Influence of postnatal overnutrition and pregnancy on non-insulin dependent diabetes induced in Wistar rats by neonatal streptozotocin

Wistar rats with non-insulin dependent diabetes induced by neonatal streptozotocin (STZ) administration were raised either in large or in small litters. The STZ-treated rats from small litters showed a higher body weight as well as increased blood glucose levels compared with vehicle- and STZ-treated rats reared in large nests at an age of 8 weeks. The higher body weight of these rats was maintained until an age of 15 weeks, whereas the basal blood glucose was normalized. However, both STZ-treated groups exhibited an impaired glucose tolerance. During pregnancy only the glucose tolerance of the STZ-treated animals from large nests was improved although not normalized. The STZ-treated rats from small nests failed to adapt to pregnancy because the blood glucose levels after glucose load were similar to values found in the virgin state. The body weight of pregnant STZ treated rats raised in small litters was significantly lower than in vehicle- or STZ-terated rats from large nests. The number of fetuses per litter was similar in all groups tested. Compared with the vehicle-treated rats from large litters the fetal body weight of STZ-treated rats from small nests was decreased and that of STZ rats raised in large litters was increased. These results suggest that the rats with the more impaired glucose tolerance produce growth-retarded pups and, conversely, rats with rather mild impairment have bigger fetuses than the vehicle-treated ones. In the present study we have examined for the first time the combined effects of postnatal overnutrition and pregnancy on glucose homeostasis of rats treated neonatally with STZ. Our data demonstrate that postnatal overnutrition is an aggravating factor in the development of a diabetic state in these rats, especially at times when the insulin requirement is higher such as puberty and pregnancy.

Transient diabetes insipidus in pregnancy--a consequence of enhanced placental clearance of arginine vasopressin

We report a patient who presented with transient diabetes insipidus in pregnancy on a background of previous postoperative diabetes insipidus following surgical excision of a prolactinoma. The patient illustrates how the complex changes in water homeostasis occurring during normal pregnancy may unmask latent diabetes insipidus. The major factors operating appear to be a physiological reduction in the thresholds for thirst and arginine vasopressin secretion coupled with a substantial increase in placental clearance of arginine vasopressin. Reversal of these changes after delivery results in normalization of the disordered water homeostasis, with consequent resolution of the diabetes insipidus.

Assessing the risk of gestational diabetes in twin gestation

This study examines the hypothesis that twin gestation is a risk factor for gestational diabetes. In a retrospective analysis, the incidence of gestational diabetes in twin and singleton pregnancies was determined in groups matched for maternal age, weight, and parity. One-hour oral glucose challenge tests (50 g) were used to screen 9185 pregnant women. Gestational diabetes was diagnosed when abnormal screens (> or = 130 mg/dL) were followed by two or more abnormal values on a 3-hour (100 g) glucose tolerance test using National Diabetes Data Group (NDDG) criteria. A twin gestation was identified in 1.5% (138/9185) of the pregnancies. Gestational diabetes was diagnosed in 5.8% (8/138) and 5.4% (439/9047) of the twin and singleton pregnancies, respectively. The incidence of gestational diabetes is similar for singleton and twin gestations.

Gestational diabetes and neonatal macrosomia in the polycystic ovary syndrome

Since patients with polycystic ovary syndrome (PCOS) commonly have insulin resistance, albeit with normal glucose tolerance, we evaluated glucose tolerance in PCOS patients exposed to the diabetogenic effect of pregnancy. The clinical material was obtained from two centers, in Springfield, Illinois (22 patients), and New York, New York (31 patients), and the results were compared with a control population with 2,306 consecutive general pregnancies. There were no differences between PCOS patients from the two centers in regard to age or ponderal index (P greater than .1). A review of the medical records showed that the incidence of gestational diabetes in the PCOS patients was 7.5%, similar (P greater than .1) to the 6.6% frequency of gestational diabetes in the controls. The overall incidence of neonatal macrosomia (birth weight greater than 4,000 g) was 7% (4 of 57) among infants born to PCOS women. That was similar to the 12.4% incidence of neonatal macrosomia among infants born to women with normal glucose tolerance and to the 14.5% incidence among infants born to women with gestational diabetes. Preexisting PCOS does not appear to increase the risk of developing gestational diabetes or neonatal macrosomia.

Insulin-dependent diabetes mellitus and immunogenetics: maternal and fetal considerations

It has now become clear that certain HLA antigens are associated with disease susceptibility more than any other genetic markers. Insulin-dependent diabetes mellitus (IDDM or type I) is an HLA-associated condition. Moreover, there is evidence to show that IDDM is a genetically programmed autoimmune disease. Studies of the HLA-DR region have shown a strong association with IDDM, with over 90 per cent of IDDM patients possessing DR3 and/or DR4. Although the HLA-DR region is a major component in the inherited disease susceptibility, it is not the only gene region involved. Recent studies demonstrated that HLA-DQ may be more closely linked to the disease locus than HLA-DR. Sequence analysis of the HLA-DQ3 gene products suggest that a single amino acid (aspartic acid) at position 57 is uniquely important for determining susceptibility or resistance to IDDM. Although there is a strong association of certain HLA loci with IDDM, it may not explain nor account for all the genetic susceptibility to the disease. It seems that 60 per cent of the genetic basis of IDDM is related to the HLA gene (chromosome 6) and another 40 per cent is non-HLA-associated (i.e., chromosomes 2, 7, 11, and 14). Even though great progress has been made in the understanding of the genetics of IDDM, the mode of inheritance of the disease remains controversial. The present review discusses various aspects of the autoimmune process believed to be involved in pancreatic beta cell destruction in individuals genetically susceptible to IDDM. The possible modes of inheritance and new data regarding estimated risks of transmitting the disease are presented.

Diet composition modifies embryotoxic effects induced by experimental diabetes in rats

Despite improvements in prenatal care, the incidence of congenital malformations in diabetic pregnancies is still 3-4 times higher than in normal pregnancies. These defects could be attributed to alterations of intrauterine environment due to disorder of the maternal metabolism. If this were true, the quality of food could play a role in diabetes-induced embryotoxicity. To check this hypothesis, female CD rats were made diabetic by injecting intravenously 50 mg/kg of streptozotocin 2 weeks before mating. From the first day of pregnancy they were divided into three groups and maintained on the following diets: (1) standard diet (Italiana Mangimi); (2) purified high protein diet (protein 55%, carbohydrates 25.5%, fat 7.5%, fiber 4.5%, ash 7.5%); (3) purified normoprotein diet (protein 19%, carbohydrates 62.5%, fat 7.5%, fiber 4%, ash 7%). Nondiabetic pregnant females fed with standard diet served as negative control. No significant differences were observed in blood glucose levels among the groups (range 410-500 mg/dl). The group fed on normoprotein diet showed at term of pregnancy: (1) higher rate of resorptions; (2) lower fetal weight; (3) higher frequency of major malformations than the groups fed standard and hyperproteic diets. Although we are not able at this time to discriminate between a protective effect of a diet with a high protein content and a disruptive effect of a diet containing high quantity of carbohydrates, the results of this trial support the hypothesis of a fuel-mediated teratogenesis in diabetic pregnancy.

Risk factors for gestational diabetes in black population

In a long-term longitudinal study of gestational diabetes mellitus in Black women, risk factors that were identified were age, obesity, a family history of diabetes, and the presence of hypertension. Poor predictors were a history of a previous large-for-date infant, parity, and age at first pregnancy. The prevalence of smooth muscle and nuclear autoantibodies was higher in gestational diabetic subjects. Gestational diabetic subjects who required insulin for glycemic control were more obese, had a lower frequency of the Bf-F phenotype and a higher frequency of the Bf-F1 phenotype, and had a lower frequency of the type 2 allele at the polymorphic locus adjacent to the insulin gene. Restriction-fragment-length polymorphisms flanking the insulin and apolipoprotein A-I and C-III genes, although not associated with gestational diabetes mellitus, may be associated with hyperlipidemia and subsequent atherosclerosis.

[The role of insulin in reproductive endocrinology and perinatal medicine]

Soskin, in his 1946 textbook, stated that insulin may be regarded as the dominant instrument in the symphony of endocrine action that results in normal carbohydrate metabolism. After almost half a century, great progress in the medical field has revealed that insulin plays more than even he described. Some aspects of important actions of insulin in our field as investigated in our laboratory are summarized below. 1. Role of insulin in reproductive endocrinology. (1) Correlation of insulin and testosterone in normal young women and patients with polycystic ovary syndrome (PCO). The sum of serum insulin values during 75g OGTT and serum testosterone values were positively correlated in normal women and patients with PCO. Glucose transport activities in isolated adipocytes from a typical PCO patient were decreased, but insulin binding activities were not, which indicates that insulin resistance in this patients is due to some post-receptor defects. (2) Insulin may be a risk factor of endometrial carcinoma. It is well-recognized that several diseases associate with hyperinsulinemia, such as obesity, PCO, diabetes mellitus, and hypertension are risk factors for endometrial carcinoma. The sum of the insulin values during OGTT was significantly higher in patients with endometrial carcinoma than in those without. 2. Role of insulin in perinatal medicine. (1) Increase in insulin secretion during pregnancy. High serum insulin concentration during OGTT, increased secretion of urinary C-peptide, and enhanced staining of insulin in B cells by the PAP method suggest that insulin secretion is enhanced during pregnancy. (2) Insulin resistance during pregnancy. Glucose utilization rate in both pregnant and progesterone-treated rats, as assessed by a glucose clamp technique, is significantly decreased as compared to nonpregnant rats. The technique of 2-deoxyglucose injection revealed that whole body insulin resistance is due to insulin resistance in individual insulin-sensitive tissues. The activities of 3-0-methyl-D-glucose transport in isolated rat skeletal muscle and human adipocytes were found to decrease during late pregnancy, but insulin binding activities were not. These results suggest that insulin resistance during pregnancy is due to some post-receptor mechanisms. (3) Physiological meaning of insulin in fetal growth.(ABSTRACT TRUNCATED AT 250 WORDS)

[Adrenal adenoma disclosing after delivery]

Pregnancy and Cushing's syndrome are seldom found together (40 cases in the literature), since hyperadrenocorticism is often responsible for anovulation by gonadotropin suppression. We report the case of a 25-year old para II woman whose pregnancy was complicated by diabetes and arterial hypertension at 31 weeks and who received the conventional treatments (special diet, insulin therapy, pindolol). Caesarean section, motivated by premature rupture of the membranes, was performed at 37 weeks, delivering a healthy infant. The diagnosis of hypercortisolism with low ACTH level was made post partum. An adrenal tumour (the most frequent cause of Cushing's syndrome occurring during pregnancy) was removed after pre-operative treatment with ketoconazole, and endocrine functions returned to normal.

How reliable is the fifty-gram, one-hour glucose screening test?

The Second International Workshop-Conference on Gestational Diabetes recommended screening all pregnant women with a 1-hour 50 gm oral glucose screening test, given without regard to time of day or time elapsed from the last meal. This study was designed to evaluate the reproducibility of that test, given under those clinical conditions. Thirty women with gestational diabetes and 80 control volunteers between 24 and 28 weeks' gestation were tested at the same time of day on two successive days. Of the 30 women with diabetes, three (10%) had glucose screening test results below the 135 mg/dl threshold on both days and 10 (33%) had results that straddled the threshold on successive days. Test results of 11 control women also straddled the threshold. Among these 21 women with results that straddled the threshold, there was no difference in mean glucose screening test results in diabetic women compared with nondiabetic ones. We conclude that, as currently recommended, the 1-hour glucose screening test is moderately reproducible. Reliance should not be placed on a single normal test result, particularly among patients with risk factors.

Factors predisposing to and outcome of gestational diabetes

Two hundred thirteen women with abnormal glucose tolerance tests (GTTs) were diagnosed over 9 years by a screening program involving the total antenatal population. Each subject was matched for age, parity, and ethnic group with a control. The gestational diabetics were subdivided into classes A1 or A2 based on the fasting plasma glucose value of their GTT: A1 when below 6.0 mmol/L (108 mg/dL) and A2 when 6.0 mmol/L (108 mg/dL) or higher. All received treatment with dietary advice and some with insulin. Birth weight was not related to maternal age or severity of diabetes, but was related to maternal obesity. However, neonatal morbidity indices such as admission to the special care baby unit for longer than 48 hours and polycythemia (hematocrit above 65%) were related significantly to the severity of the diabetes and not to maternal age or obesity.

The course and outcome of pregnancy after ovarian electrocautery in women with polycystic ovarian syndrome: the influence of body-weight

In 89 women with polycystic ovary syndrome (PCOS) who conceived after ovarian electrocautery, the pregnancy continued beyond 31 weeks in 62. In this group the frequency of pre-eclampsia and diabetes was 12.9 and 8.1% respectively. The increased frequencies were confined to overweight women. The frequency of major and minor malformations was 1% and 3.8% respectively. The rate of early miscarriage of the first pregnancy after ovarian electrocautery was 15%, and when later pregnancies were included the rate reduced to 10.3%. These data do not indicate any impact upon the course or outcome of pregnancy from the state of PCOS per se or the ovarian electrocautery that induced ovulation in this series.

Should all pregnant women be screened for gestational glucose intolerance?

Although gestational glucose intolerance is associated with the remote development of diabetes mellitus, the risk to the mother during the index pregnancy and the risk to her fetus remain uncertain. Nevertheless, universal screening for gestational glucose intolerance has many strong advocates. The scientific data supporting a universal screening programme--showing that treatment of gestational glucose intolerance does more good than harm--are limited. Until the evidence can be extended beyond that on infant birthweight, a more restrained approach than universal screening may be appropriate.

[Risk factors for changes in glucose metabolism in pregnancy]

Eighty women were studied having between 20-25 weeks of gestation at the National Institute of Perinatology. Weight and height were taken, and they were questioned about the risk factors (positive family history of diabetes mellitus, age, overweight and number of gestations). Two hours postprandial glucose tests were carried out using 100 g glucose load. Plasma glucose values were determinated according to the glucose-oxidase technique. Results showed that 36% of the population had at least glucose metabolism alteration (GMA) (glucose value 120 mg/dL). No significant difference was found for the weeks of gestation, nor number of gestations to define any cut point. On the other hand, significant values were found for the other risk factors, such as being 35 years or older, having 119% and 103% or more of pregestational and gestational weight for height respectively and having positive maternal family history of diabetes mellitus. The risk factor that is more capable to identify the subjects with an GMA is age 35 years followed by positive maternal family history of diabetes mellitus; when the combination of 4 risk factors is observed (gestas factor is excluded because it is a confusion element), the pregestational and pregestational and gestational weights work more like secondary supplementary risk factors than like determinants of the metabolic process. In view of these facts, it was found that positive maternal history of diabetes mellitus and the age less than or equal to 35 years individually and the presence of 3-4 risk factors can be considered high risk characteristics to develop GMA.