women with Type 1 and Type 2 diabetes mellitus (17.6 mU/l; 95% confidence interval (CI) 11.7-26.4) compared with women with gestational diabetes mellitus (GDM) (8.2 mU/l; 95% CI 4.8-13.8, P = 0.02) or impaired glucose tolerance (IGT) (6.2mU/l; 95% CI 4.9-8.0, P = 0.0001). In the group with macrosomic fetuses (birth weight > 90th centile for gestational age), there was a significantly higher incidence of elective Caesarean section (CS) and emergency CS (12/22) compared to those with appropriate for gestational age (AGA) fetal weights (birth weight > 10th and < 90th centiles for gestational age) (9/41, P = 0.009). There was no significant correlation between raised AFI and macrosomia except in the Type 1 diabetic women, in whom the AGA group mean was 13.2 mU/l (95% CI 7.4-23.3), and 34.6mU/l (95% CI 17.5-68.4 P = 0.022) in macrosomia. In the latter group, hypoglycaemia requiring treatment was significantly more common in the macrosomic hyperinsulinaemic neonates (8/13), compared to normoinsulinaemic neonates in the same group (0/9, P = 0.005).

CONCLUSIONS

Identification of the hyperinsulinaemic fetus before delivery might allow the intensification of maternal insulin therapy leading to a reduction in incidence and severity of diabetic fetopathy. Pregnancy with a normoinsulinaemic fetus could be allowed to continue to the onset of spontaneous labour, which might result in a lower CS rate.

Anti-insulin antibodies and birth weight in pregnancies complicated by diabetes

Free insulin cannot cross the placenta but insulin complexed to anti-insulin antibodies has been demonstrated in cord blood. We studied whether antibody-bound insulin in diabetic patients can evoke fetal macrosomia independently of maternal metabolic control. In 457 non insulin-treated controls and 173 insulin-treated diabetic patients we measured 1187 anti-insulin antibody levels and maternal blood glucose, maternal fructosamine, cord blood insulin, cord blood C-peptide, cord blood fructosamine and amniotic fluid insulin. Mean anti-insulin antibody levels in maternal blood and cord blood were significantly higher in insulin treated diabetic patients (4.6 and 5.4 U/ml) than in controls (1.8 and 1.7 U/ml) with maxima of 89.2 in maternal and 120.0 U/ml in cord blood, respectively. In insulin treated diabetic patients 16.6% (maternal blood) and 22% (cord blood) anti-insulin antibody levels were above the 97th percentile. There was a high significant correlation between maternal and cord blood anti-insulin antibodies (R = 0.987, P = < 0.0001), but no correlation of anti-insulin antibodies with maternal (glucose, fructosamine) or fetal (insulin, C-peptide, and fructosamine in cord blood, amniotic fluid insulin) metabolic parameters. While maternal and fetal metabolic parameters correlated with birth weight neither maternal nor cord blood anti-insulin antibody levels correlated with birth weight. These findings do not support the hypothesis that maternal anti-insulin antibodies independently influence fetal weight.

Amniotic fluid insulin testing in gestational diabetes: safety and acceptance of amniocentesis

OBJECTIVES

We analyzed the safety and patient acceptance of amniotic fluid insulin measurements by third-trimester amniocentesis in women with gestational diabetes mellitus.

STUDY DESIGN

We studied the rate of early uterine contractions, need for tocolysis, premature rupture of membranes, mode of delivery, length of gestation, and fetal weight and length at birth in 194 women with gestational diabetes mellitus who underwent third-trimester amniocentesis and 268 controls. Patient acceptance of amniocentesis was assessed prospectively with a visual rating scale and a semistructured interview comparing 50 women with gestational diabetes mellitus to 50 women undergoing second-trimester amniocentesis for fetal karyotyping.

RESULTS

Only the length of gestation differed significantly but without clinical relevance (39.5 +/- 1.9 vs 40.0 +/- 2.0, P = .006) between women with gestational diabetes mellitus who had amniocentesis and controls. Patient acceptance was equally high both for second-trimester and third-trimester amniocentesis.

CONCLUSIONS

Third-trimester amniocentesis for measuring amniotic fluid insulin is safe and well accepted by the patients. This is important information both for treating and counseling women with gestational diabetes mellitus.

Hyperinsulinism, neonatal obesity and placental immaturity in infants born to women with one abnormal glucose tolerance test value

Several groups have reported a risk of fetal macrosomia in pregnancies with maternal glucose intolerance which is intermediate between gestational diabetes (GDM) and normal glucose tolerance. The present study was designed to determine whether these pregnancies are also at risk for fetal obesity, hyperinsulinism and placental villous immaturity. 325 women with risk factors for GDM underwent a 75 g OGTT interpreted according to the O'Sullivan criteria. All women who met the criteria for GDM were managed with diet therapy. Insulin therapy was added for women with a mean serum glucose value > 100 mg/dl on a 24 hour glucose profile. Patients not meeting the GDM criteria were managed without special intervention. Primary outcome variables were measures of neonatal weight and skinfold thickness, fetal and neonatal insulin and glucose concentration, and placental villous maturation. Outcome parameters were compared among three groups: pregnancies with normal OGTT (control, n = 95), 1 abnormal value in the OGTT (1 abnl, n = 76) and GDM (n = 154). The outcome of pregnancies with 1 abnormal value in the OGTT was different from those with normal OGTT. Regarding fetal growth, rates of LGA were approximately twice as high in groups with one abnormal value and GDM (21% and 24%) compared to women with normal OGTTs (11%: p < 0.05 vs GDM and p = 0.07 vs 1 abnormal value). The percent of infants with skinfold thickness > 90th percentile was also greater in the 1 abnormal value and GDM groups (31.1 and 31.6% respectively) compared to controls (19.2%; p < 0.05 for GDM vs control only). Regarding fetal hyperinsulinism, AFI concentrations were similar in control and GDM groups (3.1 +/- 0.4 and 3.4 +/- 0.8 microU/ml, respectively), but were higher in the group with one abnormal OGTT value (4.3 +/- 1.2 microU/ml, p < 0.05 vs controls). Cord blood insulin: glucose ratios were elevated in both the 1 abnormal value and GDM groups (0.22 +/- 0.05 and 0.20 +/- 0.02 microU/ml per mg/dl), compared to controls (0.12 +/- 0.01 microU/ml per mg/dl, p < 0.05 vs 1 abnormal value). Neonatal glycemia < 30 mg/dl was significantly more common in the one abnormal value than in the control group (49% vs 34% of infants) and intermediate in the GDM group (40%). Severe placental villous immaturity was more than twice as frequent in the 1 abnormal value group compared to controls (24% vs 9%, p < 0.05) and the most frequent in the GDM group (33%; p < 0.001 vs controls). Pregnancies with glucose intolerance below the thresholds for diagnosis of GDM have an increased risk for fetal obesity, hyperinsulinism, postpartum hypoglycemia and placental immaturity. These findings indicate the continuum of risk for fetal morbidity associated with increasing maternal glucose intolerance in pregnancy.

Levels of amniotic fluid insulin and profiles of maternal blood glucose in pregnant women with diabetes type-I

The aim of this study was to investigate the relationship between amniotic fluid insulin (AF-insulin) measurements and maternal blood glucose levels in pregnancies complicated by insulin-dependent maternal diabetes mellitus (IDDM). Twenty-five patients with IDDM underwent amniocentesis (AC) in the third trimester. Twelve patients had a second amniocentesis after 2-3 weeks. The maternal blood glucose values (MBG) 2 weeks before amniocentesis were correlated with AF-insulin. Mean (+/-S.D.) MBG in the group with AF-insulin > 97th centile (n = 7) was 6.1 +/- 1 mmol/l. MBG in the group with AF-insulin < 97th centile (n = 18) was 5.3 +/- 1.2 mmol/l (r = 0.2948; P-value 0.162). In the group with repeated AC and AF-insulin > 97th centile (n = 6) the correlation coefficient was 0.722 (P = 0.043), whereas in the group with normal AF-insulin (n = 6) no correlation was found (r = -0.213; P = 0.686). These results indicate that no significant correlation exists between MBG values and concentration of AF-insulin. MBG is not appropriate for the diagnosis of fetal hyperinsulinism in well-controlled women with IDDM. In individual cases with AF-insulin > 97th centile a decrease of MBG causes lower AF-insulin levels. These results indicate that there seems to be an individual threshold for maternal MBG which causes hyperinsulinism. Fetal hyperinsulinism not only depends on blood glucose levels. Different fetal sensitivity to maternal glucose stimuli or a different glucose transport across the placenta in the individual fetus could be responsible for these results.

Fructosamine in relation to maternofetal glucose and insulin homeostasis in gestational diabetes

The problem in screening for gestational diabetes is recognizing fetuses endangered by hyperinsulinism. 21.8% of patients with gestational diabetes (defined as a glucose peak exceeding 160 mg/dl after an oral glucose load of 1 g per kg body weight) develop fetal hyperinsulinism. Thus, is indicated by an elevated amniotic fluid insulin (AFI) concentration and requires insulin treatment. Since fetal hyperinsulinism can be neither predicted nor ruled out by single parameters of maternal metabolism, every patient with gestational diabetes had to undergo amniocentesis for amniotic fluid analysis. In 110 gestational diabetics and 822 controls, fetal hyperinsulinism was predicted by the combination of the oGTT (greater than or equal to 160 mg/dl) and maternal serum fructosamine (greater than or equal to 2.6 mmol/l) with a sensitivity of 95.8% and a specificity of 91.8%. Thus, 73% of gestational diabetics need not undergo amniocentesis. With a sensitivity of 20.8%, the combination of the oGTT and HbA1c is not useful in identifying hyperinsulinemic fetuses.

Serum fructosamine and amniotic fluid insulin levels in patients with gestational diabetes and healthy control subjects

Gestational diabetic pregnancies with fetal hyperinsulinism should be identified because these cases require insulin therapy. To determine the relationship between the serum fructosamine and amniotic fluid insulin concentrations, these substances were measured in 87 pregnant women with impaired glucose tolerance. Fructosamine was also measured in 678 healthy pregnant control subjects, in 113 of whom amniotic fluid insulin levels were available. Fetal hyperinsulinism was rare at serum fructosamine levels of less than 2.6 mmol/L. These results suggest that when both the oral glucose tolerance test and fructosamine level are used, only 30% of women with gestational diabetes need to undergo amniocentesis to assess fetal insulin homeostasis.