Oral antihyperglycemic agents during pregnancy and lactation: a review

Neonatal metformin short exposure inhibits male reproductive dysfunction caused by a high-fat diet in adult rats

Metformin (Met) is widely used to control blood glucose levels and acts on various organs, including reproductive tissues, to improve reproductive and lifespan. This study evaluated whether neonatal Met exposure prevented male reproductive dysfunction caused by being overweight during adulthood. Randomized Wistar rat pups received an intraperitoneal injection from postnatal days (PNDs) 1 to 12of saline (Sal; 0.9% NaCl/day in 2mL/kg) or Met (100 mg/kg/day in 2 mL/kg). From PNDs 60 to 90, the animals received a regular (R; 4.5% fat; Sal R and Met R groups) or a high-fat (HF; 35% fat; Sal HF and Met HF groups) diet. At PND 90, all animals were euthanized to evaluate their biometric and reproductive parameters. The Sal and Met groups with R showed similar body weights, however, the HF diet increased the body weight in both groups. The Sal HF group showed testicular damage regarding in antioxidant status and inflammatory profile in the epididymal cauda. The HF diet reduced Leydig and Sertoli cells numbers, with lower sperm quality. The Met R animals showed positive reproductive programming, due to improved antioxidant defense, inflammatory biomarkers, and sperm morphology. Met HF prevented HF diet damage to reproductive organs and sperm morphology, but not to sperm motility. Early Met exposure positively affected the male reproductive system of adult rats, preventing reproductive HF disorders. STATEMENT OF NOVELTY AND SIGNIFICANCE: Metformin is used to control type 2 diabetes mellitus and can act to improve metabolism and lifespan. Metformin avoidance is recommended during pregnancy, but there is no information regarding its use when breastfeeding. For the first time, we showed in this current study that metformin positively acts in the male reproductive tissues and helps involved in later life. These data showed a better antioxidant defense and anti-inflammatory profile of Metformin animals than Saline animals and might directly improve reproductive organs morphophysiology and sperm morphology. Also, the neonatal Met application programs the male reproduction to counterbalance damages from an obesogenic environment in later life.

Dose-dependent effects of prenatal exposure of pioglitazone, the PPARγ agonist, on the hippocampus development and learning and memory performance of rat offspring

It is known that pioglitazone, defined as a PPARγ agonist, has neuron-protective properties in nervous system disorders. The aim of this study is to investigate the effects of pioglitazone administration at different doses during prenatal period on the neurons, glial cells and learning-memory levels in the hippocampus of rat offspring. Pregnant rats were divided into three groups; Low-Dose Pioglitazone (LDP), High-Dose Pioglitazone (HDP) and control (C) (n = 3). Pregnant rats in the HDP and LDP groups were given pioglitazone at 30 mg/kg and 5 mg/kg doses, respectively, by gavage once a day during their pregnancy. No procedure was applied to the rats in the control group. Morris water tank test was applied to offspring obtained from postnatal 24th to 28th day. The offspring were sacrificed on the 29th postal day and their brain tissues removed. Stereological, histopathological and immunohistochemical techniques were used to analyze brain tissues. As a result of the analysis, it was observed that there were delays in learning and memory, the number of pyramidal neurons decreased, and the density of cells stained with glial fibrillar acidic protein (GFAP) positive increased in the HDP group compared to the other groups (p < 0.05). No significant difference was found between the LDP and control groups in terms of these parameters (p > 0.05). Our results showed that pioglitazone administered in the prenatal period had an effect on the hippocampus development and learning and memory performance of rats, depending on the dose.

DNA damage and its cellular response in mother and fetus exposed to hyperglycemic environment

The increased production of reactive oxygen species (ROS) plays a key role in pathogenesis of diabetic complications. ROS are generated by exogenous and endogenous factors such as during hyperglycemia. When ROS production exceeds the detoxification and scavenging capacity of the cell, oxidative stress ensues. Oxidative stress induces DNA damage and when DNA damage exceeds the cellular capacity to repair it, the accumulation of errors can overwhelm the cell resulting in cell death or fixation of genome mutations that can be transmitted to future cell generations. These mutations can lead to and/or play a role in cancer development. This review aims at (i) understanding the types and consequences of DNA damage during hyperglycemic pregnancy; (ii) identifying the biological role of DNA repair during pregnancy, and (iii) proposing clinical interventions to maintain genome integrity. While hyperglycemia can damage the maternal genetic material, the impact of hyperglycemia on fetal cells is still unclear. DNA repair mechanisms may be important to prevent the deleterious effects of hyperglycemia both in mother and in fetus DNA and, as such, prevent the development of diseases in adulthood. Hence, in clinical practice, maternal glycemic control may represent an important point of intervention to prevent the deleterious effects of maternal hyperglycemia to DNA.

The protective effect of glibenclamide in a model of hemorrhagic encephalopathy of prematurity

We studied a model of hemorrhagic encephalopathy of prematurity (EP) that closely recapitulates findings in humans with hemorrhagic EP. This model involves tandem insults of 20 min intrauterine ischemia (IUI) plus an episode of elevated venous pressure induced by intraperitoneal glycerol on post-natal day (P) 0. We examined Sur1 expression, which is upregulated after focal ischemia but has not been studied after brief global ischemia including IUI. We found that 20 min IUI resulted in robust upregulation of Sur1 in periventricular microvessels and tissues. We studied tandem insult pups from untreated or vehicle-treated dams (TI-CTR), and tandem insult pups from dams administered a low-dose, non-hypoglycemogenic infusion of the Sur1 blocker, glibenclamide, for 1 week after IUI (TI-GLIB). Compared to pups from the TI-CTR group, pups from the TI-GLIB group had significantly fewer and less severe hemorrhages on P1, performed significantly better on the beam walk and accelerating Rotarod on P35 and in tests of thigmotaxis and rapid learning on P35–49, and had significantly greater body and brain weights at P52. We conclude that low-dose glibenclamide administered to the mother at the end of pregnancy protects pups subjected to IUI from post-natal events of elevated venous pressure and its consequences.

Gestational diabetes mellitus: Non-insulin management

Gestational diabetes mellitus (GDM) complicates a substantial number of pregnancies. There is consensus that in patients of GDM, excellent blood glucose control, with diet and, when necessary, oral hypoglycemics and insulin results in improved perinatal outcomes, and appreciably reduces the probability of serious neonatal morbidity compared with routine prenatal care. Goals of metabolic management of a pregnancy complicated with GDM have to balance the needs of a healthy pregnancy with the requirements to control glucose level. Medical nutrition therapy is the cornerstone of therapy for women with GDM. Surveillance with daily self-monitoring of blood glucose has been found to help guide management in a much better way than blood glucose checking in labs and clinics, which tends to be less frequent. Historically, insulin has been the therapeutic agent of choice for controlling hyperglycemia in pregnant women. However, difficulty in medication administration with multiple daily injections, potential for hypoglycemia, and increase in appetite and weight make this therapeutic option cumbersome for many pregnant patients. Use of oral hypogycemic agents (OHAs) in pregnancy has opened new vistas for GDM management. At present, there is a growing acceptance of glyburide (glibenclamide) use as the primary therapy for GDM. Glyburide and metformin have been found to be safe, effective and economical for the treatment of gestational diabetes. Insulin, however, still has an important role to play in GDM. GDM is a window of opportunity, which needs to be seized, for prevention of diabetes in future life. Goal of our educational programs should be not only to improve pregnancy outcomes but also to promote healthy lifestyle changes for the mother that will last long after delivery. Team effort on part of obstetricians and endocrinologists is required to make "the diabetes capital of the world" into "the diabetes care capital of the world".

Probiotics decreased the bioavailability of the bile acid analog, monoketocholic acid, when coadministered with gliclazide, in healthy but not diabetic rats

In recent studies we showed that gliclazide has no hypoglycemic effect on type 1 diabetic (T1D) rats while MKC does, and their combination exerted a better hypoglycemic effect than MKC alone. We also showed that the most hypoglycemic effect was noticed when T1D rats were treated with probiotics then gavaged with MKC + gliclazide (blood glucose decreased from 24 ± 3 to 10 ± 2 mmol/l). The aim of this study is to investigate the influence of probiotics on MKC pharmacokinetics when coadministered with gliclazide, in T1D rats. 80 male Wistar rats (weight 350 ± 50 g) were randomly allocated into 8 groups (10 rats/group), 4 of which were injected with alloxan (30 mg/kg) to induce T1D. Group 1 was healthy and group 2 was diabetic. Groups 3 (healthy) and 4 (diabetic) were gavaged with probiotics (75 mg/kg) every 12 h for 3 days and 12 h later all groups received a single oral dose of MKC + gliclazide (4 and 20 mg/kg respectively). The remaining 4 groups were treated in the same way but administered MKC + gliclazide via the i.v. route. Blood samples collected from T1D rats prior to MKC + gliclazide revealed that probiotic treatment alone reduced blood glucose levels twofold. When coadministered with gliclazide, the bioavailability of MKC was reduced in healthy rats treated with probiotics but remained the same in diabetic pretreated rats. The decrease in MKC bioavailability, when administered with gliclazide, caused by probiotic treatment in healthy but not diabetic rats suggests that probiotic treatment induced MKC metabolism or impaired its absorption, only in healthy animals. The different MKC bioavailability in healthy and diabetic rats could be explained by different induction of presystemic elimination of MKC in the gut by probiotic treatment.

Type 2 diabetes in pregnancy: a wolf in sheep's clothing

Type 2 diabetes is now the most common form of pregestational diabetes. Recent data suggest that pregnancies complicated by type 2 diabetes are associated with unacceptably high fetal mortality and morbidity, at an incidence comparable to pregnancies complicated by type 1 diabetes. This review examines the literature on type 2 diabetes in pregnancy, including its incidence and potential complications. There is a need to highlight the dangers of type 2 diabetes in pregnancy to both patients and medical practitioners. Peri-conception care needs to improve to achieve better pregnancy outcomes.

Recent advances in the treatment of gestational diabetes

Despite four decades of research there is a lack of international consensus on the screening, diagnosis, treatment and follow up of gestational diabetes mellitus (GDM). Currently, GDM is managed by diet modification, exercise and exogenous human insulin. During the last decade, several insulin analogues and oral antihyperglycaemic drugs have revolutionised the management of diabetes mellitus in non-pregnant women. Most of these recent drugs still remain investigational in GDM due to concerns about their safety in pregnancy. This review will focus primarily on the pharmacological treatment of GDM. It will objectively assess the value of these exciting new drugs in pregnancy as they could potentially benefit every woman with GDM.

The role of sulphonylureas in the management of type 2 diabetes mellitus

The sulphonylureas act by triggering insulin release from the pancreatic beta cell. A specific site on the adenosine triphosphate (ATP)-sensitive potassium channels is occupied by sulphonylureas leading to closure of the potassium channels and subsequent opening of calcium channels. This results in exocytosis of insulin. The meglitinides are not sulphonylureas but also occupy the sulphonylurea receptor unit coupled to the ATP-sensitive potassium channel. Glibenclamide (glyburide), gliclazide, glipizide and glimepiride are the primary sulphonylureas in current clinical use for type 2 diabetes mellitus. Glibenclamide has a higher frequency of hypoglycaemia than the other agents. With long-term use, there is a progressive decrease in the effectiveness of sulphonylureas. This loss of effect is the result of a reduction in insulin-producing capacity by the pancreatic beta cell and is also seen with other antihyperglycaemic agents. The major adverse effect of sulphonylureas is hypoglycaemia. There is a theoretical concern that sulphonylureas may affect cardiac potassium channels resulting in a diminished response to ischaemia. There are now many choices for initial therapy of type 2 diabetes in addition to sulphonylureas. Metformin and thiazolidinediones affect insulin sensitivity by independent mechanisms. Disaccharidase inhibitors reduce rapid carbohydrate absorption. No single agent appears capable of achieving target glucose levels in the majority of patients with type 2 diabetes. Combinations of agents are successful in lowering glycosylated haemoglobin levels more than with a single agent. Sulphonylureas are particularly beneficial when combined with agents such as metformin that decrease insulin resistance. Sulphonylureas can also be given with a basal insulin injection to provide enhanced endogenous insulin secretion after meals. Sulphonylureas will continue to be used both primarily and as part of combined therapy for most patients with type 2 diabetes.

Drugs that affect the fetus and newborn infant via the placenta or breast milk

In general, drugs that are taken by a mother during pregnancy or after birth may be transferred to the fetus or the infant (through breast milk). Many factors are involved that determine the amount of drugs that are transferred and their potential effects on the fetus or infant. A careful assessment of the risk versus benefit is necessary and should be individualized. In the breastfed infant, many measures can be undertaken further so that the amount of drug transferred to the infant is minimized.