Validation in type 2 diabetes of a metabolomic signature of all-cause mortality.

CONTEXT: Mortality in type 2 diabetes is twice that of the normoglycemic population. Unravelling biomarkers that identify high-risk patients for referral to the most aggressive and costly prevention strategies is needed. OBJECTIVE: To validate in type 2 diabetes the association with all-cause mortality of a 14-metabolite score (14-MS) previously reported in the general population and whether this score can be used to improve well-established mortality prediction models. METHODS: This is a sub-study consisting of 600 patients from the "Sapienza University Mortality and Morbidity Event Rate" (SUMMER) study in diabetes, a prospective multicentre investigation on all-cause mortality in patients with type 2 diabetes. Metabolic biomarkers were quantified from serum samples using high-throughput proton nuclear magnetic resonance metabolomics. RESULTS: In type 2 diabetes, the 14-MS showed a significant (p < 0.0001) association with mortality, which was lower (p < 0.0001) than that reported in the general population. This difference was mainly due to two metabolites (histidine and ratio of polyunsaturated fatty acids to total fatty acids) with an effect size that was significantly (p = 0.01) lower in diabetes than in the general population. A parsimonious 12-MS (i.e. lacking the 2 metabolites mentioned above) improved patient discrimination and classification of two well-established mortality prediction models (p < 0.0001 for all measures). CONCLUSIONS: The metabolomic signature of mortality in the general population is only partially effective in type 2 diabetes. Prediction markers developed and validated in the general population must be revalidated if they are to be used in patients with diabetes.

Hepatic steatosis with significant fibrosis is associated with an increased 10-year estimated risk of cardiovascular disease in adults with type 1 diabetes mellitus.

BACKGROUND: We assessed whether hepatic steatosis with or without significant fibrosis (determined by validated non-invasive biomarkers) is associated with an increased 10-year estimated risk for cardiovascular disease (CVD) in people with type 1 diabetes mellitus (T1DM). METHODS: We conducted a retrospective, multicenter, cross-sectional study involving 1,254 adults with established T1DM without pre-existing CVD. We used the hepatic steatosis index (HSI) and fibrosis (FIB)-4 index for non-invasively detecting hepatic steatosis (defined as HSI > 36), with or without coexisting significant fibrosis (defined as FIB-4 index ≥ 1.3 or < 1.3). We calculated the Steno type 1 risk engine and the atherosclerotic CVD (ASCVD) risk score to estimate the 10-year risk of developing a first fatal or nonfatal CVD event. RESULTS: Using the Steno type 1 risk engine, a significantly greater proportion of patients with hepatic steatosis and significant fibrosis (n = 91) had a high 10-year estimated CVD risk compared to those with hepatic steatosis alone (n = 509) or without steatosis (n = 654) (75.8% vs. 23.2% vs. 24.9%, p < 0.001). After adjustment for sex, BMI, diabetes duration, hemoglobin A1c, chronic kidney disease, and lipid-lowering medication use, patients with hepatic steatosis and significant fibrosis had an increased 10-year estimated risk of developing a first fatal or nonfatal CVD event (adjusted-odds ratio 11.4, 95% confidence interval 3.54-36.9) than those without steatosis. We observed almost identical results using the ASCVD risk calculator. CONCLUSIONS: The 10-year estimated CVD risk is remarkably greater in T1DM adults with hepatic steatosis and significant fibrosis than in their counterparts with hepatic steatosis alone or without steatosis.

Association of osteocalcin, osteoprotegerin, and osteopontin with cardiovascular disease and retinopathy in type 2 diabetes.

BACKGROUND: Novel biomarkers of vascular disease in diabetes could help identify new mechanistic pathways. Osteocalcin, osteoprotegerin, and osteopontin are key molecules involved in bone and vascular calcification processes, both of which are compromised in diabetes. We aimed to evaluate possible associations of osteocalcin, osteoprotegerin, and osteopontin with cardiovascular disease (CVD) and diabetic retinopathy (DR) among people with type 2 diabetes (T2D). MATERIALS AND METHODS: Osteocalcin, osteoprotegerin, and osteopontin concentrations were measured at enrolment in 848 participants with T2D from the Sapienza University Mortality and Morbidity Event Rate (SUMMER) Study (ClinicalTrials.gov: NCT02311244). Logistic regression models and propensity score matching were used to assess possible associations of osteocalcin, osteoprotegerin, and osteopontin with a history of CVD and with evidence of any grade of DR adjusting for confounders. RESULTS: Previous CVD was reported in 139 (16.4%) participants, while 144 (17.0%) had DR. After adjusting for possible confounders, osteocalcin but not osteoprotegerin or osteopontin concentrations were associated with a history of CVD (Odds Ratio [OR] and 95% CI for one standard deviation (SD) increase in osteocalcin concentrations (natural log): 1.35 (1.06-1.72), p = 0.014). Associations with prevalent DR were seen for osteoprotegerin (OR for one SD increase in osteoprotegerin concentrations (natural log): 1.25 (1.01-1.55), p = 0.047) and osteopontin (OR for one SD increase in osteopontin concentrations (natural log): 1.25 (1.02-1.53), p = 0.022), but not osteocalcin. CONCLUSIONS: In T2D, higher serum osteocalcin concentrations are associated with macrovascular complications and higher osteoprotegerin and osteopontin concentrations with microvascular complications, suggesting that these osteokines might be involved in pathways directly related to vascular disease.

Reduced Lipopolysaccharide-Binding Protein (LBP) Levels Are Associated with Non-Alcoholic Fatty Liver Disease (NAFLD) and Adipose Inflammation in Human Obesity.

Lipopolysaccharide (LPS) and its binding protein LBP have emerged as potential contributors to the progression from overweight/obesity to overt metabolic diseases and NAFLD. While LPS is known to activate hepatocyte inflammation, thus contributing toward NAFLD development, the role of LBP is more intricate, and recent data have shown that experimental reduction in hepatic LBP promotes NAFLD progression. In this cross-sectional investigation, we evaluated circulating LBP in relation to obesity, NAFLD, visceral adipose tissue (VAT) inflammation, and type 2 diabetes (T2D). We recruited 186 individuals (M/F: 81/105; age: 47 ± 10.4 years; BMI: 35.5 ± 8.6 kg/m2); a subgroup (n = 81) underwent bariatric surgery with intra-operative VAT and liver biopsies. LBP levels were higher in obese individuals than non-obese individuals but were inversely correlated with the parameters of glucose metabolism. Reduced LBP predicted T2D independent of age, sex, and BMI (p < 0.001). LBP levels decreased across more severe stages of hepatosteatosis and lobular inflammation, and were inversely associated with VAT inflammation signatures. In conclusion, LBP levels are increased in obese individuals and are associated with a more favorable metabolic profile and lower NAFLD/NASH prevalence. A possible explanation for these findings is that hepatic LBP production may be triggered by chronic caloric excess and facilitate LPS degradation in the liver, thus protecting these individuals from the metabolic consequences of obesity.

Deep Resequencing of 9 Candidate Genes Identifies a Role for ARAP1 and IGF2BP2 in Modulating Insulin Secretion Adjusted for Insulin Resistance in Obese Southern Europeans.

Type 2 diabetes is characterized by impairment in insulin secretion, with an established genetic contribution. We aimed to evaluate common and low-frequency (1-5%) variants in nine genes strongly associated with insulin secretion by targeted sequencing in subjects selected from the extremes of insulin release measured by the disposition index. Collapsing data by gene and/or function, the association between disposition index and nonsense variants were significant, also after adjustment for confounding factors (OR = 0.25, 95% CI = 0.11-0.59, p = 0.001). Evaluating variants individually, three novel variants in ARAP1, IGF2BP2 and GCK, out of eight reaching significance singularly, remained associated after adjustment. Constructing a genetic risk model combining the effects of the three variants, only carriers of the ARAP1 and IGF2BP2 variants were significantly associated with a reduced probability to be in the lower, worst, extreme of insulin secretion (OR = 0.223, 95% CI = 0.105-0.473, p < 0.001). Observing a high number of normal glucose tolerance between carriers, a regression posthoc analysis was performed. Carriers of genetic risk model variants had higher probability to be normoglycemic, also after adjustment (OR = 2.411, 95% CI = 1.136-5.116, p = 0.022). Thus, in our southern European cohort, nonsense variants in all nine candidate genes showed association with better insulin secretion adjusted for insulin resistance, and we established the role of ARAP1 and IGF2BP2 in modulating insulin secretion.

Neck circumference as reliable predictor of mechanical ventilation support in adult inpatients with COVID-19: A multicentric prospective evaluation.

AIMS: COVID-19 is especially severe for elderly subjects with cardiometabolic and respiratory comorbidities. Neck circumference (NC) has been shown to be strongly related to cardiometabolic and respiratory illnesses even after adjustment for body mass index (BMI). We performed a prospective study to investigate the potential of NC to predict the need for invasive mechanical ventilation (IMV) in adult COVID-19 inpatients. MATERIALS AND METHODS: We prospectively and consecutively enrolled COVID-19 adult patients admitted to dedicated medical wards of two Italian hospitals from 25 March to 7 April 2020. On admission, clinical, biochemical and anthropometric data, including BMI and NC were collected. As primary outcome measure, the maximum respiratory support received was evaluated. Follow-up time was 30 days from hospital admission. RESULTS: We enrolled 132 subjects (55.0-75.8 years, 32% female). During the study period, 26 (19.7%) patients underwent IMV. In multivariable logistic regression analyses, after adjusting for age, sex, diabetes, hypertension and COPD, NC resulted independently and significantly associated with IMV risk (adjusted OR 1.260-per 1 cm increase 95% CI:1.120-1.417; P < .001), with a stronger association in the subgroup with BMI ≤30 Kg/m2 (adjusted OR 1.526; 95% CI:1.243-1.874; P < .001). NC showed a good discrimination power in predicting patients requiring IMV (AUC 0.783; 95% CI:0.684-0.882; P < .001). In particular, NC > 40.5 cm (>37.5 for females and >42.5 for males) showed a higher and earlier IMV risk compared to subjects with lower NC (Log-rank test: P < .001). CONCLUSIONS: NC is an easy to measure parameter able to predict the need for IMV in adult COVID-19 inpatients.

Adipose tissue remodelling in obese subjects is a determinant of presence and severity of fatty liver disease.

AIMS: Experimental data suggest that visceral adipose tissue (VAT) dysfunction contributes to non-alcoholic fatty liver disease (NAFLD) development in obesity, however, data on humans are limited. Aims of this study were to investigate the relationship between NAFLD and VAT morphofunctional impairment and to determine whether the extent of VAT remodelling is associated with liver damage and metabolic alterations in obesity. METHODS: We analysed data from 40 obese individuals candidate to bariatric surgery in whom paired intraoperative liver and omental biopsies were performed for diagnosing NAFLD and VAT inflammation by immunohistochemistry and mRNA expression studies. RESULTS: Within our study population, NAFLD was significantly associated with greater VAT CD68+ macrophages infiltration (P = .04), fibrosis (P = .04) and impaired microvascular density (P = .03) as well as increased expression of markers of local hypoxia, apoptosis and inflammation (UNC5B, CASP7, HIF1-α, IL-8, MIP2, WISP-1, all P < .01). The degree of VAT inflammation correlated with the severity of hepatic injury (steatosis, inflammation, fibrosis; all P < .01) and impaired gluco-metabolic profile. CONCLUSIONS: In obese patients, NAFLD is associated in a dose-dependent manner with signs of VAT remodelling, which reflect more severe clinical metabolic impairment. Our study depicts morphological alterations and novel mediators of VAT dysfunction, adding knowledge for future therapeutic approaches to NAFLD and its metabolic complications.

Differential involvement of myelinated and unmyelinated nerve fibers in painful diabetic polyneuropathy.

BACKGROUND: We aimed at evaluating the differential involvement of large myelinated Aß-, small myelinated Aδ-, and unmyelinated C-fibers in patients with diabetic polyneuropathy and how they contribute to neuropathic pain. METHODS: We collected clinical and diagnostic test variables in 133 consecutive patients with diabetic polyneuropathy. All patients underwent Aß-fiber mediated nerve conduction study, Aδ-fiber mediated laser-evoked potentials and skin biopsy mainly assessing unmyelinated C-fibers. RESULTS: Pure large-fiber and small-fiber polyneuropathy were relatively uncommon; conversely mixed-fiber polyneuropathy was the most common type of diabetic polyneuropathy (74%). The frequency of neuropathic pain was similar in the three different polyneuropathies. Ongoing burning pain and dynamic mechanical allodynia were similarly associated with specific small-fiber related variables. CONCLUSIONS: Diabetic polyneuropathy mainly manifests as a mixed-fiber polyneuropathy, simultaneously involving Aß-, Aδ-, and C-fibers. In most patients, neuropathic pain is distinctly associated with small-fiber damage. The evidence that the frequency of neuropathic pain does not differ across pure large-, pure small-, and mixed-fiber polyneuropathy, raises the possibility that in patients with pure large-fiber polyneuropathy nociceptive nerve terminal involvement might be undetected by standard diagnostic techniques.

Effects of the COVID-19 lockdown on glycaemic control in subjects with type 2 diabetes: the glycalock study.

AIM: To assess the effect of the coronavirus disease 2019 (COVID-19) lockdown on glycaemic control in subjects with type 2 diabetes (T2D). MATERIALS AND METHODS: In this observational, multicentre, retrospective study conducted in the Lazio region, Italy, we compared the differences in the HbA1c levels of 141 subjects with T2D exposed to lockdown with 123 matched controls with T2D who attended the study centres 1 year before. Basal data were collected from 9 December to 9 March and follow-up data from 3 June to 10 July in 2020 for the lockdown group, and during the same timeframes in 2019 for the control groups. Changes in HbA1c (ΔHbA1c) and body mass index (ΔBMI) during lockdown were compared among patients with different psychological well-being, as evaluated by tertiles of the Psychological General Well-Being Index (PGWBS). RESULTS: No difference in ΔHbA1c was found between the lockdown and control groups (lockdown group -0.1% [-0.5%-0.3%] vs. control group -0.1% [-0.4%-0.2%]; p = .482). Also, no difference was found in ΔBMI (p = .316) or ΔGlucose (p = .538). In the lockdown group, subjects with worse PGWBS showed a worsening of HbA1c (p = .041 for the trend among PGWBS tertiles) and BMI (p = .022). CONCLUSIONS: The COVID-19 lockdown did not significantly impact glycaemic control in people with T2D. People with poor psychological well-being may experience a worsening a glycaemic control because of restrictions resulting from lockdown. These findings may aid healthcare providers in diabetes management once the second wave of COVID-19 has ended.

Circulating dipeptidyl peptidase-4 is independently associated with the presence and severity of NAFLD/NASH in individuals with and without obesity and metabolic disease.

INTRODUCTION: Dipeptidyl peptidase 4 (DPP4) levels are associated to metabolic and cardiovascular diseases in humans; initial evidence reported a relationship between DPP4 and chronic liver diseases. Aim of this study was to investigate hepatic and systemic DPP4 levels/activity in relation to NAFLD/NASH in individuals with and without metabolic disease. METHODS: We recruited fifty-two obese individuals undergoing bariatric surgery and intra-operative liver biopsy at Sapienza University, Rome, Italy. The association between DPP4 levels/activity and NAFLD was also evaluated in 126 non-obese individuals recruited in the same setting. RESULTS: NAFLD patients had significantly higher circulating DPP4 activity than no-NAFLD in both the obese and non-obese cohorts; plasma DPP4 activity and levels linearly correlated with steatosis grade and inflammation at the liver biopsy. Hepatic DPP4 mRNA was not associated to either its circulating levels/activity or NAFLD. In the multivariate logistic regression analysis on all the study participants (n = 178), higher circulating DPP4 activity was associated with NAFLD independently of potential confounders with OR (95% CI): 3.5 (1.2-10.21), p = 0.022. CONCLUSIONS: This study demonstrates the coexistence of increased plasma DPP4 levels and activity in NAFLD. Circulating DPP4 measurement may represent a novel cost-effective strategy for NAFLD/NASH risk stratification and a potential tool for monitoring disease's progression in established NAFLD.

Covid-19 and diabesity: when a pandemia cross another pandemia.

The Covid-19 epidemic is having a strong impact on the population with pre-existing chronic diseases. The collision between the Covid-19 pandemic and the current diabesity epidemic has highlighted that obese and diabetic patients have a worse prognosis due to the impairment of the immune response to infections and due to the mechanical limits that make the management of the hospitalized patients with severe obesity more difficult. The limitations imposed on accessibility to non-urgent care during the lockdown of "phase 1" of this pandemic have created the need to revolutionize clinical practice to meet the health demands of chronic and high-risk diseases such as obesity and diabetes. The use of technology and risk stratification to establish the priority of access to the treatments that we have been forced to undertake will be useful tools for a new phase of a more efficient and successful treatment of diabesity.

Relationship between hepatic and systemic angiopoietin-like 3, hepatic Vitamin D receptor expression and NAFLD in obesity.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and an independent risk factor for cardiovascular mortality. Angiopoietin-like proteins (ANGPTLs) are targets for vitamin D receptor (VDR)-mediated gene transcription and this axis may promote NAFLD. ANGPTL3 is a hepatokine which inhibits lipoprotein lipase and its experimentally induced inactivation reduces hepatosteatosis. Little is known on ANGPTL3 in human NAFLD and no data exist on its relationship with hepatic VDR/VD-related genes. The aim of this research was to investigate hepatic ANGPTLs and VDR/VD-related gene expression in human obesity in relation to NAFLD. METHODS: We conducted a cross-sectional investigation on forty obese subjects with/without NAFLD. We evaluated hepatic ANGPTL3, ANGPTL4, ANGPTL8, LPL, VDR, CYP27A1 and CYP2R1 mRNA expression in liver biopsies by RT-PCR; VDR expression was further investigated by immunohistochemistry; circulating ANGPTL3 was measured by Milliplex assay. RESULTS: Compared to non-NAFLD, NAFLD individuals had significantly higher hepatic VDR, ANGPTL3 and LPL expression. ANGPTL3 correlated with steatosis grade, LPL, VDR, CYP27A1 and CYP2R1 expression. Plasma ANGPTL3 concentrations were positively associated with clinical/histological markers of NAFLD/NASH and with hepatic ANGPTL3 expression. Greater hepatic VDR expression was the main determinant of hepatic ANGPTL3 after adjusting for multiple confounders. CONCLUSIONS: Hepatic ANGPTL3 expression correlates with greater VDR expression, presence and severity of NAFLD and translates in increased circulating ANGPTL3, likely as a result of its modulation by up-regulated hepatic VDR in NAFLD. This study provides novel insights to potential mechanisms underlying ANGPTLs-mediated ectopic fat accumulation and NAFLD development in obesity.

Insulin resistance, but not insulin response, during oral glucose tolerance test (OGTT) is associated to worse histological outcome in obese NAFLD.

BACKGROUND AND AIM: Obese subjects are at high risk of nonalcoholic fatty liver disease (NAFLD) and diabetes (T2D) due to insulin resistance (IR). Since high glucose levels are as toxic as lipids for hepatic metabolism, we hypothesize that altered response to oral glucose tolerance test (OGTT) is associated to more severe NAFLD with significant/advanced liver damage. METHODS AND RESULTS: We studied 90 subjects with morbid obesity (73F/17M, BMI = 43.2 ± 5,9 kg/m2) undergoing bariatric surgery and intraoperative liver biopsy, and measured HbA1c, HOMA-IR (fasting Glucose x Insulin/22.5), OGTT glucose and insulin profile, and calculated OGIS (muscle insulin sensitivity), hepatic-IR (glucose [AUC0-30] x insulin [AUC0-30]) during OGTT, insulin response as (insulin [dAUC0-120]/glucose [dAUC0-120] or Insulinogenic Index (IGI = (I30-I0)/(G30-G0)). Patients were divided in 3 groups according to liver biopsy: A (no-NAFLD, 23%), B (simple steatosis (SS), 53%) and C (NASH, 24%) with similar age, gender and BMI. Diabetes was 0% in no-NAFLD, 13% in SS, 35% in NASH. During OGTT, OGIS decreased from A to C (422 vs 360 vs 338, p < 0.01). Increased insulin concentrations, HbA1c, HOMA-IR and OGIS, not Hep-IR, were strongly associated to hepatic steatosis (p = 0.03, p = 0.0001 and p = 0.01 respectively). Hepatic fibrosis stage was mild as most of the patients had fibrosis grade-1 (69% vs. 8% no fibrosis) and associated to fasting insulin, HbA1c and HOMA-IR. dAUC-I/dAUC-G was similar in the 3 groups, while only AUC-I was strongly associated to steatosis (r = 0.35, p = 0.005), but not to fibrosis. CONCLUSIONS: In morbid obesity indexes of IR, and not of insulin response, are markers of histological severity of liver disease.

Angiopoietin-Like Protein 4 Overexpression in Visceral Adipose Tissue from Obese Subjects with Impaired Glucose Metabolism and Relationship with Lipoprotein Lipase.

Angiopoietin-like protein 4 (ANGPTL4) regulates lipid partitioning by inhibiting circulating and tissue lipoprotein lipase (LPL); ANGPTL4 loss-of-function variants improve insulin sensitivity and reduce type 2 diabetes (T2D) risk with mechanisms partially unknown. This study was designed to explore metabolic implications of differential ANGPTL4 and LPL expression in human adipose tissue (AT). We recruited eighty-eight obese individuals, with and without abnormal glucose metabolism (AGM), undergoing bariatric surgery; visceral AT (VAT) fragments were obtained intra-operatively and analyzed by immunohistochemistry and mRNA by rt-PCR. Data on hepatic ANGPTL4 mRNA were available for 40 participants. VAT ANGPTL4 expression was higher in AGM individuals than in those with normal glucose tolerance (NGT) and associated with VAT inflammation, insulin resistance, and presence of adipocyte size heterogeneity. Increased ANGPTL4 was associated with AGM with OR = 5.1 (95% C.I.: 1.2-23; p = 0.02) and AUROC = 0.76 (95% C.I.: 1.2-23; p < 0.001). High LPL was associated with the detection of homogeneous adipocyte size, reduced microvessel density, and higher HIF-1α levels and inversely correlated to blood transaminases. In conclusion, in obese individuals, VAT ANGPTL4 levels are increased in the presence of local inflammation and AGM. Conversely, higher LPL expression describes a condition of increased lipid storage in adipocytes, which may serve as a protective mechanism against ectopic fat accumulation and related metabolic disease in obesity.

Reduced Biliverdin Reductase-A Expression in Visceral Adipose Tissue is Associated with Adipocyte Dysfunction and NAFLD in Human Obesity.

Biliverdin reductase A (BVR-A) is an enzyme involved in the regulation of insulin signalling. Knockout (KO) mice for hepatic BVR-A, on a high-fat diet, develop more severe glucose impairment and hepato-steatosis than the wild type, whereas loss of adipocyte BVR-A is associated with increased visceral adipose tissue (VAT) inflammation and adipocyte size. However, BVR-A expression in human VAT has not been investigated. We evaluated BVR-A mRNA expression levels by real-time PCR in the intra-operative omental biopsy of 38 obese subjects and investigated the association with metabolic impairment, VAT dysfunction, and biopsy-proven non-alcoholic fatty liver disease (NAFLD). Individuals with lower VAT BVR-A mRNA levels had significantly greater VAT IL-8 and Caspase 3 expression than those with higher BVR-A. Lower VAT BVR-A mRNA levels were associated with an increased adipocytes' size. An association between lower VAT BVR-A expression and higher plasma gamma-glutamyl transpeptidase was also observed. Reduced VAT BVR-A was associated with NAFLD with an odds ratio of 1.38 (95% confidence interval: 1.02-1.9; χ2 test) and with AUROC = 0.89 (p = 0.002, 95% CI = 0.76-1.0). In conclusion, reduced BVR-A expression in omental adipose tissue is associated with VAT dysfunction and NAFLD, suggesting a possible involvement of BVR-A in the regulation of VAT homeostasis in presence of obesity.

Elevated plasma copeptin levels identify the presence and severity of non-alcoholic fatty liver disease in obesity.

INTRODUCTION: Copeptin is the stable surrogate marker of vasopressin (VP), which is released in response to elevated plasma osmolality or low blood pressure. Elevated plasma copeptin levels are associated with higher risk of insulin resistance-related disorders, such as type 2 diabetes (T2DM), metabolic syndrome (MS), and cardiovascular disease, and experimental reduction of circulating VP levels is shown to significantly decrease hepatic fat content in obese rats, independently from body adiposity. However, the association between copeptin and non-alcoholic fatty liver disease and steatohepatitis (NAFLD/NASH) in humans has not been explored yet. The aim of this study was to explore the relationship between plasma copeptin and the presence/severity of NAFLD/NASH. METHODS: For this study, we recruited 60 obese patients candidate to bariatric surgery for clinical purposes in which intraoperative liver biopsies were performed for diagnosing NAFLD/NASH. Circulating copeptin levels were also assessed in 60 age- and sex-comparable non-obese individuals without NAFLD at liver ultrasonography. Plasma copeptin was measured by sandwich immunoluminometric assay (Thermo Fisher Scientific). RESULTS: Obese patients with biopsy-proven NAFLD (53%) had significantly higher copeptin levels than both obese individuals without NAFLD and non-obese subjects (ob/NAFLD+ 9.5 ± 4.9; ob/NAFLD- 6.4 ± 2.6; and non-ob/NAFLD- 7.4 ± 5.1 pmol/L; p = 0.004 and p = 0.01 respectively). Plasma copeptin concentration positively correlated with hepatic macro- and micro-vesicular steatosis (r = 0.36, p = 0.026; r = 0.31, p = 0.05), lobular inflammation (r = 0.37, p = 0.024) and significantly increased throughout degrees of NASH severity, as expressed as absence, borderline, and overt NASH at the liver biopsy (r = 0.35, p = 0.01). Greater circulating copeptin predicted the presence of NASH with OR = 1.73 (95% CI = 1.02-2.93) after multivariate adjustment for age, sex, renal function and presence of T2DM and MS components. CONCLUSIONS: Increased plasma copeptin is independently associated with the presence and severity of NAFLD and NASH, pointing to a novel mechanism behind human fatty liver disease potentially modifiable by pharmacological treatment and lifestyle intervention.

Evidence of diabetes-specific autoimmunity in obese subjects with normal glucose tolerance.

BACKGROUND: Recently, significant attention has been paid to the possible activation of an autoimmune response in the presence of obesity. The aim of this study was to evaluate and compare the frequencies of autoantibodies typical of autoimmune diabetes in obese patients with normal glucose tolerance (NGT), obese patients with type 2 diabetes (T2D) and controls. We also evaluated the presence of immunoreactivity to Hashimoto's thyroiditis and autoimmune gastritis. MATERIALS AND METHODS: Consecutive sera from obese patients, 444 with NGT, 322 with T2D, and 212 controls were analysed by radioimmunoassay or enzyme-linked immunosorbent assay for glutamic acid decarboxylase, protein tyrosine phosphatase islet antigen-2 (IA-2)IC and IA-2(256-760) , islet beta-cell zinc cation transporter (ZnT8), thyroid peroxidase, and anti-parietal cell autoantibodies. RESULTS: Altogether the presence of organ-specific autoantibodies was significantly more frequent in obese patients with NGT (128/444, 28.5%) and obese with T2D (79/322, 24.5%) than in controls (36/212, 17%; P = 0.002). Thyroid peroxidase immunoreactivity was prevalent in all groups of subjects investigated. The frequencies of diabetes-specific autoantibodies were slightly higher in obese patients with NGT (20/444, 4.5%) than in obese with T2D (12/322, 3.7%) and controls (4/212, 1.9%). The anti IA-2(256-760) was the most frequent islet autoantibody in obese subjects with NGT (14/20, 70%). CONCLUSIONS: We observed significant evidence of immunoreactivity specific to diabetes, thyroid, and gastric-parietal cells in obese patients with NGT. The relatively higher frequency of the diabetes-related IA-2(256-760) autoantibodies in obese patients with NGT may suggest that this autoantibody could be associated with obesity the presence of obesity itself.

The vitamin D receptor functional variant rs2228570 (C>T) does not associate with type 2 diabetes mellitus.

AIM: Vitamin D acts through the binding to the vitamin D receptor (VDR). Several polymorphisms in VDR gene have been studied. Among these, the rs2228570 C>T (FokI) variant has been demonstrated to be functional, leading to a protein with a different size and activity. So far, genetic studies on the association between VDR gene rs2228570 single nucleotide polymorphism (SNP) and type 2 diabetes mellitus (T2DM) showed contradictory results. Thus, we performed an association study in a large cohort of adult Italian subjects with T2DM and in nondiabetic controls. MATERIALS AND METHODS: For this study, 1713 subjects, 883 T2DM patients and 830 controls, were genotyped for the polymorphism. All participants without a diagnosis of diabetes underwent oral glucose tolerance test (OGTT), with measurement of glucose and insulin levels. Indices of insulin resistance (Homeostatic model assessment of insulin resistance, insulin sensitivity index), secretion (homeostatic model assessment for beta-cell, corrected insulin response at 30 minutes) and disposition index were calculated. RESULTS: Genotype distributions and allele frequencies did not show difference between T2DM subjects and controls. We did not find significant differences among the three genotypes regarding gender, age, BMI, waist, hip, waist-to-hip ratio, and blood pressure. There were also no significant differences in lipid parameters, aspartate aminotransferase, and alanine aminotransferase levels. We tested for association with OGTT-derived data and surrogate indices of insulin resistance and secretion. We did not find significant differences among the genotypes in any of above-mentioned parameters. Furthermore, vitamin D levels were measured in a subgroup of subjects. We did not find significant differences among the genotypes. CONCLUSIONS: Our study does not provide evidence for the association of the rs2228570 polymorphism with T2DM in a Caucasian population.

The perilipin 2 (PLIN2) gene Ser251Pro missense mutation is associated with reduced insulin secretion and increased insulin sensitivity in Italian obese subjects.

BACKGROUND: Perilipin 2 (PLIN2), a member of the family of perilipin lipid droplets coating proteins, is very widely expressed. The Ser251Pro (rs35568725) missense mutation in exon 6 of PLIN2 gene was previously associated with increased lipid accumulation, decreased lipolysis and increased number of small lipid droplets per cell. Furthermore, the Pro251 mutation was associated with decreased plasma triglyceride and very low density lipoprotein concentrations in population studies. The aim of this study was to evaluate the effect of the Ser251Pro mutation of PLIN2 gene in a cohort with a higher predisposition to obesity-associated metabolic alterations, such as insulin resistance, decreased insulin-secretion, hyperglycaemia, and dyslipidaemia. METHODS: A large cohort (N = 1692) of Italian obese subjects (mean body mass index = 41 kg/m(2) ) was genotyped for the Ser251Pro mutation. All participants underwent oral glucose tolerance tests (OGTT), with measurement of glucose and insulin levels. Indices of insulin resistance and of insulin secretion were also calculated. Clinical and biochemical parameters were collected for all participants. RESULTS: We observed that insulin concentration was significantly reduced at 120 min after the administration of glucose in Pro251 allele carriers, whereas glucose levels were similar in Pro251 allele carriers and non-carriers throughout the OGTT. Furthermore, the CIR120 index of insulin secretion was significantly lower (P < 0.035) and the ISI index of insulin-sensitivity was significantly higher (P < 0.031) in carriers of the Pro251 allele. When we analysed men and women separately to test for gender-specific associations, we observed that in women insulin levels were significantly lower in Pro251 allele carriers compared with wild-type subjects throughout the whole OGTT. In men, we confirmed a significant reduction in insulin concentration only at 120 min after the OGTT. No significant differences between genotype groups regarding triglyceride levels and anyother clinical and metabolic parameters were observed. CONCLUSION: We observed a strong significant association between the PLIN2 Pro251 mutation and lower insulin secretion associated with an increased insulin sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.

Female obesity: clinical and psychological assessment toward the best treatment.

Obesity is a heterogeneous condition which results from complex interactions among sex/gender, sociocultural, environmental, and biological factors. Obesity is more prevalent in women in most developed countries, and several clinical and psychological obesity complications show sex-specific patterns. Females differ regarding fat distribution, with males tending to store more visceral fat, which is highly correlated to increased cardiovascular risk. Although women are more likely to be diagnosed with obesity and appear more motivated to lose weight, as confirmed by their greater representation in clinical trials, males show better outcomes in terms of body weight and intra-abdominal fat loss and improvements in the metabolic risk profile. However, only a few relatively recent studies have investigated gender differences in obesity, and sex/gender is rarely considered in the assessment and management of the disease. This review summarizes the evidence of gender differences in obesity prevalence, contributing factors, clinical complications, and psychological challenges. In addition, we explored gender differences in response to obesity treatments in the specific context of new anti-obesity drugs.