Erythrocyte indicators of oxidative stress in gestational diabetes

Inflammation and Oxidative Stress Induced by Obesity, Gestational Diabetes, and Preeclampsia in Pregnancy: Role of High-Density Lipoproteins as Vectors for Bioactive Compounds

Inflammation and oxidative stress are essential components in a myriad of pathogenic entities that lead to metabolic and chronic diseases. Moreover, inflammation in its different phases is necessary for the initiation and maintenance of a healthy pregnancy. Therefore, an equilibrium between a necessary/pathologic level of inflammation and oxidative stress during pregnancy is needed to avoid disease development. High-density lipoproteins (HDL) are important for a healthy pregnancy and a good neonatal outcome. Their role in fetal development during challenging situations is vital for maintaining the equilibrium. However, in certain conditions, such as obesity, diabetes, and other cardiovascular diseases, it has been observed that HDL loses its protective properties, becoming dysfunctional. Bioactive compounds have been widely studied as mediators of inflammation and oxidative stress in different diseases, but their mechanisms of action are still unknown. Nonetheless, these agents, which are obtained from functional foods, increase the concentration of HDL, TRC, and antioxidant activity. Therefore, this review first summarizes several mechanisms of HDL participation in the equilibrium between inflammation and oxidative stress. Second, it gives an insight into how HDL may act as a vector for bioactive compounds. Third, it describes the relationships between the inflammation process in pregnancy and HDL activity. Consequently, different databases were used, including MEDLINE, PubMed, and Scopus, where scientific articles published in the English language up to 2023 were identified.

Dysregulation of Mir-193B and Mir-376A as a Biomarker of Prediabetes in Offspring of Gestational Diabetic Mice

Gestational diabetes mellitus (GDM) is a type of diabetes initiated during pregnancy and is characterized by maternal hyperglycemia that induces complications in mothers and children. In the current study, we used a GDM mouse model (through i.p. injection of a single dose of streptozocin, STZ, 60 mg/kg/bw) to investigate the biochemical and immunological changes in the blood and brain of diabetic mothers and their offspring relative to their appropriate controls. In addition, we estimated the expression levels of a set of microRNAs (miRNAs) to link between the dysregulation in the levels of miRNAs and the exposure to oxidative stress during embryonic development, as well as metabolic changes that occur after birth and during puberty in offspring (5-weeks-old). At the biochemical level, newborn pups appeared mostly to suffer from the same oxidative stress conditions of their mothers as shown by the significant increase in nitric oxide (NO) and malondialdehyde (MDA) in blood and brain of diabetic mothers and their pups. However, the 5-week-old offspring showed a significant increase in proinflammatory cytokines, IL-1β, IL-6, and TNF-α, and based on their blood glucose levels, could be considered as prediabetic (with glucose mean value of 165 mg/dl). In the meantime, the tested miRNAs, especially miR-15b, miR-146a, and miR-138 showed mostly similar expression levels in diabetic mothers and newborn pups. In this regard, miR-15a and -15b, miR-146a, and miR-138 are downregulated in diabetic mothers and their newborn pups relative to their appropriate controls. However, in offspring of diabetic mothers at puberty age, these miRNAs displayed different expression levels relative to mothers and control offspring. Interestingly, miR-193 and miR-763 expression levels were significantly lower in diabetic mothers but upregulated in their 5-week-old offspring, suggesting that miR-193 and miR-763 could be used as biomarkers to differentiate between prediabetes and diabetes.

Effect of gestational diabetes mellitus on testis and pancreatic tissues of male offspring

The purpose of this study was to determine the effect of gestational diabetes mellitus (GDM) on some reproductive characteristics, testicular and pancreatic oxidative status and pancreatic endocrine receptor densities of male offspring at post-pubertal stage. A total of 36 1-day-old Wistar Albino male offspring including 12 pups of nontreated mothers (control group), 14 pups of 40 mg/kg STZ-injected mothers (STZ-40 group) and 10 pups of 60 mg/kg STZ-injected mothers (STZ-60 group) were used. The offspring were euthanised on post-natal day 60, their blood, reproductive organs and pancreatic tissues were obtained and examined. When compared with the control group, there was a significant decrease in body and absolute reproductive organ weights, serum testosterone level, testicular and pancreatic catalase activities, pancreatic glutathione level, epididymal sperm concentration of both STZ-40 and STZ-60 groups as well as in testicular glutathione level of only STZ-60 group. Significant increases were determined in testicular and pancreatic malondialdehyde level and glutathione peroxidase activity in both groups and in fasting serum glucose of only STZ-60 group in comparison with the control group. Although some histopathological damages were observed in testes of both STZ-40 and STZ-60 groups, there were no detectable differences between the groups in density of insulin, glucagon and somatostatin receptors in pancreas. In conclusion, GDM has negative effects on reproductive efficiency and testicular-pancreatic tissue oxidant/antioxidant balance of male offspring at post-pubertal stage.

Serum Malondialdehyde Concentration and Glutathione Peroxidase Activity in a Longitudinal Study of Gestational Diabetes

Aims

The main goal of this study was to evaluate the presence of oxidative damage and to quantify its level in gestational diabetes.

Methods

Thirty-six healthy women and thirty-six women with gestational diabetes were studied in the three trimesters of pregnancy regarding their levels of oxidative stress markers. These women were diagnosed with diabetes in the second trimester of pregnancy. Blood glucose levels after 100g glucose tolerance test were higher than 190, 165 or 145 mg/dl, 1, 2 or 3 hours after glucose intake.

Results

The group of women with gestational diabetes had higher serum malondialdehyde levels, with significant differences between groups in the first and second trimester. The mean values of serum glutathione peroxidase activity in the diabetic women were significantly lower in the first trimester. In the group of women with gestational diabetes there was a negative linear correlation between serum malondialdehyde concentration and glutathione peroxidase activity in the second and third trimester.

Conclusions

In this observational and longitudinal study in pregnant women, the alterations attributable to oxidative stress were present before the biochemical detection of the HbA1c increase. Usual recommendations once GD is detected (adequate metabolic control, as well as any other normally proposed to these patients) lowered the concentration of malondialdehyde at the end of pregnancy to the same levels of the healthy controls. Serum glutathione peroxidase activity in women with gestational diabetes increased during the gestational period.

The reduction of birth weight by fine particulate matter and its modification by maternal and neighbourhood-level factors: a multilevel analysis in British Columbia, Canada

BACKGROUND

The purpose of this research was to determine the relationship between modeled particulate matter (PM2.5) exposure and birth weight, including the potential modification by maternal risk factors and indicators of socioeconomic status (SES).

METHODS

Birth records from 2001 to 2006 (N = 231,929) were linked to modeled PM2.5 data from a national land-use regression model along with neighbourhood-level SES and socio-demographic data using 6-digit residential postal codes. Multilevel random coefficient models were used to estimate the effects of PM2.5, SES and other individual and neighbourhood-level covariates on continuous birth weight and test interactions. Gestational age was modeled with a random slope to assess potential neighbourhood-level differences of its effect on birth weight and whether any between-neighbourhood variability can be explained by cross-level interactions.

RESULTS

Models adjusted for individual and neighbourhood-level covariates showed a significant non-linear negative association between PM2.5 and birth weight explaining 8.5 % of the between-neighbourhood differences in mean birth weight. A significant interaction between SES and PM2.5 was observed, revealing a more pronounced negative effect of PM2.5 on birth weight in lower SES neighbourhoods. Further positive and negative modification of the PM2.5 effect was observed with maternal smoking, maternal age, gestational diabetes, and suspected maternal drug or alcohol use. The random intercept variance indicating between-neighbourhood birth weight differences was reduced by 75 % in the final model, while the random slope variance for between-neighbourhood gestational age effects remained virtually unchanged.

CONCLUSION

We provide evidence that neighbourhood-level SES variables and PM2.5 have both independent and interacting associations with birth weight, and together account for 49 % of the between-neighbourhood differences in birth weight. Evidence of effect modification of PM2.5 on birth weight across various maternal and neighbourhood-level factors suggests that certain sub-populations may be more or less vulnerable to relatively low doses PM2.5 exposure.

Oxidative stress and antioxidant status in women with gestational diabetes mellitus diagnosed by IADPSG criteria

AIMS

The relationship between oxidative stress and the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria diagnosed gestational diabetes mellitus GDM isn't well known. Our aim is to evaluate the oxidative stress in women diagnosed by the IADPSG criteria versus the American Diabetes Association (ADA) criteria in China.

METHODS

Malondialdehyde (MDA), 8-isoprostane (8IsoP), xanthine oxidize (XO), lipid peroxides (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (TAC), vitamin C (Vc) and vitamins E (Ve) were determined in maternal and cord plasma and placenta of 68 pregnant women. Among these, 28 were diagnosed with GDM while the other 40 were controls.

RESULTS

The maternal, cord and placental MDA, XO and 8IsoP levels were significantly higher while SOD and TAC levels were significantly lower in GDM women by either criterion (P < 0.05). XO and 8IsoP levels were higher in ADA group than IADPSG only group while TAC levels significant lower (P < 0.05). Cord MDA, cord and placental XO, and maternal and cord 8IsoP showed significant positive relationship with HbA1c values (P < 0.05). Cord XO levels increased (P < 0.05) while maternal and placental SOD levels decreased (P < 0.05) in women who received cesarean section compared with those delivered normally. Increased XO levels and decreased Ve levels in cord plasma were also found in macrosomia (P < 0.05).

CONCLUSIONS

Oxidative stress is present in women diagnosed by IADPSG but to a lesser degree than by ADA. All these women should be monitored and perhaps antioxidant supplemented.

Reduced fetal telomere length in gestational diabetes

Gestational diabetes mellitus (GDM) is an important complication of pregnancy that poses significant threats to women and their offspring. Telomere length shortens as cellular damage increases and is associated with metabolic diseases. Telomere length in fetal leucocytes was determined in 82 infants of women with GDM (N = 82) and 65 normal pregnant women (N = 65). Women with preeclampsia (N = 45) and gestational hypertension (N = 23) were also studied. In the GDM group, telomere length was significantly shorter than normal pregnancy (P = 0.028), but there were no significant differences in fetal telomere length between preeclampsia and normal pregnancy (P = 0.841) and between gestational hypertension and normal pregnancy (P = 0.561). Regression analysis revealed that fetal telomere length was significantly associated with intrauterine exposure to GDM (P = 0.027 after adjustment for maternal age, gestational age at delivery, birth weight and fetal gender). Shortened telomere length may increase the risk of metabolic diseases in adulthood of GDM offspring.

Maternal supplementation of diabetic mice with thymoquinone protects their offspring from abnormal obesity and diabetes by modulating their lipid profile and free radical production and restoring lymphocyte proliferation via PI3K/AKT signaling

Background

Epidemiological studies have shown that the offspring of mothers who experience diabetes mellitus during pregnancy are seven times more likely to develop health complications than the offspring of mothers who do not suffer from diabetes during pregnancy. The present study was designed to investigate whether supplementation of streptozotocin (STZ)-induced diabetic pregnant mice with thymoquinone (TQ) during pregnancy and lactation improves the risk of developing diabetic complications acquired by their offspring.

Methods

Three groups of pregnant female mice were used: non-diabetic control dams (CD), diabetic dams (DD), and diabetic dams supplemented with TQ (DD + TQ) during pregnancy and lactation (n = 10 female mice in each group).

Results

Our data demonstrated a marked decrease in the number of neonates born to DD, and these neonates showed a marked increase in their mean body weight (macrosomic pups) compared to those born to CD and DD + TQ. The induction of diabetes during pregnancy and lactation resulted in macrosomic pups with several postpartum complications, such as a marked increase in their levels of blood glucose, free radicals, plasma pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), and lipids, and a tendency toward abnormal obesity compared to the offspring of CD. By contrast, macrosomic offspring born to DD exhibited a marked reduction in plasma cytokine levels (IL-2, -4 and -7), an obvious reduction in the number of circulating lymphocytes, decreased proliferation of superantigen (SEB)-stimulated lymphocytes and aberrant AKT phosphorylation. Interestingly, the supplementation of DD with TQ during pregnancy and lactation had an obvious and significant effect on the number and mean body weight of neonates. Furthermore, TQ significantly restored the levels of blood glucose, insulin, free radicals, plasma cytokines, and lipids as well as lymphocyte proliferation in the offspring.

Conclusions

Our data suggest that the nutritional supplementation of DD with the natural antioxidant TQ during pregnancy and lactation protects their offspring from developing diabetic complications and preserves an efficient lymphocyte immune response later in life.

Maternal and fetal indicators of oxidative stress in various obstetric complications

The present study demonstrates the incidence of increased lipid peroxidation and protein oxidation in both maternal and fetal erythrocytes as markers of oxygen radical activity in different complications of pregnancy. In fetuses born after premature rupture of membranes, lipid peroxidation was significantly elevated as indicated by increased malondialdehyde levels (p<0.05) as compared to controls. Proteolytic activity in the erythrocytes of mothers in this group was also significantly high (p<0.01). In patients delivered by lower segment cesarian section, lipid peroxidation and proteolytic activity in maternal erythrocytes were significantly high (p<0.05 and p<0.001 respectively). In patients with prolonged second stage of labour, lipid peroxidation and proteolytic activity in maternal erythrocytes was significantly higher than in controls (p<0.001 and p<0.05 respectively). In this group, endogenous protein damage due to oxidative stress was significantly high both in the mother and the fetus (p<0.001 and p<0.05 respectively).

Maternal and fetal indicators of oxidative stress during intrauterine growth retardation (IUGR)

The present study demonstrates the possibility of increased lipid peroxidation and protein oxidation in both maternal and fetal erythrocytes as markers of oxygen radical activity during intrauterine growth retardation. The erythrocyte MDA levels were significantly elevated in mothers of IUGR babies when compared to controls (p<0.01). The endogenous protein damage due to oxidative stress was significantly higher in IUGR mothers when compared to controls (p<0.05). Similarly the proteolytic activity in erythrocyte lysates against oxidatively damaged hemoglobin was significantly increased in mothers of IUGR babies compared to controls (p<0.001).In fetuses born with IUGR, both lipid peroxidation and proteolytic activity were significantly increased when compared to normal newborns (p<0.01).The result of this study indicates that oxidative stress was induced both in IUGR babies and their mothers which is manifested as increased lipid peroxidation and protein oxidant damage.

Zinc supplementation prevents cardiomyocyte apoptosis and congenital heart defects in embryos of diabetic mice

Oxidative stress induced by maternal diabetes plays an important role in the development of cardiac malformations. Zinc (Zn) supplementation of animals and humans has been shown to ameliorate oxidative stress induced by diabetic cardiomyopathy. However, the role of Zn in the prevention of oxidative stress induced by diabetic cardiac embryopathy remains unknown. We analyzed the preventive role of Zn in diabetic cardiac embryopathy by both in vivo and in vitro studies. In vivo study revealed a significant decrease in lipid peroxidation, superoxide ions, and oxidized glutathione and an increase in reduced glutathione, nitric oxide, and superoxide dismutase in the developing heart at embryonic days (E) 13.5 and 15.5 in the Zn-supplemented diabetic group when compared to the diabetic group. In addition, significantly down-regulated protein and mRNA expression of metallothionein (MT) in the developing heart of embryos from diabetic group was rescued by Zn supplement. Further, the nuclear microscopy results showed that trace elements such as phosphorus, calcium, and Zn levels were significantly increased (P<0.001), whereas the iron level was significantly decreased (P<0.05) in the developing heart of embryos from the Zn-supplemented diabetic group. In vitro study showed a significant increase in cellular apoptosis and the generation of reactive oxygen species (ROS) in H9c2 (rat embryonic cardiomyoblast) cells exposed to high glucose concentrations. Supplementation with Zn significantly decreased apoptosis and reduced the levels of ROS. In summary, oxidative stress induced by maternal diabetes could play a role in the development and progression of cardiac embryopathy, and Zn supplementation could be a potential therapy for diabetic cardiac embryopathy.

The role of oxidative stress in the pathophysiology of gestational diabetes mellitus

Normal human pregnancy is considered a state of enhanced oxidative stress. In pregnancy, it plays important roles in embryo development, implantation, placental development and function, fetal development, and labor. However, pathologic pregnancies, including gestational diabetes mellitus (GDM), are associated with a heightened level of oxidative stress, owing to both overproduction of free radicals and/or a defect in the antioxidant defenses. This has important implications on the mother, placental function, and fetal well-being. Animal models of diabetes have confirmed the important role of oxidative stress in the etiology of congenital malformations; the relative immaturity of the antioxidant system facilitates the exposure of embryos and fetuses to the damaging effects of oxidative stress. Of note, there are only a few clinical studies evaluating the potential beneficial effects of antioxidants in GDM. Thus, whether or not increased antioxidant intake can reduce the complications of GDM in both mother and fetus needs to be explored. This review provides an overview and updated data on our current understanding of the complications associated with oxidative changes in GDM.

Umbilical cord oxidative stress in infants of diabetic mothers and its relation to maternal hyperglycemia

AIMS

There is growing body of evidence that oxidative stress plays an important role in the pathogenesis of diabetes mellitus (DM) and in development of maternal and fetal complications of diabetic pregnancies. The aim of the present study was to investigate total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in infants of diabetic mothers (IDM) and to reveal the influence of maternal hyperglycemia on these parameters.

METHODS

A prospective controlled study was conducted between March 2010 and November 2010. Umbilical cord blood was taken from IDM and controls for TAC and TOS measurement, and OSI was calculated. IDM were divided into two groups, either of mothers treated with insulin during pregnancy or of those treated with a carbohydrate-restricted diet.

RESULTS

Thirty-six IDM and 14 infants born to non-diabetic mothers were enrolled. Infants of insulin-treated mothers (group 1) and infants of mothers managed with a carbohydrate-restricted diet (group 2) had significantly higher TOS (p < 0.001 and p = 0.001, respectively) and OSI (p < 0.001 and p = 0.001, respectively) levels compared to controls. However, TAC levels were similar in all three groups. Maternal HbA(1c) values were correlated to TOS (p < 0.001, r = 0.694) and OSI (p < 0.001, r = 0.683).

CONCLUSIONS

Oxidative stress is increased in IDM, and a significant relation exists between the degree of maternal hyperglycemia in pregnancy and oxidative stress in the newborn at birth.

The incidence of placental abnormalities, maternal and cord plasma malondialdehyde and vascular endothelial growth factor levels in women with gestational diabetes mellitus and nondiabetic controls

BACKGROUND/AIMS

To evaluate the incidence of placental abnormalities, cord plasma erythropoietin (EPO) levels and nucleated red blood cell (NRBC) counts, maternal and cord plasma malondialdehyde (MDA) and vascular endothelial growth factor (VEGF) levels in women with gestational diabetes mellitus (GDM) and nondiabetic controls.

METHODS

Twenty-two women with GDM, diagnosed according to the current criteria of the American Diabetes Association, were compared with 22 controls. Maternal and cord blood and placental samples were obtained from all pregnant women. Cord plasma EPO levels and NRBC counts, maternal and cord plasma MDA and VEGF levels were determined. Placental tissues were examined histologically.

RESULTS

Maternal and cord plasma levels of MDA and cord plasma EPO levels and NRBC counts were significantly higher in GDM pregnancies (p < 0.01). The presence of villous immaturity, chorangiosis and ischemia were significantly increased in the placentas of women with GDM (p < 0.05). The maternal and cord plasma levels of MDA increased (p = 0.007 and p = 0.001, respectively), whereas VEGF decreased (p = 0.046 and p = 0.001, respectively) with the presence of villous immaturity.

CONCLUSION

The complex process of villous development and maturity might be influenced by the maternal and fetal oxidative and angiogenetic milieu. The placenta that shows abnormalities in angiogenesis and maturation may lead to fetal hypoxia and compromise.

Evaluation of serum selenium levels in Turkish women with gestational diabetes mellitus, glucose intolerants, and normal controls

The aim of the study was to investigate the association between serum selenium levels in patients with gestational diabetes mellitus (GDM) and glucose intolerants and compare them with those of glucose-tolerant pregnant women. This cross-sectional study was prospectively performed in a total of 178 pregnant women undergoing a 50-g oral glucose tolerance test between 24 and 28 weeks of gestation who were grouped according to their status of glucose tolerance as with gestational diabetes (group A, abnormal 1- and 3-h glucose tolerance test; n = 30), glucose intolerant (group B, abnormal 1-h but normal 3-h glucose tolerance test; n = 47), or normal controls (group C, normal 1-h glucose test; n = 101). Serum selenium levels were measured with a graphite furnace atomic absorption spectrophotometer using a matrix modifier. Median maternal age and gestational age at the time of diagnosis in group A (gestational age = 24.8 [24-27]), group B (gestational age = 24.7 [24-27]), and group C (gestational age = 25 [24-28]) did not differ. Patients with gestational diabetes mellitus and those with glucose intolerants had lower selenium level than that of the normal pregnant women (P < 0.001). There was a significant inverse correlation between selenium and blood glucose level, and also selenium supplementation might prove beneficial on patients with GDM and prevent or retard them from secondary complications of diabetes.

Role of lipids and fatty acids in macrosomic offspring of diabetic pregnancy

Diabetic pregnancy frequently results in macrosomia or fetal obesity. It seems that the anomalies in carbohydrate and lipid metabolism in macrosomic infants of diabetic mothers are due to maternal hyperglycemia, which leads to fetal hyperinsulinemia. We have developed a rat model of macrosomic offspring and assessed the onset of obesity in these animals. The macrosomic offspring born to diabetic mothers are prone to the development of glucose intolerance and obesity as a function of age. It seems that in utero programming during diabetic pregnancy creates a "metabolic memory" which is responsible for the development of obesity in macrosomic offspring. We have demonstrated that the metabolism of lipids, and altered anti-oxidant status and immune system are implicated in the etiopathology of obesity in these animals. We have reported beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) in obese animals, born to diabetic dams.

Could antioxidant supplementation prevent pre-eclampsia?

Pre-eclampsia is a disorder characterised by pregnancy-induced hypertension and new-onset proteinuria occurring in the second half of pregnancy. Worldwide, approximately 2–3% of all pregnant women develop pre-eclampsia. The condition is a major cause of maternal and fetal morbidity and mortality. Abnormal placentation is an important predisposing factor for pre-eclampsia, while endothelial activation appears to be central to the pathophysiological changes, possibly indicative of a two-stage disorder characterised by reduced placental perfusion and a maternal syndrome. There is increasing evidence that pre-eclampsia is associated with both increased oxidative stress and reduced antioxidant defences, which has led to the hypothesis that oxidative stress may play an important role in the pathogenesis of pre-eclampsia, perhaps acting as the link in a two-stage model of pre-eclampsia. In support of this hypothesis a small, but important, preliminary study has shown a highly significant (P= 0.02) reduction in the incidence of pre-eclampsia in women at risk who were taking a supplement of vitamins C and E from mid-pregnancy. Furthermore, these findings support the hypothesis that oxidative stress is at least partly responsible for the endothelial dysfunction of pre-eclampsia. Several larger multicentre trials are currently underway to evaluate the efficacy, safety and cost benefits of antioxidant supplementation during pregnancy for the prevention of pre-eclampsia in both low- and high-risk women, including women with diabetes. The results of these trials are awaited with interest.

N-3 Fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring

OBJECTIVE

We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring.

DESIGN

Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days.

MEASUREMENTS

Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitamin A, E and C concentrations, and (iii) antioxidant enzymes activities in erythrocytes. The plasma lipid concentrations and fatty acid composition were also determined.

RESULTS

Diabetes increased plasma triglyceride and cholesterol concentrations, whereas macrosomia was associated with enhanced plasma cholesterol and triglyceride levels, which diminished by feeding n-3 PUFA diet. N-3 PUFA diet also reduced increased plasma TBARS and corrected the decreased ORAC values in diabetic rats and their macrosomic offspring. EPAX diet increased the diminished vitamin A levels in diabetic mothers and vitamin C concentrations in macrosomic pups. Also, this diet improved the decreased erythrocyte superoxide dismutase and glutathione peroxidase activities in diabetic and macrosomic animals.

CONCLUSION

Diabetes and macrosomia were associated with altered lipid metabolism, antioxidant enzyme activities and vitamin concentrations. N-3 PUFA diet improved hyperlipidemia and restored antioxidant status in diabetic dams and MAC offspring.

Oxidative stress: changes in pregnancy and with gestational diabetes mellitus

Pregnancy is susceptible to oxidative stress and antioxidant defenses can be altered in response to elevated levels of oxidative stress. Limited data in gestational diabetes mellitus (GDM) suggest that products of lipid peroxidation may be increased and antioxidant enzyme activities decreased, although the results have been inconsistent. As in type 2 diabetes mellitus (T2DM), glycemic levels in patients with GDM correlate with concentrations of lipid peroxides. The effects of supplementation with antioxidants or antioxidant-rich food in T2DM are controversial. Whether or not increased antioxidant intake can reduce the complications of GDM in both mother and fetus has not been explored.

Gestational hyperglycemia, zinc, selenium, and antioxidant vitamins

OBJECTIVE

Lower levels of selenium and vitamin E have been described in gestational diabetes, a condition similar to type 2 diabetes, but few data are available about zinc (known to be associated with diabetes) and gestational hyperglycemia. This study evaluated the dietary intake of antioxidant vitamins, zinc, selenium, and serum levels of zinc and selenium in women with gestational hyperglycemia and normoglycemia.

METHODS

A food-frequency questionnaire was administered to 504 pregnant women (210 with hyperglycemia and 294 with normoglycemia). Serum levels of zinc and selenium were analyzed during pregnancy in a second cohort of 71 hyperglycemic and 123 normoglycemic women, with a mean age and body mass index similar to those in the first cohort.

RESULTS

Dietary intakes of zinc and selenium were significantly lower in hyperglycemic patients. In multiple logistic regression analysis, intakes were negatively associated with gestational hyperglycemia (odds ratios of 0.89 for zinc and 0.97 for selenium) after multiple adjustments. There were no significant differences in vitamin intakes. In the second cohort of 194 patients, serum levels of zinc and selenium were significantly lower in patients who had impaired glucose tolerance and negatively associated with gestational hyperglycemia in a multiple logistic regression model (odds ratios of 0.93 for serum zinc and 0.92 for serum selenium).

CONCLUSIONS

Our data suggested a significant inverse association of dietary intakes and serum levels of zinc and selenium with gestational hyperglycemia. If future studies confirm these results, it might be a useful interventional approach to appropriate dietary counseling in order to evaluate the possible decrease in gestational metabolic abnormalities and their adverse consequences.

Altered placental oxidative stress status in gestational diabetes mellitus

Oxidative stress has been clearly linked to type 2 diabetes mellitus, however, limited data are available on the involvement of oxidative stress in gestational diabetes mellitus (GDM), a disease of similar pathophysiology. The aim of this study was to investigate the status of placental oxidative stress in healthy pregnant women and women with GDM. The hypothesis to be tested was that tissue markers of oxidative stress are significantly increased in GDM compared to normal placental tissues. Markers of oxidative stress measured were the release of 8-isoprostane (8-epi-prostaglandin F(2alpha)) from human term placental explants (n=11), the activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase (n=10), and protein carbonyl content (n=12). Placental release of 8-isoprostane was 2-fold greater from women with GDM (P<0.001) compared to healthy pregnant women. Superoxide dismutase activity and protein carbonyl content were elevated in placentae obtained from women with GDM (P<0.04 and P<0.004 respectively), whilst there was no significant difference in the activity of glutathione peroxidase. These data demonstrate the presence of oxidative stress in the placenta from women with GDM, in addition to the induction of a key antioxidant, collectively indicating a state of existing oxidative stress in this condition.

Oxidative and antioxidative status in pregnant women with either gestational or type 1 diabetes

OBJECTIVES

To evaluate oxidative and antioxidative status in pregnant diabetic women between 26 and 32 weeks of gestation.

DESIGN AND METHODS

Free and total malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPX), and vitamins A and E were determined in plasma and erythrocytes of 54 pregnant women. Among these, 27 were diabetics with either gestational diabetes mellitus (GDM), sub-group I, or previous insulin-dependent diabetes mellitus (type 1 diabetes), sub-group II. The other 27 patients were controls. Fasting plasma glucose and HbA(1c) levels were determined in all women.

RESULTS

HbA(1c) levels, plasma-, and erythrocyte-free MDA levels were significantly higher in all diabetic women and in both sub-groups than in controls. Plasma vitamin E and erythrocyte vitamin A levels were significantly lower in all diabetic women than in controls. Moreover, GPX and SOD activities were significantly reduced in all diabetic women, GPX in both sub-groups and SOD only in type 1 diabetes.

CONCLUSIONS

The increased oxidative stress we demonstrated in pregnant women with previous type 1 diabetes or with GDM should be monitored by strictly controlling blood glucose during pregnancy with stringent recommendations and perhaps antioxidant supplementation.

Iron and oxidative stress in pregnancy

Pregnancy, mostly because of the mitochondria-rich placenta, is a condition that favors oxidative stress. Transitional metals, especially iron, which is particularly abundant in the placenta, are important in the production of free radicals. Protective mechanisms against free radical generation and damage increase throughout pregnancy and protect the fetus, which, however, is subjected to a degree of oxidative stress. Oxidative stress peaks by the second trimester of pregnancy, ending what appears to be a vulnerable period for fetal health and gestational progress. Conditions restricted to pregnancy, such as gestational hypertension, insulin resistance and diabetes, exhibit exaggerated indications of free radical damage. Antioxidants as well as avoidance of iron excess ameliorate maternal and early fetal damage. In rats both iron deficiency and excess result in free radical mitochondrial damage. Estimates of gestational iron requirements and of the proportion of iron absorbed from different iron supplemental doses suggest that with present supplementation schemes the intestinal mucosal cells are constantly exposed to unabsorbed iron excess and oxidative stress. Unpublished work carried out in Mexico City with nonanemic women at midpregnancy indicates that 60 mg/d of iron increases the risk of hemoconcentration, low birth weight and premature birth and produces a progressive decline in plasma copper. These risks are not observed in women supplemented with 120 mg iron once or twice per week. Studies on the influence of iron supplementation schemes on oxidative stress are needed.

Maternal diabetes and its cell membrane abnormalities as they affect the foetus: implications for the mother and birth defects

My brief is to discuss maternal diabetes and its implications for birth defects. The perinatal mortality in Britain has fallen in the last 70 years from 60 per 1000 live births to less than 10. For the baby of the diabetic mother there has been a more dramatic decrease from 249 per thousand live births reported by Peel and Oakley in 1949 to approximately 30 in the Swedish cohort in 1993. However even in countries such as Sweden with one of the lowest figures there is still a three fold higher perinatal mortality for the baby of the diabetic mother compared with the background population. There has been a much less dramatic decrease in the incidence of congenital malformations. Peel and Oakley reported an incidence of 6.9% in 1949, and Hanson from Sweden in 1993 reported only a marginally lower incidence of 6.1%. Recent observations indicate that gestational diabetes (GDM) may be associated with increased incidence of fetal malformation and perinatal mortality. The most frequent and significant morbidity is fetal macrosomia, which in turn is associated with increased risk of birth injuries and asphyxia, (Persson and Hanson. 1998). Detection and definition of congenital malformation vary but in spite of this and the much better maternal diabetic control, congenital malformation today forms a major cause of the perinatal morbidity and mortality.

Low whole blood glutathione levels in pregnancies complicated by preeclampsia and diabetes

Nineteen pregnancies with preeclampsia, 16 with diabetic preeclampsia and 29 control pregnancies were analyzed with regards to maternal total glutathione. In preeclampsia, maternal total glutathione levels were lower than in normal pregnancy (P<0.001). Also, diabetic preeclamptics showed low total glutathione levels as compared to preeclampsia (P<0.05) and control (P<0.001). These findings indicate decreased detoxificating or free radical scavenging capacity in pregnancies complicated by preeclampsia and diabetes.

Adrenal vein thromboses in an infant of diabetic mother

Maternal diabetes is common condition complicating pregnancy and may have serious consequences for the offspring. We report on an infant of a mother with multisubstance abuse and poorly controlled type I diabetes with complications that include multifocal fetal myocardial infarcts, macrosomia, hypoxic encephalopathy and islet cell hyperplasia, and bilateral adrenal vein thromboses with necrosis, a relatively rare complication of maternal diabetes.

Diabetic embryopathy

The teratogenicity of human pregestational maternal diabetes mellitus (DM), classes B-T, is beyond any doubt and leads to a spectrum of malformations known as diabetic embryopathy (DE). Gestational DM (classes A1 and A2) is not an established teratogen yet. This is linked to its late diagnosis, usually only after the 20th week, and to the incomplete understanding of the pathogenesis of DE. Since class A-T DM affects approximately 5% of all pregnancies, intensive laboratory and clinical research continues to address the numerous aspects of DE. A review of this research during 1997 and 1998 is presented for the pediatrician in order to enhance the awareness of DE and its possible role in "idiopathic" malformations for children.