Homeostatic model assessment indices in evaluation of insulin resistance and secretion in hemodialysis patients

The impact of Hafnia alvei HA4597™ on weight loss and glycaemic control after bariatric surgery - study protocol for a triple-blinded, blocked randomized, 12-month, parallel-group, placebo-controlled clinical trial

BACKGROUND

Subjects with obesity exhibit changes in gut microbiota composition and function (i.e. dysbiosis) that contribute to metabolic dysfunction, including appetite impairment. Although bariatric surgery is an effective treatment for obesity with a great impact on weight loss, some subjects show weight regain due to increased energy intake after the surgery. This surgery involves gut microbiota changes that promote appetite control, but it seems insufficient to completely restore the obesity-associated dysbiosis - a possible contributor for weight regain. Thus, modulating gut microbiota with probiotics that could improve appetite regulation as a complementary approach to post-operative diet (i.e. Hafnia alvei HA4597™), may accentuate post-surgery weight loss and insulin sensitivity.

METHODS

This is a protocol of a triple-blinded, blocked-randomized, parallel-group, placebo-controlled clinical trial designed to determine the effect of Hafnia alvei HA4597™ supplementation on weight loss and glycaemic control 1 year after bariatric surgery. Patients of Hospital CUF Tejo, Lisbon, that undergo Roux-en-Y gastric bypass are invited to participate in this study. Men and women between 18 and 65 years old, with a BMI ≥ 35 kg/m2 and at least one severe obesity-related comorbidity, or with a BMI ≥ 40 kg/m2, and who are willing to take 2 capsules of Hafnia alvei HA4597™ probiotic supplements (equivalent to 5 × 107 CFU) vs. placebo per day for 90 days are included in this study. Assessments are carried out at baseline, 3, 6, 9, and 12 months after the surgery. Loss of weight in excess and glycated haemoglobin are considered primary outcomes. In addition, changes in other metabolic and inflammatory outcomes, gut microbiota composition and metabolites, as well as gastrointestinal quality of life are also being assessed during the trial.

DISCUSSION

The evidence obtained in this study will provide relevant information regarding the profile of the intestinal microbiota of individuals with severe obesity and the identification of the risk/benefit ratio of the use of Hafnia alvei HA4597™ as an adjunctive treatment in the maintenance of metabolic and weight control one year after the surgical intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05170867. Registered on 28 December 2021.

Efficacy of two doses of external counterpulsation (ECP) on glycemic control in people with type 2 diabetes mellitus: A randomized SHAM-controlled trial

AIMS

To determine the efficacy of two doses of external counterpulsation (ECP) on glycemic control in people with type 2 diabetes mellitus (T2D), and any persistent benefits 7 weeks following treatment.

METHODS

50 participants with T2D were randomly assigned to either 1) 20x45-minute ECP sessions over 7 weeks (ECP₄₅), 2) 20x30-minute ECP sessions over 7 weeks (ECP₃₀) or 3) SHAM control. Outcomes were assessed at baseline, after 7 weeks of the intervention and 7 weeks after the interventions finished. Efficacy was determined from changes in HbA_1c.

RESULTS

After 7 weeks, there were significant between-group differences, with ECP₄₅ lowering HbA_1c compared to SHAM (mean [95% CI] -0.7 [-0.1 to -1.3] %; -7 [-1 to -15] mmol/mol). Within group changes were; ECP₄₅ (mean±SD -0.8±0.8%; -8±8 mmol/mol), ECP₃₀ (-0.2±0.5%; -2±6 mmol/mol) and SHAM (-0.1±0.9%; -1±10 mmol/mol). HbA_1c in the ECP₄₅ group remained lower 7 weeks after completing the intervention; ECP₄₅ (7.0±1.1%; 53±26 mmol/mol), ECP₃₀ (7.7±1.4%; 60±16 mmol/mol) and SHAM (7.7±1.0%; 60±10 mmol/mol).

CONCLUSIONS

In people with T2D, ECP₄₅ for 7 weeks improved glycemic control when compared to ECP₃₀ and a SHAM control group.

Protective Effect of Hydroalcoholic Extract of Punica granatum Leaves on High Fructose Induced Insulin Resistance in Experimental Animals

BACKGROUND

Insulin resistance (IR) is a condition characterized by reduced sensitivity of body tissues to insulin, leading to impaired regulation of downstream metabolic pathways and elevated blood glucose levels. Diets rich in fructose have been proven to cause insulin resistance in test rats, resulting in decreased insulin sensitivity, particularly in the liver, and compromised disposal of glucose from the body. In the search for effective treatments, Plant-derived formulations have gained popularity because to their ability for treating a variety of ailments. One such plant is Punica granatum Linn. from the Punicaceae family, which has long been used in the treatment of diabetes and its consequences. This study investigates the insulin-resistant activity of an extract from Punica granatum leaves. The study goal is to assess the possible protective role of Punica granatum against insulin resistance through various analyses, including serum glucose and insulin levels, lipid profile assessment, measurement of liver enzymes (ALP, SGOT, SGPT), and histopathological examination of liver sections.

METHODS

The study involves several key methods to evaluate the insulin-resistant activity of Punica granatum extract in high fructose diet induced insulin resistance animal model. The extract was administered orally to the experimental animals. These methods include the measurement of serum glucose and serum insulin levels, analysis of the lipid profile, quantification of liver enzymes such as ALP, SGOT, and SGPT, and a detailed histopathological examination of liver tissue sections. These analyses collectively provide insights into the impact of Punica granatum extract on insulin resistance and related metabolic parameters.

RESULTS

Findings of this study provide insight on the possible benefits of Punica granatum extract on insulin resistance. Through the assessment of serum glucose and insulin levels, lipid profile analysis, and measurement of liver enzymes, the study elucidates the impact of the extract on key metabolic indicators. Additionally, the histopathological examination of liver sections provides visual insights into the structural changes that may occur as a result of the treatment.

CONCLUSION

In conclusion, this study highlights the ability of Punica granatum extract as a candidate for addressing insulin resistance. The findings suggest that the extract may have a protective role against insulin resistance, as evidenced by improvements in serum glucose and insulin levels, lipid profile, liver enzyme levels, and histopathological characteristics. Further research and investigations are warranted to fully understand the mechanisms underlying these observed effects and to validate the potential of Punica granatum extract as a therapeutic option for managing insulin resistance and its associated complications.

Serum and salivary adipsin levels and its association with insulin resistance in acne vulgaris patients

BACKGROUND

There is scarcity in literature about the reliability of salivary markers in acne vulgaris.

AIMS

The aims were to evaluate the insulin resistance (IR) and adipsin levels in serum and saliva in a sample of acne vulgaris patients; and to correlate IR and adipsin levels with the disease severity.

METHODS

This prospective case-control study included 60 acne vulgaris patients (patients Group), in addition, 60 apparently healthy individuals (control group). The severity of acne vulgaris was determined according to Global Acne Grading system (GAGS). Serum and salivary adipsin, fasting glucose, and fasting insulin levels were measured using ELISA kits.

RESULTS

Fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) in patients group both in serum and saliva were elevated when compared with the control group. Serum and salivary levels of adipsin and Quantitative insulin sensitivity check index (QUIKI) in patients were decreased than the control group. Adipsin serum levels show significant negative correlations with all study variables except QUIKI with which the correlation was positive both in serum and saliva. There was a significant positive correlation between serum and salivary adipsin levels (r = 0.873, p < 0.00001) and serum and salivary fasting glucose (r = 1, p < 0.00001).

CONCLUSION

Adipsin could be considered as a promising biomarker for acne vulgaris and its associated insulin resistance. Moreover, the salivary measurements may be considered as useful biomarkers in acne vulgaris patients, but more studies are still required.

Effect of Date Fruit Consumption on the Glycemic Control of Patients with Type 2 Diabetes: A Randomized Clinical Trial

Objective. Date fruit has been reported to have benefits in type 2 diabetes (T2D), though there is a concern, given the high sugar content, about its effects on glycemic control. Design and Setting. Prospective, interventional, randomized, parallel study. Participants. In total, 79 patients with T2D (39 male and 40 female). Intervention. Participants were randomly allocated to either 60 g date fruit or 60 g raisins daily of the equivalent glycemic index (amount split, given as midmorning and midafternoon snack) for 12 weeks. Main Outcome Measures. The primary outcome was to investigate the effect of date fruit on HbA1c and fasting blood glucose, and their variability, in patients with T2D in comparison to the same glycemic load of raisins. The secondary outcomes were to determine whether date fruit affected cardiovascular risk by measuring fasting lipids, C-reactive protein (CRP), blood pressure, and insulin resistance (IR) as measured by Homeostatic Model Assessment (HOMA-IR). Results. In total, 61 (27 female and 34 male) of 79 patients completed the study. There was no difference between or within groups for HbA1c or HbA1c variability, fasting glucose or glucose variability, insulin resistance (HOMA-IR), insulin sensitivity (HOMA-S), beta cell function (HOMA-B), the disposition index, lipids, systolic (SBP) or diastolic blood pressure (DBP), or C-reactive protein (CRP) (p > 0.05). Conclusion. No improvement in glycemic indices was seen following supplementation of 60 g daily date fruit or raisins, though neither had a deleterious effect on glycemic control over a 12-week period, indicating their safety when consumed in T2D. Additionally, no beneficial therapeutic effects of date fruit on other cardiovascular indices in T2D were seen.

Chronic activation of cardiac Atg-5 and pancreatic Atg-7 by intermittent fasting alleviates acute myocardial infarction in old rats

BACKGROUND

Aging is associated with cardiovascular and metabolic changes, increasing the susceptibility to acute myocardial infarction (AMI). Intermittent fasting (IF) has a beneficial effect on the age-associated cardiovascular diseases. The present study was planned to investigate the possible protective effect of IF against acute AMI induced by isoproterenol (ISO) in old rats and its possible underlying mechanisms mediated by heart and pancreatic autophagy. Thirty Male Wistar rats were divided into four groups: adult; old; Old-ISO (rats subjected to AMI by ISO) and Old-F-ISO groups (rats were subjected to IF for 4 weeks and AMI by ISO).

RESULTS

IF significantly increased the mRNA expression of cardiac Atg-5 and pancreatic Atg-7 in Old-F-ISO versus old and adult groups. This was associated with a significant decrease in serum troponin-I, serum creatine kinase (CK-MB), cardiac malondialdehyde and cardiac TNF-α, fasting plasma glucose, and HOMA-IR in Old-F-ISO compared to Old-ISO group. Also, IF significantly decreased the age-related overall and visceral obesity in Old-F-ISO versus old and Old-ISO groups. Histological studies revealed attenuation of the local inflammatory response in Old-F-ISO versus Old-ISO group. Pancreatic Atg-7 and heart Atg-5 were significantly increased in Old-ISO versus old rats.

CONCLUSIONS

IF protects against acute AMI in old rats, possibly, via chronic activation of heart Atg-5 and pancreatic Atg-7, and alleviation of age-related overall and visceral obesity. Thus, IF could be a dietary lifestyle modification for attenuation of the susceptibility to acute AMI in aged population. On the other hand, acute activation of heart and pancreatic autophagy by ISO might augment cardiac injury.

A Pilot Study on the Metabolic Impact of Mediterranean Diet in Type 2 Diabetes: Is Gut Microbiota the Key?

The Mediterranean diet (MD) has been recommended for type 2 diabetes (T2D) treatment. The impact of diet in shaping the gut microbiota is well known, particularly for MD. However, the link between MD and diabetes outcome improvement is not completely clear. This study aims to evaluate the role of microbiota modulation by a nonpharmacological intervention in patients with T2D. In this 12-week single-arm pilot study, nine participants received individual nutritional counseling sessions promoting MD. Gut microbiota, biochemical parameters, body composition, and blood pressure were assessed at baseline, 4 weeks, and 12 weeks after the intervention. Adherence to MD [assessed by Mediterranean Diet Adherence Screener (MEDAS) score] increased after the intervention. Bacterial richness increased after 4 weeks of intervention and was negatively correlated with fasting glucose levels and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Prevotella to Bacteroides ratio also increased after 4 weeks. In contrast, glycated haemoglobin (HbA1c) and HOMA-IR were only decreased at the end of study. Alkaline phosphatase activity was assessed in fecal samples and was negatively correlated with HbA1c and positively correlated with bacterial diversity. The results of this study reinforce that MD adherence results in a better glycemic control in subjects with T2D. Changes in gut bacterial richness caused by MD adherence may be relevant in mediating the metabolic impact of this dietary intervention.

Glucose tolerance in patients with and without type 2 diabetes mellitus during hemodialysis

AIMS

The disposal of a glucose bolus was studied to identify glucose metabolism in patients with and without type 2 diabetes mellitus (T2DM) during their regular hemodialysis (HD) treatment.

METHODS

Plasma glucose, insulin, and c-peptide concentrations were measured during a 60 min observation phase following a rapid glucose infusion (0.5 g/kg dry weight). Glucose disposition and elimination rates were determined from kinetic analysis, and insulinogenic index was calculated. Insulin resistance (R_HOMA) was determined by homeostatic model assessment (HOMA).

RESULTS

35 HD patients (14 with T2DM) distinguished by a higher age (median: 70 vs. 55 y, p < 0.01) in T2DM patients were studied. Glucose kinetic data showed only small differences between patients with or without T2DM, but as R_HOMA measured in all patients increased, a larger fraction of glucose was removed by the extracorporeal system (r = 0.430, p = 0.01). One hour after glucose bolus injection the glucose level was not different from that before HD also in patients with T2DM (p = 0.115).

CONCLUSIONS

The larger glucose amount recovered in dialysate in patients with increasing R_HOMA indicates that impaired glucose disposal could be measured during HD using a non-invasive dialysis quantification approach without blood sampling. Glucose infusion during HD is safe also in patients with T2DM.

Disturbances in Insulin-Glucose Metabolism in Patients With Advanced Renal Disease With and Without Diabetes

CONTEXT

Use of insulin in patients with diabetes and advanced chronic kidney disease (CKD; stages 4 to 5) is challenging and shows great variability among individuals. We explored the mechanisms underlying this variability.

EVIDENCE ACQUISITION

PubMed was searched for articles in English from 1960 to 2018 for advanced CKD and diabetes, glucose and insulin metabolism, insulin clearance, secretion and resistance, plasma insulin concentration, glycemic control, hypoglycemia, insulin dosage, and continuous glucose monitoring (CGM) in CKD.

EVIDENCE SYNTHESIS

The evidence shows that in most patients the daily dose of insulin needs to be significantly reduced with a high degree of variability; in some the dose remains unchanged, and rarely it is increased. The premise that the marked reduction in insulin requirement is essentially attributable to decreased insulin clearance by kidneys leading to prolongation of its plasma half-life, elevated blood insulin concentration, and hypoglycemia is not entirely correct. Other factors including decreases in food intake, insulin secretion, insulin clearance by peripheral tissues, and renal gluconeogenesis play important roles. There is also heightened resistance to insulin due to metabolic acidosis, uremic toxins, inflammatory state, and vitamin D deficiency. Importantly, the magnitude of changes in each of these factors varies between individuals with the same degree of CKD.

CONCLUSIONS

In the presence of diabetes with advanced CKD, the insulin regimen should be individualized based on knowledge of the daily glucose patterns. The use of CGM is promising for safer glycemic control in patients with advanced CKD and diabetes and helps prevent extremes of hypoglycemia and hyperglycemia.

[Neurological mechanism and therapeutic strategy for posttraumatic stress disorders]

Posttraumatic stress disorder (PTSD) is most often induced by traumatic events and serious public health problems. PTSD is characterized by excessive response to contextual memory and impaired fear extinction and also associated with mild cognitive impairment, attention and learning deficits. Clinical and animal studies suggest that increased susceptibility of emotion- and fear-related neuronal circuits, including those in the amygdala, prefrontal cortex and hippocampus, contributes to development and retention of PTSD symptoms. However, mechanisms underlying this susceptibility to fear are not known and the useful therapeutic approaches are limited. Recently, there have been reports that ω3 LCPUFA supplementation can prevent development of PTSD and significantly ameliorate symptoms in patients with PTSD after accidental injury such as motor vehicle accidents and natural calamities. Importantly, Fabp7 null mice exhibit enhancement of fear memory consolidation and anxiety-related behaviors that resemble PTSD-like behaviors in humans. In this review, we focused behavioral phenotype of PTSD in Fabp3 null mice. The Fabp3 null mice exhibit cognitive deficits, hyperlocomotion and impaired fear extinction, and thus show PTSD-like behaviors. Chronic administration of ramelteon, a melatonin receptor agonist, improved all PTSD-like behaviors tested in Fabp3^－/－ mice. Relevant to mechanisms underlying impaired fear extinction, we observed that Ca^2＋/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation increases in the basolateral amygdala (BLA) but remained unchanges in the hippocampus of Fabp3^－/－ mice. Likewise, the number of c-Fos positive neurons in BLA significantly increased after exposure to contextual fear conditions. Finally, chronic ramelteon administration restored abnormal c-Fos expression and CaMKII autophosphorylation in the BLA of Fabp3^－/－ mice. Taken together, Fabp3^－/－ mice show PTSD-like behaviors, and ramelteon is an attractive candidate for PTSD therapeutics in human.

Indirect insulin resistance detection: Current clinical trends and laboratory limitations

There is a steady increase in the number of overweight and obese people worldwide and increasingly, younger people. Excess adipose tissue impairs the action of insulin, leading to insulin resistance (IR). Tissue IR is a major factor in relation to cardiovascular disease, metabolic syndrome and diabetes. Thus, it is important to recognize at the pre-disease stage with the possibility of therapeutic intervention. IR is assessed using indicators of epidemiological significance, most often calculated from fasting and postprandial glucose and insulin values, so-called indirect indicators of insulin resistance. The most commonly used parameter is the Homeostatic Model Assessment (HOMA). Although the Quantitative Insulin Sensitivity Check Index (QUICKI), Matsuda Index and the Insulin Secretion-Sensitivity Index-2 (ISSI-2) are also used, the values of these indices established for IR vary for different age, sex, populations and ethnic groups. Thus, appropriate reference values of indirect indices should be determined for such groups, and when this is precluded, data from published studies carried out on the most ethnically, socio-economically and age-matched populations should be applied.

Association and risk factors of chronic kidney disease and incident diabetes: a nationwide population-based cohort study

AIMS/HYPOTHESIS

Chronic kidney disease (CKD) is a known complication of diabetes mellitus, and insulin resistance is a well-known complication of CKD. However, there is no consensus in the published data on the association of CKD with incident diabetes.

METHODS

A total of 15,403 people with CKD were identified from the Taiwan National Health Insurance Research Database to determine their risk of incident diabetes compared with that of 15,403 matched individuals without CKD. Fine and Gray regression models using death as a competing risk were performed to calculate adjusted HRs and 95% CIs. Risk factors for incident diabetes in people with CKD were also determined.

RESULTS

The CKD cohort had a higher incidence rate of diabetes compared with the non-CKD cohort (11.23/1000 person-years vs 8.93/1000 person-years). In the fully adjusted model, CKD was a significant and independent predictor of incident diabetes (adjusted HR 1.204; 95% CI 1.11, 1.31). The influence of CKD on incident diabetes showed consistent results in three levels of sensitivity analysis. In the CKD cohort, the significant risk factors for incident diabetes included increased age, geographical location, hypertension, hyperlipidaemia and gout. Of these, hypertension was associated with the highest risk of developing incident diabetes (adjusted HR 1.682; 95% CI 1.47, 1.93).

CONCLUSIONS/INTERPRETATION

People with CKD were at higher risk of developing incident diabetes. People with CKD and hypertension, hyperlipidaemia, increased age or gout and who lived in certain geographical regions of Taiwan were more likely to develop diabetes as a complication compared with people without those characteristics.

One Year of Yoga Training Alters Ghrelin Axis in Centrally Obese Adults With Metabolic Syndrome

Introduction: Metabolic syndrome (MetS) is a multiplex cardiometabolic manifestation associated with type 2 diabetes mellitus and cardiovascular diseases. Yoga training has been shown to alleviate MetS. Recently, circulatory ghrelin profile was demonstrated to be associated with MetS. This study examined the effects of 1 year of yoga training on β-cell function and insulin resistance, and the involvement of metabolic peptides, including unacylated ghrelin (UnAG), acylated ghrelin (AG), obestatin, growth hormone (GH), and insulin, in the beneficial effects of yoga training in centrally obese adults with MetS. Methods: This was a follow up study, in which data of risk factors of MetS, physical performance tests [resting heart rate (HR), chair stand test (CS), chair sit and reach test (CSR), back scratch test (BS), and single leg stand tests (SLS)] and serum samples of 79 centrally obese MetS subjects aged 58 ± 8 years (39 subjects received 1-year yoga training and 40 subjects received no training) were retrieved for analyses. β-cell function and insulin resistance were examined by Homeostasis Model Assessment (HOMA). Circulating levels of UnAG, AG, obestatin, GH, and insulin were determined by enzyme-linked immunosorbent assay using fasting serum samples. Generalized estimating equation analysis and Mann-Whitney U-test were used to detect statistically significant differences between groups. Results: Waist circumference (WC) was significantly decreased after yoga intervention (control: +2%; yoga: -4%). Significant improvements in HR (control: +2%; yoga: -5%), CS (control: -1%; yoga: +24%), CSR left (control: worsen by 0.90 cm; yoga: improved by 4.21 cm), CSR right (control: worsen by 0.75 cm; yoga: improved by 4.28 cm), right side of BS (control: improved by 0.19 cm; yoga: improved by 4.31 cm), SLS left (control: -10%; yoga: +86%), and SLS right (control: -6%; yoga: +47%) were observed after 1-year yoga training. No significant difference was found between the two groups in insulin, HOMA indices, and disposition index. Yoga training significantly increased circulating GH (control: -3%; yoga: +22%), total circulating ghrelin (control: -26%; yoga: +13%), and UnAG (control: -27%; yoga: +14%), whereas decreased AG (control: -7%; yoga: -33%) and obestatin (control: +24%; yoga: -29%). Conclusion: One-year of yoga training modulated total ghrelin, UnAG, AG, obestatin, and GH while exerting beneficial effects on physical functions and central obesity in adults with MetS. The beneficial effects of yoga may be associated with the alteration of ghrelin gene product and GH.

A Prospective Study of Renal Transplant Recipients: A Fall in Insulin Secretion Underpins Dysglycemia After Renal Transplantation

Background

Dysglycemia (encompassing impaired glucose tolerance and diabetes mellitus) arising after renal transplantation is common and confers a significant cardiovascular mortality risk. Nonetheless, the pathophysiology of posttransplant dysglycemia is not well described. The aim of this study was to prospectively and comprehensively assess glucose handling in renal transplant recipients from before to 12 months after transplantation to determine the underpinning pathophysiology.

Materials and Methods

Intravenous and oral glucose tolerance testing was conducted before and at 3 and 12 months posttransplantation. An intravenous glucose tolerance test was also performed on day 7 posttransplantation. We followed up 16 transplant recipients for 3 months and 14 recipients for 12 months. Insulin secretion, resistance and a disposition index (DI (IV)), a measure of β cell responsiveness in the context of prevailing insulin resistance, were also determined.

Results

At 12 months, 50% of renal transplant recipients had dysglycemia. Dysglycemia was associated with a dramatic fall in DI (IV) and this loss in β cell function was evident as early as 3 months posttransplantation (23.5 pretransplant; 6.4 at 3 months and 12.2 at 12 months posttransplant). Differences in the β cell response to oral glucose challenge were evident pretransplant in those destined to develop dysglycemia posttransplant (2-hour blood glucose level 5.6 mmol/L versus 6.8 mmol/L; P < 0.01).

Conclusions

Dysglycemia after renal transplantation is common, and the loss of insulin secretion is a major contributor. Subclinical differences in glucose handling are evident pretransplant in those destined to develop dysglycemia potentially heralding a susceptible β cell which under the stressors associated with transplantation fails.

The Origin of New-Onset Diabetes After Liver Transplantation: Liver, Islets, or Gut?

New-onset diabetes is a frequent complication after solid organ transplantation. Although a number of common factors are associated with the disease, including recipient age, body mass index, hepatitis C infection, and use of immunosuppressive drugs, new-onset diabetes after liver transplantation (NODALT) has the following unique aspects and thus needs to be considered its own entity. First, a liver graft becomes the patient's primary metabolic regulator after liver transplantation, but this would not be the case for kidney or other grafts. The metabolic states, as well as the genetics of the graft, play crucial roles in the development of NODALT. Second, dysfunction of the islets of Langerhans is common in cirrhotic patients and would be exacerbated by immunosuppressive agents, particularly calcineurin inhibitors. On the other hand, minimized immunosuppressive protocols have been widely advocated in liver transplantation because of liver tolerance (immune privilege). Third and last, through the "gut-liver axis," graft function is closely linked to gut microbiota, which is now considered an important metabolic organ and known to independently influence the host's metabolic homeostasis. Liver transplant recipients present with specific gut microbiota that may be prone to trigger metabolic disorders. In this review, we proposed 3 possible sites for the origin of NODALT, which are liver, islets, and gut, to help elucidate the underlying mechanism of NODALT.

Glycaemic changes in patients with chronic kidney disease

In Argentina, there have been no studies aimed at establishing the prevalence of dysglycaemia (impaired fasting glucose [IFG], impaired glucose tolerance [IGT] and diabetes mellitus [DM]) in patients with chronic kidney disease (CKD). Our group decided to conduct an observational study to evaluate the frequency with oral glucose tolerance test (OGTT) in CKD patients with no previous data for dysglycaemia in their medical records. OGTT was performed in 254 patients (60.62% male) with stage 3, 4 and 5 CKD under conservative treatment, haemodialysis or transplantation. Results for DM were found in 10 patients according to fasting glucose alone (3.94%; 95% CI: 1.35-6.53%), 11 patients with exclusively the second hour criterion (4.33%; 95% CI: 1.63-7.03%), 15 with both criteria (5.91%; 95% CI: 2.81-9.00%) and 36 patients with at least one criteria (14.17%; 95% CI: 9.69-18.66%). In a multivariate analysis, DM was associated with waist circumference (OR=1.033 per cm; 95% CI, 1.005 to 1.062; P=.019) and with conservative treatment vs. replacement therapy (OR=0.41; 95% CI: 0.19-0.92; P=.028). IGT was evident in 24.6% and 20.3 on conservative vs. replacement therapy, with no statistically significant difference. IFG (ADA criteria) was 19.75 vs. 9.24% in conservative vs. replacement therapy, with a statistically significant difference. OGTT is suggested for all CKD patients since it is able to detect the full range of unknown dysglycaemias, which avoids underdiagnoses and favours performing treatments to prevent progression in DM risk groups (IFG and/or IGT). It also aids in the selection of the most appropriate medication for transplantation or treatment initiation in new cases of undiagnosed DM to decrease morbidity and mortality.

Cut-off points of homeostasis model assessment of insulin resistance, beta-cell function, and fasting serum insulin to identify future type 2 diabetes: Tehran Lipid and Glucose Study

AIMS

To determine cut-off points of homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function (HOMA-B), insulin sensitivity (HOMA-S), and fasting insulin for identifying the subjects with type 2 diabetes mellitus (T2DM) in Iranian adults using data from a prospective population-based study.

METHODS

From participants of Tehran Lipid and Glucose Study, 4942 Iranian subjects, aged 20-86 years, were followed for incident T2DM. Fasting serum insulin was determined by the electrochemiluminescence immunoasaay. The associations between HOMA-IR, HOMA-B, HOMA-S, and fasting insulin and incident T2DM were evaluated using Cox proportional hazards models. The receiver operator characteristic curve analysis was used to determine the cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting insulin.

RESULTS

After 9.2 year follow-up, 346 (7.0 %) incident cases of T2DM were identified; the risk-factor-adjusted hazard ratios for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.15, 1.70, 0.732, 0.997, 0.974, 0.986, and 1.01 in women and 1.37, 1.67, 0.588, 0.993, 0.986, 0.991, and 1.06 in men, respectively (all p < 0.05 except for HOMA2-B in women). Optimal cut-off points for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.85, 1.41, 86.2, 72.5, 54.1, 63.7, and 11.13 µU/ml in women and 2.17, 1.18, 67.1, 74.6, 46.1, 74.1, and 9.16 µU/ml in men, respectively.

CONCLUSIONS

HOMA-IR, HOMA-B (except for HOMA2-B in women), HOMA-S, and fasting insulin were independent predictors of T2DM. Optimal cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting serum insulin were determined from a population-based study for identifying incident T2DM.

The effect of two different high-flux dialysis membranes on insulin resistance in non-diabetic end-stage renal disease patients

OBJECTIVE

The aim of this study was to investigate the effect of two different types of high-flux dialysis membranes on insulin resistance among patients who are receiving hemodialysis (HD) due to end-stage renal failure (ESRF).

MATERIALS AND METHODS

Forty-six (21 female, 25 male) patients were included in the study, who were on HD treatment due to stage-5 chronic renal failure. Prior to the study, fasting insulin resistance via Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) and fractioned urea clearance (Kt/V) values were calculated using the urokinetic model. The polysulfone (PS) dialysis membrane of all patients included in the study was replaced with "polyarylethersulfone, polyvinylpyrrolidone, polyamide (PPP)" high-flux membrane that has the same surface area over 12 weeks. At the end of the 12-week period, HOMA and Kt/V values were recalculated.

RESULTS

At the end of the 12-week period, Kt/V values rose statistically significant from 1.575 to 1.752 (p = 0.002). HOMA-IR values declined, though not statistically significant, from 3.268 to 2.926 (p = 0.085). PPP high-flux membrane increased the Kt/V values significantly compared to the PS membrane, while it decreased the insulin resistance and increased insulin sensitivity.

CONCLUSION

The two different types of high-flux dialysis membranes used for HD have different effects on insulin sensitivity. Compared to the PS membrane, PPP high-flux membrane decreased insulin resistance by increasing insulin sensitivity among non-diabetic ESRF patients.

Visceral adipose tissue is associated with insulin resistance in hemodialyzed patients

BACKGROUND

It has not been definitively established which factors affect insulin resistance (IR) and whether dialysis decreases IR. The aim of this study was to investigate factors that may have an influence on homeostasis model assessment (HOMA-IR) in hemodialyzed patients (HDpts) and to compare IR between HDpts and healthy subjects.

MATERIAL AND METHODS

We examined 33 HDpts and paired 33 subjects of the control group, matched for sex, age, and BMI. We analyzed concentrations of insulin, glucose, leptin, resistin, and total and high-molecular-weight adiponectin (HMWad) in serum. Using computed tomography in HDpts, we evaluated visceral adipose tissue (VAT), concentrations of visfatin, CRP, and IL-6.

RESULTS

HOMA-IR (median, 1.3 vs. 1.4, P=0.19), insulin (median 6.8 vs. 6.0 µIU/mL, P=0.7), glucose (79 mg/dL vs. 93 mg/dL, P=0.001). IR in HDpts is dependent on VAT (r=0.36, P=0.04) and this relationship is stronger than the relationship of BMI and IR (r=0.3, P=0.1). In HDpts we found higher concentrations of leptin (P=0.001) and resistin (P<0.001), with no relation to IR. HMWad and its percentage in relation to total adiponectin are higher in HDpts (P=0.03 and P<0.001, respectively).

CONCLUSIONS

HOMA-IR in HDpts does not differ from the control group. In HDpts it depends on the quantity of VAT and this relationship is stronger than with BMI. In HDpts leptin and resistin do not influence IR. HMWad and its percentage in total adiponectin are significantly higher in HDpts.

Kidney function, β-cell function and glucose tolerance in older men

CONTEXT

Kidney dysfunction induces insulin resistance, but it is unknown if β cell function is affected.

OBJECTIVE

To investigate insulin release (β cell function) and glucose tolerance following a standardized oral glucose tolerance test (OGTT) across kidney function strata.

SETTING AND DESIGN

Community-based cohort study from the Uppsala Longitudinal Study of Adult Men (ULSAM). PARTICIPANTS AND MAIN OUTCOME MEASURE: Included were 1015 nondiabetic Swedish men aged 70-71 years. All participants underwent OGTT and euglycaemic hyperinsulinaemic clamp (HEGC) tests, allowing determination of insulin sensitivity, β cell function, and glucose tolerance. Kidney function was estimated by cystatin C-algorithms. Mixed models were used to identify determinants of insulin secretion after the hyperglycemic load.

RESULTS

As many as 466 (46%) of participants presented moderate-advanced kidney disease. Insulin sensitivity (by HEGC) decreased across decreasing kidney function quartiles. After the OGTT challenge, however, β cell function indices (area under the curve for insulin release, the estimated first phase insulin release, and the insulinogenic index) were incrementally higher. Neither the oral disposition index nor the 2-h postload glucose tolerance differed across the kidney function strata. Mixed models showed that dynamic insulin release during the OGTT was inversely associated with kidney function, despite the correction for each individual's insulin sensitivity or its risk factors.

CONCLUSIONS

In older men, β cell function after a hyperglycemic load appropriately compensated the loss in insulin sensitivity that accompanies kidney dysfunction. As a result, the net balance between insulin sensitivity and β cell function was preserved.

Preoperative oral carbohydrate improved postoperative insulin resistance in rats through the PI3K/AKT/mTOR pathway

Background

Preoperative oral carbohydrate (OCH) improves postoperative insulin resistance (PIR) and insulin sensitivity. However, the exact mechanisms involved in the improvement of PIR with respect to preoperative OCH are still not clear. The aim of this study was to investigate the involvement of preoperative OCH and PI3K/AKT/mTOR pathway in reducing PIR in rats.

Material/Methods

Forty male Sprague-Dawley rats were randomly assigned to PreOp, glucose, saline, and fasting groups. Rats in the PreOp, glucose, and saline groups received OCH, 5% glucose solution, and saline, respectively. Rats in the fasting group did not receive anything but were fasted 3 h before surgery. Blood glucose, insulin and leucine levels, and insulin resistance, secretion, and sensitivity indexes were measured before and after surgery. mRNA and protein (total and phosphorylated) levels of mTOR, IRS-1, PI3K, PKB/AKT, and GlUT4 were measured using real-time polymerase chain reaction and Western blot in skeletal muscles.

Results

In the PIR experiment, blood glucose, serum insulin, insulin resistance, and serum leucine levels were all significantly lower in the PreOp group than in the other 3 groups (P<0.05) after surgery. HOMA-ISI were higher in the PreOp group vs the other 3 groups after surgery (P<0.05), and HOMA-β in the PreOp group was higher than that in the other 3 groups at 30 and 120 min after surgery. Additionally, post-operative phosphorylated IRS-1, PI3K, and AKT protein levels were significantly higher in the PreOp group than in the other 3 groups (P<0.05), but no significant differences were observed in their respective protein levels (P>0.05).

Conclusions

OCH decreases postoperative insulin resistance and improves postoperative insulin sensitivity in skeletal muscles through the PI3K/AKT/mTOR pathway.