Consequences of fetal exposure to maternal diabetes in offspring

Developmental programming of the metabolic syndrome - critical windows for intervention

Metabolic disease results from a complex interaction of many factors, including genetic, physiological, behavioral and environmental influences. The recent rate at which these diseases have increased suggests that environmental and behavioral influences, rather than genetic causes, are fuelling the present epidemic. In this context, the developmental origins of health and disease hypothesis has highlighted the link between the periconceptual, fetal and early infant phases of life and the subsequent development of adult obesity and the metabolic syndrome. Although the mechanisms are yet to be fully elucidated, this programming was generally considered an irreversible change in developmental trajectory. Recent work in animal models suggests that developmental programming of metabolic disorders is potentially reversible by nutritional or targeted therapeutic interventions during the period of developmental plasticity. This review will discuss critical windows of developmental plasticity and possible avenues to ameliorate the development of postnatal metabolic disorders following an adverse early life environment.

The diabetic pregnancy and offspring BMI in childhood: a systematic review and meta-analysis

AIMS/HYPOTHESIS

Offspring of mothers with diabetes are at increased risk of metabolic disorders in later life. Increased offspring BMI is a plausible mediator. We performed a systematic review and meta-analysis of studies examining offspring BMI z score in childhood in relation to maternal diabetes.

METHODS

Papers reporting BMI z scores for offspring of diabetic (all types, and pre- and during-pregnancy onset) and non-diabetic mothers were included. Citations were identified in PubMed; bibliographies of relevant articles were hand-searched and authors contacted for additional data where necessary. We compared offspring BMI z score with and without adjustment for maternal pre-pregnancy BMI. We performed fixed effect meta-analysis except where significant heterogeneity called for use of a random effects analysis.

RESULTS

Data were available from nine studies. In the diabetic group unadjusted mean offspring BMI z score was 0.28 higher (all diabetic mothers vs controls (95% CI 0.09, 0.47; p = 0.004; nine studies; offspring of diabetic mothers n = 927, controls n = 26,384) and with adjustment for maternal pre-pregnancy BMI, 0.07 higher (95% CI -0.15, 0.28; p = 0.54; three studies; offspring of diabetic mothers n = 244, controls n = 11,206). There was no evidence of a difference in offspring BMI z score in relation to type of diabetes (gestational vs type 1, p = 0.95).

CONCLUSIONS/INTERPRETATION

Maternal diabetes is associated with increased offspring BMI z score, although this is no longer apparent after adjustment for maternal pre-pregnancy BMI in the limited number of studies in which this is reported. Causal mediators of the effect of maternal diabetes on offspring outcomes remain to be established; we recommend that future research includes adjustment for maternal pre-pregnancy BMI.

[Long term outcome in children of mothers with gestational diabetes]

OBJECTIVES

To appreciate, in epidemiological studies, the impact of fetal exposure to gestational diabetes on the long term outcome of the offspring (type 2 diabetes, overweight and obesity, metabolic syndrome and neurological complications).

METHODS

A systematic search was conducted in Medline between January 1990 and April 2010. Prospective studies (follow-up of the offspring born of mothers with gestational diabetes) and retrospective studies (questionnaire about the parents'history of diabetes in diabetic patients) were searched and analysed.

RESULTS

The fetal exposure to maternal gestational diabetes is a moderate risk factor for metabolic syndrome in the offspring. But some other perinatal risk factors of metabolic syndrome carry a bigger influence. The influence of genetic factors and maternal overweight may not be easily distinguished from the impact of fetal exposure to gestational diabetes.

CONCLUSION

It remains uncertain if the control of maternal glycemia alone may be effective and sufficient to prevent the metabolic syndrome in the adult-aged offspring.

Obesity and type 2 diabetes mellitus in a birth cohort of First Nation children born to mothers with pediatric-onset type 2 diabetes

BACKGROUND

Children who are born to mothers with pediatric-onset type 2 diabetes mellitus are exposed to a hyperglycemic intra-uterine environment throughout pregnancy. The growth patterns and risk of type 2 diabetes in these offspring may be influenced by unique gene-environment interactions during intra-uterine and postnatal life.

SUBJECTS

We established a cohort of offspring of First Nation mothers with onset of type 2 diabetes before age 18 years in Manitoba, Canada.

METHODS

We measured height or length and weight at study entry and annually thereafter with fasting blood glucose in offspring aged ≥ 7 years. We collected birth and breastfeeding history and determined the population-specific hepatic nuclear factor-1α (HNF-1α) G319S genotype of offspring at age 7 years.

RESULTS

From July 2003 to April 2008, we enrolled 76 offspring of 37 mothers. Sixty-four percent (23/36) of the offspring aged 2-19 years were obese at initial assessment. The rates of obesity remained constant throughout the 5 years. As of April 2008, 7/28 (25%) of the offspring aged 7-19 years have diabetes including 6/14 (43%) aged 10-19 years. Most offspring with diabetes (5/7, 71%) were obese at diagnosis. All of the 7 offspring with diabetes have 1 or 2 copies of the G319S polymorphism.

CONCLUSIONS

The prevalence of type 2 diabetes in this cohort of offspring of First Nation women with pediatric-onset type 2 diabetes is the highest ever reported. Obesity is an important postnatal risk factor for type 2 diabetes in this population and may result from a unique gene-environment interaction.

Developmental programming of energy balance and its hypothalamic regulation

Developmental programming is an important physiological process that allows different phenotypes to originate from a single genotype. Through plasticity in early life, the developing organism can adopt a phenotype (within the limits of its genetic background) that is best suited to its expected environment. In humans, together with the relative irreversibility of the phenomenon, the low predictive value of the fetal environment for later conditions in affluent countries makes it a potential contributor to the obesity epidemic of recent decades. Here, we review the current evidence for developmental programming of energy balance. For a proper understanding of the subject, knowledge about energy balance is indispensable. Therefore, we first present an overview of the major hypothalamic routes through which energy balance is regulated and their ontogeny. With this background, we then turn to the available evidence for programming of energy balance by the early nutritional environment, in both man and rodent models. A wealth of studies suggest that energy balance can indeed be permanently affected by the early-life environment. However, the direction of the effects of programming appears to vary considerably, both between and within different animal models. Because of these inconsistencies, a comprehensive picture is still elusive. More standardization between studies seems essential to reach veritable conclusions about the role of developmental programming in adult energy balance and obesity.

Gestational diabetes mellitus alters maternal and neonatal circulating endothelial progenitor cell subsets

OBJECTIVE

The purpose of this study was to examine whether women with gestational diabetes mellitus (GDM) and their offspring have reduced endothelial progenitor cell subsets and vascular reactivity.

STUDY DESIGN

Women with GDM, healthy control subjects, and their infants participated. Maternal blood and cord blood were assessed for colony-forming unit-endothelial cells and endothelial progenitor cell subsets with the use of polychromatic flow cytometry. Cord blood endothelial colony-forming cells were enumerated. Vascular reactivity was tested by laser Doppler imaging.

RESULTS

Women with GDM had fewer CD34, CD133, CD45, and CD31 cells (circulating progenitor cells [CPCs]) at 24-32 weeks' gestation and 1-2 days after delivery, compared with control subjects. No differences were detected in colony-forming unit-endothelial cells or colony-forming unit-endothelial cells. In control subjects, CPCs were higher in the third trimester, compared with the postpartum period. Cord blood from GDM pregnancies had reduced CPCs. Vascular reactivity was not different between GDM and control subjects.

CONCLUSION

The normal physiologic increase in CPCs during pregnancy is impaired in women with GDM, which may contribute to endothelial dysfunction and GDM-associated morbidities.

Potential latent effects of prenatal cocaine exposure on growth and the risk of cardiovascular and metabolic disease in childhood

The literature strongly suggests that prenatal exposure to certain medications and substances does not cause major malformations in early childhood. However, these exposures may have far-reaching latent health effects, such as restricted growth, hypertension, and cardiovascular events in adulthood. We reviewed the literature to identify the effects of prenatal cocaine exposure on growth and the risk of cardiovascular and metabolic disease in late adolescence and early adulthood by examining studies that were published in peer-reviewed English-language journals from 1990 through 2009 and indexed in MEDLINE. We found that animal and clinical studies of the influence of prenatal cocaine exposure on child and adolescent growth and the subsequent development of myocardial and cardiometabolic disease risk factors are few and inconclusive. Studies support the hypothesis that vascular and hemodynamic functions are partially programmed in early life and thus substantially influence vascular aging and arterial stiffening in later life. Sub-optimal fetal nutrition and growth may increase blood pressure and the development of cardiovascular and metabolic disease in late life. How prenatal cocaine and other drug exposure effects this relationship is currently unknown. Despite high rates of cocaine and other drug use during pregnancy (up to 18% in some studies), little is known about the health effects of prenatal cocaine exposure in adolescence and early adulthood. The few studies of early growth deficits persisting into adolescence are inconclusive. The literature provides little information on how exposed children grow into adulthood and about their subsequent risk of cardiometabolic and vascular disease.

Fetal risk assessment in pregnancies complicated by diabetes mellitus

BACKGROUND

Hypoglycemia and hyperglycemia can pose a number of serious risks to pregnant mothers with diabetes, but these risks are not always related to glucose concentrations directly. Previous studies have shown the utility of using mathematical transformation functions to create patient risk profiles that can then be used to analyze and predict adverse outcomes in individuals with diabetes. We propose a novel use of these functions to analyze the risks posed to the fetus in pregnancies complicated by diabetes.

METHODS

We retrospectively analyzed 71 h continuous glucose monitoring system (CGMS Gold, Medtronic Northridge, CA) third trimester tracings obtained during a normal pregnancy and in those complicated by gestational diabetes mellitus (GDM), type 2 diabetes mellitus (T2DM), and type 1 diabetes mellitus (T1DM). We then used a transformation function to calculate fetal and maternal risk in each case.

RESULTS

In the normal pregnancy (0.93), the risk was at a minimum. Along with mean glucose values, the risk increased in those cases where gestation was complicated by GDM (3.12), T2DM (7.85), and T1DM (16.94). In contrast, the original patient risk profile yielded a minimal value for the GDM tracings.

CONCLUSIONS

Total fetal risk increases from normal to GDM to T2DM to T1DM pregnancies. This new risk assignment better distinguishes the stages of fetal risk than the original method and therefore may be useful in future clinical trials and applications to predict risk for adverse outcomes in pregnancies complicated by diabetes.

Animal models in diabetes and pregnancy

The worldwide increase in the incidence of diabetes, the increase in type 2 diabetes in women at reproductive ages, and the cross-generation of the intrauterine programming of type 2 diabetes are the bases for the growing interest in the use of experimental diabetic models in order to gain insight into the mechanisms of induction of developmental alterations in maternal diabetes. In this scenario, experimental models that present the most common features of diabetes in pregnancy are highly required. Several important aspects of human diabetic pregnancies such as the increased rates of spontaneous abortions, malformations, fetoplacental impairments, and offspring diseases in later life can be approached by using the appropriate animal models. The purpose of this review is to give a practical and critical guide into the most frequently used experimental models in diabetes and pregnancy, discuss their advantages and limitations, and describe the aspects of diabetes and pregnancy for which these models are thought to be adequate. This review provides a comprehensive view and an extensive analysis of the different models and phenotypes addressed in diabetic animals throughout pregnancy. The review includes an analysis of the surgical, chemical-induced, and genetic experimental models of diabetes and an evaluation of their use to analyze early pregnancy defects, induction of congenital malformations, placental and fetal alterations, and the intrauterine programming of metabolic diseases in the offspring's later life.

In utero exposure to maternal diabetes impairs vascular expression of prostacyclin receptor in rat offspring

OBJECTIVE

To evaluate modifications of arterial structure, gene expression, and function in our model of rats exposed to maternal diabetes.

RESEARCH DESIGN AND METHODS

Morphometric analyses of elastic vessels structure and determination of thoracic aortic gene expression profile with oligonucleotide chips (Agilent, G4130, 22k) were performed before the onset of established hypertension (3 months).

RESULTS

Arterial parameters of in situ fixed thoracic aorta were not significantly different between control mother offspring and diabetic mother offspring (DMO). The aortic gene expression profile of DMO is characterized by modifications of several members of the arachidonic acid metabolism including a twofold underexpression of prostacyclin receptor, which could contribute to decreased vasodilatation. This was confirmed by ex vivo experiments on isolated aortic rings. Pharmacological studies on conscious rats showed that systolic blood pressure decline in response to a PGI(2) analog was impaired in DMO rats.

CONCLUSIONS

These results suggest an abnormal vascular fetal programming of prostacyclin receptor in rats exposed in utero to maternal hyperglycemia that is associated with impaired vasodilatation and may be involved in the pathophysiology of hypertension in this model.

Fetal exposure to maternal type 1 diabetes is associated with renal dysfunction at adult age

OBJECTIVE

In animal studies, hyperglycemia during fetal development reduces nephron numbers. We tested whether this observation translates into renal dysfunction in humans by studying renal functional reserve in adult offspring exposed in utero to maternal type 1 diabetes.

RESEARCH DESIGN AND METHODS

We compared 19 nondiabetic offspring of type 1 diabetic mothers with 18 offspring of type 1 diabetic fathers (control subjects). Glomerular filtration rate ((51)Cr-EDTA clearance), effective renal plasma flow ((123)I-hippurate clearance), mean arterial pressure, and renal vascular resistances were measured at baseline and during amino acid infusion, which mobilizes renal functional reserve.

RESULTS

Offspring of type 1 diabetic mothers were similar to control subjects for age (median 27, range 18-41, years), sex, BMI (23.1 ± 3.7 kg/m(2)), and birth weight (3,288 ± 550 vs. 3,440 ± 489 g). During amino acid infusion, glomerular filtration rate and effective renal plasma flow increased less in offspring of type 1 diabetic mothers than in control subjects: from 103 ± 14 to 111 ± 17 ml/min (8 ± 13%) vs. from 108 ± 17 to 128 ± 23 ml/min (19 ± 7%, P = 0.009) and from 509 ± 58 to 536 ± 80 ml/min (5 ± 9%) vs. from 536 ± 114 to 620 ± 140 ml/min (16 ± 11%, P = 0.0035). Mean arterial pressure and renal vascular resistances declined less than in control subjects: 2 ± 5 vs. -2 ± 3% (P = 0.019) and 3 ± 9 vs. -14 ± 8% (P = 0.001).

CONCLUSIONS

Reduced functional reserve may reflect a reduced number of nephrons undergoing individual hyperfiltration. If so, offspring of type 1 diabetic mothers may be predisposed to glomerular and vascular diseases.

Mechanisms of developmental programming of the metabolic syndrome and related disorders

There is consistent epidemiological evidence linking low birth weight, preterm birth and adverse fetal growth to an elevated risk of the metabolic syndrome (obesity, raised blood pressure, raised serum triglycerides, lowered serum high-density lipoprotein cholesterol and impaired glucose tolerance or insulin resistance) and related disorders. This “fetal or developmental origins/programming of disease” concept is now well accepted but the “programming” mechanisms remain poorly understood. We reviewed the major evidence, implications and limitations of current hypotheses in interpreting developmental programming and discuss future research directions. Major current hypotheses to interpret developmental programming include: (1) thrifty phenotype; (2) postnatal accelerated or catch-up growth; (3) glucocorticoid effects; (4) epigenetic changes; (5) oxidative stress; (6) prenatal hypoxia; (7) placental dysfunction; and (8) reduced stem cell number. Some hypothetical mechanisms (2, 4 and 8) could be driven by other upstream “driver” mechanisms. There is a lack of animal studies addressing multiple mechanisms simultaneously and a lack of strong evidence linking clinical outcomes to biomarkers of the proposed programming mechanisms in humans. There are needs for (1) experimental studies addressing multiple hypothetical mechanisms simultaneously; and (2) prospective pregnancy cohort studies linking biomarkers of the proposed mechanisms to clinical outcomes or surrogate biomarker endpoints. A better understanding of the programming mechanisms is a prerequisite for developing early life interventions to arrest the increasing epidemic of the metabolic syndrome, type 2 diabetes and other related disorders.

Maternal family history of diabetes is associated with a reduced risk of cardiovascular disease in women with type 2 diabetes: the Fremantle Diabetes Study

OBJECTIVE

To investigate whether parental family history of diabetes influences cardiovascular outcomes in type 2 diabetes.

RESEARCH DESIGN AND METHODS

We studied 1,294 type 2 diabetic patients (mean age 64.1 years, 51.2% female) recruited to a community-based cohort study from 1993 to 1996 and followed until mid-2006. A data linkage system assessed all-cause and cardiac mortality, incident myocardial infarction, and stroke. Cox proportional hazards modeling was used to determine the influence of maternal or paternal family history on these outcomes.

RESULTS

A maternal family history of diabetes was reported by 20.4% of the cohort, 8.3% reported paternal family history, and 2.0% reported both parents affected. Maternal and paternal family history was associated with earlier age of diabetes onset, and maternal family history was associated with worse glycemic control. For all patients, maternal family history was significantly associated with reduced risk of all-cause mortality and cardiac mortality. When analyzed by sex, maternal family history had no effect on male patients, whereas female patients with diabetic mothers had significantly reduced hazard ratios for death from all causes (0.63 [95% CI 0.41-0.96]; P = 0.033), for death from cardiac causes (0.32 [0.14-0.72]; P = 0.006), and for first myocardial infarction (0.45 [0.26-0.76]; P = 0.003). Paternal family history status was not associated with these outcomes.

CONCLUSIONS

A maternal family history of diabetes confers relative protection against cardiovascular disease in female patients but not in male patients with type 2 diabetes. Paternal family history is associated with risks equivalent to those without a family history of diabetes. Some of the clinical heterogeneity of type 2 diabetes is related to maternal transmission effects with differential impact on male and female patients.

Dysglycemias in pregnancy: from diagnosis to treatment. Brazilian consensus statement

There is an urgent need to find consensus on screening, diagnosing and treating all degrees of dysglycemia that may occur during pregnancies in Brazil, considering that many cases of dysglycemia in pregnant women are currently not diagnosed, leading to maternal and fetal complications. For this reason the Brazilian Diabetes Society (SBD) and the Brazilian Federation of Gynecology and Obstetrics Societies (FEBRASGO), got together to introduce this proposal. We present here a joint consensus regarding the standardization of clinical management for pregnant women with any degree of dysglycemia, on the basis of current information, to improve medical assistance and to avoid related complications of dysglycemia in pregnancy to the mother and the fetus. This consensus aims to standardize the diagnosis among general practitioners, endocrinologists and obstetricians allowing the dissemination of information in basic health units, public and private services, that are responsible for screening, diagnosing and treating disglycemic pregnant patients.

Association of intrauterine and early-life exposures with diagnosis of uterine leiomyomata by 35 years of age in the Sister Study

BACKGROUND

Early-life exposures to hormonally active compounds and other factors may affect later response to estrogen or progesterone and hence may influence development of uterine leiomyomata (fibroids).

OBJECTIVES

We evaluated associations of in utero and early-life exposures, including soy formula, with self-report of physician-diagnosed fibroids by 35 years of age.

METHODS

Our study included 19,972 non-Hispanic white women who were 35-59 years of age when they enrolled in the Sister Study in 20032007. We estimated risk ratios (RRs) and 95% confidence intervals (CIs) using log-binomial regression models for fibroid associations with adjustment for participant's age and education, maternal age at participant's birth, birth order, and childhood family income.

RESULTS

Greater risk of early fibroid diagnosis was associated with soy formula during infancy (RR = 1.25; 95% CI, 0.971.61), maternal prepregnancy diabetes (RR = 2.05; 95% CI, 1.163.63), low childhood socioeconomic status (RR = 1.28; 95% CI, 1.011.63), and gestational age at birth (RR = 1.64; 95% CI, 1.272.13, for being born at least 1 month early). In utero diethylstilbestrol (DES) exposure was also associated with early fibroid diagnosis (RR = 1.42; 95% CI, 1.131.80), but this association was driven by women reporting probable rather than definite exposure.

CONCLUSIONS

There are plausible biological pathways by which these early-life factors could promote fibroid pathogenesis. This is the first epidemiologic study to evaluate such exposures, with the exception of in utero DES, in relation to fibroid risk, and replication of findings in other populations is needed.

Hyperglycemia perturbs biochemical networks in human trophoblast BeWo cells

Determining the effects of hyperglycemia on gene expression in placental trophoblast is important to gain a better understanding of how diabetes adversely affects pregnancy. In this study, we examined whether exposure to high glucose during forskolin-induced differentiation affects gene expression in differentiated trophoblasts. Human trophoblast BeWo cells were differentiated under low glucose (LG: 11 mM) or high glucose (HG: 25 mM) conditions. Gene expression was analyzed using a GeneChip system and the obtained data were analyzed using Ingenuity Pathways Analysis. In HG conditions, there were marked alterations in gene expression in differentiated BeWo cells compared with LG conditions. In particular, BeWo cells responded to HG with major changes in the expression levels of cell cycle- and metabolism-related genes. We selected the aromatase gene for further investigation of the molecular mechanisms. Mannitol or 3-O-methylglucose did not mimic the expression changes caused by HG, indicating that the effect of glucose was not due to a difference in osmotic pressure, and that glucose metabolism plays an essential role in inducing the HG effects. Cotreatment with N-acetylcysteine reduced the effect of HG on aromatase gene expression, suggesting that hyperglycemia may perturb biochemical networks because of the elevation of oxidative stress. Overall, our results will aid further understanding of the effect of diabetes on the regulation of trophoblast differentiation and function.

Effects of ooplasm transfer on paternal genome function in mice

BACKGROUND

The ooplasm plays a central role in forming the paternal pronucleus, and subsequently in regulating the expression of paternally inherited chromosomes. Previous studies in mice have revealed genetic differences in paternal genome processing by ooplasm of different genotypes. Ooplasm donation coupled to intracytoplasmic sperm injection (ICSI) has been used in human assisted reproductive technology (ART). This procedure exposes the developing paternal pronucleus to 'foreign' ooplasm, which may direct aberrant epigenetic processing. The potential effects of the foreign ooplasm on epigenetic information in the paternal pronucleus are unknown; however, some human progeny from ooplasm donation procedures display abnormalities.

METHODS

In this study, we employed inter-genotype ooplasm transfer followed by ICSI using two mouse strains, C57BL/6 and DBA/2, to explore the influence of foreign ooplasm on paternal pronucleus function. In order to assay for effects on the paternal genome without masking effects of the maternal genome, we examined ooplasm effects in diploid androgenones, which are produced by pronuclear transfer to contain exclusively two paternal sets of chromosomes, in combination with ICSI.

RESULTS

There was no significant effect of intra-strain ooplasm transfer among androgenones made with either C57BL/6 or DBA/2 oocytes. There was a significant negative effect on androgenone blastocyst development with inter-genotype transfer (10% volume) of DBA/2 ooplasm to C57BL/6 oocytes (P < 0.05). The reciprocal inter-genotype ooplasm transfer had no significant effect.

CONCLUSIONS

Thus, inter-genotype ooplasm transfer in conjunction with ICSI can alter the function of the paternal genome. However, the effect of foreign ooplasm is restricted to a negative effect, with no evidence of a positive effect. This study provides important new information about the possible consequences of ooplasm donation in human ART.

Maternal arsenic exposure and impaired glucose tolerance during pregnancy

BACKGROUND

Accumulating evidence has shown an increased risk of type 2 diabetes in general populations exposed to arsenic, but little is known about exposures during pregnancy and the association with gestational diabetes (GD).

OBJECTIVES

We studied 532 women living proximate to the Tar Creek Superfund Site to investigate whether arsenic exposure is associated with impaired glucose tolerance during pregnancy.

METHODS

Blood glucose was measured between 24 and 28 weeks gestation after a 1-hr oral glucose tolerance test (GTT) as part of routine prenatal care. Blood and hair were collected at delivery and analyzed for arsenic using inductively coupled plasma mass spectrometry with dynamic reaction cell.

RESULTS

Arsenic concentrations ranged from 0.2 to 24.1 microg/L (ppb) (mean +/- SD, 1.7 +/-1.5) and 1.1 to 724.4 ng/g (ppb) (mean +/- SD, 27.4 +/- 61.6) in blood and hair, respectively. One-hour glucose levels ranged from 40 to 284 mg/dL (mean +/- SD, 108.7 +/- 29.5); impaired glucose tolerance was observed in 11.9% of women when using standard screening criterion (> 140 mg/dL). Adjusting for age, Native-American race, prepregnancy body mass index, Medicaid use, and marital status, women in the highest quartile of blood arsenic exposure had 2.8 higher odds of impaired GTT than women in the lowest quartile of exposure (95% confidence interval, 1.1-6.9) (p-trend = 0.008).

CONCLUSIONS

Among this population of pregnant women, arsenic exposure was associated with increased risk of impaired GTT at 24-28 weeks gestation and therefore may be associated with increased risk of GD.

The effect of paternal and maternal history of diabetes mellitus on the development of gestational diabetes mellitus

BACKGROUND

There is an ongoing debate whether maternal diabetes is a more important risk factor for gestational diabetes (GDM) development than paternal diabetes.

AIM

To describe the risk of GDM associated with paternal and maternal diabetes, and to further characterise GDM women with maternal diabetes.

SUBJECTS AND METHODS

Case-control study within a population-based GDM screening program in an urban area of Hungary in 2002-2003. All GDM women (no.=133) and an age-matched control group (no.=135) with a mean age of 31 years was evaluated. Blood pressure, anthropometric data, and blood glucose values from a 75 g Oral Glucose Tolerance Test (OGTT) were recorded at 24-28 weeks of gestation. Family history data were by self-report.

RESULTS

Known paternal diabetes was not related to GDM risk [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.35-2.00]. Known maternal diabetes (OR 2.90, 95% CI 0.99-8.49) and diabetes in the maternal line (OR 2.83, 95% CI 1.16-6.89) were both related to GDM after adjustment for body mass index (BMI). GDM women with known maternal diabetes had a higher BMI, 31.6 [9.1] kg/m2 median [interquartile range], than GDM women with or without diabetes in the maternal line, 26.1 [4.9] and 26.3 [6.1] kg/m2, respectively, while figures for fasting glucose during OGTT were 5.2 [0.7] vs 4.4 [1.1] vs 4.9 [0.8] mmol/l respectively (all p<0.05).

CONCLUSIONS

Maternal history of diabetes and history of diabetes in the maternal line seems to be a stronger predictor of GDM than paternal history.

Childhood overweight status predicts diabetes at age 21 years: a follow-up study

We examined the prospective association of childhood BMI z-score and BMI categories (normal or overweight) with young adult diabetes, controlling for early life, childhood, and adolescence factors. A subsample of 2,639 young adults from the Mater-University study of pregnancy (MUSP) and its outcomes, a prospective birth cohort who were born in Brisbane, Australia and for whom we had measured height and weight at 5 years and self-reported diabetes at age 21 years. The risk of developing diabetes by age 21 years was greater among young adults who had greater BMI z-score or were overweight at age 5 years than those who had normal BMI at age 5 years. Young adults who were overweight at age 5 years had an increased odds ratio of 2.60 (95% confidence interval (CI): 1.29, 5.22, in age- and sex-adjusted model) of experiencing diabetes by age 21 years. Adjustment for potential confounders and mediators including intrauterine environmental factors, childhood dietary patterns, television watching, participation in sports and exercise, and current weight, did not substantively alter these associations. Overweight and increasing BMI z-score at childhood is an independent predictor of young adult's type 1 and type 2 diabetes. Findings of this study suggest that childhood BMI may be central to the development and rising incidence of all diabetes.

Offspring of diabetic pregnancy: long-term outcomes

Diabetes in pregnancy has been shown to induce long-term effects in offspring. While considerable attention is focused on the increased incidence of type 2 diabetes mellitus (T2DM) in adult offspring from diabetic mothers, cardiovascular alterations, including hypertension, are also part of lifelong consequences of in-utero exposure to increased glucose concentrations. This review examines the epidemiologic and mechanistic issues involved in the developmental programming of long-term consequences in offspring of diabetic mothers, with a particular emphasis on the renal and vascular mechanisms of hypertension. The factors of increased incidence of T2DM and of obesity in adults born after exposure to diabetes during pregnancy are also discussed, as evidence is accumulating that a vicious circle involving lifelong consequences of diabetes in pregnancy in offspring contributes to the current worldwide epidemic of T2DM.

Pregnancy and diabetes scenario around the world: China

Asians adopting a modern lifestyle have a higher risk of diabetes than their white counterparts living in high-income countries. Asian ethnicity is an independent risk factor for gestational diabetes mellitus (GDM), which is associated with a 2-fold increased risk of diabetes. In this burgeoning epidemic of diabetes, 40 million people in China are affected, with the most rapid rate of increase in disease prevalence in the young to middle-aged group. This rising trend of young onset diabetes is largely driven by the rising prevalence of childhood obesity/metabolic syndrome. In Asia, both low and high birth weights are independent risk factors for diabetes and metabolic syndrome. Apart from the high prevalence of maternal history of diabetes in women with diabetes, the metabolic milieu of GDM may have long-term effects on the metabolic profile and future risk of diabetes in the offspring. This complex interplay between environmental, genetic, and perinatal factors puts both mothers with a history of GDM and their offspring at risk of diabetes and metabolic syndrome, thus setting up a vicious cycle of "diabetes begetting diabetes." Given the public health burden of diabetes in low-income nations such as China, there is an urgent need to design and implement large-scale awareness and intervention programs targeted at these mother-offspring pairs to interrupt this transgenerational effect of diabetes and the socioeconomic and humanistic impacts.

Hypertrophic cardiomyopathy and transposition of great arteries associated with maternal diabetes and presumed gestational diabetes

Maternal diabetes mellitus affects the foetal heart both structurally and functionally. In early gestation, it has a teratogenic effect causing defects of primary cardiogenesis. In late gestation, it causes a unique form of hypertrophic cardiomyopathy. We report an infant of a diabetic mother and an infant where there was presumed gestational diabetes during the pregnancy who presented with combined severe hypertrophic cardiomyopathy and complex transposition of the great arteries. This rare combination of structural and functional cardiac abnormalities reflects the different mechanisms and timings of injury that may occur to the foetal heart in association with maternal diabetes and has not been previously reported. The combination has significant implications regarding medical and surgical management, and necessitates prolonged supportive therapy whilst awaiting regression of the hypertrophic cardiomyopathy followed by delayed arterial switch operation.

CONCLUSION

We describe two infants with the unusual combination of both hypertrophic cardiomyopathy and transposition of the great arteries. One was an infant of a diabetic mother, and the second was associated with presumed gestational diabetes.

A family history of type 2 diabetes is associated with glucose intolerance and obesity-related traits with evidence of excess maternal transmission for obesity-related traits in a South East Asian population

AIM

To evaluate family history (FH) of type 2 diabetes (T2DM) as a risk factor for impaired fasting glucose (IFG), impaired glucose tolerance (IGT), T2DM and related metabolic traits in South East Asia and to compare the effects of a paternal versus maternal history.

METHODS

We studied 4717 men and women (68% Chinese, 18% Malays and 14% Asian Indians) living in Singapore. FH was considered positive if at least one first degree relative had T2DM. Obesity, fasting lipids, glucose and insulin levels were measured for all subjects. Insulin resistance (IR) was estimated by homeostasis model assessment (HOMA). An oral glucose tolerance test was carried for all subjects except those on diabetes medication.

RESULTS

A positive FH was associated with increased risk of IFG/IGT (OR=1.67, 95% CI=1.42-1.97) and T2DM (OR=2.95, 95% CI=2.36-3.70) as well as higher levels of obesity, HOMA-IR, fasting triglyceride (TG), and lower levels of high density lipoprotein (HDL) cholesterol and HOMA-beta. A maternal history of T2DM appeared to have a greater impact on obesity-related traits than a paternal history of T2DM. Compared to individuals with no FH of T2DM, a maternal history was associated with (i) greater body mass index (BMI) (24.15kg/m(2) vs. 23.42kg/m(2), p=0.016) and waist-to-hip ratio (WHR) (0.874 vs. 0.865, p=0.037) in men; and (ii) greater WHR (0.788 vs. 0.779, p=0.004), fasting triglyceride (1.23mmol/L vs. 1.09mmol/L, p<0.001), HOMA-IR (2.02 vs. 1.75, p<0.001), fasting plasma glucose (5.25mmol/L vs. 5.18mmol/L, p=0.005) and 2-h plasma glucose (6.01mmol/L vs. 5.78mmol/L, p=0.001) and lower HDL-C (1.41mmol/L vs. 1.47mmol/L, p=0.031) in women.

CONCLUSION

T2DM appears to be heritable in South East Asians with excess maternal transmission of obesity, IR and dyslipidemia.

Exposure to maternal diabetes induces salt-sensitive hypertension and impairs renal function in adult rat offspring

OBJECTIVE

Epidemiological and experimental studies have led to the hypothesis of fetal origin of adult diseases, suggesting that some adult diseases might be determined before birth by altered fetal development. We have previously demonstrated in the rat that in utero exposure to maternal diabetes impairs renal development leading to a reduction in nephron number. Little is known on the long-term consequences of in utero exposure to maternal diabetes. The aim of the study was to assess, in the rat, long-term effects of in utero exposure to maternal diabetes on blood pressure and renal function in adulthood.

RESEARCH DESIGN AND METHODS

Diabetes was induced in Sprague-Dawley pregnant rats by streptozotocin on day 0 of gestation. Systolic blood pressure, plasma renin activity, and renal function were measured in the offspring from 1 to 18 months of age. High-salt diet experiments were performed at the prehypertensive stage, and the abundance of tubular sodium transporters was evaluated by Western blot analysis. Kidney tissues were processed for histopathology and glomerular computer-assisted histomorphometry.

RESULTS AND CONCLUSIONS

We demonstrated that in utero exposure to maternal diabetes induces a salt-sensitive hypertension in the offspring associated with a decrease in renal function in adulthood. High-salt diet experiments show an alteration of renal sodium handling that may be explained by a fetal reprogramming of tubular functions in association or as a result of the inborn nephron deficit induced by in utero exposure to maternal diabetes.

Metabolic programming in the immediate postnatal period

In recent decades, there has been a dramatic increase in the incidence of obesity in all age groups of the population in the USA. In addition to genetics and life style changes, the important role of metabolic programming effects in the etiology of the obesity epidemic is being increasingly recognized. Although the role of a compromised intrauterine environment in fetal metabolic programming is well documented to contribute to the development of adult-onset diseases, vulnerability in the immediate postnatal period to similar conditions has also been shown. Metabolic programming effects induced by altered nutritional experiences in the immediate postnatal period can give rise to long-term consequences in the context of the current obesity epidemic.

In vitro hyperglycemia or a diabetic intrauterine environment reduces neonatal endothelial colony-forming cell numbers and function

OBJECTIVE

Emerging data demonstrate that maternal diabetes has long-term health consequences for offspring, including the development of hypertension. In adults, circulating endothelial progenitor cells (EPCs) participate in vascular repair, and EPC numbers and function inversely correlate with the risk of developing vascular disease. Therefore, our objectives were to determine whether hyperglycemia or exposure to a diabetic intrauterine environment alters EPC function.

RESEARCH DESIGN AND METHODS

We used well-established clonogenic endothelial colony-forming cell (ECFC) assays and murine transplantation experiments to examine human vasculogenesis.

RESULTS

Both in vitro hyperglycemia and a diabetic intrauterine environment reduced ECFC colony formation, self-renewal capacity, and capillary-like tube formation in matrigel. This cellular phenotype was linked to premature senescence and reduced proliferation. Further, cord blood ECFCs from diabetic pregnancies formed fewer chimeric vessels de novo after transplantation into immunodeficient mice compared with neonatal ECFCs harvested from uncomplicated pregnancies. CONCLUSIONS; Collectively, these data demonstrate that hyperglycemia or exposure to a diabetic intrauterine environment diminishes neonatal ECFC function both in vitro and in vivo, providing potential mechanistic insights into the long-term cardiovascular complications observed in newborns of diabetic pregnancies.

Are the available experimental models of type 2 diabetes appropriate for a gender perspective?

Several experimental models have so far been developed to improve our knowledge of the pathogenetic mechanisms of type 2 diabetes mellitus (T2D), to determine the possible pharmacological targets of this disease and to better evaluate diabetes-associated complications, e.g. the cardiovascular disease. In particular, the study of T2D gained the attention of several groups working with different animal species: rodents, cats or pigs, as well as other non-human primate species. Each of these species provided useful and different clues. However, T2D has to be considered as a gender-associated disease: sex differences play in fact a key role in the onset as well as in the progression of the disease and a higher mortality for cardiovascular diseases is detected in diabetic women with respect to men. The results obtained from all the available animal models appear to only partially address this issue so that the search for more precise information in this respect appears to be mandatory. In this review we summarize these concepts and literature in the field and propose a reappraisal of the various animal models for a study of T2D that would take into consideration a gender perspective.

Does the fetal genotype affect maternal physiology during pregnancy?

Conventional wisdom states that associations between fetal growth and diseases in pregnancy, such as pregnancy-induced hypertension (PIH) and gestational diabetes (GDM), result from effects of the mother's genotype or environment acting on her physiology which subsequently affect the fetus. However, recent evidence from human mothers carrying macrosomic offspring with Beckwith Wiedemann syndrome and pregnant mice carrying p57(kip2)-null offspring suggest that variation in the fetal genome can modify maternal physiology to increase fetal nutrient delivery and optimise growth. These are some of the first documented examples of such effects, whereby the genome of one individual directly affects the physiology of another related individual from the same species. We propose that this mechanism is involved in the aetiology of PIH and GDM.