Prenatal Malnutrition-Induced Epigenetic Dysregulation as a Risk Factor for Type 2 Diabetes

Association between protein undernutrition and diabetes: Molecular implications in the reduction of insulin secretion

Undernutrition is still a recurring nutritional problem in low and middle-income countries. It is directly associated with the social and economic sphere, but it can also negatively impact the health of the population. In this sense, it is believed that undernourished individuals may be more susceptible to the development of non-communicable diseases, such as diabetes mellitus, throughout life. This hypothesis was postulated and confirmed until today by several studies that demonstrate that experimental models submitted to protein undernutrition present alterations in glycemic homeostasis linked, in part, to the reduction of insulin secretion. Therefore, understanding the changes that lead to a reduction in the secretion of this hormone is essential to prevent the development of diabetes in undernourished individuals. This narrative review aims to describe the main molecular changes already characterized in pancreatic β cells that will contribute to the reduction of insulin secretion in protein undernutrition. So, it will provide new perspectives and targets for postulation and action of therapeutic strategies to improve glycemic homeostasis during this nutritional deficiency.

The Natural Sweetener Stevia: An Updated Review on its Phytochemistry, Health Benefits, and Anti-diabetic Study

Stevia rebaudiana Bertoni is one of the significant high qualities of non-caloric sugar substitute sweetener plants against diabetes disease. Diabetes mellitus is one of the most common metabolic diseases caused by insulin secretion defects, insulin resistance in peripheral tissues, or both. Stevia rebaudiana is a perennial shrub of the Compositae family that is grown in several places around the world. It contains a plethora of different bioactive constituents which are responsible for several activities and sweetness. This sweetness is due to the presence of steviol glycosides which is 100-300 times sweeter than sucrose. Furthermore, stevia reduces oxidative stress, lowering the risk of diabetes. Its leaves have been used to control and treat diabetes and a variety of other metabolic diseases. This review summarizes the history, bioactive constituents of S. rebaudiana extract, pharmacology, anti-diabetic activity, and its application, especially in food supplements.

Epigenetic Network in Immunometabolic Disease

Although a large amount of data consistently shows that genes affect immunometabolic characteristics and outcomes, epigenetic mechanisms are also heavily implicated. Epigenetic changes, including DNA methylation, histone modification, and noncoding RNA, determine gene activity by altering the accessibility of chromatin to transcription factors. Various factors influence these alterations, including genetics, lifestyle, and environmental cues. Moreover, acquired epigenetic signals can be transmitted across generations, thus contributing to early disease traits in the offspring. A closer investigation is critical in this aspect as it can help to understand the underlying molecular mechanisms further and gain insights into potential therapeutic targets for preventing and treating diseases arising from immuno-metabolic dysregulation. In this review, the role of chromatin alterations in the transcriptional modulation of genes involved in insulin resistance, systemic inflammation, macrophage polarization, endothelial dysfunction, metabolic cardiomyopathy, and nonalcoholic fatty liver disease (NAFLD), is discussed. An overview of emerging chromatin-modifying drugs and the importance of the individual epigenetic profile for personalized therapeutic approaches in patients with immuno-metabolic disorders is also presented.

Comparison of Feto-maternal Outcomes Among Various BMI Groups As Per Asia Pacific Standards: An Observational Retrospective Comparative Study in a Private Tertiary Care Center in Delhi

Objective

To compare the feto-maternal outcomes among various BMI groups as per Asia Pacific Standards.

Method

This is a retrospective non-interventional observational study on 1396 antenatal women with singleton pregnancy. Their BMI based on pre-pregnancy weight was calculated and the women were divided into various groups as per Asia Pacific standards for BMI classification. Details of associated morbidities and delivery outcomes were noted in a pre-structured proforma and a comparison was made among the various groups using Chi square test. A p value of < 0.05 was taken as significant.

Results

Among the 1396 women under study, 10.6% were underweight, 36% had normal weight, 21% were overweight while 32% were obese or very obese. There was a significant association of low BMI with preterm labor (p value 0.03) and fetal growth restriction (p value < 0.01). Overweight and obese women were found to be more prone to hypertensive disorders of pregnancy (p value- 0.002), gestational diabetes (p value- 0.003) and overweight women were more prone to cholestasis of pregnancy (p value 0.03). The women with higher BMI had a significantly higher requirement of induction of labor (p value-0.0002). There was significant increased number of babies more than 90th percentile in overweight and obese women (p value 0.003). However, there was no change in Neonatal ICU admissions (p value 0.85) or neonatal mortality.

Conclusion

Asia Pacific references should be used for studies related to all studies on BMI and pregnancy. All women having BMI outside the normal BMI spectrum are at increased risk of antenatal and postnatal complications. Early identification of such women will enable careful evaluation and counseling to improve the reproductive outcome and feto-maternal health.

Towards a better understanding of diabetes mellitus using organoid models

Our understanding of diabetes mellitus has benefited from a combination of clinical investigations and work in model organisms and cell lines. Organoid models for a wide range of tissues are emerging as an additional tool enabling the study of diabetes mellitus. The applications for organoid models include studying human pancreatic cell development, pancreatic physiology, the response of target organs to pancreatic hormones and how glucose toxicity can affect tissues such as the blood vessels, retina, kidney and nerves. Organoids can be derived from human tissue cells or pluripotent stem cells and enable the production of human cell assemblies mimicking human organs. Many organ mimics relevant to diabetes mellitus are already available, but only a few relevant studies have been performed. We discuss the models that have been developed for the pancreas, liver, kidney, nerves and vasculature, how they complement other models, and their limitations. In addition, as diabetes mellitus is a multi-organ disease, we highlight how a merger between the organoid and bioengineering fields will provide integrative models.

Exposure in utero to adverse events and health late-in-life: Evidence from China

This paper estimates the effect of in utero exposure to adverse events on late life diabetes, cardiovascular disease risks and cognition deficiency. We merge data on the regional violence during the Cultural Revolution and the excessive death rates during the Chinese Great Famine with data from the China Health and Retirement Longitudinal Study survey. Results show that female babies who were exposed in utero to the famine have higher diabetes risks, while male babies who were exposed to the Cultural Revolution are shown to have lower cognitive abilities.

The incidence of insulin resistance based on indices calculated using the HOMA and Belfiore methods and its impact on the occurrence of metabolic complications in prepubertal children born small for gestational age

INTRODUCTION

Children born small for gestational age (SGA) are predisposed to obesity, insulin resistance (IR), and lipid disorders. The HOMA-IR index is commonly used to assess IR (IRIHOMA), calculated from fasting glucose and insulin. However, sometimes, during the oral glucose tolerance test (OGTT), elevated and prolonged postprandial insulin secretion is observed despite normal fasting insulin levels. IRIBelfiore is an IR index that analyses glucose and insulin levels during OGTT according to the method proposed by Belfiore.

THE AIM OF THE STUDY

was to assess the frequency of IR based on IRIHOMA and IRIBelfiore results in SGA children aged 6-8 years, after catch-up phenomenon, to determine the usefulness of IRIBelfiore in diagnosis of IR and in predicting future metabolic complications.

MATERIAL AND METHODS

In 129 SGA normal-height children, aged 6-8 years, height, weight, waist circumference, blood pressure, as well as lipids, IGF-1, cortisol, C-peptide, leptin, adiponectin, and resistin concentrations were measured. The glucose and insulin concentrations were evaluated at 0, 60, and 120 minutes of OGTT.

RESULTS

IRIHOMA was normal in all children, while elevated IRIBelfiore was found in 22.5% of them. Children with IR diagnosed by IRIBelfiore were taller, had higher blood pressure, higher leptin, and lower HDL-cholesterol concentrations.

CONCLUSIONS

It seems worth recommending IRIBelfiore derived from OGTT as a valuable diagnostic tool for identifying IR in SGA prepubertal children. Abnormal IRIBelfiore is related to higher blood pressure and lower HDL-cholesterol concentration in this group.

A Low Dose of Ouabain Alters the Metabolic Profile of Adult Rats Experiencing Intrauterine Growth Restriction in a Sex-Specific Manner

Intrauterine growth restriction (IUGR) increases the risk of type 2 diabetes mellitus (T2DM) and metabolic diseases. The pancreas of fetuses with IUGR is usually characterized by pancreatic dysplasia and reduced levels of insulin secretion caused by the diminished replication of β-cells. Previous studies showed that a low dose of ouabain could reduce the apoptosis of embryonic nephric cells during IUGR and partially restore the number of nephrons at birth. The rescued kidneys functioned well and decreased the prevalence of hypertension. Thus, we hypothesized that ouabain could rescue pancreatic development during IUGR and reduce the morbidity of T2DM and metabolic diseases. Maternal malnutrition was used to induce the IUGR model, and then a low dose of ouabain was administered to rats with IUGR during pregnancy. Throughout the experiment, we monitored the pattern of weight increase and evaluated the metabolic parameters in the offspring in different stages. Male, but not female, offspring in the IUGR group presented catch-up growth. Ouabain could benefit the impaired glucose tolerance of male offspring; however, this desirable effect was eliminated by aging. The insulin sensitivity was significantly impaired in male offspring with IUGR, but it was improved by ouabain, even during old age. However, in the female offspring, low birth weight appeared to be a beneficial factor even in old age; administering ouabain exacerbated these favorable effects. Our data suggested that IUGR influenced glucose metabolism in a sex-specific manner and ouabain treatment during pregnancy exerted strongly contrasting effects in male and female rats.

Therapeutic advances in overcoming intrauterine growth restriction induced metabolic syndrome

Intrauterine growth restriction (IUGR) remains a great public health challenge as it affects neonatal survival and influences their normal biological development and metabolism. Several clinical researches have revealed the occurrence of metabolic syndrome, such as insulin resistance, obesity, type 2 diabetes mellitus, oxidative stress, dyslipidemia, as direct results of IUGR. Therefore, it is essential to understand its underlying mechanism, impact and develop effective therapies. The purpose of this work is to review the current knowledge on IUGR induced metabolic syndrome and relevant therapies. Here in, we elaborate on the characteristics and causes of IUGR by pointing out recent research findings. Furthermore, we discuss the impact of IUGR on different organs of the body, followed by preclinical studies on IUGR using suitable animal models. Additionally, various metabolic disorders with their genetic implications, such as insulin resistance, type 2 diabetes mellitus, dyslipidemia, obesity are detailed. Finally, the current therapeutic options used in the treatment of IUGR are summarized with some prospective therapies highlighted.

Natural sweetener Stevia rebaudiana: Functionalities, health benefits and potential risks

Stevia rebaudiana is a South American plant, the cultivation of which is increasing worldwide due to its high content of sweet compounds. Stevia sweetness is mainly due to steviol glycosides, that are ~250-300 times sweeter than sucrose. Many studies have suggested the benefits of Stevia extract over sugar and artificial sweeteners, but it is still not a very popular sugar substitute. This review summarizes current data on the biological activities of S. rebaudiana extract and its individual glycosides, including anti-hypertensive, anti-obesity, anti-diabetic, antioxidant, anti-cancer, anti-inflammatory, and antimicrobial effects and improvement of kidney function. Possible side effects and toxicity of Stevia extract are also discussed.

Early AGEing and metabolic diseases: is perinatal exposure to glycotoxins programming for adult-life metabolic syndrome?

Perinatal early nutritional disorders are critical for the developmental origins of health and disease. Glycotoxins, or advanced glycation end-products, and their precursors such as the methylglyoxal, which are formed endogenously and commonly found in processed foods and infant formulas, may be associated with acute and long-term metabolic disorders. Besides general aspects of glycotoxins, such as their endogenous production, exogenous sources, and their role in the development of metabolic syndrome, we discuss in this review the sources of perinatal exposure to glycotoxins and their involvement in metabolic programming mechanisms. The role of perinatal glycotoxin exposure in the onset of insulin resistance, central nervous system development, cardiovascular diseases, and early aging also are discussed, as are possible interventions that may prevent or reduce such effects.

Toxicological risk factors in the burden of malnutrition: The case of nutrition (and risk) transition in sub-Saharan Africa

Toxicant exposures may worsen the micronutrient status, especially during the womb-to-childhood development, impairing organism programming and increasing the risk for health disorders in adulthood. Growing evidence calls for an integrated risk analysis of the interplay of environment, behavior and lifestyle, where a) imbalanced diet and micronutrient deficiencies may increase the vulnerability to toxicants and alter body defence systems and b) intake of antinutrients and contaminants may increase nutritional requirements. Such scenarios are especially evident in communities undergoing a fast nutrition transition, such as in many countries of sub-Saharan Africa. Specific challenges of toxicological risk analysis in sub-Saharan Africa still need a thorough assessment, including: rapid changes of lifestyle and consumers' preferences; dumping of foods and consumer' products; risk management under weak or non-existent awareness, legislation enforcement and infrastructures. The significant and growing literature from Africa-led scientific research should be used to build quality-controlled data repositories supporting regulatory top-down actions. Meanwhile, bottom-up actions (eg consumer's empowerment) could exploit social and economic drivers toward a qualified African presence in the global and local markets. A science-based combination of top-down and bottom-up actions on preventable toxicological risk factors will contribute fighting the new forms of malnutrition and prevent multi-factorial diseases. Exposures to toxicants should be included in the integrated approach proposed by WHO to address the urgent health challenge of simultaneously reduce the risk or burden of both malnutrition (ie deficiency of one or more essential nutrients) and overweight, obesity, and diet-related NCDs.

Developmental origins of type 2 diabetes: Focus on epigenetics

Traditionally, genetics and lifestyle are considered as main determinants of aging-associated pathological conditions. Accumulating evidence, however, suggests that risk of many age-related diseases is not only determined by genetic and adult lifestyle factors but also by factors acting during early development. Type 2 diabetes (T2D), an age-related disease generally manifested after the age of 40, is among such disorders. Since several age-related conditions, such as pro-inflammatory states, are characteristic of both T2D and aging, this disease is conceptualized by many authors as a kind of premature or accelerated aging. There is substantial evidence that intrauterine growth restriction (IUGR), induced by poor or unbalanced nutrient intake, exposure to xenobiotics, maternal substance abuse etc., may impair fetal development, thereby causing the fetal adipose tissue and pancreatic beta cell dysfunction. Consequently, persisting adaptive changes may occur in the glucose-insulin metabolism, including reduced capacity for insulin secretion and insulin resistance. These changes can lead to an improved ability to store fat, thus predisposing to T2D development in later life. The modulation of epigenetic regulation of gene expression likely plays a central role in linking the adverse environmental conditions early in life to the risk of T2D in adulthood. In animal models of IUGR, long-term persistent changes in both DNA methylation and expression of genes implicated in metabolic processes have been repeatedly reported. Findings from human studies confirming the role of epigenetic mechanisms in linking early-life adverse experiences to the risk for T2D in adult life are scarce compared to data from animal studies, mainly because of limited access to suitable biological samples. It is, however, convincing evidence that these mechanisms may also operate in human beings. In this review, theoretical models and research findings evidencing the role of developmental epigenetic variation in the pathogenesis of T2D are summarized and discussed.