Insulin resistance and beta-cell dysfunction in newly diagnosed type 2 diabetes: Expression, aggregation and predominance. Verona Newly Diagnosed Type 2 Diabetes Study 10.

AIMS: We investigated quantitative expression, mutual aggregation and relation with hyperglycemia of insulin resistance (IR) and beta-cell dysfunction (BCD) in newly diagnosed type 2 diabetes. METHODS: We assessed IR with euglycemic hyperinsulinemic clamp and BCD with modelled glucose/C-peptide response to oral glucose in 729 mostly drug-naïve patients. We measured glycated hemoglobin, pre-prandial, post-prandial and meal-related excursion of blood glucose. RESULTS: IR was found in 87.8% [95% confidence intervals 85.4-90.2] and BCD in 90.0% [87.8-92.2] of subjects, ranging from mild to moderate or severe. Approximately 20% of subjects had solely one defect: BCD 10.8% [8.6-13.1] or IR 8.6% [6.6-10.7]. Insulin resistance and BCD aggregated in most subjects (79.1% [76.2-82.1]). We arbitrarily set nine possible combinations of mild, moderate or severe IR and mild, moderate or severe BCD, finding that each had a similar frequency (∼10%). In multiple regression analyses parameters of glucose control were related more strongly with BCD than with IR. CONCLUSIONS: In newly-diagnosed type 2 diabetes, IR and BCD are very common with a wide range of expression but no specific pattern of aggregation. Beta-cell dysfunction is likely to play a greater quantitative role than IR in causing/sustaining hyperglycemia in newly-diagnosed type 2 diabetes.

Current treatment for polycystic ovary syndrome: focus on adolescence.

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women and it is associated with an increased rate of infertility. Its etiology remains largely unknown, although both genetic and environmental factors play a role. PCOS is characterized by insulin resistance, metabolic disorders and low-grade chronic inflammation. To date, the treatment of PCOS is mainly symptomatic and aimed at reducing clinical signs of hyperandrogenism (hirsutism and acne), at improving menstrual cyclicity and at favoring ovulation. Since PCOS pathophysiology is still largely unknown, the therapeutic interventions currently in place are rarely cause-specific. In such cases, the therapy is mainly directed at improving hormonal and metabolic dysregulations typical of this condition. Diet and exercise represent the main environmental factors influencing PCOS. Thus, therapeutic lifestyle changes represent the first line of intervention, which, in combination with oral contraceptives, represent the customary treatment. Insulin resistance is becoming an increasingly studied target for therapy, most evidence stemming from the time-honored metformin use. Relatively novel strategies also include the use of thiazolidinediones and GLP1-receptor agonists. In recent years, a nutraceutical approach has been added to the therapeutic toolkit targeting insulin resistance. Indeed, emerging data support inositol and alpha-lipoic acid as alternative compounds, alone or in combination with the aforementioned strategies, with favorable effects on ovulation, insulin resistance and inflammation. Nevertheless, additional studies are required in adolescents, in order to assess the effectiveness of diet supplements in preventing negative impacts of PCOS on fertility in adult age. This review focuses on the main therapeutic options for PCOS to date.

Trans-ethnic Meta-analysis and Functional Annotation Illuminates the Genetic Architecture of Fasting Glucose and Insulin.

Knowledge of the genetic basis of the type 2 diabetes (T2D)-related quantitative traits fasting glucose (FG) and insulin (FI) in African ancestry (AA) individuals has been limited. In non-diabetic subjects of AA (n = 20,209) and European ancestry (EA; n = 57,292), we performed trans-ethnic (AA+EA) fine-mapping of 54 established EA FG or FI loci with detailed functional annotation, assessed their relevance in AA individuals, and sought previously undescribed loci through trans-ethnic (AA+EA) meta-analysis. We narrowed credible sets of variants driving association signals for 22/54 EA-associated loci; 18/22 credible sets overlapped with active islet-specific enhancers or transcription factor (TF) binding sites, and 21/22 contained at least one TF motif. Of the 54 EA-associated loci, 23 were shared between EA and AA. Replication with an additional 10,096 AA individuals identified two previously undescribed FI loci, chrX FAM133A (rs213676) and chr5 PELO (rs6450057). Trans-ethnic analyses with regulatory annotation illuminate the genetic architecture of glycemic traits and suggest gene regulation as a target to advance precision medicine for T2D. Our approach to utilize state-of-the-art functional annotation and implement trans-ethnic association analysis for discovery and fine-mapping offers a framework for further follow-up and characterization of GWAS signals of complex trait loci.

Association between non-alcoholic fatty liver disease and risk of atrial fibrillation in adult individuals: An updated meta-analysis.

BACKGROUND & AIMS: Recent studies examined the association between non-alcoholic fatty liver disease (NAFLD) and risk of atrial fibrillation (AF) in adults, but the findings have been inconsistent. We provided a quantitative estimate of the magnitude of the association between NAFLD and risk of AF. METHODS: We searched publication databases using predefined keywords to identify observational studies (published up to December 14, 2018), in which NAFLD was diagnosed by biopsy, imaging or biochemistry and AF was diagnosed by medical history and electrocardiograms. Data from selected studies were extracted and meta-analysis was performed using random-effects modelling. RESULTS: Nine cross-sectional and longitudinal studies were included in the final analysis (n = 364 919 individuals). Meta-analysis of data from 5 cross-sectional studies showed that NAFLD was associated with an increased risk of prevalent AF (random-effects odds ratio 2.07, 95% CI 1.38-3.10; I2  = 54.7%), independent of age, sex, body mass index, hypertension and other common AF risk factors. This risk was particularly high among patients with established diabetes (n = 1 study; random-effects odds ratio 5.17, 95% CI 2.05-13.02). Meta-analysis of data from 4 longitudinal studies showed that NAFLD was independently associated with a 10-year increased risk of incident AF only in type 2 diabetic patients (n = 1 study; random-effects hazard ratio 4.96, 95% CI 1.42-17.28). Sensitivity analyses did not modify these findings. Funnel plots did not reveal significant publication bias. CONCLUSIONS: NAFLD is associated with an increased risk of AF in middle-aged and elderly individuals (especially in those with type 2 diabetes). However, the observational design of the eligible studies does not allow for proving causality.

Diabetes mellitus in stroke unit: prevalence and outcomes-the Verona acute coronary syndrome and stroke in diabetes outcome (VASD-OUTCOME) study.

BACKGROUND: Cerebrovascular accidents (CVA) represent a major complication in diabetes (DM). Real-life evidence as to whether modern management of CVA and DM have softened this relationship is limited. Therefore, we estimated prevalence and impact of DM on in-hospital survival and complications in a contemporary cohort of subjects with CVA. METHODS: We retrospectively evaluated the records of 937 patients admitted for CVA at the Stroke Unit of Verona University Hospital during a 3-year period. Pre-existing or de novo DM was ascertained by prior diagnosis, glucose-lowering therapy at admission/discharge or admittance plasma glucose ≥ 200 mg/dL. Multiple regressions were applied to test DM as predictor of in-hospital mortality, complications (composite of infections, cardio- and cerebrovascular complications, major bleeding and pulmonary complications), duration and costs of hospitalization. RESULTS: Diabetes prevalence was 21%, of which 22% de novo diagnoses. Compared to non-DM, diabetic individuals were older and carried an increased burden of cardiovascular risk factors. Compared to known DM, de novo DM individuals were younger, had higher admittance plasma glucose and poorer cardiovascular comorbidities. Overall, DM versus non-DM individuals did not show significantly increased risk of death (14.0 vs. 9.3%; crude-OR 1.59 95% CI 0.99-2.56). Controlling for confounders did not improve significance. DM resulted independent predictor for in-hospital complications (36.2% vs. 26.9%; adj-OR 1.49, 1.04-2.13), but not for duration and costs of hospitalization. CONCLUSION: DM frequently occurs in patients admitted for stroke and carries an excess burden of adverse in-hospital complications, urgently calling for strategies to anticipate DM diagnosis and tailored treatment in high-risk individuals.

Non-alcoholic fatty liver disease is associated with an increased prevalence of atrial fibrillation in hospitalized patients with type 2 diabetes.

NAFLD (non-alcoholic fatty liver disease) and AF (atrial fibrillation) are two pathological conditions that are highly prevalent in developed countries and share multiple risk factors. The relationship between NAFLD and AF in Type 2 diabetes is currently unknown. We studied a hospital-based sample of 702 patients with Type 2 diabetes discharged from our Division of Endocrinology during 2007-2011. The diagnosis of AF was confirmed in affected participants on the basis of ECGs and medical history by experienced cardiologists. NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Of the 702 hospitalized patients included in the study, 514 (73.2%) of them had NAFLD and 85 (12.1%) had persistent or permanent AF. NAFLD was associated with an increased risk of prevalent AF {OR (odds ratio), 3.04 [95% CI (confidence interval), 1.54-6.02]; P<0.001}. Adjustments for age, sex, systolic BP (blood pressure), HbA1c, (glycated haemoglobin), estimated GFR (glomerular filtration rate), total cholesterol, electrocardiographic LVH (left ventricular hypertrophy), COPD (chronic obstructive pulmonary disease), and prior history of HF (heart failure), VHD (valvular heart disease) or hyperthyroidism did not attenuate the association between NAFLD and AF [adjusted OR, 5.88 (95% CI, 2.72-12.7); P<0.001]. In conclusion, our results show that ultrasound-diagnosed NAFLD is strongly associated with an increased prevalence of persistent or permanent AF in patients with Type 2 diabetes, independently of several clinical risk factors for AF. The potential impact of NAFLD on AF deserves particular attention, especially with respect to the implications for screening and surveillance strategies in the growing number of patients with NAFLD.

Use of DPP4 inhibitors in Italy does not correlate with diabetes prevalence among COVID-19 deaths.

In a nationwide study of 3818 charts from patients with fatal COVID-19, we found that geographical differences in Dipeptidyl peptidase 4 (DPP4) inhibitors use did not correlate with diabetes prevalence among COVID-19 deaths, thus not supporting the hypothesis of a clinically relevant involvement of DPP4 inhibition in COVID-19 development and progression.

Depressive symptoms and glycaemic control in adults with type 1 diabetes: an exploratory study on the role of family functioning.

AIMS: Psychological distress and family functioning have a considerable impact on diabetes self-management and glycaemic control in individuals with type 1 diabetes (T1D). However, the influence of both individual and family factors on glycaemic control has not been adequately investigated yet. This study aimed at examining the relationship between perceived family functioning and depressive symptoms with the frequency of capillary self-monitoring of blood glucose (SMBG) and glycaemic control (HbA1c) in a large sample of adults with T1D. METHODS: In a cross-sectional study design, we consecutively enrolled 90 adults with T1D diagnosis from at least 1 year and currently living in their family of origin or conjugal family from at least 1 year before the enrolment. Questionnaires were administered to assess family functioning and depressive symptoms. The SMBG frequency over the past 3 months and the most recent HbA1c measurement were also collected in each individual. Correlation and mediation analyses were carried out. RESULTS: Glycaemic control showed a positive relationship with depressive symptoms and family balanced cohesion, while SMBG frequency was correlated with family balanced flexibility and rigidity, but not with depressive symptoms. Mediation analyses showed that family rigidity mediates the effect of depressive symptoms on glycaemic control. CONCLUSIONS: This exploratory study highlighted the significance of a cohesive family context to facilitate the achievement of individual glycaemic goals in individuals with T1D. These observations, if confirmed in larger data sets, would timely call for a comprehensive family care assessment as part of the evaluations routinely carried out in the ambulatory care of these individuals.

Fifteen-Year Trends of Cardiogenic Shock and Mortality in Patients with Diabetes and Acute Coronary Syndromes.

PURPOSE: Our study was intended to examine time trends of management and mortality of acute coronary syndrome patients with associated diabetes mellitus. METHODS: We analyzed data from 5 nationwide registries established between 2001 and 2014, including consecutive acute coronary syndrome patients admitted to the Italian Intensive Cardiac Care Units. RESULTS: Of 28,225 participants, 8521 (30.2%) had diabetes: as compared with patients without diabetes, they were older and had significantly higher rates of prior myocardial infarction and comorbidities (all P < .0001). Prevalence of diabetes and comorbidities increased over time (P for trend < .0001). Cardiogenic shock rates were higher in patients with diabetes, as compared with those without diabetes (7.8% vs 2.8%, P < .0001), and decreased significantly over time only in patients without diabetes (P = .007). Revascularization rates increased over time in patients both with and without diabetes (both P for trend < .0001), although with persistingly lower rates in patients with diabetes. All-cause in-hospital mortality was higher in patients with diabetes (5.4 vs 2.5%, respectively, P < .0001) and decreased more consistently in patients without diabetes (P for trend = .007 and < .0001, respectively). At multivariable analysis, diabetes remains an independent predictor of both cardiogenic shock (odds ratio 2.03; 95% confidence interval, 1.77-2.32; P < .0001) and mortality (odds ratio 1.95; 95% confidence interval, 1.69-2.26; P < .0001). CONCLUSIONS: Despite significant mortality reductions observed over 15 years in acute coronary syndromes, patients with diabetes continue to show threefold higher rates of cardiogenic shock and lower revascularization rates as compared with patients without diabetes. These findings may explain the persistingly higher mortality of patients with diabetes and acute coronary syndromes.

Chronic complications in patients with newly diagnosed type 2 diabetes: prevalence and related metabolic and clinical features: the Verona Newly Diagnosed Type 2 Diabetes Study (VNDS) 9.

INTRODUCTION: We explored the presence of chronic complications in subjects with newly diagnosed type 2 diabetes referred to the Verona Diabetes Clinic. Metabolic (insulin secretion and sensitivity) and clinical features associated with complications were also investigated. RESEARCH DESIGN AND METHODS: The comprehensive assessment of microvascular and macrovascular complications included detailed medical history, resting ECG, ultrasonography of carotid and lower limb arteries, quantitative neurological evaluation, cardiovascular autonomic tests, ophthalmoscopy, kidney function tests. Insulin sensitivity and beta-cell function were assessed by state-of-the-art techniques (insulin clamp and mathematical modeling of glucose/C-peptide curves during oral glucose tolerance test). RESULTS: We examined 806 patients (median age years, two-thirds males), of whom prior clinical cardiovascular disease (CVD) was revealed in 11.2% and preclinical CVD in 7.7%. Somatic neuropathy was found in 21.2% and cardiovascular autonomic neuropathy in 18.6%. Retinopathy was observed in 4.9% (background 4.2%, proliferative 0.7%). Chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m2) was found in 8.8% and excessive albuminuria in 13.2% (microalbuminuria 11.9%, macroalbuminuria 1.3%).Isolated microvascular disease occurred in 30.8%, isolated macrovascular disease in 9.3%, a combination of both in 9.1%, any complication in 49.2% and no complications in 50.8%.Gender, age, body mass index, smoking, hemoglobin A1c and/or hypertension were independently associated with one or more complications. Insulin resistance and beta-cell dysfunction were associated with macrovascular but not microvascular disease. CONCLUSIONS: Despite a generally earlier diagnosis for an increased awareness of the disease, as many as ~50% of patients with newly diagnosed type 2 diabetes had clinical or preclinical manifestations of microvascular and/or macrovascular disease. Insulin resistance might play an independent role in macrovascular disease. TRIAL REGISTRATION NUMBER: NCT01526720.

Effects of Aerobic and Resistance Training on Circulating Micro-RNA Expression Profile in Subjects With Type 2 Diabetes.

CONTEXT: Structured exercise programs are of great benefit for the treatment of type 2 diabetes (T2DM). However, whether aerobic (AER) or resistance (RES) exercise training exerts specific epigenetic changes through the expression profile of circulating miRNAs (c-miRNAs) is still largely unknown. OBJECTIVE: To assess whether the c-miRNAs profile changes after either AER or RES training in subjects with T2DM. DESIGN: Twenty-four patients with T2DM randomized to AER or RES training protocols were randomly selected from the Resistance vs. Aerobic Exercise in Type 2 Diabetes (RAED2) Trial (NAER = 12; NRES = 12). The baseline and post-training levels of 179 c-miRNAs were initially measured by RT-PCR in 6 individuals (NAER = 3; NRES = 3). C-miRNAs exhibiting ≥40% fold change variation and/or nominal significance from baseline were measured in the whole group. RESULTS: Nineteen c-miRNAs were eventually assessed in the whole group. Compared with baseline, the post-training levels of miR-423-3p, miR-451a, and miR-766-3p were significantly up-regulated, irrespective of exercise type (P < 0.0026; 0.05/19), and targeted upstream pathways relevant to fatty acids biosynthesis and metabolic regulation. MiR-451a and miR-423-3p were significantly correlated with fat loss (ρ = 0.45 and 0.43, respectively) and resulted, alone or in combination, in being predictors of fat loss in generalized linear regression models including exercise type as covariate. Only the association with miR-451a eventually retained significance after further correction for age, sex, body mass index, and HbA1c. CONCLUSIONS: Exercise training in T2DM is associated with substantial c-miRNAs profile changes, irrespective of exercise type and other relevant metabolic covariates. The mechanistic significance of the observed relationship between fat loss and the epigenetic modifications induced by exercise warrants further investigation in larger datasets.

A Case Report of Insulinoma Relapse on Background Nesidioblastosis: A Rare Cause of Adult Hypoglycemia.

Context: Nesidioblastosis is a rare cause of adult hypoglycemia. Current medical therapy can mitigate disease symptoms. However, side effects and limited efficacy may prevent long-term disease management. Case Description: A 63-year-old white woman presented at our institution on April 2017 with a history of distal spleno-pancreatectomy for well-differentiated insulinoma in 2013. Hypoglycemic events did not resolve after surgery, and residual nesidioblastosis near the pancreatic resection margins was identified. Hypoglycemic episodes increased in frequency and severity despite high-dose diazoxide (DZX) therapy. On April 2016, octreotide was introduced but soon discontinued for inefficacy. When the patient arrived at our attention, add-on pasireotide was started and glucose levels monitored by subcutaneous sensor. Compared with DZX, 225 mg/d alone, sensor glucose during pasireotide + DZX 75 mg/d showed occurrence of severe hypoglycemia. Pasireotide was discontinued, and the instrumental workup (68Ga-DOTATOC CT/positron emission tomography, 99mTc-nanocolloid scintigraphy and echo-endoscopy + fine-needle aspiration biopsy) identified an insulinoma relapse. Subtotal pancreatectomy was performed without further recurrence of hypoglycemia over 9 months of follow-up. Conclusions: Although insulinoma relapses on background nesidioblastosis rarely occur, they should be considered as an alternate diagnosis when medical therapy fails to prevent hypoglycemia. Further studies are warranted to test whether the immunophenotypic signature of nesidioblastosis/insulinoma may provide insights for a tailored use of pasireotide.

Systematic review with meta-analysis: non-alcoholic fatty liver disease is associated with a history of osteoporotic fractures but not with low bone mineral density.

BACKGROUND: Several studies have explored the effect of non-alcoholic fatty liver disease (NAFLD) on bone mineral density (BMD) and risk of osteoporotic fractures in adults. However, the extent to which NAFLD adversely affects bone health remains uncertain. AIM: To provide a quantitative estimation of the magnitude of the association of NAFLD with BMD or history of osteoporotic fractures in adults. METHODS: We searched PubMed, Web of Science, and Scopus using predefined keywords to identify all observational studies, published up to 31 August 2018, in which NAFLD was diagnosed by imaging or histology; BMD was measured by dual energy X-ray absorptiometry; and a self-reported history of osteoporotic fractures was collected with interviewer-assisted questionnaires. Data from selected studies were extracted, and meta-analysis was performed using random-effects modelling. RESULTS: Twelve cross-sectional or case-control studies with aggregate data on 30 041 adults of predominantly Asian ethnicity (30% with NAFLD) were included in the final analysis. No significant differences in BMD at different skeletal sites (whole body, lumbar spine, or femur) were observed between individuals with and without NAFLD. Conversely, NAFLD was associated with increased odds of osteoporotic fractures, especially in older Chinese men (n = 2 studies; random-effects odds ratio 2.10, 95% CI 1.36-3.25; I2  = 0%). Sensitivity analyses did not alter these findings. The funnel plot and Egger test did not reveal significant publication bias. CONCLUSIONS: This meta-analysis suggests that imaging-defined or biopsy-proven NAFLD is associated with a self-reported history of osteoporotic fractures (principally in Chinese men), but not with low BMD, in middle-aged and elderly individuals.

Contribution of a genetic risk score to clinical prediction of hepatic steatosis in obese children and adolescents.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the commonest liver disease in children and adolescents in Western countries. Complex traits arise from the interplay between environmental and genetic factors in the pathogenesis of NAFLD. AIMS: We examined the association between NAFLD and eleven single nucleotide polymorphisms (SNPs) at genetic loci potentially associated with liver damage (GCKR, MBOAT7, GPR120), oxidative stress (SOD2), lipid metabolism (PNPLA3, TM6SF2, LPIN1, ELOVL2, FADS2, MTTP) and fibrogenesis (KLF6) in a paediatric population. A genetic risk score (GRS) was performed taking into account both these SNPs and clinical risk factors. METHODS: We recruited a cohort of 514 obese children and adolescents (mean age [±SD]: 11.2 ±â€¯2.8 years, z-BMI 3.3 ±â€¯0.8). NAFLD was identified by ultrasonography. Genotyping was performed by TaqMan-based RT-PCR system. RESULTS: The overall prevalence of NAFLD was 67.5% (347 patients). Among the eleven genotyped SNPs, the genetic variants in TM6SF2 rs58542926 (OR = 4.13, p = 0.002), GCKR rs1260326 (OR = 1.53, p = 0.003), PNPLA3 rs738409 (OR = 1.58, p = 0.004) and ELOVL2 rs2236212 (OR = 1.34, p = 0.047) were significantly associated with a higher risk of NAFLD. Addition of a 11-polymorphism GRS to established clinical risk factors significantly (albeit modestly) improved the discriminatory capability of the regression model for predicting the risk of NAFLD (with SNPs C-statistic 0.81 [95%CI 0.75-0.88] vs. 0.77 [0.70-0.84] without SNPs; p = 0.047). CONCLUSIONS: NAFLD was strongly associated with three genetic variants, TM6SF2 rs58542926, PNPLA3 rs738409 and GCKR rs1260326, and more slightly with ELOVL2 rs2236212, in obese children and adolescents. Addition of a 11-polymorphism GRS to clinical risk factors improved the predictability of NAFLD.

Ten years of experience with DPP-4 inhibitors for the treatment of type 2 diabetes mellitus.

Achieving and maintaining recommended glycemic targets without causing adverse e ffects, including hypoglycemia, is challenging, especially in older patients with type 2 diabetes mellitus (T2DM). The introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, more than 10 years ago, has provided an alternative to conventional medications for the intensification of glucose-lowering treatment after failure of metformin monotherapy, and therefore, marked an important advance in the management of T2DM. By prolonging the activity of incretin hormones, DPP-4 inhibitors induce insulin release and decrease glucagon secretion in a glucose-dependent manner. This results in a more physiologic glycemic control as compared to that ensured by insulin secretagogues (sulfonylureas and glinides). Overall, DPP-4 inhibitors have a favorable safety profile and can be used without dose adjustments in older adults and in patients with mild renal impairment; they have a neutral effect on body weight and do not cause hypoglycemia by themselves. Safety issues, reported mainly in post-marketing surveillance programs and including cardiovascular outcomes and the risk of acute pancreatitis, are being extensively investigated. The aim of this review is to discuss the impact of DPP-4 inhibitors on the treatment of T2DM, after 10 years of experience, with an emphasis on diabetes care in Italy. We will first describe T2DM treatment in Italy and then provide an overview of the main findings from randomized controlled trials, real-world studies and post-marketing surveillance programs with DPP-4 inhibitors.

SGLT1 and SGLT1 Inhibitors: A Role to Be Assessed in the Current Clinical Practice.

Diabetes is a complex disease of increasingly common occurrence worldwide. Attaining optimal glycemic control is the main challenge to prevent the development of diabetes-related complications and/or to stop their progression. In recent years, the pharmacologic toolkit for the treatment of diabetes has considerably expanded, thus paving the way to more pathophysiology-oriented therapies. For instance, the sodium-glucose cotransporters SGLT2 and SGLT1 have been in the spotlight because of better knowledge of their physiology and therapeutic potential. At present, whereas the SGLT2 inhibitors are widely applied in current clinical practice as an effective and well-tolerated treatment that increases the urinary excretion of glucose, less is known about the use of SGLT1 inhibitors. SGLT1s are of primary importance in the small intestine, an organ that does not express SGLT2, while in the kidney they are expressed in the late renal proximal tubules, where it reabsorbs the glucose escaped from the upstream SGLT2. Hence, SGLT1-mediated glucose reabsorption in the kidney is increased when the tubular glucose load overwhelms the capacity of SGLT2 or when the latter is inhibited. The role of SGLT1 in intestinal and renal glucose transport makes the transporter a potential target for antidiabetic therapy. Here, we briefly report the evidence on LX2761, a new inhibitor against SGLT1 and SGLT2 in vitro, which acts in vivo as a selective inhibitor of SGLT1 in the gastrointestinal tract. LX2761 improves glycemic control without the glycosuria-related side effects of SGLT2 inhibitors, particularly genitourinary tract infections. However, whether it represents a valid therapeutic option for all patients with diabetes or is more appropriate for specific phenotypes, e.g., patients with concomitant diabetes and chronic kidney disease, who may benefit less from the renal mechanism of selective SGLT2 inhibitors, remains to be tested in large randomized controlled trials.

Metabolic syndrome and uric acid nephrolithiasis: insulin resistance in focus.

Uric acid nephrolithiasis (UAN) is an increasingly common disease in ethnically diverse populations and constitutes about 10% of all kidney stones. Metabolic syndrome and diabetes mellitus are accounted among the major risk factors for UAN, together with environmental exposure, individual lifestyle habits and genetic predisposition. The development and overt manifestation of UAN appears to stem on the background of insulin resistance, which acts at the kidney level by reducing urinary pH, thus hampering the ability of the kidney to generate renal ammonium in response to an acid load. Unduly acidic urinary pH and overt UAN are both considered renal manifestations of insulin resistance. The mechanisms underlying increased endogenous acid production and/or defective ammonium excretion are yet to be completely understood. Although the development of UAN and, more in general, of kidney stones largely recognizes modifiable individual determining factors, the rising prevalence of diabetes, obesity and accompanying metabolic disorders calls for the identification of novel therapeutic approaches and intervention targets. This review aims at providing an updated picture of existing evidence on the relationship between insulin resistance and UAN in the context of metabolic syndrome and in light of the most recent advancements in our understanding of its genetic signature.

A closed-loop multi-level model of glucose homeostasis.

BACKGROUND: The pathophysiologic processes underlying the regulation of glucose homeostasis are considerably complex at both cellular and systemic level. A comprehensive and structured specification for the several layers of abstraction of glucose metabolism is often elusive, an issue currently solvable with the hierarchical description provided by multi-level models. In this study we propose a multi-level closed-loop model of whole-body glucose homeostasis, coupled with the molecular specifications of the insulin signaling cascade in adipocytes, under the experimental conditions of normal glucose regulation and type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: The ordinary differential equations of the model, describing the dynamics of glucose and key regulatory hormones and their reciprocal interactions among gut, liver, muscle and adipose tissue, were designed for being embedded in a modular, hierarchical structure. The closed-loop model structure allowed self-sustained simulations to represent an ideal in silico subject that adjusts its own metabolism to the fasting and feeding states, depending on the hormonal context and invariant to circadian fluctuations. The cellular level of the model provided a seamless dynamic description of the molecular mechanisms downstream the insulin receptor in the adipocytes by accounting for variations in the surrounding metabolic context. CONCLUSIONS/SIGNIFICANCE: The combination of a multi-level and closed-loop modeling approach provided a fair dynamic description of the core determinants of glucose homeostasis at both cellular and systemic scales. This model architecture is intrinsically open to incorporate supplementary layers of specifications describing further individual components influencing glucose metabolism.