Chronic kidney disease attenuates the plasma metabolome response to insulin.
ABSTRACT: Chronic kidney disease (CKD) leads to decreased sensitivity to the metabolic effects of insulin, contributing to protein energy wasting and muscle atrophy. Targeted metabolomics profiling during hyperinsulinemic-euglycemic insulin clamp testing may help identify aberrant metabolic pathways contributing to insulin resistance in CKD. Using targeted metabolomics profiling, we examined the plasma metabolome in 95 adults without diabetes in the fasted state (58 with CKD, 37 with normal glomerular filtration rate [GFR]) who underwent hyperinsulinemic-euglycemic clamp. We assessed heterogeneity in fasting metabolites and the response to insulin to identify potential metabolic pathways linking CKD with insulin resistance. Baseline differences and effect modification by CKD status on changes with insulin clamp testing were adjusted for confounders. Mean GFR among participants with CKD was 37.3 compared with 89.3 ml/min per 1.73 m2 among controls. Fasted-state differences between CKD and controls included abnormalities in tryptophan metabolism, ubiquinone biosynthesis, and the TCA cycle. Insulin infusion markedly decreased metabolite levels, predominantly amino acids and their metabolites. CKD was associated with attenuated insulin-induced changes in nicotinamide, arachidonic acid, and glutamine/glutamate metabolic pathways. Metabolomics profiling suggests disruption in amino acid metabolism and mitochondrial function as putative manifestations or mechanisms of the impaired anabolic effects of insulin in CKD.
Project description:Patients with chronic kidney disease (CKD) are at high risk of progression to end stage renal disease and cardiovascular events. Physical activity may reduce these risks by improving metabolic health. We tested associations of physical activity with central components of metabolic health among people with moderate-severe non-diabetic CKD.We performed a cross-sectional study of 47 people with CKD (estimated GFR <60 ml/min/1.73 m2) and 29 healthy control subjects. Accelerometry was used to measured physical activity over 7 days, the hyperinsulinemic-euglycemic clamp was used to measure insulin sensitivity, and DXA was used to measured fat mass. We tested associations of physical activity with insulin sensitivity, fat mass, blood pressure, serum lipid concentrations, and serum high sensitivity C-reactive protein concentration using multivariable linear regression, adjusting for possible confounding factors.Participants with CKD were less active than participants without CKD (mean (SD) 468.1 (233.1) versus 662.3 (292.5) counts per minute) and had lower insulin sensitivity (4.1 (2.1) versus 5.2 (2.0 (mg/min)/(?U/mL)), higher fat mass (32.0 (11.4) versus 29.4 (14.8) kg), and higher triglyceride concentrations (153.2 (91.6) versus 99.6 (66.8) mg/dL). With adjustment for demographics, comorbidity, medications, and estimated GFR, each two-fold higher level of physical activity was associated with a 0.9 (mg/min)/(?U/mL) higher insulin sensitivity (95% CI 0.2, 1.5, p?=?0.006), an 8.0 kg lower fat mass (-12.9, -3.1, p?=?0.001), and a 37.9 mg/dL lower triglyceride concentration (-71.9, -3.9, p?=?0.03). Associations of physical activity with insulin sensitivity and triglycerides did not differ significantly by CKD status (p-values for interaction >0.3).Greater physical activity is associated with multiple manifestations of metabolic health among people with moderate-severe CKD.
Project description:Intrauterine growth restriction (IUGR) results in dysregulated glucose homeostasis and adiposity in the adult. We hypothesized that with aging, these perturbations will wane, and superimposition of postnatal growth restriction (PNGR) on IUGR [intrauterine and postnatal growth restriction (IPGR)] will reverse the residual IUGR phenotype. We therefore undertook hyperinsulinemic-euglycemic clamp, energy balance, and physical activity studies during fed, fasted, and refed states, in light and dark cycles, on postweaned chow diet-fed more than 17-month aging male IUGR, PNGR, and IPGR vs. control (CON) rat offspring. Hyperinsulinemic-euglycemic clamp revealed similar whole-body insulin sensitivity and physical activity in the nonobese IUGR vs. CON, despite reduced heat production and energy expenditure. Compared with CON and IUGR, IPGR mimicking PNGR was lean and growth restricted with increased physical activity, O(2) consumption (VO(2)), energy intake, and expenditure. Although insulin sensitivity was no different in IPGR and PNGR, skeletal muscle insulin-induced glucose uptake was enhanced. This presentation proved protective against the chronologically earlier (5.5 months) development of obesity and dysregulated energy homeostasis after 19 wk on a postweaned high-fat diet. This protective role of PNGR on the metabolic IUGR phenotype needs future fine tuning aimed at minimizing unintended consequences.
Project description:The goal of this study was to analyse the effect of a 12 weeks treatment with rosiglitazone on insulin sensitivity in the adipose tissue of type 2 diabetic patients. Diabetic patients were submitted to a 3 hours hyperinsulinemic- euglycemic clamp. Adipose tissue biopsies were taken before and after the clamp, labelled A & B respectively. Then, the patients were treated with rosiglitazone, agonist of PPAR gamma, during 12 weeks. After the treatment, all the patients were submitted to a second 3 hours hyperinsulinemic-euglycemic clamp. Adipose tissue biopsies were taken before and after the clamp, labelled C & D respectively. Overall design: Adipose tissues Biopsies from 7 diabetic patients were used in this study. The samples from the same patients (obtained before and after the hyperinsulinemic-euglycemic clamp) were compared on the same microarray. Biopsie taken before the clamp was considered as the control. A dye switch protocol was applied.
Project description:Our objective was to determine if the insulin-sensitizing drug pioglitazone acutely reduces insulin secretion and causes metabolic deceleration in vivo independently of change in insulin sensitivity. We assessed glucose homeostasis by hyperinsulinemic-euglycemic and hyperglycemic clamp studies and energy expenditure by indirect calorimetry and biotelemetry in male Wistar and obese hyperinsulinemic Zucker diabetic fatty (ZDF) rats 45 min after a single oral dose of pioglitazone (30 mg/kg). In vivo insulin secretion during clamped hyperglycemia was reduced in both Wistar and ZDF rats after pioglitazone administration. Insulin clearance was slightly increased in Wistar but not in ZDF rats. Insulin sensitivity in Wistar rats assessed by the hyperinsulinemic-euglycemic clamp was minimally affected by pioglitazone at this early time point. Pioglitazone also reduced energy expenditure in Wistar rats without altering respiratory exchange ratio or core body temperature. Glucose-induced insulin secretion (GIIS) and oxygen consumption were reduced by pioglitazone in isolated islets and INS832/13 cells. In conclusion, pioglitazone acutely induces whole-body metabolic slowing down and reduces GIIS, the latter being largely independent of the insulin-sensitizing action of the drug. The results suggest that pioglitazone has direct metabolic deceleration effects on the ?-cell that may contribute to its capacity to lower insulinemia and antidiabetic action.
Project description:Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARγ ligands. We transcriptionally profiled 364 biopsies gathered from 72 human subjects harvested before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Subjects range from insulin-sensitive to insulin-resistant. Insulin resistant subjects responded to TZD treatment with varied improvements in insulin sensitivity, thus they were ranked by their degree of TZD response to define responder and non-responder subgroups. Overall design: Skeletal muscle biopsies were obtained from vastus lateralis before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Adipose tissue biopsies were obtained from abdominal subcutaneous before clamp, at baseline and after three-month TZD treatment. *** CEL files not provided for 40 Samples. ***
Project description:Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPAR? ligands. We transcriptionally profiled 364 biopsies gathered from 72 human subjects harvested before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Subjects range from insulin-sensitive to insulin-resistant. Insulin resistant subjects responded to TZD treatment with varied improvements in insulin sensitivity, thus they were ranked by their degree of TZD response to define responder and non-responder subgroups. Skeletal muscle biopsies were obtained from vastus lateralis before and after hyperinsulinemic-euglycemic clamp, at baseline and after three-month TZD treatment. Adipose tissue biopsies were obtained from abdominal subcutaneous before clamp, at baseline and after three-month TZD treatment. *** CEL files not provided for 40 Samples. ***
Project description:Alteration of various metabolites has been linked to type 2 diabetes (T2D) and insulin resistance. However, identifying significant associations between metabolites and tissue-specific phenotypes requires a multi-omics approach. In a cohort of 42 subjects with different levels of glucose tolerance (normal, prediabetes and T2D) matched for age and body mass index, we calculated associations between parameters of whole-body positron emission tomography (PET)/magnetic resonance imaging (MRI) during hyperinsulinemic euglycemic clamp and non-targeted metabolomics profiling for subcutaneous adipose tissue (SAT) and plasma. Plasma metabolomics profiling revealed that hepatic fat content was positively associated with tyrosine, and negatively associated with lysoPC(P-16:0). Visceral adipose tissue (VAT) and SAT insulin sensitivity (Ki), were positively associated with several lysophospholipids, while the opposite applied to branched-chain amino acids. The adipose tissue metabolomics revealed a positive association between non-esterified fatty acids and, VAT and liver Ki. Bile acids and carnitines in adipose tissue were inversely associated with VAT Ki. Furthermore, we detected several metabolites that were significantly higher in T2D than normal/prediabetes. In this study we present novel associations between several metabolites from SAT and plasma with the fat fraction, volume and insulin sensitivity of various tissues throughout the body, demonstrating the benefit of an integrative multi-omics approach.
Project description:We hypothesized that acute lipid-induced insulin resistance would be attenuated in high-oxidative muscle of lean trained (LT) endurance athletes due to their enhanced metabolic flexibility and mitochondrial capacity. Lean sedentary (LS), obese sedentary (OS), and LT participants completed two hyperinsulinemic euglycemic clamp studies with and without (glycerol control) the coinfusion of Intralipid. Metabolic flexibility was measured by indirect calorimetry as the oxidation of fatty acids and glucose during fasted and insulin-stimulated conditions, the latter with and without lipid oversupply. Muscle biopsies were obtained for mitochondrial and insulin-signaling studies. During hyperinsulinemia without lipid, glucose infusion rate (GIR) was lowest in OS due to lower rates of nonoxidative glucose disposal (NOGD), whereas state 4 respiration was increased in all groups. Lipid infusion reduced GIR similarly in all subjects and reduced state 4 respiration. However, in LT subjects, fat oxidation was higher with lipid oversupply, and although glucose oxidation was reduced, NOGD was better preserved compared with LS and OS subjects. Mitochondrial performance was positively associated with better NOGD and insulin sensitivity in both conditions. We conclude that enhanced mitochondrial performance with exercise is related to better metabolic flexibility and insulin sensitivity in response to lipid overload.
Project description:Context:3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) are widely prescribed. Statins may have important metabolic effects on insulin sensitivity and liver fat, but limited studies have assessed these effects by using euglycemic hyperinsulinemic clamp, stable isotopes, and 1H magnetic resonance spectroscopy (MRS) for liver fat quantification. Objective:To study the effects of pitavastatin on hepatic fat and insulin sensitivity. Design:Six-month, double-blind, randomized, placebo-controlled trial. Setting:Academic clinical research center in Boston, Massachusetts. Participants:Overweight, insulin-resistant men aged 40 to 65 years who had not received statin therapy for ?1 year. Interventions:Pitavastatin 4 mg or placebo daily. Outcome:The primary endpoints were changes in insulin sensitivity measured by euglycemic hyperinsulinemic clamp and liver fat measured by 1H MRS. Results:Pitavastatin showed no effect on endogenous glucose production (?Ra glucose 0.07 ± 0.07 vs 0.04 ± 0.07 mg/kg/min, pitavastatin vs placebo, P = 0.76) or insulin-stimulated glucose uptake during "low dose" (?M 0.1 ± 0.1 vs -0.3 ± 0.2 mg/kg/min, P = 0.11) and "high dose" (?M -0.5 ± 0.3 vs -0.7 ± 0.4 mg/kg/min, P = 0.70) euglycemic hyperinsulinemic clamps. There was also no effect of pitavastatin on fasting glucose, HbA1c, and 2-hour glucose after 75-g glucose challenge. There was also no change in liver fat fraction (-1 ± 1 vs -0 ± 1%, P = 0.56). Conclusion:Compared with placebo, pitavastatin did not affect hepatic or whole-body insulin sensitivity, and it did not reduce liver fat.
Project description:Insulin resistance in skeletal muscle is an early phenomenon in the pathogenesis of type 2 diabetes. Muscle is mainly responsible for insulin-stimulated glucose clearance from the bloodstream. Thus, regulation of gene expression in muscle tissue may be involved in the pathogenesis of insulin resistance. The objective was to investigate gene expression and metabolic pathways alterations in skeletal muscle tissue following an euglycemic-hyperinsulinemic clamp in obese insulin-resistant subjects. We carried out a transcriptome comparison of skeletal muscle tissue before and after a 3-h euglycemic-hyperinsulinemic clamp following 8-week supplementation with n-3 polyunsaturated fatty acid (PUFA) (1.8 g/day) with or without a supplement of fish gelatin (FG) (25 % of daily protein intake) in 16 obese insulin-resistant subjects. Results indicate that approximately 5 % (1932) of expressed transcripts were significantly changed after the clamp in both n-3 PUFA and n-3 PUFA + FG supplementation periods. Of these differentially expressed transcripts, 1394 genes associated with enzymes, transcription and translation regulators, transporters, G protein-coupled receptors, cytokines, and ligand-dependent nuclear receptors were modified. Metabolic pathways that were significantly modified included liver X receptor/retinoid X receptors (RXR) activation, vitamin D receptor/RXR activation, interleukin (IL)-8, acute phase response, IL10, triggering receptor expressed on myeloid cells 1, peroxisome proliferator-activated receptor, G-beta/gamma and hepatocyte growth factor and IL6 signaling. Taken together, results suggest that mainly inflammatory and transcription factors are modified following clamp in obese insulin-resistant subjects. Overall, understanding the changes in metabolic pathways due to insulin may be a potential target for the management of insulin resistance.