Effects of Empagliflozin Treatment on Glycerol-Derived Hepatic Gluconeogenesis in Adults with Obesity: A Randomized Clinical Trial

Phytochemical analysis and antihyperglycemic activity of Castilleja arvensis

Castilleja genus comprises approximately 211 species, some of them exhibiting potential in treating various diseases. Remarkably, despite its abundance, there is a significant lack of scientific studies that explore the chemical composition and/or therapeutic activity of this genus. In this work, the chemical composition of Castilleja arvensis was determined, and its antihyperglycemic activity was evaluated in vivo, in vitro, and ex vivo. Hydroalcoholic extract of C. arvensis (HECa) was obtained from the maceration of aerial parts. HECa was fractionated by liquid-liquid extractions to obtain the CH2Cl2 fraction (DF), EtOAc fraction (EF), n-BuOH fraction (BF) and aqueous residue (AR). The antihyperglycemic activity was determined in vivo through oral glucose and sucrose tolerance tests in normoglycemic CD-1 mice. Ex vivo assays were performed to determine intestinal glucose absorption, muscular glucose uptake and hepatic glucose production. α-glucosidase inhibitory activity was evaluated in vitro. Phytochemical screening was carried out through conventional chromatography techniques. Structure elucidation of the isolated compounds was performed by GC-MS and NMR experiments. HECa, its fractions and AR showed significant antihyperglycemic activity in vivo. According to the in vitro and ex vivo assays, this effect can be attributed to different mechanisms of action, including a delay in intestinal glucose absorption, an improvement in insulin sensitivity, and the regulation of hepatic glucose production. These effects may be due to different metabolites identified in fractions from the HECa, including genkwanin, acacetin, verbascoside and ipolamiide. Thus, current research shows that C. arvensis is an important source of bioactive compounds for the management of glycemia.

SGLT2 inhibitors: Beyond glycemic control

Multiple randomized controlled trials have extensively examined the therapeutic effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors, ushering in a transformative approach to treating individuals with type 2 diabetes mellitus (DM). Notably, emerging reports have drawn attention to the potential positive impacts of SGLT2 inhibitors in nondiabetic patients. In an effort to delve into this phenomenon, a comprehensive systematic literature review spanning PubMed (NLM), Medline (Ovid), and Cochrane Library, covering publications from 2000 to 2024 was undertaken. This systematic review encompassed twenty-six randomized control trials (RCTs) involving 35,317 participants. The findings unveiled a multifaceted role for SGLT2 inhibitors, showcasing their ability to enhance metabolic control and yield cardioprotective effects through a reduction in cardiovascular death (CVD) and hospitalization related to heart failure (HF). Additionally, a renalprotective effect was observed, evidenced by a slowdown in chronic kidney disease (CKD) progression and a decrease in albuminuria. Importantly, these benefits were coupled with an acceptable safety profile. The literature also points to various biological plausibility and underlying mechanistic pathways, offering insights into the association between SGLT2 inhibitors and these positive outcomes in nondiabetic individuals. Current research trends indicate a continual exploration of additional role for SGLT2 inhibitors in. Nevertheless, further research is imperative to fully elucidate the mechanisms and long-term outcomes associated with the nondiabetic use of SGLT2 inhibitors.

Blockade of sodium-glucose co-transporters improves peritoneal ultrafiltration in uraemic rodent models

BACKGROUND

The most used PD fluids contain glucose as a primary osmotic agent. Glucose peritoneal absorption during dwell decreases the osmotic gradient of peritoneal fluids and causes undesirable metabolic consequences. Inhibitors of sodium-glucose co-transporter (SGLT) type 2 are wildly used for the treatment of diabetes, heart and kidney failure. Previous attempts to use SGLT2 blockers in experimental peritoneal dialysis yielded contrasting results. We studied whether peritoneal SGLTs blockade may improve ultrafiltration (UF) via partial inhibition of glucose uptake from dialysis fluids.

METHODS

Kidney failure was induced in mice and rats by bilateral ureteral ligation, and dwell was performed by injection of glucose-containing dialysis fluids. The effect of SGLT inhibitors on glucose absorption during fluid dwell and UF was measured in vivo.

RESULTS

Diffusion of glucose from dialysis fluid into the blood appeared to be sodium-dependent, and blockade of SGLTs by phlorizin and sotagliflozin attenuated blood glucose increment thereby decreasing fluid absorption. Specific SGLT2 inhibitors failed to reduce glucose and fluid absorption from the peritoneal cavity in a rodent kidney failure model.

CONCLUSIONS

Our study suggests that peritoneal non-type 2 SGLTs facilitate glucose diffusion from dialysis solutions, and we propose that limiting glucose reabsorption by specific SGLT inhibitors may emerge as a novel strategy in PD treatment to enhance UF and mitigate the deleterious effects of hyperglycaemia.

SGLT2 Inhibitors' Cardiovascular Benefits in Individuals Without Diabetes, Heart Failure, and/or Chronic Kidney Disease: A Systematic Review

Despite the growing body of evidence regarding the beneficial cardiovascular effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors, clinical data in individuals without diabetes, heart failure (HF), and/or chronic kidney disease (CKD) is limited. A systematic review of the literature was conducted in PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar, from database inception until May 4, 2023, to explore new evidence of SGLT2 inhibitors' cardiovascular benefits in individuals without diabetes, HF, and/or CKD. A total of 1156 individuals from 14 studies (13 randomized controlled trials and 1 nonrandomized study) were included. The results showed the benefits of SGLT2 inhibitors on blood pressure, weight, and body mass index in this population with an acceptable safety profile. The current evidence supports the potential role of SGLT2 inhibitors as primary prevention in individuals without diabetes, HF, and/or CKD. This review may shed light on the use of SGLT2 inhibitors in conditions such as stage A HF and metabolic syndrome. The literature trend is going toward uncovering SGLT2 inhibitors' role in stage B HF, different types of myocardial infarction, and cardiac arrhythmias.

A Systematic Review on Participant Diversity in Clinical Trials-Have We Made Progress for the Management of Obesity and Its Metabolic Sequelae in Diet, Drug, and Surgical Trials

OBJECTIVE

Individuals from Black and Hispanic backgrounds represent a minority of the overall US population, yet are the populations most affected by the disease of obesity and its comorbid conditions. Black and Hispanic individuals remain underrepresented among participants in obesity clinical trials, despite the mandate by the National Institutes of Health (NIH) Revitalization Act of 1993. This systematic review evaluates the racial, ethnic, and gender diversity of clinical trials focused on obesity at a national level.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of clinicaltrials.gov, PubMed, Cochrane Central, and Web of Science was undertaken to locate phase 3 and phase 4 clinical trials on the topic of obesity that met associated inclusion/exclusion criteria. Ultimately, 18 studies were included for review.

RESULTS

White non-Hispanic individuals represented the majority of clinical trial participants, as did females. No study classified participants by gender identity. Reporting of race/ethnicity was not uniform, with noted variability among racial/ethnic subgroups.

CONCLUSIONS

Our findings suggest that disparities remain in the diverse racial, ethnic, and gender representation of participants engaged in clinical trials on obesity relative to the prevalence of obesity in underrepresented populations. Commitment to inclusive and intentional recruiting practices is needed to increase the representation of underrepresented groups, thus increasing the generalizability of future research.

Body Fat Distribution, Diabetes Mellitus, and Cardiovascular Disease: an Update

PURPOSE OF REVIEW

Specific measures of body fat distribution may have particular value in the development and treatment of cardiometabolic conditions, such as cardiovascular disease (CVD) and diabetes mellitus (DM). Here, we review the pathophysiology, epidemiology, and recent advances in the identification and management of body fat distribution as it relates to DM and CVD risk.

RECENT FINDINGS

Accumulation of visceral and ectopic fat is a major contributor to CVD and DM risk above and beyond the body mass index (BMI), yet implementation of fat distribution assessment into clinical practice remains a challenge. Newer imaging-based methods offer improved sensitivity and specificity for measuring specific fat depots. Lifestyle, pharmacological, and surgical interventions allow a multidisciplinary approach to reduce visceral and ectopic fat. A focus on implementation of body fat distribution measurements into clinical practice should be a priority over the next 5 to 10 years, and clinical assessment of fat distribution can be considered to refine risk evaluation and to develop improved and effective preventive and therapeutic strategies for high-risk obesity.

Recent progress in analysis of intermediary metabolism by ex vivo 13 C NMR

Advanced imaging technologies, large-scale metabolomics, and the measurement of gene transcripts or enzyme expression all enable investigations of intermediary metabolism in human patients. Complementary information about fluxes in individual metabolic pathways may be obtained by ex vivo ¹³ C NMR of blood or tissue biopsies. Simple molecules such as ¹³ C-labeled glucose are readily administered to patients prior to surgical biopsies, and ¹³ C-labeled glycerol is easily administered orally to outpatients. Here, we review recent progress in practical applications of ¹³ C NMR to study cancer biology, the response to oxidative stress, gluconeogenesis, triglyceride synthesis in patients, as well as new insights into compartmentation of metabolism in the cytosol. The technical aspects of obtaining the sample, preparing material for analysis, and acquiring the spectra are relatively simple. This approach enables convenient, valuable, and quantitative insights into intermediary metabolism in patients.

SGLT2 inhibitor versus carbohydrate-restricted isocaloric diet: reprogramming substrate oxidation in type 2 diabetes

OBJECTIVE

Based on the whole-body energy metabolism and insulin action, the difference between increased excretion of carbohydrate in urine by SGLT2i and reduced same amount of oral carbohydrate intake are scarce. This study aimed to compare the effect of carbohydrate availability with reduced oral intake (carbohydrate-restricted isocaloric diet: CRIC diet) or lost in urine, as urinary glucosuria on sodium/glucose cotransporter-2 inhibitor (SGLT2i) treatment, focus on the insulin requirement and the macronutrient oxidation within insulin treated type 2 diabetes.

METHODS

This is randomized 3-arm open-label prospective study. Subjects treated with titrated basal-bolus insulin regimen subsequent to three diet regimens, control diet (CON), administration of canagliflozin 100 mg/day to CON (SGLT2i), or CRIC diet, with a week admission to the endocrinology ward followed by 12 weeks outpatients' management. The main outcome measures including the total insulin dose (TID) required to achieve euglycemia, fasting and postprandial energy expenditure (EE) and respiratory quotient (RQ) at 1-week and 12-week.

RESULTS

We enrolled 23 patients with type 2 diabetes (male/female: 14/9, age: 53.6 ± 14.2 years, body mass index: 26.9 ± 4.8 kg/m², HbA1c: 12.5 ± 1.6%). The TID was similar with CON and SGLT2i at both 1 and 12-weeks. Although comparable net carbohydrate availability in SGLT2i and CRIC groups, the TID was significantly higher in the CRIC (p = 0.02) compare to the SGLT2i at both 1 and 12-weeks. Fasting EE was similar in all groups, postprandial EE was significantly elevated in the SGLT2i and CRIC groups compared to the CON group (p = 0.03 and 0.04). Compare to the CON, lower basal fasting RQ (p = 0.049) and decreased delta-RQ (postprandial RQ/fasting RQ) indicated continuous lipid substrate utilization in the SGLT2i (p = 0.04) and CRIC (p = 0.03) groups.

CONCLUSION

The CRIC diet resulted in a similar fasting and postprandial EE and substrate oxidation compared to the SGLT2i. The increased insulin requirement in the CRIC diet indicates that a relatively highly lipid and protein consumption, compared to the SGLT2i and CON, may influence insulin requirement.

Effect of Empagliflozin on Sphingolipid Catabolism in Diabetic and Hypertensive Rats

The profile of sphingomyelin and its metabolites shows changes in the plasma, organs, and tissues of patients with cardiovascular, renal, and metabolic diseases. The objective of this study was to investigate the effect of empagliflozin on the levels of sphingomyelin and its metabolites, as well as on the activity of acid and neutral sphingomyelinase (aSMase and nSMase) and neutral ceramidase (nCDase) in the plasma, kidney, heart, and liver of streptozotocin-induced diabetic and Angiotensin II (Ang II)-induced hypertension rats. Empagliflozin treatment decreased hyperglycemia in diabetic rats whereas blood pressure remained elevated in hypertensive rats. In diabetic rats, empagliflozin treatment decreased sphingomyelin in the plasma and liver, ceramide in the heart, sphingosine-1-phosphate (S1P) in the kidney, and nCDase activity in the plasma, heart, and liver. In hypertensive rats, empagliflozin treatment decreased sphingomyelin in the plasma, kidney, and liver; S1P in the plasma and kidney; aSMase in the heart, and nCDase activity in the plasma, kidney, and heart. Our results suggest that empagliflozin downregulates the interaction of the de novo pathway and the catabolic pathway of sphingolipid metabolism in the diabetes, whereas in Ang II-dependent hypertension, it only downregulates the sphingolipid catabolic pathway.

A randomized clinical trial evaluating the effect of empagliflozin on triglycerides in obese adults: Role of visceral fat

Background

Empagliflozin, a sodium glucose cotransporter 2 inhibitor, is a medication to treat type 2 diabetes. The effect of empagliflozin in persons without diabetes has received less attention. Here we conducted a randomized, double-blind placebo-controlled clinical trial to examine the effect of empagliflozin on plasma triglycerides in obese non-diabetic adults.

Methods

Participants (n = 35; BMI ≥ 30 kg/m²) underwent body composition assessments using MRI, and were randomly assigned to either placebo or empagliflozin (10 mg/d) for three months. At the baseline and post-treatment visit, after an overnight fast, blood was drawn for biochemical analysis. Participants received [U–¹³C₃]glycerol orally followed by multiple blood draws over 3 h to examine glycerol incorporation into triglycerides using NMR spectroscopy.

Results

The changes in blood triglyceride concentration with empagliflozin therapy related to the mass of baseline visceral adipose tissue (VAT; r = 0.53, p = 0.04). Empagliflozin slightly lowered triglycerides in obese subjects with low VAT, but increased triglycerides in the subjects with high VAT. Consistently, empagliflozin effectively suppressed triglyceride synthesis following [U–¹³C₃]glycerol administration in the subjects with low VAT (p < 0.05), but not in the subjects with high VAT. The subjects with high VAT lost body weight after three months of empagliflozin treatment. In all subjects, about 20% of the triglyceride backbone originated from mitochondrial metabolism of glycerol.

Conclusions

The effect of empagliflozin on triglycerides in obese adults differed depending on VAT. Empagliflozin suppressed triglyceride synthesis in the subjects with low VAT, but tended to increase triglycerides in those with high VAT.

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Visceral fat modulates the effect of empagliflozin on triglycerides in obese adults.

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Empagliflozin suppresses triglyceride synthesis in obese adults with low visceral fat.

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Empagliflozin tends to increase triglycerides in obese adults with high visceral fat.

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Empagliflozin induces weight loss in obese adults with high visceral fat.

Empagliflozin Inhibits Hepatic Gluconeogenesis and Increases Glycogen Synthesis by AMPK/CREB/GSK3β Signalling Pathway

Increases in glucose production and decreases in hepatic glycogen storage induce glucose metabolic abnormalities in type 2 diabetes (T2DM). Empagliflozin, a sodium-dependent glucose transporter 2 (SGLT2) inhibitor, is an effective hypoglycemic drug; however, the effects of empagliflozin on hepatic gluconeogenesis and glycogenesis are still unclear. In this study, we investigated the effects and mechanisms of empagliflozin on hepatic gluconeogenesis and glycogenesis in vivo and in vitro. Empagliflozin was administered via gavage to db/db mice for 8 weeks, and human hepatocyte HL7702 cells were treated with empagliflozin after palmitic acid (PA) stimulation. Compared with the control db/db mice, empagliflozin-treated mice showed a significant reduction in urine glucose levels, blood glucose levels, body weight and intraperitoneal glucose tolerance test (IPGTT) blood glucose levels. Moreover, the expression levels and activities of key gluconeogenesis enzymes PEPCK and G6Pase were dramatically reduced in the empagliflozin-treated mice, and the protein expression levels of AMPK/CREB/GSK3β signalling pathway-related molecules were significantly changed. In HL7702 cells, empagliflozin ameliorated glucose production and PEPCK and G6Pase expression and activity. Empagliflozin could also prevent the decreases in glycogen content and regulate the protein expression levels of AMPK/CREB/GSK3β signalling pathway-related molecules. Then, we selected the AMPK agonist AICAR and inhibitor compound C to further verify the effects of the AMPK signalling pathway on hepatic gluconeogenesis and glycogen synthesis. The results of the 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AIACR) intervention in HL7702 cells were consistent with those of empagliflozin treatment, and the effects of empagliflozin were abolished by compound C. In summary, empagliflozin could maintain glucose homoeostasis by reducing gluconeogenesis and increasing glycogenesis through the AMPK/CREB/GSK3β signalling pathway.

Sodium-glucose co-transporter 2 inhibitors on weight change and cardiometabolic profiles in individuals with overweight or obesity and without diabetes: A meta-analysis

Several meta-analyses have been conducted to evaluate the weight loss effect of sodium-glucose cotransporter 2 (SGLT-2) inhibitors in patients with type 2 diabetes, whereas pooled analysis focusing on individuals without diabetes is lacking. The objective of this systematic review and meta-analysis is to evaluate the effect of SGLT-2 inhibitor monotherapy on weight change and cardiometabolic profiles. Multiple databases were searched for randomized controlled trials reporting weight change effect of SGLT-2 inhibitor treatment compared with placebo for more than 12 weeks among individuals with overweight or obesity and without diabetes. A total of eight randomized controlled trials with 750 subjects were identified. SGLT-2 monotherapy was associated with significant reduction in body weight of -2.32 kg, compared to -1.01 kg for placebo, giving a mean difference of -1.31 kg. Significant reductions in body mass index and fasting blood glucose were observed, but not for the changes in waist circumference, fat mass, blood pressure, and lipid profile compared with placebo. SGLT-2 inhibitor monotherapy for 12 weeks or more can result in modest weight loss among people with overweight or obesity and without diabetes. Depending on pre-existing comorbidities or risk factors, SGLT-2 inhibitors can be considered adjuncts in the treatment of obesity.

Mechanism exploration of Gouqi-wentang formula against type 2 diabetes mellitus by phytochemistry and network pharmacology-based analysis and biological validation

BACKGROUND

The Gouqi-wentang formula (GQWTF) is a herbal formula used by Academician Xiao-lin Tong for the clinical treatment of T2DM. GQWTF is beneficial to qi, nourishes Yin, clears heat, and promotes fluid production, but the effective components and their mechanism of action remain unclear.

METHODS

The main components of GQWTF were detected by LC-MS, and the multi-target mechanisms of GQWTF in T2DM were elucidated using network pharmacology analysis, including target prediction, protein-protein interaction network construction and analysis, Gene Ontology (GO) terms, Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway annotation, and other network construction. Finally, the efficacy of the GQWTF was verified using biological experiments.

RESULTS

First, the "herb-channel tropism" network suggested that GQWTF focuses more on treating diseases by recuperating the liver, which is considered as an important insulin-sensitive organ. Subsequently, a total of 16 active ingredients in GQWTF were detected and screened, and their biological targets were predicted. Then, "compound-target" network was constructed, where enrichment analysis of GQWTF targets reflected its potential pharmacological activities. After T2DM-related target identification, 39 cross targets of GQWTF and T2DM were obtained, and 30 key targets highly responsible for the beneficial effect of GQWTF on T2DM were identified by PPI analysis. GO analysis of these key targets showed that many biological processes of GQWTF in treating T2DM are key in the occurrence and development of T2DM, including components related to inflammatory/immune response, insulin, and metabolism. KEGG analysis revealed the regulation of multiple signalling pathways, such as insulin resistance, PPAR signalling pathway, FoxO signalling pathway, Fc epsilon RI signalling pathway, and pathways that influence diabetes primarily by regulating metabolism as well as other T2DM directly related pathways. Furthermore, a "formula-compound-pathway-symptom" network was constructed to represent a global view of GQWTF in the treatment of T2DM.

CONCLUSIONS

This study explored the mechanism of action of GQWTF in T2DM by multi-component and multi-target multi pathways, which could provide a theoretical basis for the development and clinical application of GQWTF.

Do SGLT2 Inhibitors Improve Cardio-Renal Outcomes in Patients With Type II Diabetes Mellitus: A Systematic Review

Diabetes mellitus (DM) is associated with dreadful changes in the cardiovascular and renal systems, causing increased morbidity and mortality. Sodium-glucose cotransport-2 (SGLT2) inhibitors belong to the oral hypoglycemic group of drugs believed to reduce these events by various mechanisms in DM. We performed a systematic review to determine the effectiveness of SGLT2 inhibitors in reducing cardiovascular and renal complications and address safety concerns in participants with type 2 diabetes mellitus (T2DM). We explored PubMed, PubMed Central, Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane library, and ResearchGate for randomized controlled trials and observational studies done on the advantages of SGLT2 inhibitors in the prevention or reduction of worsening cardiovascular and renal changes in T2DM. Studies were screened for the quality assessment using the Cochrane risk-of-bias assessment tool and Newcastle-Ottawa scale. We screened 5615 articles, out of which 22 articles with 7,02,977 diabetes mellitus patients treated with SGLT2 inhibitors were used for the systematic review after meticulously filtering articles based on inclusion and exclusion criteria. The trials included one of the following drugs - empagliflozin, dapagliflozin, canagliflozin, and luseogliflozin. SGLT2 inhibitors significantly reduced the risk of heart failure (HF), frequency of hospitalizations due to HF, all-cause mortality, cardiovascular mortality, and nonfatal myocardial infarction. Renal outcomes showed a significant lowering of risk of acute kidney failure, progression of chronic kidney disease, renal mortality, and improvement in urinary albumin creatinine ratio. We noticed an initial worsening of the estimated glomerular filtration rate followed by stabilizing and reaching the baseline on long-term treatment, especially in end-stage renal failure patients. The review showed that SGLT2 inhibitors have adverse reactions similar to that of a placebo, with a slight increase in treatable genital mycotic and urinary tract infections but no evidence of diabetic ketoacidosis, fractures, and amputations. According to the available data, SGLT2 inhibitors can significantly prevent or reduce cardiovascular diseases and kidney abnormalities in patients with type 2 diabetes mellitus with tolerable safety outcomes.

Management of Obesity in Cardiovascular Practice: JACC Focus Seminar

Obesity contributes to reduced life expectancy because of its link with type 2 diabetes and cardiovascular disease. Yet, targeting this poorly diagnosed, ill-defined, and underaddressed modifiable risk factor remains a challenge. In this review, we emphasize that the tendency among health care professionals to amalgam all forms of obesity altogether as a single entity may contribute to such difficulties and discrepancies. Obesity is a heterogeneous condition both in terms of causes and health consequences. Attention should be given to 2 prevalent subgroups of individuals: 1) patients who are overweight or moderately obese with excess visceral adipose tissue; and 2) patients with severe obesity, the latter group having distinct additional health issues related to their large body fat mass. The challenge of tackling high-cardiovascular-risk forms of obesity through a combination of personalized clinical approaches and population-based solutions is compounded by the current obesogenic environment and economy.

Empagliflozin therapy and insulin resistance-associated disorders: effects and promises beyond a diabetic state

Empagliflozin is a SGLT2 inhibitor that has shown remarkable cardiovascular and renal activities in patients with type 2 diabetes (T2D). Preclinical and clinical studies of empagliflozin in T2D population have demonstrated significant improvements in body weight, waist circumference, insulin sensitivity, and blood pressure – effects beyond its antihyperglycaemic control. Moreover, several studies suggested that this drug possesses significant anti-inflammatory and antioxidative stress properties. This paper explores extensively the main preclinical and clinical evidence of empagliflozin administration in insulin resistance-related disorders beyond a diabetic state. It also discusses its future perspectives, as a therapeutic approach, in this high cardiovascular-risk population.