Lower Plasma Ghrelin Levels are Found in Women with Diabetes-Complicated Pregnancies

Biomarkers of Gestational Diabetes Mellitus: Mechanisms, Advances, and Clinical Utility

Gestational diabetes mellitus (GDM) continues to pose a significant challenge to maternal and fetal health, driving the need for advanced diagnostic and therapeutic strategies. Biomarker discovery has proven essential for early detection, mechanistic insights, and targeted interventions. This review provides an in-depth examination of biomarkers related to GDM, focusing on glucose metabolism, insulin resistance, inflammatory signaling, adipokines, oxidative stress markers, and genetic/epigenetic determinants. We also evaluate novel biomarkers emerging from omics technologies and their translational potential in clinical practice. Additionally, we explore the role of microRNAs and extracellular vesicles as emerging biomarkers that could offer new perspectives on GDM pathophysiology. Integration of these biomarkers into predictive models holds the potential to improve risk assessment and patient health outcomes.

Ghrelin regulates the endoplasmic reticulum stress signalling pathway in gestational diabetes mellitus

OBJECTIVE

We aimed to investigate the effects and mechanisms of the ghrelin-regulated endoplasmic reticulum stress (ERS) signalling pathway in gestational diabetes mellitus (GDM).

METHODS

Pregnant female C57BL/6 mice were randomly divided into a normal group, GDM group (high-fat diet + STZ), GDM + ghrelin group (acyl ghrelin), and GDM + ghrelin + ghrelin inhibitor group ([D-lys3]-GHRP-6). We measured body weight, the intake of water and food, glucose, cholesterol, triglyceride and fasting insulin levels in each group. HE staining was used to observe the morphological changes in the pancreas. The TUNEL method was used to detect the apoptosis rate of islet cells. qPCR and Western boltting were performed to detect the relative expression levels of PERK, ATF6, IREIα, GRP78, CHOP and caspase-12, which are related to the ERS signalling pathway in the pancreas. Then, NIT-1 cells were cultured to verify whether ghrelin regulates ERS under high-glucose or tunicamycin conditions.

RESULTS

Compared with the GDM group, the GDM + ghrelin group showed improved physical conditions and significantly decreased the fasting blood glucose, glucose tolerance, cholesterol, triglyceride and fasting insulin levels. Damaged islet areas were inhibited by ghrelin in the GDM group. The GDM + ghrelin group showed reduced β-cell apoptosis compared to the GDM and GDM + ghrelin + ghrelin inhibitor groups. ERS-associated factors (PERK, ATF6, IREIα, GRP78, CHOP and caspase-12) mRNA and protein levels were obviously lower in the GDM + ghrelin group than in the GDM group, while expression levels were restored in the inhibitor group. Ghrelin treatment improved the high-glucose or tunicamycin-induced apoptosis, increased insulin levels and upregulation of GRP78, CHOP and caspase-12 in NIT-1 cells.

CONCLUSION

Ghrelin suppressed ERS signalling and apoptosis in GDM mice and in NIT-1 cells. This study established a link between ghrelin and GDM, and the targeting of ERS with ghrelin represents a promising therapeutic strategy for GDM.

Gestational Diabetes Mellitus and Colostral Appetite-Regulating Adipokines

Gestational diabetes mellitus (GDM) is a complex metabolic disorder that has short- and long-term effects on maternal and offspring health. This study aimed to assess the impact of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment) on colostral appetite-regulating molecules. Colostrum samples were collected from hyperglycemic (N = 30) and normoglycemic (N = 21) mothers, and the concentrations of milk hormones were determined by immunoenzymatic assay. A difference was found for milk ghrelin, but not for molecules such as adiponectin, leptin, resistin, or IGF-I levels, in relation to maternal hyperglycemia. The colostral ghrelin in the GDM-G1 cohort (0.21 ng/mL) was significantly lower than for GDM-G2 (0.38 ng/mL) and non-GDM groups (0.36 ng/mL). However, colostral resistin was higher, but not significantly, for GDM-G1 (13.33 ng/mL) and GDM-G2 (12.81 ng/mL) cohorts than for normoglycemic mothers (7.89 ng/mL). The lack of difference in relation to hyperglycemia for milk leptin, adiponectin, leptin-adiponectin ratio, resistin, and IGF-I levels might be the outcome of effective treatment of GDM during pregnancy. The shift between ghrelin and other appetite-regulating hormones might translate into altered ability to regulate energy balance, affecting offspring's metabolic homeostasis.

The Mother-Child Dyad Adipokine Pattern: A Review of Current Knowledge

An important role in the network of interconnections between the mother and child is played by adipokines, which are adipose tissue hormones engaged in the regulation of metabolism. Alternations of maternal adipokines translate to the worsening of maternal insulin resistance as well as metabolic stress, altered placenta functions, and fetal development, which finally contribute to long-term metabolic unfavorable conditions. This paper is the first to summarize the current state of knowledge concerning the concentrations of individual adipokines in different biological fluids of maternal and cord plasma, newborn/infant plasma, milk, and the placenta, where it highlights the impact of adverse perinatal risk factors, including gestational diabetes mellitus, preeclampsia, intrauterine growth restriction, preterm delivery, and maternal obesity on the adipokine patterns in maternal-infant dyads. The importance of adipokine measurement and relationships in biological fluids during pregnancy and lactation is crucial for public health in the area of prevention of most diet-related metabolic diseases. The review highlights the huge knowledge gap in the field of hormones participating in the energy homeostasis and metabolic pathways during perinatal and postnatal periods in the mother-child dyad. An in-depth characterization is needed to confirm if the adverse outcomes of early developmental programming might be modulated via maternal lifestyle intervention.

Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant

The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.

State Scientific Institution “Center for Innovative Medical Technologies of the National Academy of Sciences of Ukraine”, Kyiv, Ukraine, Kosiukhno S, Usenko O, Shalimov National Institute of Surgery and Transplantology, Kyiv, Ukraine, Todurov I, State Scientific Institution “Center for Innovative Medical Technologies of the National Academy of Sciences of Ukraine”, Kyiv, Ukraine, Plehutsa О, State Scientific Institution “Center for Innovative Medical Technologies of the National Academy of Sciences of Ukraine”, Kyiv, Ukraine. CHANGE OF GHRELIN CONCENTRATION IN TYPE 2 DIABETES MELLITUS ASSOCIATED WITH OBESITY IN THE EARLY AND DELAYED PERIOD AFTER LAPAROSCOPIC SLEEVE GASTRECTOMY

Laparoscopic sleeve gastrectomy (LSG) is an effective method of treating obesity complicated by type 2 diabetes mellitus (T2DM). The performance of this metabolic surgical intervention involves removal fundus of the stomach, which in turn leads to an effect on the eating behavior of patients in the form of a decrease in appetite and loss of excess body weight with a parallel effect on the compensation of T2DM in the postoperative period, regardless of the loss of body weight. At present, mechanisms of T2DM compensation after LSG have not yet been clearly defined. The aim of our study was to study the effect of LSG on the dynamics of changes in the blood plasma ghrelin levels in patients with T2DM associated with obesity. The plasma ghrelin levels were assessed in the fasted state, 15, 30, 60, and 90 min after a standard breakfast carbohydrate preload, which included 125 ml of Nutricia Nutridrink, a balanced high-energy protein. The examination was carried out before the operation, on the 4th postoperative day and 3 months after the operation. 7 patients were diagnosed with T2DM for the first time, 3 had a history of diabetes for 2 years, one patient had a history of 3.5 years, and another had a history of 10 years. The average content of glycated hemoglobin before the operation was 7.7%, 3 months after LSG - 5.9%. The fasting ghrelin concentration before LSG performing was 6.8 ng/ml, on the 4th postoperative day – 4.6 ng/ml, and 3 months after the operation – 4.4 ng/ml (P = 0.001) in comparison with preoperative indicators). The peak insulin concentration was noted 30 min after the carbohydrate preload 3 months after the operation and was 175.1 μU/ml, and its fasting levels in the postoperative period reached a statistically significant difference compared to the preoperative values (30 μU/ml before surgery and 25.3 μU/ml 3 months after LSG). Thus, LSG leads to an early and significant suppression of fasting ghrelin secretion in patients with obesity-associated T2DM and likely to restore insulin secretion and/or reduce insulin resistance. Rapid postoperative improvement of carbohydrate metabolism components indicates the importance of the early reduction of ghrelin secretion in combination with the incretin effect of LSG in the implementation of the mechanisms of early compensation of T2DM and explains the metabolic activity of this operation and the significant role of the stomach in the regulation of glucose metabolism.

Effect of d-β-Hydroxybutyrate-(R)-1,3 Butanediol on Appetite Regulation in People with Prediabetes

SCOPE

The main aim of the present study is to study the effect of acute ketosis on parameters of appetite regulation in prediabetes.

METHODS AND RESULTS

This is a randomized controlled trial registered under ClinicalTrials.gov identifier NCT03889210. After an overnight fast, 18 adults with prediabetes are assigned to consume a ketone monoester (d-β-hydroxybutyrate-(R)-1,3 butanediol) drink and a placebo drink in cross-over fashion. Blood samples are collected every 30 min, from baseline to 150 min. Paired t test is used to compare the total area under the curve (AUC) for the changes in parameters of appetite regulation (acylated ghrelin, peptide YY [PYY], and hunger) following both drinks. Significant elevation in blood β-hydroxybutyrate from 0.2 to 3.5 mmol L^-1 (p < 0.001) is achieved within 30 min. Acute ketosis does not result in statistically significant differences in the AUCs for ghrelin, PYY, and hunger.

CONCLUSION

Acute ketosis consistently does not affect both objective and subjective parameters of appetite regulation in prediabetes.

The Impact of Gestational Diabetes Mellitus on Human Milk Metabolic Hormones: A Systematic Review

Gestational diabetes mellitus (GDM) is a common pregnancy complication with short- and long-term health consequences for the infant and mother. Breastfeeding is the recommended mode of feeding as it offers an opportunity to reduce the risk of GDM consequences, likely partially mediated through changes in human milk (HM) composition. This review systematically reviewed 12 identified studies that investigated the impact of GDM on concentrations of HM metabolic hormones. Meta-analysis was not possible due to significant heterogeneity in study designs and hormone measurement techniques. The risk of bias was assessed using the National Institute for Clinical Excellence (NICE) tool. The methodological qualities were medium in half of the studies, while 25% (3/12) of studies carried a high risk of bias. Significant relationships were reported between GDM and concentrations of HM ghrelin (3/3 studies), insulin (2/4), and adiponectin (2/6), which may play an integral role in infant growth and development. In conclusion, preliminary evidence suggests that GDM may alter HM metabolic hormone concentrations; however, these relationships may be limited to the early lactation stage.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

Changes in serum levels of calcitonin gene-related peptide, adiponectin, and ghrelin in pregnant women with gestational diabetes mellitus

AIM

This study was designed to determine serum calcitonin gene-related peptide (CGRP) levels and define whether serum CGRP concentration is associated with adiponectin and ghrelin in pregnant women with gestational diabetes mellitus (GDM).

STUDY DESIGN

Thirty-six pregnant women with GDM and 43 normal pregnant women without glucose intolerance were evaluated in this study. The serum concentration of CGRP, adiponectin, and ghrelin were measured in two groups at the last trimester of gestation.

MAIN FINDINGS

The serum CGRP level in the GDM group was significantly higher than the control group. Serum levels of adiponectin and ghrelin in the GDM group were significantly lower than in the control group. In pregnant women with GDM, there was a significant negative correlation between serum CGRP level and adiponectin level. However, the correlation between maternal serum CGRP levels and ghrelin levels was not significant.

CONCLUSION

Our investigation shows that serum CGRP level was significantly higher in pregnant women with GDM in comparison with the control group. These results suggest that CGRP may play a very important role in GDM pathogenesis.

Diabetes during Pregnancy: A Maternal Disease Complicating the Course of Pregnancy with Long-Term Deleterious Effects on the Offspring. A Clinical Review

In spite of the huge progress in the treatment of diabetes mellitus, we are still in the situation that both pregestational (PGDM) and gestational diabetes (GDM) impose an additional risk to the embryo, fetus, and course of pregnancy. PGDM may increase the rate of congenital malformations, especially cardiac, nervous system, musculoskeletal system, and limbs. PGDM may interfere with fetal growth, often causing macrosomia, but in the presence of severe maternal complications, especially nephropathy, it may inhibit fetal growth. PGDM may also induce a variety of perinatal complications such as stillbirth and perinatal death, cardiomyopathy, respiratory morbidity, and perinatal asphyxia. GDM that generally develops in the second half of pregnancy induces similar but generally less severe complications. Their severity is higher with earlier onset of GDM and inversely correlated with the degree of glycemic control. Early initiation of GDM might even cause some increase in the rate of congenital malformations. Both PGDM and GDM may cause various motor and behavioral neurodevelopmental problems, including an increased incidence of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Most complications are reduced in incidence and severity with the improvement in diabetic control. Mechanisms of diabetic-induced damage in pregnancy are related to maternal and fetal hyperglycemia, enhanced oxidative stress, epigenetic changes, and other, less defined, pathogenic mechanisms.

The effect of postpartum period back massage on serum ghrelin, leptin, adiponectin and visfatin levels

In addition to the initiation and continuity of lactation, hormones transferred from mother plasma to milk during breastfeeding are also important. The aim of this study was to determine the effect of back massage on maternal serum ghrelin, leptin, adiponectin and visfatin levels in women giving birth. A total of 60 mothers, participated in this experimental study. Massage was applied in the first 3-4 h after birth. Blood sample was taken in the postnatal routine. It was determined that the intervention group did not make a statistically significant difference in ghrelin (1.37 ± 0.7, 1.00 ± 0.2), leptin (0.76 ± 0.5, 0.70 ± 0.1), adiponectin (3.55 ± 0.8, 3.05 ± 0.5) levels compared to the control group (p > 0.05). However, visfatin (10.53 ± 2.4, 9.97 ± 2.0) levels were statistically higher than the control group (p < 0.05). Back massage was found to be beneficial in terms of increased growth factors in breast milk production and content.

Leu72Met polymorphism of GHRL gene decreases susceptibility to type 2 diabetes mellitus in a Mexican population

BACKGROUND

Type 2 diabetes mellitus (T2D) is the most frequent type of diabetes. It has a multifactorial etiology, affecting millions of people worldwide. Ghrelin gene (GHRL) encodes the ghrelin peptide, which promotes food intake, induces body weight and adipogenesis. Several single nucleotide polymorphisms (SNPs) in GHRL gene have been associated with metabolic diseases. A protective effect of the Leu72Met (rs696217) polymorphism has been described for T2D in some populations, but this effect seems to depend on the ethnicity of the patients studied.

METHODS

The aim of this study was to investigate the association between the GHRL Leu72Met (rs696217) SNP with the development of T2D and serum ghrelin levels in a Western Mexican population. We performed a case-control study in which we included 284 subjects (159 with previous T2D diagnosis and 125 control subjects (CS)). Leu72Met SNP was genotyped by using PCR-RFLPs technique. Serum ghrelin levels were measured using a commercial enzyme immunoassay. Genotypic and allelic distributions were compared using Chi square test. Student T-test and Mann-Whitney U test were used to compare quantitative variables. Odds ratio (OR) was used to evaluate the association between alleles or genotypes and T2D. Multiple and logistic regression models were performed for adjustment. A two-tailed p-value ≤0.05 was considered statistically significant.

RESULTS

Leu72Leu genotype was more frequent among T2D compared to CS (p < 0.05). After adjusting for age and body composition, there was a significant protective effect of the 72Met allele for T2D development (OR 0.40 IC 95% 0.23-0.70; p ≤ 0.001). Fasting serum ghrelin levels were lower in T2D than CS (p ≤ 0.0001) irrespective of age, body weight and BMI. No associations were found between genotypes and ghrelin serum levels in our population.

CONCLUSIONS

The GHRL 72Met allele decreases susceptibility for T2D development in a Western Mexican population. Serum ghrelin levels are lower in T2D independently of Leu72Met polymorphism genotype.

Ghrelin suppresses insulin secretion in human islets and type 2 diabetes patients have diminished islet ghrelin cell number and lower plasma ghrelin levels

It is not known how ghrelin affects insulin secretion in human islets from patients with type 2 diabetes (T2D) or whether islet ghrelin expression or circulating ghrelin levels are altered in T2D. Here we sought out to identify the effect of ghrelin on insulin secretion in human islets and the impact of T2D on circulating ghrelin levels and on islet ghrelin cells. The effect of ghrelin on insulin secretion was assessed in human T2D and non-T2D islets. Ghrelin expression was assessed with RNA-sequencing (n = 191) and immunohistochemistry (n = 21). Plasma ghrelin was measured with ELISA in 40 T2D and 40 non-T2D subjects. Ghrelin exerted a glucose-dependent insulin-suppressing effect in islets from both T2D and non-T2D donors. Compared with non-T2D donors, T2D donors had reduced ghrelin mRNA expression and 75% less islet ghrelin cells, and ghrelin mRNA expression correlated negatively with HbA1c. T2D subjects had 25% lower fasting plasma ghrelin levels than matched controls. Thus, ghrelin has direct insulin-suppressing effects in human islets and T2D patients have lower fasting ghrelin levels, likely as a result of reduced number of islet ghrelin cells. These findings support inhibition of ghrelin signaling as a potential therapeutic avenue for stimulation of insulin secretion in T2D patients.

Ghrelin in Serum and Urine of Post-Partum Women with Gestational Diabetes Mellitus

Women with a previous history of gestational diabetes mellitus (GDM) have a significantly increased risk of developing type 2 diabetes, obesity, and cardiovascular diseases in the future. The aim of the study was to evaluate ghrelin concentrations in serum and urine in the GDM group in the early post-partum period, with reference to laboratory results, body composition, and hydration status. The study subjects were divided into two groups, that is, 28 healthy controls and 26 patients with diagnosed GDM. The maternal body composition and hydration status were evaluated by the bioelectrical impedance analysis (BIA) method. The concentrations of ghrelin in the maternal serum and urine were determined via enzyme-linked immunosorbent assay (ELISA). The laboratory and BIA results of the mothers with GDM were different from those without GDM. Urine ghrelin positively correlated with serum ghrelin and high-density lipoprotein cholesterol (HDL) levels in healthy mothers. There were direct correlations between urine ghrelin and HDL as well as triglycerides levels in the GDM group. Neither the lean tissue index nor body cell mass index were related to the serum ghrelin concentrations in this group. Only the urine ghrelin of healthy mothers correlated with the fat tissue index. Our results draw attention to urine as an easily available and appropriable biological material for further studies.

Maternal serum uric acid levels in pregnancy and fetal growth

Objective: Studies of maternal serum uric acid (UA) in pregnancy focus primarily on high levels of UA, however, both low and high UA levels can be markers of oxidative stress, a biological state potentially linked to fetal growth. We therefore aimed to test whether low and high maternal serum UA levels during pregnancy are associated with atypical fetal growth (unusually small or large) measured as birthweight (BW) for gestational age.Methods: The Pregnancy Outcomes and Community Health Study enrolled 3019 pregnant women between their 16th-27th week of pregnancy from 52 clinics in five Michigan communities (1998-2004). Maternal UA levels were measured in blood collected at enrollment among a subcohort of 1291 participants. Infant BW and gestational age were used to calculate gestational age-specific BW Z-score. Infants were grouped as small (SGA = BW < 10th percentile), appropriate (AGA = BW 10th-90th percentile), or large (LGA) = BW > 90th percentile) for their gestational age. Analyses considered multiple potential confounders. Linear spline or multiple linear regression models were applied to evaluate the relationship between maternal UA levels and BW Z-score overall and within SGA, AGA, and LGA groups. Model robustness was tested through bootstrap, sensitivity analysis, and cross-validation techniques.Results: The relation between maternal UA levels and BW Z-score varied by infant group. Among SGA infants, the relation was nonlinear (J-shape): both extremes of UA had lower BW Z-score with a breakpoint of 0.267 mmol/L UA (adjusted regression coefficient β = 2.32, p = .01 for lower UA; adjusted β = -37.38, p < .01 for higher UA). Among AGA infants, there was no significant association, and among LGA infants, the relation was linear (adjusted β = 2.86, p = .03).Conclusions: Future research on maternal UA levels in pregnancy may benefit from considering both very low and high levels, and identifying in utero conditions associated with the two extremes.