Search Results (55)

Metabolic syndrome (MetS) increases the risk of cardiovascular disease development, with sex differences playing a significant role. AMP-activated protein kinase (AMPK), a key regulator of cellular energy homeostasis, becomes dysregulated in MetS, making it a potential therapeutic target. Therefore, we aimed to investigate the role of AMPK in the development of cardiovascular comorbidities in male and female rats with MetS. MetS was induced in young Wistar–Kyoto (WKY) rats through a high-fat diet (HFD; 10 weeks), and the function of AMPK was studied using Compound C (Cmpd C; 1.5 mg/kg, twice per week, during the last 4 weeks). An HFD induced MetS in males, but, in females, it did not affect body weight, blood pressure, or glycemia until AMPK inhibition occurred. Endothelial dysfunction, oxidative stress, and inflammation developed in both HFD male groups, while, in females, these arose only with AMPK inhibition. In both sexes, α1-AMPK activation decreased with eNOS and Nrf2 protein levels after HFD + Cmpd C treatment. Estradiol levels significantly dropped in HFD and Cmpd C females, whereas testosterone levels remained unchanged. Our results suggest that MetS and related cardiovascular comorbidities in males are driven by oxidative stress, inflammation, and endothelial dysfunction, with minimal additive effect of AMPK. In females, MetS arose only when inhibition of AMPK impaired estrogen signalling, emphasising their protective roles. Targeting AMPK-estrogen pathways may provide a therapeutic strategy, particularly for high-risk cardiovascular females and menopausal women. Full article

Background/Objectives: Argania spinosa L. Skeels is a Moroccan endemic plant widely used by the local population as folk medicine. This study aimed to investigate the effects of Argan fruit pulp on lipid metabolism disorders and liver steatosis in hypercaloric diet-fed mice. Methods: Animals were treated with the Argan fruit pulp extract and its fractions for 12 weeks at 100 and 200 mg Kg⁻¹ BW daily. The analysis was conducted on lipid levels in plasma, liver, feces, and bile as well as on glycemia. The liver glutathione, malondialdehyde, and antioxidant enzyme activities were assessed. The hepatic steatosis was evaluated by measuring transaminases and alkaline phosphatase activities and examining histological sections. The polyphenol profiles were determined using HPLC-DAD. Possible underlying mechanisms in the hypolipidemic and hepatoprotective activities were predicted by molecular docking. Results: The crude extract and its aqueous fraction (rich in protocatechuic and gallic acids) significantly restored plasma lipids and glucose levels. Indeed, total cholesterol level (TCHO) was decreased in the liver but increased in bile and feces. The treatment also reduced body weight and liver and adipose tissue mass and prevented liver steatosis. The ethyl acetate fraction exhibited no effect on lipid metabolism but significantly prevented liver oxidative stress. The crude extract and its fractions appear to be nontoxic (LD50 > 5000 mg Kg⁻¹) in mice. The phenolic acids demonstrated strong binding affinity to key targets involved in regulating lipid homeostasis, including ABCA-1, LXR, CYP7A1, HMH-CoA reductase, and PCSK-9. However, the identified flavonoids exhibited high affinities to targets involved in oxidative stress defense (SOD, CAT, and CYP2E1). Conclusions: The Argan fruit pulp, particularly its polyphenols, could be a promising natural approach for preventing cardio-metabolic diseases by improving lipid metabolism and reducing liver oxidative stress. Full article

Background: Advanced glycation end-products (AGEs) are linked to the development of oxidative stress, insulin resistance, and impaired insulin secretion. Adverse early life conditions, such as exposure to AGEs and their precursors, may lead offspring to the development of metabolic dysfunction in adulthood. Nonetheless, the early impact in offspring metabolism by maternal intake of AGEs precursors during lactation is not known. Objective: Investigate early life metabolism of the offspring whose breastfeeding dams were orally exposed to AGEs precursor. Methods: Breastfeeding Wistar rats were daily treated with the glycation precursor methylglyoxal (MG—60 mg/kg of bodyweight) by gavage or saline 0.9% control (CO) until weaning. In vivo glycemic homeostasis in male offspring was assessed, followed by euthanasia for tissue sample collection for ex vivo assessments. Results: At weaning, MG offspring presented decreased bodyweight (p < 0.05), perigonadal (p < 0.01) and retroperitoneal (p < 0.01) fat. MG offspring presented decreased glucose tolerance (p < 0.05), lower basal insulinemia (p < 0.001), reduced high-glucose static insulin secretion (p < 0.05), and reduced pancreatic islet area (p < 0.05). Accordingly, MG offspring pancreas showed lower GSH and SOD activity (p < 0.05; p < 0.001, respectively) and increased MPO (p < 0.05) activity. Conclusions: The consumption of AGE precursors by breastfeeding dams impaired offspring pancreatic function and glycemic homeostasis early in life. Full article

Adipokines related to gestational diabetes mellitus (GDM) are an emerging area of interest. The aim of this study was to evaluate the associations between GDM and adipokine levels in human milk. This was an observational cohort study targeting mothers with gestational diabetes, which evaluated the association of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment), with colostral adipokines involved in pro- and anti-inflammatory processes. Colostrum was collected from hyperglycemic (N = 34) and normoglycemic (N = 26) mothers, and adipokine levels were determined by immunoenzymatic assay. Among anti-inflammatory adipokines, only for irisin and vaspin, but not for obestatin and adropin, were significantly different levels noted between the GDM-G1, GDM-G2 and non-GDM cohorts. Colostrum of the GDM-G2 subgroup contained more vaspin (4.77 ng/mL) than that of normoglycemic mothers (3.12 ng/mL) and more irisin (26.95 μg/mL) than in the GDM-G1 subgroup (17.59 μg/mL). The levels of pro-inflammatory adipokines, namely, dermcidin, chemerin and visfatin, were at similar levels irrespective of maternal glycemia. Moreover, irisin showed a negative correlation with dermcidin in GDM-G2 and non-GDM cohorts. Associations were observed between colostral irisin and maternal preconception BMI, dermcidin and gestational age, and vaspin and maternal age. This study provides evidence that the way of restoring glucose homeostasis in pregnant women has an impact on the anti-inflammatory adipokines irisin and vaspin, but not on obestatin and adropin. GDM, regardless of severity, did not influence the colostral pro-inflammatory adipokines visfatin, chemerin and dermcidin. Full article

Introduction: Glucose homeostasis may be dependent on liver conditions and influence health-related markers and quality of life (QoL) objective measurements. This study aimed to analyze the interactions of glycemia with liver and health status in a prediabetic population. Subjects and methods: This study included 2220 overweight/obese prediabetics from the multinational PREVIEW project. Anthropometrics; clinical, metabolic and other health-related markers; and QoL variables were analyzed. Univariate and multilinear-adjusted regression models were run to explain the interrelationships and effect modification between glycemia, health-related QoL (applying SF-12) and metabolic/liver health (using the HSI, a putative marker of fatty liver). Results: Relevant age/sex interactions were found concerning the levels of insulin, HOMA-IR, C peptide and transaminases in this prediabetic population. Multivariate models identified age, sex, glucose, WC and QoL as important predictors of HSI variability (adj. R value = 0.1393, p < 0.001), whereas the QoL status was statistically related to age, sex, HOMA-IR and HSI (adj. R value = 0.1130, p < 0.001) in this glycemia-impaired group. Furthermore, the QoL values declined with increased HSI scores, where a significant interaction was found (p = 0.011) when the data were analyzed when comparing lower glycemia vs. higher glycemia in prediabetics. Indeed, an effect modification was featured depending on the glycemia levels concerning the QoL and HSI worsening. Conclusion: Glycemia associations with the QoL status and liver metabolism markers were evidenced, with clinical implications for diabetes and liver disease precision management given the modification of the QoL outcomes depending on the liver status and glycemia concentrations. Notably, independent associations of circulating glucose with age, sex, adiposity, inflammation and C peptide levels were found. Full article

Both perinatal malnutrition and elevated glucocorticoids are pivotal triggers of the growing global pandemic of metabolic diseases. Here, we studied the effects of metabolic stress responsiveness on glucose–insulin homeostasis and pancreatic-islet function in male Wistar offspring whose mothers underwent protein restriction during lactation. During the first two weeks after delivery, lactating dams were fed a low-protein (4% protein, LP group) or normal-protein diet (22.5% protein, NP group). At 90 days of age, male rat offspring were challenged with food deprivation (72 h of fasting), intracerebroventricular (icv) injection of dexamethasone (2 µL, 2.115 mmol/L) or chronic intraperitoneal injection of dexamethasone (1 mg/kg body weight/5 days). Body weight, food intake, intravenous glucose tolerance test (ivGTT) results, insulin secretion and biochemical parameters were assessed. LP rats did not display significant metabolic changes after long-term starvation (p > 0.05) or under the central effect of dexamethasone (p = 0.999). Chronic dexamethasone induced rapid hyperglycemia (~1.2-fold, p < 0.001) and hyperinsulinemia (NP: 65%; LP: 216%; p < 0.001), decreased insulin sensitivity (NP: ~2-fold; LP: ~4-fold; p < 0.001), reduced insulinemia (20%) and increased glycemia (35%) only in NP rats under ivGTT conditions (p < 0.001). Glucose and acetylcholine insulinotropic effects, as well as the muscarinic receptor antagonist response, were reduced by chronic dexamethasone only in pancreatic islets from NP rats (p < 0.05). The direct effect of dexamethasone on pancreatic islets reduced insulin secretion (NP: 60.2%, p < 0.001; LP: 33.8%, p < 0.001). Peripheral glucose–insulin dyshomeostasis and functional failure of pancreatic islets in LP rats, as evidenced by an impaired acute and chronic response to metabolic stress, may be due to excessive corticosterone action as a long-term consequence. Full article

Background/Objectives: Predicting post-COVID-19 diabetes is crucial for enhancing patient care and public health. This study investigates the role of metabolic factors in predicting the glycemic outcomes in patients recovering from moderate to severe COVID-19. Methods: We conducted a retrospective analysis of 135 patients without pre-existing diabetes, selected from a cohort of 1980 individuals hospitalized between January 2020 and December 2022. Metabolic parameters, including blood glucose, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), Triglyceride/Glucose (TyG) index, and high-sensitivity C-reactive protein (hs-CRP), were assessed at discharge and followed up after 4 months (T4) and 12 months (T12). Results: Statistical analysis revealed significant correlations of initial glycemia, HOMA-IR, and hs-CRP with the subsequent glycemic levels at T4 and T12. Multiple regression analysis confirmed that initial glycemia, HOMA-IR, and hs-CRP were strong predictors of elevated glycemia, while the TyG index did not show a significant predictive value. Conventional diabetes risk factors, including body mass index (BMI) and lipid profiles, showed low predictive power for post-COVID-19 glycemia. Conclusions: This research highlights the critical role of metabolic and inflammatory pathways in managing glycemic control in COVID-19 patients. Markers like blood glucose, HOMA-IR, and hs-CRP are significant predictors of blood glucose levels, while the TyG index appears less helpful in this context. Early, targeted interventions based on these markers can improve patient outcomes and reduce the risk of post-COVID-19 complications like diabetes. Full article

Type 2 diabetes mellitus has been referred to as being closely related to oxidative stress, which may affect brain functions and brain glucose metabolism due to its high metabolic activity and lipid-rich content. Na,K-ATPase is an essential enzyme maintaining intracellular homeostasis, with properties that can sensitively mirror various pathophysiological conditions such as diabetes. The goal of this study was to determine oxidative stress markers as well as Na,K-ATPase activities in the cerebellum of Zucker diabetic fatty (ZDF) rats depending on diabetes severity. The following groups of male rats were used: Wistar, ZDF Lean (fa/+), and ZDF (fa/fa) rats, arbitrarily divided according to glycemia into ZDF obese (ZO, less severe diabetes) and ZDF diabetic (ZOD, advanced diabetes) groups. In addition to basic biometry and biochemistry, oxidative stress markers were assessed in plasma and cerebellar tissues. The Na, K-ATPase enzyme activity was measured at varying ATP substrate concentrations. The results indicate significant differences in basic biometric and biochemical parameters within all the studied groups. Furthermore, oxidative damage was greater in the cerebellum of both ZDF (fa/fa) groups compared with the controls. Interestingly, Na,K-ATPase enzyme activity was highest to lowest in the following order: ZOD > ZO > Wistar > ZDF lean rats. In conclusion, an increase in systemic oxidative stress resulting from diabetic conditions has a significant impact on the cerebellar tissue independently of diabetes severity. The increased cerebellar Na,K-ATPase activity may reflect compensatory mechanisms in aged ZDF (fa/fa) animals, rather than indicating cerebellar neurodegeneration: a phenomenon that warrants further investigation. Full article

Obesity disrupts glucose metabolism, leading to insulin resistance (IR) and cardiometabolic diseases. Consumption of cow’s milk and other dairy products may influence glucose metabolism. Within the complex matrix of cow’s milk, various carbohydrates, lipids, and peptides act as bioactive molecules to alter human metabolism. Here, we summarize data from human studies and rodent experiments illustrating how these bioactive molecules regulate insulin and glucose homeostasis, supplemented with in vitro studies of the mechanisms behind their effects. Bioactive carbohydrates, including lactose, galactose, and oligosaccharides, generally reduce hyperglycemia, possibly by preventing gut microbiota dysbiosis. Milk-derived lipids of the milk fat globular membrane improve activation of insulin signaling pathways in animal trials but seem to have little impact on glycemia in human studies. However, other lipids produced by ruminants, including polar lipids, odd-chain, trans-, and branched-chain fatty acids, produce neutral or contradictory effects on glucose metabolism. Bioactive peptides derived from whey and casein may exert their effects both directly through their insulinotropic effects or renin-angiotensin-aldosterone system inhibition and indirectly by the regulation of incretin hormones. Overall, the results bolster many observational studies in humans and suggest that cow’s milk intake reduces the risk of, and can perhaps be used in treating, metabolic disorders. However, the mechanisms of action for most bioactive compounds in milk are still largely undiscovered. Full article

Maternal blood glucose regulation adaptation to pregnancy aims to support fetal growth but may also lead to the development of gestational diabetes mellitus, the most common pregnancy complication. MiRNAs are small RNA molecules secreted and stable in the blood, where they could have paracrine hormone-like functions (ribo-hormone) and regulate metabolic processes including fetal growth and glucose metabolism. The objective of this study was to identify plasmatic microRNA (miRNAs) measured during the first trimester of pregnancy that were associated with glucose levels during a 75 g oral glucose tolerance test (OGTT) at ~26 weeks of pregnancy. miRNAs were quantified using next-generation sequencing in 444 pregnant women and replicated in an independent cohort of 106 pregnant women. MiRNAs associated with glucose levels were identified with the DESeq2 package. We identified 24 miRNAs associated with fasting glycemia, of which 18 were common to both cohorts (q-value < 0.1). However, no association was found between miRNAs and 1 h or 2 h post OGTT glycemia. To conclude, we identified 18 miRNAs early in pregnancy that were associated with fasting blood glucose measured 3 months later. Our findings offer new insights into the mechanisms involved in fasting glucose homeostasis regulation in pregnancy, which is critical to understanding how gestational diabetes develops. Full article

Recent studies of Cardiovascular-Kidney-Metabolic Syndrome (CKMS) indicate that elevated concentrations of derivatives of phospholipids (ceramide, sphingosine), oxidized LDL, and lipoproteins (a, b) are toxic to kidney and heart function. Energy production for renal proximal tubule resorption of critical fuels and electrolytes is required for homeostasis. Cardiac energy for ventricular contraction/relaxation is preferentially supplied by long chain fatty acids. Metabolism of long chain fatty acids is accomplished within the cardiomyocyte cytoplasm and mitochondria by means of the glycolytic, tricarboxylic acid, and electron transport cycles. Toxic lipids and excessive lipid concentrations may inhibit cardiac function. Cardiac contraction requires calcium movement from the sarcoplasmic reticulum from a high to a low concentration at relatively low energy cost. Cardiac relaxation involves calcium return to the sarcoplasmic reticulum from a lower to a higher concentration and requires more energy consumption. Diastolic cardiac dysfunction occurs when cardiomyocyte energy conversion is inadequate. Diastolic dysfunction from diminished ATP availability occurs in the presence of inadequate blood pressure, glycemia, or lipid control and may lead to heart failure. Similar disruption of renal proximal tubular resorption of fuels/electrolytes has been found to be associated with phospholipid (sphingolipid) accumulation. Elevated concentrations of tissue oxidized low-density lipoprotein cholesterols are associated with loss of filtration efficiency at the level of the renal glomerular podocyte. Macroscopically excessive deposits of epicardial and intra-nephric adipose are associated with vascular pathology, fibrosis, and inhibition of essential functions in both heart and kidney. Chronic triglyceride accumulation is associated with fibrosis of the liver, cardiac and renal structures. Successful liver, kidney, or cardiac allograft of these vital organs does not eliminate the risk of lipid toxicity. Lipid lowering therapy may assist in protecting vital organ function before and after allograft transplantation. Full article

Introduction. Osteoporosis (OP) affects 30% of postmenopausal women, often complicated by metabolic syndrome (MetS) with a still controversial role. We aimed to characterize MetS and its components in relation to bone mineral density (BMD), body mass index (BMI), and insulin resistance. Methods. Patients (n = 188) underwent DEXA scans, spine X-rays, and metabolic and hormonal investigations, including bone biomarkers, muscular strength, and physical performance tests, while insulin resistance was evaluated by the Homeostasis Model Assessment (HOMA-IR). Results. Patients with a normal BMD or osteopenia (n = 68) and with OP (n = 120) displayed 51.5% and 30.8% of MetS, but without differences in insulin resistance. When BMD was studied as a function of the cumulative MetS criteria and centiles of BMI, lower levels of BMD were observed beyond an inflection point of 27.2 kg/m² for BMI, allowing for further stratification as lean and overweight/obese (OW/OB) subjects. In contrast with lean individuals (n = 74), in OW/OB patients (n = 46), MetS was associated with HbA1c (p < 0.0037, OR 9.6, 95% CI [1.64–55.6]) and insulin resistance (p < 0.0076, OR 6.7, 95% CI [1.49–30.8]) in the context where BMD values were lower than those predicted from BMI in non-OP subjects. In OP patients with fragility fractures (31% of MetS), glycemia also appeared to be the dominant factor for MetS (p < 0.0005, OR 4.1, 95% CI [1.63–10.39]). Conclusions. These data indicate a detrimental effect of insulin resistance in MetS on OP patients, while the prevalence of the syndrome depends on the proportion of obesity. These findings provide new insights into the pathogenic role of MetS and reveal the need to consider different strata of BMI and insulin resistance when studying postmenopausal OP. Full article

The consumption of non-sugar sweeteners (NSS) has increased during pregnancy. The European Food Safety Agency suggested that steviol glycosides, such as Rebaudioside A (RebA), the major sweetener component of stevia, are safe for humans up to a dose of 4 mg/kg body weight/day. However, the World Health Organization recommended in 2023 the restraint of using NSS, including stevia, at any life stage, highlighting the need to study NSS safety in early periods of development. We aimed to study the mitochondrial and cardiometabolic effects of long-term RebA consumption during the reproductive stage of the life cycle. Female rats were exposed to RebA (4 mg steviol equivalents/kg body weight/day) in the drinking water from 4 weeks before mating until weaning. Morphometry, food and water consumption, glucose and lipid homeostasis, heart structure, function, and mitochondrial function were assessed. RebA showed an atrophic effect in the heart, decreasing cardiomyocyte cross-sectional area and myocardial fibrosis without repercussions on cardiac function. Mitochondrial and myofilamentary functions were not altered. Glucose tolerance and insulin sensitivity were not affected, but fasting glycemia and total plasma cholesterol decreased. This work suggests that this RebA dose is safe for female consumption during the reproductive stage, from a cardiometabolic perspective. However, studies on the effects of RebA exposure on the offspring are mandatory. Full article

The BiP co-chaperone DNAJC3 protects cells during ER stress. In mice, the deficiency of DNAJC3 leads to beta-cell apoptosis and the gradual onset of hyperglycemia. In humans, biallelic DNAJC3 variants cause a multisystem disease, including early-onset diabetes mellitus. Recently, hyperinsulinemic hypoglycemia (HH) has been recognized as part of this syndrome. This report presents a case study of an individual with HH caused by DNAJC3 variants and provides an overview of the metabolic phenotype of individuals with HH and DNAJC3 variants. The study demonstrates that HH may be a primary symptom of DNAJC3 deficiency and can persist until adolescence. Additionally, glycemia and insulin release were analyzed in young DNACJ3 knockout (K.O.) mice, which are equivalent to human infants. In the youngest experimentally accessible age group of 4-week-old mice, the in vivo glycemic phenotype was already dominated by a reduced total insulin secretion capacity. However, on a cellular level, the degree of insulin release of DNAJC3 K.O. islets was higher during periods of increased synthetic activity (high-glucose stimulation). We propose that calcium leakage from the ER into the cytosol, due to disrupted DNAJC3-controlled gating of the Sec61 channel, is the most likely mechanism for HH. This is the first genetic mechanism explaining HH solely by the disruption of intracellular calcium homeostasis. Clinicians should screen for HH in DNAJC3 deficiency and consider DNAJC3 variants in the differential diagnosis of congenital hyperinsulinism. Full article

This pre-clinical study investigated the transient receptor potential ankyrin-1 (TRPA1) channels on modulating targets for glucose homeostasis using agonists: the electrophilic agonists, cinnamaldehyde (CIN) and allyl isothiocyanate (AITC), and the non-electrophilic agonist, carvacrol (CRV). A glucose tolerance test was performed on rats. CIN and AITC (5, 10 and 20 mg/kg) or CRV (25, 100, 300, and 600 mg/kg) were administered intraperitoneally (i.p.), and glycemia was measured. In the intestine, Glucagon-like peptide-1 (GLP-1) and disaccharidase activity were evaluated (in vivo and in vitro, respectively). Furthermore, in vivo and in vitro insulin secretion was determined. Islets were used to measure insulin secretion and calcium influx. CIN and AITC improved glucose tolerance and increased insulin secretion in vivo and in vitro. CRV was unable to reduce glycemia. Electrophilic agonists, CIN and AITC, inhibited disaccharidases and acted as secretagogues in the intestine by inducing GLP-1 release in vivo and in vitro and contributed to insulin secretion and glycemia. The effect of CIN on calcium influx in pancreatic islets (insulin secretion) involves voltage-dependent calcium channels and calcium from stores. TRPA1 triggers calcium influx and potentiates intracellular calcium release to induce insulin secretion, suggesting that electrophilic agonists mediate this signaling transduction for the control of glycemia. Full article