Postpartum uptake of diabetes screening tests in women with gestational diabetes: The PANDORA study

AIMS

To determine rates and predictors of postpartum diabetes screening among Aboriginal and/or Torres Strait Islander and non-Indigenous women with gestational diabetes mellitus (GDM).

METHODS

PANDORA is a prospective longitudinal cohort of women recruited in pregnancy. Postpartum diabetes screening rates at 12 weeks (75-g oral glucose tolerance test (OGTT)) and 6, 12 and 18 months (OGTT, glycated haemoglobin [HbA1C ] or fasting plasma glucose) were assessed for women with GDM (n = 712). Associations between antenatal factors and screening with any test (OGTT, HbA1C , fasting plasma glucose) by 6 months postpartum were examined using Cox proportional hazards regression.

RESULTS

Postpartum screening rates with an OGTT by 12 weeks and 6 months postpartum were lower among Aboriginal and/or Torres Strait Islander women than non-Indigenous women (18% vs. 30% at 12 weeks, and 23% vs. 37% at 6 months, p < 0.001). Aboriginal and/or Torres Strait Islander women were more likely to have completed a 6-month HbA1C compared to non-Indigenous women (16% vs. 2%, p < 0.001). Screening by 6 months postpartum with any test was 41% for Aboriginal and/or Torres Strait Islander women and 45% for non-Indigenous women (p = 0.304). Characteristics associated with higher screening rates with any test by 6 months postpartum included, insulin use in pregnancy, first pregnancy, not smoking and lower BMI.

CONCLUSIONS

Given very high rates of type 2 diabetes among Aboriginal and Torres Strait Islander women, early postpartum screening with the most feasible test should be prioritised to detect prediabetes and diabetes for intervention.

Association between hyperglycaemia in pregnancy and growth of offspring in early childhood: The PANDORA study

BACKGROUND

Few studies have assessed whether children exposed to in utero hyperglycaemia experience different growth trajectories compared to unexposed children.

OBJECTIVES

To assess association of type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) with early childhood weight, length/height and body mass index (BMI) trajectories, and with timing and magnitude of peak BMI in infancy.

METHODS

PANDORA is a birth cohort recruited from an Australian hyperglycaemia in pregnancy register, and women with normoglycaemia recruited from the community. Offspring growth measures were obtained from health records over a median follow-up of 3.0 years (interquartile range 1.9-4.0). This analysis included children born to Aboriginal mothers with in utero normoglycaemia (n = 95), GDM (n = 228) or T2D (n = 131). Growth trajectories (weight, length/height and BMI) were estimated using linear mixed models with cubic spline functions of child age.

RESULTS

After adjustment for maternal factors (age, BMI, parity, smoking, and socioeconomic measures) and child factors (age, gestational age at birth, and sex), children born to mothers with T2D or GDM had lower weight, length/height and BMI trajectories in infancy than children born to mothers with normoglycaemia, but similar weight and BMI by completion of follow-up. Children exposed to T2D had lower mean peak BMI 17.6 kg/m² (95% confidence interval [CI] 17.3-18.0) than children exposed to normoglycaemia (18.6 kg/m² [18.1-18.9]) (p = 0.001).

CONCLUSIONS

Maternal hyperglycaemia was associated with differences in early childhood growth trajectories after adjustment for maternal BMI. Exploration of associations between in utero hyperglycaemia exposure and growth trajectories into later childhood is required.

Breastfeeding and infant growth in offspring of mothers with hyperglycaemia in pregnancy: The pregnancy and neonatal diabetes outcomes in remote Australia study

BACKGROUND

Benefits of breastfeeding on infant growth in children born to mothers with gestational diabetes mellitus (GDM) are uncertain.

OBJECTIVES

To describe growth trajectories between birth and 14 months according to breastfeeding and maternal hyperglycaemia in pregnancy, and assess associations between breastfeeding and 14 month growth outcomes among children born to mothers with GDM.

SUBJECTS/METHODS

Data on 258 Aboriginal and Torres Strait Islander infants from the PANDORA study born to mothers with normoglycaemia (n = 73), GDM (n = 122), or with pre-existing type 2 diabetes (n = 63) in pregnancy were assessed. Infant weight and BMI growth trajectories according to predominant breastfeeding at 6 months and hyperglycaemia in pregnancy were developed using mixed-effect models and cubic splines. Associations between breastfeeding and 14-month growth outcomes (z-scores: weight-for-age, weight-for-length and BMI) were evaluated using linear regression in a subgroup of infants born to mothers with GDM.

RESULTS

Predominantly breastfed infants had lower BMI trajectories compared to those not predominantly breastfed, irrespective of maternal hyperglycaemia in pregnancy status (p < 0.01 for all groups), and lower weight trajectories among those born to mothers with GDM (p = 0.006). Among offspring of women with GDM, predominant breastfeeding was only associated with lower weight-for-age at 14 months, however adjusting for maternal obesity, smoking, and parity attenuated observed associations. Maternal obesity remained significantly associated with greater infant growth.

CONCLUSIONS

Predominant breastfeeding was associated with reduced growth among children born to women with and without hyperglycaemia in pregnancy. However, among children exposed to GDM in utero, maternal obesity largely explained this association.

Associations of gestational diabetes and type 2 diabetes during pregnancy with breastfeeding at hospital discharge and up to 6 months: the PANDORA study

AIMS/HYPOTHESIS

Women with gestational diabetes mellitus (GDM) and obesity experience lower rates of breastfeeding. Little is known about breastfeeding among mothers with type 2 diabetes. Australian Indigenous women have a high prevalence of type 2 diabetes in pregnancy. We aimed to evaluate the association of hyperglycaemia, including type 2 diabetes, with breastfeeding outcomes.

METHODS

Indigenous (n = 495) and non-Indigenous (n = 555) participants of the Pregnancy And Neonatal Diabetes Outcomes in Remote Australia (PANDORA) cohort included women without hyperglycaemia in pregnancy (n = 222), with GDM (n = 684) and with type 2 diabetes (n = 144). The associations of hyperglycaemia in pregnancy and breastfeeding at hospital discharge, 6 weeks and 6 months post-partum were evaluated with logistic regression, after adjustment for maternal obesity, ethnicity, maternal and neonatal characteristics.

RESULTS

Indigenous women were more likely to predominantly breastfeed at 6 weeks across all levels of hyperglycaemia. Compared with women with no hyperglycaemia in pregnancy, women with type 2 diabetes had lower odds for exclusive breastfeeding at discharge (adjusted OR for exclusive breastfeeding 0.4 [95% CI 0.2, 0.8] p = 0.006). At 6 weeks and 6 months, the relationship between type 2 diabetes and predominant breastfeeding was not statistically significant (6 weeks 0.7 [0.3, 1.6] p = 0.40, 6 months 0.8 [0.4, 1.6] p = 0.60). Women with gestational diabetes were as likely to achieve predominant breastfeeding at 6 weeks and 6 months as women without hyperglycaemia in pregnancy.

CONCLUSIONS/INTERPRETATION

Indigenous women had high rates of breastfeeding. Women with type 2 diabetes had difficulty establishing exclusive breastfeeding at hospital discharge. Further research is needed to assess the impact on long-term breastfeeding outcomes. Graphical abstract.

Pregnancy And Neonatal Diabetes Outcomes in Remote Australia: the PANDORA study-an observational birth cohort

BACKGROUND

In Australia's Northern Territory, 33% of babies are born to Indigenous mothers, who experience high rates of hyperglycemia in pregnancy. We aimed to determine the extent to which pregnancy outcomes for Indigenous Australian women are explained by relative frequencies of diabetes type [type 2 diabetes (T2DM) and gestational diabetes (GDM)].

METHODS

This prospective birth cohort study examined participants recruited from a hyperglycemia in pregnancy register. Baseline data collected were antenatal and perinatal clinical information, cord blood and neonatal anthropometry. Of 1135 women (48% Indigenous), 900 had diabetes: 175 T2DM, 86 newly diagnosed diabetes in pregnancy (DIP) and 639 had GDM. A group of 235 women without hyperglycemia in pregnancy was also recruited.

RESULTS

Diabetes type differed for Indigenous and non-Indigenous women (T2DM, 36 vs 5%; DIP, 15 vs 7%; GDM, 49 vs 88%, p < 0.001). Within each diabetes type, Indigenous women were younger and had higher smoking rates. Among women with GDM/DIP, Indigenous women demonstrated poorer birth outcomes than non-Indigenous women: large for gestational age, 19 vs 11%, p = 0·002; neonatal fat 11.3 vs 10.2%, p < 0.001. In the full cohort, on multivariate regression, T2DM and DIP were independently associated (and Indigenous ethnicity was not) with pregnancy outcomes.

CONCLUSIONS

Higher rates of T2DM among Indigenous women predominantly contribute to absolute poorer pregnancy outcomes among Indigenous women with hyperglycemia. As with Indigenous and minority populations globally, prevention or delay of type 2 diabetes in younger women is vital to improve pregnancy outcomes and possibly to improve the long-term health of their offspring.

Progression of Kidney Disease in Indigenous Australians: The eGFR Follow-up Study

BACKGROUND AND OBJECTIVES

Indigenous Australians experience a heavy burden of CKD. To address this burden, the eGFR Follow-Up Study recruited and followed an Indigenous Australian cohort from regions of Australia with the greatest ESRD burden. We sought to better understand factors contributing to the progression of kidney disease. Specific objectives were to assess rates of progression of eGFR in Indigenous Australians with and without CKD and identify factors associated with a decline in eGFR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This observational longitudinal study of Indigenous Australian adults was conducted in >20 sites. The baseline cohort was recruited from community and primary care clinic sites across five strata of health, diabetes status, and kidney function. Participants were then invited to follow up at 2-4 years; if unavailable, vital status, progression to RRT, and serum creatinine were obtained from medical records. Primary outcomes were annual eGFR change and combined renal outcome (first of ≥30% eGFR decline with follow-up eGFR<60 ml/min per 1.73 m(2), progression to RRT, or renal death).

RESULTS

Participants (n=550) were followed for a median of 3.0 years. Baseline and follow-up eGFR (geometric mean [95% confidence interval], 83.9 (80.7 to 87.3) and 70.1 (65.9 to 74.5) ml/min per 1.73 m(2), respectively. Overall mean annual eGFR change was -3.1 (-3.6 to -2.5) ml/min per 1.73 m(2). Stratified by baseline eGFR (≥90, 60-89, <60 ml/min per 1.73 m(2)), annual eGFR changes were -3.0 (-3.6 to -2.4), -1.9 (-3.3 to -0.5), and -5.0 (-6.5 to -3.6) ml/min per 1.73 m(2). Across baseline eGFR categories, annual eGFR decline was greatest among adults with baseline albumin-to-creatinine ratio (ACR) >265 mg/g (30 mg/mmol). Baseline determinants of the combined renal outcome (experienced by 66 participants) were higher urine ACR, diabetes, lower measured GFR, and higher C-reactive protein.

CONCLUSIONS

The observed eGFR decline was three times higher than described in nonindigenous populations. ACR was confirmed as a powerful predictor for eGFR decline across diverse geographic regions.

Alterations of uromodulin biology: a common denominator of the genetically heterogeneous FJHN/MCKD syndrome

Autosomal dominant hyperuricemia, gout, renal cysts, and progressive renal insufficiency are hallmarks of a disease complex comprising familial juvenile hyperuricemic nephropathy and medullary cystic kidney diseases type 1 and type 2. In some families the disease is associated with mutations of the gene coding for uromodulin, but the link between the genetic heterogeneity and mechanism(s) leading to the common phenotype symptoms is not clear. In 19 families, we investigated relevant biochemical parameters, performed linkage analysis to known disease loci, sequenced uromodulin gene, expressed and characterized mutant uromodulin proteins, and performed immunohistochemical and electronoptical investigation in kidney tissues. We proved genetic heterogeneity of the disease. Uromodulin mutations were identified in six families. Expressed, mutant proteins showed distinct glycosylation patterns, impaired intracellular trafficking, and decreased ability to be exposed on the plasma membrane, which corresponded with the observations in the patient's kidney tissue. We found a reduction in urinary uromodulin excretion as a common feature shared by almost all of the families. This was associated with case-specific differences in the uromodulin immunohistochemical staining patterns in kidney. Our results suggest that various genetic defects interfere with uromodulin biology, which could lead to the development of the common disease phenotype. 'Uromodulin-associated kidney diseases' may be thus a more appropriate term for this syndrome.

The effect of dominant vestigial alleles upon vestigial-mediated wing patterning during development of Drosophila melanogaster

The vestigial gene product is required for the completion of wing development in Drosophila melanogaster. In the absence of vestigial gene expression, cells within the larval wing and haltere imaginal discs fail to proliferate normally thus producing adults with severely reduced wings. Of a large number of vestigial mutations that have been characterized, only two are currently known to exist, vestigial(U) and vestigial(W), which manifest a significant dominant phenotype. Both are associated with chromosomal inversions that fuse the majority of the vestigial coding regions to other genes; mastermind in vestigial(U) and invected in vestigial(W) Examination of vestigial expression in the presence of these dominant alleles shows alterations in the disc-specific expression of vestigial during later stages of larval development. These patterning disruptions are specific to cells of the wing imaginal disc, as significant suppression of total levels of vestigial expression within entire larvae could not be detected. This dominant interference of vestigial patterning appears to be mediated in part by the vestigial coding sequences that are within the gene fusions. Further evidence that the dominant phenotype is the result of disrupted vestigial patterning comes from observations that the dominant alleles can be partially suppressed by mutations within the Drosophila-epidermal growth factor receptor gene. Mutagenesis of vestigial(U) and vestigial(W) produced a series of alleles with partially dominant phenotypes that restored various amounts of the adult wing. These phenotypes can be correlated with alterations in specific portions of the vestigial sequences associated with the dominant alleles. In the presence of these partially dominant alleles, wing imaginal discs have significantly more cells which express vestigial compared with the number associated with the original dominant phenotype. Additionally, eliminating some of the dominant effect causes alterations in the patterns of early stage apoptotic cell death associated with dominant vestigial alleles. Utilizing these new vestigial alleles, it is possible to correlate the consequence of altered vestigial expression to subsequent changes in patterning of the wing disc.

The influence of 2-chloro-2'-deoxyadenosine on metabolism of deoxyadenosine in human primary CNS lymphoma

The effects of 2-chloro-2'-deoxyadenosine (2CdA) on the activity of enzymes important for the metabolism of deoxyadenosine were studied in lysates prepared from human primary central nervous system (CNS) lymphomas and normal human lymphocytes. Strong inhibition (approximately 100%) of the phosphorylation of deoxyadenosine to its deoxynucleotide phosphate derivatives was produced in both systems in the presence of 2CdA, which was phosphorylated concomitantly to 2-chloro-2'-deoxyAMP. Interestingly, 2CdA was also found to be an inhibitor of the deamination of both deoxyadenosine (over 50%) and AMP (70%). These findings add to our understanding of the mechanisms of toxicity of this drug, especially considering that 2CdA is resistant to deamination by adenosine deaminase. These results challenge the existing theories of 2CdA toxicity, which have been limited to the formation of phosphate derivatives of 2CdA. The present in vitro studies have demonstrated that 2CdA also inhibits both phosphorylation and deamination of deoxyadenosine (dAdo), suggesting that its mechanism of toxicity includes a block in dAdo metabolic pathways. This has important implications for the perturbation of cell methylation, a functionality associated with, for example, apoptosis.

Substrate specificity of methylthioadenosine phosphorylase from human liver

Methylthioadenosine (MTA) phosphorylase purified 615-fold from human liver cleaved phosphorolytically nucleoside analogues at the decreasing specific activity: 5'-deoxyadenosine > 5'-iodo-5'-deoxyadenosine > MTA > adenosine > 2-chloroadenosine > 2-chloro-5'-O-methyl-2'-deoxyadenosine > 2-chloro-2'-deoxyadenosine > > 2'-deoxyadenosine. Adenosine and analogues of 5'-deoxyadenosine were strong competitive inhibitors of MTA phosphorolysis catalysed by the human liver enzyme.

Dopamine modulation of prolactin and vasopressin but not behavior on satiation of sheep

We have investigated the rapid changes in plasma prolactin and arginine vasopressin (AVP) associated with water satiation in ruminants. Sheep deprived of water for 72 h were allowed voluntary access to ad libitum water. Each sheep drank approximately 5 liters in a single draft. This was performed in a head-down position, which was maintained for approximately 2-3 min and ceased rapidly with an abrupt movement to the upright position. During dehydration, plasma sodium, osmolality, and AVP all increased significantly, but prolactin was unaffected. On rehydration, AVP fell to basal levels within 5 min, but prolactin increased as a short pulse, after which it rapidly fell again. Plasma sodium and osmolality returned to predehydration levels within 6 h of satiation. A possible role of dopaminergic mechanisms in these responses was investigated by the administration of the dopamine agonist bromocriptine or the antagonist metoclopramide. Neither of these agents had any observable effects on the drinking behavior of the sheep during water satiation. During metoclopramide treatment, dehydration was associated with a marked fall in prolactin, and on rehydration there was a prompt and very marked increase in prolactin level. There was also an exaggerated increase of AVP during dehydration and a decrease on rehydration. Bromocriptine had relatively little effect on prolactin responses but prevented the drinking-associated inhibition of AVP, demonstrating an unexpected dissociation between AVP secretion and the stereotyped drinking response.

Relation of endogenous systemic and brain angiotensin II, arginine vasopressin and prolactin with the genesis of salt appetite in cattle

Angiotensin II (AII), arginine vasopressin (AVP) and prolactin (PRL) were measured by radioimmunoassay in plasma and cerebrospinal fluid (CSF) in concurrent daily samples from conscious unrestrained steers. Packed cell volume, [Na+] and osmolality were also measured from these samples. Salt appetite was assessed during a 5-min daily session of operant conditioning. Food and water was always available. Unilateral parotid duct fistulation was effected under xylazine analgesia and halothane/O2 anaesthesia. To prevent a sodium deficit developing from loss of [Na+] in the extruded saliva, 0.3 M NaHCO3 was available ad libitum so that each animal could ingest sufficiently to balance the salivary loss. A week later epidural cannulae were implanted in the cisternae magna using the same anaesthesia. Three days afterwards when the saliva [Na] was 78 mmol/1, the 0.3-M NaHCO3 supplement was withdrawn for 7 days so that sodium deficiency developed to a degree which evoked salt appetite. When the NaHCO3 supplement was restored ad libitum, all aspects of [Na+] deficiency and salt appetite were completely ameliorated within 2-3 days. Packed cell volume increased and body weight decreased (p less than 0.05) during depletion, but rapidly returned to normal on day 2 of repletion. Both plasma and CSF osmolality were reduced during depletion as were plasma [Na+] (p less than 0.01) and CSF [Na+] (p less than 0.001). From a basal value of 64.7 +/- 9.35 fmol/ml on day 0, plasma AII increased to 229.2 +/- 46.65 fmol/ml (p less than 0.001) on day 3, prior to the onset of salt appetite on days 4-7. In marked contrast to plasma AII during sodium depletion, CSF AII was unchanged during salt appetite. There was no correlation between plasma and CSF AII during behavioural salt appetite.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetotoxicity in rats following chronic exposure to halothane, nitrous oxide, or methoxyflurane

An animal model was used to investigate the comparative fetal toxicities of three inhalational anesthetics. Pregnant Sprague-Dawley rats were exposed for eight hours a day throughout the 21 days of gestation to graded concentrations of halothane (0.16-0.32 per cent), or nitrous oxide (1-50 per cent), or a nitrous oxide (10 per cent) and halothane (0.16 per cent) mixture, or methoxyflurane (0.01-0.08 per cent). High subanesthetic concentrations of all the inhalational anesthetics could cause fetal growth retardation (e.g., 3-21 per cent decreases in normal fetal weights), but this was unaccompanied by significant fetal loss (overall rate: 4.8 +/- 1.2 per cent, mean +/- SE, in anesthetic groups) or any evidence of skeletal or gross abnormalities related to treatment. It is concluded that these rodent studies do not implicate any specific inhalational anesthetic agent in fetal toxicity, and that the effects of additional factors, such as stress, must be considered.