Preoperative carbohydrate supplementation attenuates post-surgery insulin resistance via reduced inflammatory inhibition of the insulin-mediated restraint on muscle pyruvate dehydrogenase kinase 4 expression

Effect of preoperative oral carbohydrate on postoperative delirium in elderly patients undergoing lower extremity orthopedic surgery: a prospective randomized trial

BACKGROUND

Postoperative metabolic disorders and inflammatory responses are closely associated with postoperative delirium (POD). Preoperative oral carbohydrate intake can alleviate postoperative insulin resistance and the inflammatory response. This study aimed to evaluate the effects of preoperative oral carbohydrate intake on the incidence of POD in older patients undergoing lower limb orthopedic surgery.

METHODS

Eighty patients were randomly assigned to oral intake of 200 mL carbohydrate solution (Group CHO) 2 h before surgery or fasting for 8 h before surgery (Group C). The primary outcome was the incidence of POD. Fasting plasma glucose, interleukin (IL)-6, and C-reactive protein (CRP) levels were assessed before surgery and 1, 3, and 5 days after surgery (D1, D3, and D5).

RESULTS

The incidence of POD in Group CHO was lower than that in Group C (P = 0.005). Blood glucose, IL-6 and CRP levels of Group CHO were significantly lower than those of Group C on D1 and D3 (P < 0.05).

CONCLUSIONS

Preoperative oral carbohydrate intake can reduce the incidence of POD in older patients by ameliorating postoperative metabolic disorders and reducing inflammatory responses.

TRIAL REGISTRATION

ChiCTR2300070154, Date of registration: 03/04/2023.

Identification of PDK4 as Hub Gene for Diabetic Nephropathy Using Co-Expression Network Analysis

INTRODUCTION

Diabetic nephropathy (DN) is related to type 1 and type 2 diabetes. They are the leading cause of end-stage renal disease, but the underling specific pathogenesis of DN is not yet clear. Our study was conducted to explore how DN changed the transcriptome profiles in the kidney.

METHODS

The gene expression profile of microdissected glomeruli of 41 type 2 DN patients and 20 healthy controls were included. The sample dataset GSE96804 was obtained from the GEO database. Differentially expressed genes (DEGs) were analyzed in R with the limma package and the important modules were found by weighted gene co-expression network analysis (WGCNA) clustering. The modules were then analyzed based on Gene Ontology (GO) gene set enrichment analysis, and the hub genes were found out. We next validated the hub gene, PDK4, in a cell model of DN. We also constructed the PDK4-related PPI network to investigate the correlation between PDK4 expression and other genes.

RESULTS

Heatmap and volcano map were drawn to illustrate the mRNA expression profile of 1,204 DEGs in both samples of DN patients and the control group. Using WGCNA, we selected the blue module in which genes showed the strongest correlation with the phenotype and the smallest p value. We also identified PDK4 as a hub gene. PDK4 expression was upregulated in human diabetic kidney tissue. Moreover, PDK4 was speculated to play a role in glomerular basement membrane development and kidney development according to the enrichment of functions and signaling pathways. Furthermore, PDK4 and two key genes GSTA2 and G6PC protein expression were verified highly expressed in the cell model of DN.

CONCLUSION

During the pathogenesis of DN, many genes may change expression in a coordinated manner. The discovery of PDK4 as key gene using WGCNA is of great significance for the development of new treatment strategies to block the development of DN.

Guidelines for Perioperative Care for Liver Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations 2022

BACKGROUND

Enhanced Recovery After Surgery (ERAS) has been widely applied in liver surgery since the publication of the first ERAS guidelines in 2016. The aim of the present article was to update the ERAS guidelines in liver surgery using a modified Delphi method based on a systematic review of the literature.

METHODS

A systematic literature review was performed using MEDLINE/PubMed, Embase, and the Cochrane Library. A modified Delphi method including 15 international experts was used. Consensus was judged to be reached when >80% of the experts agreed on the recommended items. Recommendations were based on the Grading of Recommendations, Assessment, Development and Evaluations system.

RESULTS

A total of 7541 manuscripts were screened, and 240 articles were finally included. Twenty-five recommendation items were elaborated. All of them obtained consensus (>80% agreement) after 3 Delphi rounds. Nine items (36%) had a high level of evidence and 16 (64%) a strong recommendation grade. Compared to the first ERAS guidelines published, 3 novel items were introduced: prehabilitation in high-risk patients, preoperative biliary drainage in cholestatic liver, and preoperative smoking and alcohol cessation at least 4 weeks before hepatectomy.

CONCLUSIONS

These guidelines based on the best available evidence allow standardization of the perioperative management of patients undergoing liver surgery. Specific studies on hepatectomy in cirrhotic patients following an ERAS program are still needed.

Preoperative Carbohydrate Drink Intake Increases Glycemic Variability in Patients with Type 2 Diabetes Mellitus in Total Joint Arthroplasty: A Prospective Randomized Trial

BACKGROUND

Preoperative carbohydrate treatment attenuates insulin resistance and improves metabolism to an anabolic state. Despite these benefits, impaired glycemic control and aspiration risk related to gastroparesis represent concerns for patients with diabetes undergoing surgery. This randomized controlled trial investigated the effects of oral carbohydrate therapy on perioperative glucose variability, metabolic responses, and gastric volume in diabetic patients undergoing elective total hip or knee arthroplasty.

METHODS

Fifty diabetic patients scheduled to undergo elective total knee or hip arthroplasty during August 2019-October 2020 were randomly assigned to a control or carbohydrate therapy (CHO) group. CHO group of patients received a 400-mL carbohydrate drink 2-3 h before anesthesia; control group of patients underwent overnight fasting from midnight, one night before surgery. Blood glucose levels were measured before intake of the carbohydrate drink, before spinal anesthesia, preoperatively, immediately postoperatively, and 1 h postoperatively. Insulin level and gastric volume were measured before spinal anesthesia.

RESULTS

The glucose variability of patients in the CHO group was significantly higher than that of those in the control group (16.5 vs. 10.1%, P = 0.008). Similarly, insulin resistance was higher in the CHO group than in the control group (8.5 vs. 2.7, P < 0.001). The gastric volume did not differ significantly between the groups (61.3 vs. 15.2 ml, P = 0.082).

CONCLUSIONS

Preoperative oral carbohydrate therapy increases glucose variability and insulin resistance in diabetic patients. Therefore, carbohydrate beverages should be cautiously administered to diabetic patients, considering metabolic and safety aspects. Trial registration number ClinicalTrials.gov (No. NCT04013594).

The effect of glucose control in liver surgery on glucose kinetics and insulin resistance

BACKGROUND & AIMS

Clinical outcome is negatively correlated to postoperative insulin resistance and hyperglycemia. The magnitude of insulin resistance can be modulated by glucose control, preoperative nutrition, adequate pain management and minimal invasive surgery. Effects of glucose control on perioperative glucose kinetics in liver surgery is less studied.

METHODS

18 patients scheduled for open hepatectomy were studied per protocol in this prospective, randomized study. In the treatment group (n = 9), insulin was administered intravenously to keep arterial blood glucose between 6 and 8 mmol/l during surgery. The control group (n = 9) received insulin if blood glucose >11.5 mmol/l. Insulin sensitivity was measured by an insulin clamp on the day before surgery and immediately postoperatively. Glucose kinetics were assessed during the clamp and surgery.

RESULTS

Mean intraoperative glucose was 7.0 mM (SD 0.7) vs 9.1 mM (SD 1.9) in the insulin and control group respectively (p < 0.001; ANOVA). Insulin sensitivity decreased in both groups but significantly (p = 0.03, ANOVA) more in the control group (M value: 4.6 (4.4-6.8) to 2.1 (1.2-2.6) and 4.6 (4.1-5.0) to 0.6 (0.1-1.8) mg/kg/min in the treatment and control group respectively). Endogenous glucose production (EGP) increased and glucose disposal (WGD) decreased significantly between the pre- and post-operative clamps in both groups, with no significant difference between the groups. Intraoperative kinetics demonstrated that glucose control decreased EGP (p = 0.02) while WGD remained unchanged (p = 0.67).

CONCLUSION

Glucose control reduces postoperative insulin resistance in liver surgery. EGP increases and WGD is diminished immediately postoperatively. Insulin seems to modulate both reactions, but mostly the WGD is affected. Intraoperative EGP decreased while WGD remained unaltered.

REGISTRATION NUMBER OF CLINICAL TRIAL

ANZCTR 12614000278639.

Major elective abdominal surgery acutely impairs lower limb muscle pyruvate dehydrogenase complex activity and mitochondrial function

BACKGROUND & AIMS

This post hoc study aimed to determine whether major elective abdominal surgery had any acute impact on mitochondrial pyruvate dehydrogenase complex (PDC) activity and maximal mitochondrial ATP production rates (MAPR) in a large muscle group (vastus lateralis -VL) distant to the site of surgical trauma.

METHODS

Fifteen patients undergoing major elective open abdominal surgery were studied. Muscle biopsies were obtained after the induction of anesthesia from the VL immediately before and after surgery for the determination of PDC and maximal MAPR (utilizing a variety of energy substrates).

RESULTS

Muscle PDC activity was reduced by >50% at the end of surgery compared with pre-surgery (p < 0.05). Muscle MAPR were comprehensively suppressed by surgery for the substrate combinations: glutamate + succinate; glutamate + malate; palmitoylcarnitine + malate; and pyruvate + malate (all p < 0.05), and could not be explained by a lower mitochondrial yield.

CONCLUSIONS

PDC activity and mitochondrial ATP production capacity were acutely impaired in muscle distant to the site of surgical trauma. In keeping with the limited data available, we surmise these events resulted from the general anesthesia procedures employed and the surgery related trauma. These findings further the understanding of the acute dysregulation of mitochondrial function in muscle distant to the site of major surgical trauma in patients, and point to the combination of general anesthesia and trauma related inflammation as being drivers of muscle metabolic insult that warrants further investigation.

CLINICAL TRIAL REGISTRATION

Registered at (NCT01134809).

PPARδ and FOXO1 Mediate Palmitate-Induced Inhibition of Muscle Pyruvate Dehydrogenase Complex and CHO Oxidation, Events Reversed by Electrical Pulse Stimulation

The mechanisms behind the reduction in muscle pyruvate dehydrogenase complex (PDC)-controlled carbohydrate (CHO) oxidation during chronic high-fat dietary intake are poorly understood, as is the basis of CHO oxidation restoration during muscle contraction. C2C12 myotubes were treated with (300 μM) palmitate or without (control) for 16 h in the presence and absence of electrical pulse stimulation (EPS, 11.5 V, 1 Hz, 2 ms). Compared to control, palmitate reduced cell glucose uptake (p < 0.05), PDC activity (p < 0.01), acetylcarnitine accumulation (p < 0.05) and glucose-derived mitochondrial ATP production (p < 0.01) and increased pyruvate dehydrogenase kinase isoform 4 (PDK4) (p < 0.01), peroxisome proliferator-activated receptor alpha (PPARα) (p < 0.01) and peroxisome proliferator-activated receptor delta (PPARδ) (p < 0.01) proteins, and reduced the whole-cell p-FOXO1/t-FOXO1 (Forkhead Box O1) ratio (p < 0.01). EPS rescued palmitate-induced inhibition of CHO oxidation, reflected by increased glucose uptake (p < 0.01), PDC activity (p < 0.01) and glucose-derived mitochondrial ATP production (p < 0.01) compared to palmitate alone. EPS was also associated with less PDK4 (p < 0.01) and PPARδ (p < 0.01) proteins, and lower nuclear p-FOXO1/t-FOXO1 ratio normalised to the cytoplasmic ratio, but with no changes in PPARα protein. Collectively, these data suggest PPARδ, and FOXO1 transcription factors increased PDK4 protein in the presence of palmitate, which limited PDC activity and flux, and blunted CHO oxidation and glucose uptake. Conversely, EPS rescued these metabolic events by modulating the same transcription factors.

The effects of vitamin-rich carbohydrate pretreatment on the surgical stress response and S-100β after splenectomy in elderly rats

Background

Preoperative oral carbohydrates has been suggested to attenuate insulin resistance and decrease postoperative complications. In this study, a vitamin-rich carbohydrate beverage was administered before surgery in an animal model to investigate its effects on the surgical stress response and S-100β levels.

Methods

Thirty aged male Sprague-Dawley rats were randomly assigned to three groups: control group (n = 6), fasting group (n = 12), and carbohydrate-treated group (CHO group, n = 12). Rats in the control group were not given any treatment. Rats in the fasting group received splenectomy after 12 h of fasting. In the CHO group, rats were given 5 ml of vitamin-rich carbohydrate by gavage 2 h before surgery. Fasting plasma glucose, insulin, insulin resistance (HOMA-IR index, IRI), the S-100β protein level, and the inflammatory mediators IL-1β, IL-6 and TNF-α were assessed after surgery (postoperative day (POD) 1 and 3).

Results

Postoperative insulin resistance was significantly greater in the fasting group than in the control and CHO group. The median plasma S-100β level was significantly higher in the fasting group than in the control and CHO groups on POD 1. The median plasma IL-1β level was significantly lower in the CHO group than in the fasting group on POD 1; however, no other differences in the concentrations of immunological biomarkers of stress were found between the fasting group and the CHO group.

Conclusions

Vitamin-rich carbohydrate pretreatment attenuated the metabolic aspect of the surgical stress response and decreased the level of plasma S-100β, which may decrease the risk of postoperative complications in elderly rats.

High Fat Diet Upregulates Fatty Acid Oxidation and Ketogenesis via Intervention of PPAR-γ

Background/Aims:

Systemic hyperlipidemia and intracellular lipid accumulation induced by chronic high fat diet (HFD) leads to enhanced fatty acid oxidation (FAO) and ketogenesis. The present study was aimed to determine whether activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) by surplus free fatty acids (FA) in hyperlipidemic condition, has a positive feedback regulation over FAO and ketogenic enzymes controlling lipotoxicity and cardiac apoptosis.

Methods:

8 weeks old C57BL/6 wild type (WT) or PPAR-γ^−/− mice were challenged with 16 weeks 60% HFD to induce obesity mediated type 2 diabetes mellitus (T2DM) and diabetic cardiomyopathy. Treatment course was followed by echocardiographic measurements, glycemic and lipid profiling, immunoblot, qPCR and immunohistochemistry (IHC) analysis of PPAR-γ and following mitochondrial metabolic enzymes 3-hydroxy-3- methylglutaryl-CoA synthase (HMGCS2), mitochondrial β-hydroxy butyrate dehydrogenase (BDH1) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In vivo model was translated in vitro, with neonatal rat cardiomyocytes (NRCM) treated with PPAR-γ agonist/antagonist and PPAR-γ overexpression adenovirus in presence of palmitic acid (PA). Apoptosis was determined in vivo from left ventricular heart by TUNEL assay and immunoblot analysis.

Results:

We found exaggerated circulating ketone bodies production and expressions of the related mitochondrial enzymes HMGCS2, BDH1 and PDK4 in HFD-induced diabetic hearts and in PA-treated NRCM. As a mechanistic approach we found HFD mediated activation of PPAR-03B3 is associated with the above-mentioned mitochondrial enzymes. HFD-fed PPAR-γ^−/− mice display decreased hyperglycemia, hyperlipidemia associated with increased insulin responsiveness as compared to HFD-fed WT mice PPAR-γ^−/−−HFD mice demonstrated a more robust functional recovery after diabetes induction, as well as significantly reduced myocyte apoptosis and improved cardiac function.

Conclusions:

PPAR-γ has been described previously to regulate lipid metabolism and adipogenesis. The present study suggests for the first time that increased PPAR-γ expression by HFD is responsible for cardiac dysfunction via upregulation of mitochondrial enzymes HMGCS2, BDH1 and PDK4. Targeting PPAR-γ and its downstream mitochondrial enzymes will provide novel strategies in preventing metabolic and myocardial dysfunction in diabetes mellitus.

Influence of IL-6, TNF-α and Hs-CRP on Insulin Sensitivity in Patients after Laparoscopic Cholecystectomy or Open Hernia Repair

BACKGROUND

The aim of this study was to investigate the influence of IL-6, TNF-α and hs-CRP on insulin sensitivity during postoperative follow-up in patients with laparoscopic cholecystectomy (LC) or open hernia repair (OHR).

METHODS

65 patients were studied: after laparoscopic cholecystectomy (LC; n=40) or open hernia repair (OHR; n=25). Glucose, insulin, hs-CRP, IL-6 and TNF-a were determined at day 0 (before the operation) and at days 1, 3 and 7 (after the operation).

RESULTS

There were no difference between LC and OHR groups concerning age, BMI, glucose, insulin, hs-CRP, IL-6 and TNF-α at day 0. hs-CRP increased at day 1, 3 and 7 vs. day 0 (p<0.0005), without difference between groups (p=0.561). IL-6 increased at day 1 and day 3 vs. day 0 (p<0.005). IL-6 was higher at day 1 in OHR group in comparison with LC group (p=0.044). There were no differences in TNF-a levels between LC and OHR groups (p=0.056). There was increase of HOMA-IR at day 1, 3 and 7 vs. day 0 (p<0.0005) in both groups. Significantly higher increase of HOMA-IR was in OHR group compared with LC group at day 1 (p=0.045). There was a positive correlation between hs-CRP and HOMA-IR (r=0.46; p=0.025) and between IL-6 and HOMA-IR at day 1 in OHR group (r=0.44; p=0.030).

CONCLUSIONS

Significantly higher HOMA-IR was found in OHR group compared with LC. Positive correlation between hs-CRP and IL-6 with HOMA-IR in OHR group at day 1, indicate possible influence of this mediators on impairment of insulin sensitivity.

Prognostic Value of Preoperative Neutrophil-to-lymphocyte Ratio for Prediction of Severe Cholecystitis

BACKGROUND

The predictive value of preoperative neutrophil-to-lymphocyte ratio (NLR) in patients with cholecystitis has not been established. The aim of this study was to investigate preoperative NLR in patients with cholecystitis and to identify a relevant NLR value that discriminates between simple and severe cholecystitis.

METHODS

This study included 136 patients who under went laparoscopic cholecystectomy due to cholecystitis. The Receiver Operating Characteristic (ROC) analysis was performed to identify the most useful NLR cut-off value in relation to the severity of cholecystitis. The patients were di vided into two groups according to the cut-off NLR value: high NLR group (≥4.18, n=23) and low NLR group (<4.18, n=113). Severe cholecystitis was defined as a state which includes inflammation, empyema, gangrene, perforation of gallbladder, adhesions or difficulty in dissecting Calot's triangle.

RESULTS

In the high NLR group, severe cholecystitis (p<0.0001) and higher C-reactive protein level (CRP) and white blood cells count (WBC) (p<0.0001) were significantly more frequent. There was no difference in homeostatic model assessment-insulin resistance index (HOMA-IR) between both groups before the operation (p<0.634). The incidence of severe cholecystitis was 16.9%. The NLR of 4.18 could predict severe cholecystitis with 78.3% sensitivity and 74.3% specificity. Spearman's correlation revealed significant association between the preoperative NLR and HOMA-IR on day 1, (r=0.254, p=0.030) and between preoperative NLR and CRP on day 1 (ρ=0.355; p<0.0001).

CONCLUSIONS

NLR ≥4.18 was significantly associated with severe cholecystitis. The preoperative NLR in patients under going cholecystectomy due to cholecystitis could be a useful surrogate marker of severe cholecystitis.

Postoperative inflammation and insulin resistance in relation to body composition, adiposity and carbohydrate treatment: A randomised controlled study

Background & aims

The aims of this study were to identify whether differences in distribution of adipose tissue and skeletal muscle in obese and non-obese individuals contribute to the magnitude of the postoperative inflammatory response and insulin resistance, with and without preoperative treatment with carbohydrate drinks.

Methods

Thirty-two adults (16 obese/16 non-obese) undergoing elective major open abdominal surgery participated in this 2 × 2 factorial, randomised, double-blind, placebo-controlled study. Participants received Nutricia preOp^® or placebo (800 ml on the night before surgery/400 ml 2–3 h preoperatively) after stratifying for obesity. Insulin sensitivity was measured using the hyperinsulinaemic-euglycaemic clamp preoperatively and on the 1st postoperative day. Vastus lateralis, omental and subcutaneous fat biopsies were taken pre- and postoperatively and analysed after RNA extraction. The primary endpoint was within subject differences in insulin sensitivity.

Results

Major abdominal surgery was associated with a 42% reduction in insulin sensitivity from mean(SD) M value of 37.3(11.8) μmol kg⁻¹ fat free mass (FFM) to 21.7(7.4) μmol kg⁻¹ FFM, but this was not influenced by obesity or preoperative carbohydrate treatment. Activation of the triggering receptor expressed on myeloid cells (TREM1) pathway was seen in response to surgery in omental fat samples. In postoperative muscle samples, gene expression differences indicated activation of the peroxisome proliferator-activated receptor (PPAR-α)/retinoid X-receptor (RXR-α) pathway in obese but not in non-obese participants. There were no significant changes in gene expression pathways associated with carbohydrate treatment.

Conclusion

The reduction in insulin sensitivity associated with major abdominal surgery was confirmed but there were no differences associated with preoperative carbohydrates or obesity.

Inflammation increases pyruvate dehydrogenase kinase 4 (PDK4) expression via the Jun N-Terminal Kinase (JNK) pathway in C2C12 cells

Chronic inflammation augments the deleterious effects of several diseases, particularly diabetes, cancer, and sepsis. It is also involved in the process of metabolic shift from glucose oxidation to lactate production. Although several studies suggest that the change in activity of the pyruvate dehydrogenase complex (PDC) is a major factor causing this metabolic change, the exact mechanism of the inflammatory state remains unclear. In this study, we investigated the effect of lipopolysaccharide (LPS) on the expression of pyruvate dehydrogenase kinase 4 (PDK4), which is strongly associated with inactivation of the PDC in C2C12 myoblasts. In C2C12 myoblasts, LPS exposure led to increased PDK4 mRNA and protein expression levels as well as lactate production in culture medium. However, the expression levels of other PDK isoenzymes (PDK1 - 3) remained unchanged. Additionally, we observed that LPS treatment induced phosphorylation of Jun N-Terminal Kinases (JNK). To confirm the role of JNK, we inhibited the JNK pathway and observed that PDK4 expression and lactate production were decreased, but p38 and ERK were not significantly changed. Taken together, our results suggest that LPS induces PDK4 expression and alters glucose metabolism via the JNK pathway.