Blood-derived miRNA levels are not correlated with metabolic or anthropometric parameters in obese pre-diabetic subjects but with systemic inflammation.

As blood-derived miRNAs (c-miRNAs) are modulated by exercise and nutrition, we postulated that they might be used to monitor the effects of a lifestyle intervention (LI) to prevent diabetes development. To challenge this hypothesis, obese Asian Indian pre-diabetic patients were submitted to diet modifications and physical activity for 4 months (LI group) and compared to a control group which was given recommendations only. We have considered 2 periods of time to analyze the data, i.e.; a first one to study the response to the intervention (4 months), and a second one post-intervention (8 months). At basal, 4 months and 8 months post-intervention the levels of 17 c-miRNAs were quantified, selected either for their relevance to the pathology or because they are known to be modulated by physical activity or diet. Their variations were correlated with variations of 25 metabolic and anthropometric parameters and cytokines. As expected, fasting-glycaemia, insulin-sensitivity, levels of exercise- and obesity-induced cytokines were ameliorated after 4 months. In addition, the levels of 4 miRNAs (i.e.; miR-128-3p, miR-374a-5p, miR-221-3p, and miR-133a-3p) were changed only in the LI group and were correlated with metabolic improvement (insulin sensitivity, cytokine levels, waist circumference and systolic blood pressure). However, 8 months post-intervention almost all ameliorated metabolic parameters declined indicating that the volunteers did not continue the protocol on their own. Surprisingly, the LI positive effects on c-miRNA levels were still detected, and were even more pronounced 8 months post-intervention. In parallel, MCP-1, involved in tissue infiltration by immune cells, and Il-6, adiponectin and irisin, which have anti-inflammatory effects, continued to be significantly and positively modified, 8 months post-intervention. These data demonstrated for the first time, that c-miRNA correlations with metabolic parameters and insulin sensitivity are in fact only indirect and likely associated with the level systemic inflammation. More generally speaking, this important result explains the high variability between the previous studies designed to identify specific c-miRNAs associated with the severity of insulin-resistance. The results of all these studies should take into account the level of inflammation of the patients. In addition, this finding could also explain why, whatever the pathology considered (i.e.; cancers, diabetes, neurodegenerative disorders, inflammatory diseases) the same subset of miRNAs is always found altered in the blood of patients vs healthy subjects, as these pathologies are all associated with the development of inflammation.

Beneficial Primary Outcomes of Metabolic Surgery with Changes in Telomere Length and Mitochondrial DNA in Obese Asian Indians with Dysglycemia.

INTRODUCTION: Although metabolic surgery has been shown to offer beneficial primary outcome results in obese individuals / obese Type 2 diabetes mellitus (T2DM) patients, there is paucity of information on the underlying mechanisms. In the recent years, estimations of non-invasive molecular parameters viz., telomere length and mtDNA copy number (mtDNAcn) assume significance as robust biomarkers. However, there is lack of evidence about this especially, in the Indian context. To assess the changes in the telomere length and mtDNAcn levels after metabolic surgery in obese Asian Indians with dysglycemia along with routine measurements of anthropometry, glycemic/lipidimic parameters and inflammatory markers. METHODS: This study is a prospective one-year follow-up study of 16 obese individuals with dysglycemia who underwent metabolic surgery at a tertiary diabetes centre in South India. Telomere length, mtDNAcn, serum adiponectin, glycated haemoglobin and high- sensitivity C-reactive protein (hs-CRP) levels were analysed before surgery and at 6 and 12 months after surgery. RESULTS: There was a significant reduction in weight (p<0.001), BMI (p<0.001), waist circumference (p<0.001), fasting and postprandial glucose (p<0.05), HbA1c (p<0.001), triglycerides (p<0.05), hs CRP (p<0.05) and increase in serum adiponectin (p<0.05) at 6 and 12 months post-surgery compared to the preoperative status. There was a significant reduction in mtDNAcn (p<0.001) and a significant increase in telomere length (p<0.001) at 6 and 12 months post metabolic surgery. CONCLUSION: We report an increase in telomere length and decrease in circulatory mtDNA copy number levels at 6 and 12 months post metabolic surgery in obese individuals with T2DM in India.

A comparative study on the cellular stressors in mesenchymal stem cells (MSCs) and pancreatic ß-cells under hyperglycemic milieu.

ß-cell dysfunction is a critical determinant for both type 1 diabetes and type 2 diabetes and ß-cells are shown to be highly susceptible to cellular stressors. Mesenchymal stem cells (MSCs) on the other hand are known to have immunomodulatory potential and preferred in clinical applications. However, there is paucity of a comparative study on these cells in relation to several cellular stressors in response to hyperglycemia and this forms the rationale for the present study. INS1 ß-cells and MSCs were subjected to high-glucose treatment without and with Metformin, Lactoferrin, or TUDCA and assessed for stress signaling alterations using gene expression, protein expression, as well as functional read-outs. Compared to the untreated control cells, INS1 ß-cells or MSCs treated with high glucose showed significant increase in mRNA expressions of ER stress, senescence, and proinflammation. This was accompanied by increased miR146a target genes and decreased levels of SIRT1, NRF2, and miR146a in both the cell types. Consistent with the mRNA results, protein expression levels do reflect the same alterations. Notably, the alterations are relatively less extent in MSCs compared to INS1 ß-cells. Interestingly, three different agents, viz., Metformin, Lactoferrin, or TUDCA, were found to overcome the high glucose-induced cellular stresses in a concerted and inter-linked way and restored the proliferation and migration capacity in MSCs as well as normalized the glucose-stimulated insulin secretion in INS1 ß-cells. While our study gives a directionality for potential supplementation of metformin/lactoferrin/TUDCA in optimization protocols of MSCs, we suggest that in vitro preconditioning of MSCs with such factors should be further explored with in-depth investigations to harness and enhance the therapeutic capacity/potential of MSCs.

Outcomes of metabolic surgery in obese patients with type 2 diabetes with respect to impact on beta cell function, insulin sensitivity and diabetes remission - A study from south India.

BACKGROUND AND AIMS: Metabolic surgery is gaining popularity as a procedure for the treatment of morbid obesity among patients with type 2 diabetes (T2DM). The aim of the study was to evaluate the effects of metabolic surgery on beta cell function, insulin sensitivity and glycemic status in obese Asian Indian patients. METHODS: This is a prospective study of 26 patients with T2DM who underwent metabolic surgery. Complete diabetes remission was defined as FPG<100 mg/dl and HbA1c < 6%, without antidiabetic medications one-year post surgery. Anthropometry, HOMA-IR (insulin resistance), HOMA-insulin sensitivity, beta cell function and antidiabetic drug usage were measured at baseline, 6 months and 12 months post-surgery. RESULTS: The overall duration of diabetes was 10.3 ± 5.4 years. At one year, 7 (27%) of 26 T2DM patients, achieved diabetes remission while the other 19 had improvement in diabetes status. ROC curves showed that those who had diabetes duration <8.5 years achieved remission. There was a significant decrease in HOMA-IR [3.7 ± 1.8 vs 1.4 ± 0.9 vs1.2 ± 0.6, p < 0.001] and improvement in HOMA-Insulin sensitivity [34 ± 17 vs 93 ± 50 vs 112 ± 62, p < 0.001] from baseline to 6 and 12 months post-surgery respectively. There was a significant (p < 0.001) reduction in the usage of anti-diabetes medications post-surgery. The limitations of this study are small sample size and limited follow up period of 1 year. CONCLUSIONS: Among T2DM patients, metabolic surgery resulted in significant improvement in beta cell function and insulin sensitivity along with reduction in anti-diabetes medication. Diabetes remission was mainly seen in those who had duration of diabetes <8.5 years.

Bisphenol A exposure under metabolic stress induces accelerated cellular senescence in vivo in a p53 independent manner.

Senescence is an irreversible process that is a characteristic of age-associated disease like Type 2 diabetes (T2D). Bisphenol-A (BPA), one of the most common endocrine disruptor chemicals, received special attention in the development of insulin resistance and T2D. To understand the role played by BPA in cellular senescence under metabolic stress, zebrafish embryos were exposed to BPA in the absence and presence of hyperglycaemia. Transcriptional levels of the senescence markers p15, p53, Rb1 and ß-galactosidase were increased when BPA was combined with metabolic stress. In addition, zebrafish embryos that were exposed to combination of hyperglycaemia and BPA exhibited increased levels of apoptosis. However, cellular senescence remained induced by a combination of hyperglycaemia and BPA exposure even in the absence of a translated p53 protein suggesting that senescence is primarily independent of it but dependent on the p15-Rb1 pathway under our experimental conditions. To confirm that our results hold true in adult mammalian tissues, we validated our embryonic experiments in an adult mammalian metabolic model of skeletal muscle cells. Our work reveals a novel and unique converging role of senescence and apoptosis axis contributing to glucose dyshomeostasis. Thus, we conclude that BPA exposure can exacerbate existing metabolic stress to increase cellular senescence that leads to aggravation of disease phenotype in age-associated diseases like type 2 diabetes.

Novel insights of elevated systemic levels of bisphenol-A (BPA) linked to poor glycemic control, accelerated cellular senescence and insulin resistance in patients with type 2 diabetes.

There is a striking interaction of genes and environment in the etiology of type 2 diabetes mellitus (T2DM). While endocrine disrupting chemicals (EDCs) like bisphenol-A (BPA) have received special attention for their mechanistic role in metabolic disruption, there is a lack of clinically relevant data on BPA levels in Asian Indians, a population which is more susceptible to type 2 diabetes mellitus (T2DM) and cardiovascular diseases. Therefore, we measured systemic levels of BPA in patients with T2DM compared to individuals with normal glucose tolerance (n = 30 each). Serum BPA levels were estimated using ELISA kit, and biochemical determinations were done by standard protocols. Peripheral blood mononuclear cells (PBMCs) were used to profile the gene expression alterations with special reference to inflammation, estrogen receptors, and cellular senescence in these subjects. Serum levels of BPA were significantly higher in patients with T2DM compared to control individuals and positively correlated to poor glycemic control and insulin resistance. Patients with T2DM exhibited significantly elevated mRNA levels of senescence (GLB1, p16, p21, and p53) and inflammatory (IL6 and TNF-α) markers, shortened telomeres as well as elevated levels of estrogen-related receptor gamma (ERRγ), a recently identified receptor for BPA. BPA levels were positively correlated to senescence indicators, inflammatory markers and ERRγ and negatively correlated to telomere length. Our study is the first data in the clinical diabetes setting to demonstrate an association of increased BPA levels with cellular senescence, proinflammation, poor glycemic control, insulin resistance, and shortened telomeres in patients with T2DM.

Sestrin2 regulates monocyte activation through AMPK-mTOR nexus under high-glucose and dyslipidemic conditions.

The vicious cycle between hyperinsulinemia and insulin resistance results in the progression of atherosclerosis in the vessel wall. The complex interaction between hyperglycemia and lipoprotein abnormalities promotes the development of atherogenesis. In the early phase of atherosclerosis, macrophage-derived foam cells play an important role in vascular remodeling. Mechanistic target of rapamycin (mTOR) signaling pathway has been identified to play an essential role in the initiation, progression, and complication of atherosclerosis. Recently sestrin2, an antioxidant, was shown to modulate TOR activity and thereby regulating glucose and lipid metabolism. But the role of sestrin2 in monocyte activation is still not clearly understood. Hence, this study is focussed on investigating the role of sestrin2 in monocyte activation under hyperglycemic and dyslipidemic conditions. High-glucose and oxidized low-density lipoprotein (LDL) treatments mediated proinflammatory cytokine production (M1) with a concomitant decrease in the anti-inflammatory cytokine (M2) levels in human monocytic THP1 cells. Both glucose and oxidized LDL (OxLDL) in a dose and time-dependent manner increased the mTOR activation with a marked reduction in the levels of pAMPK and sestrin2 expression. Both high-glucose and OxLDL treatment increased foam cell formation and adhesion of THP1 cells to endothelial cells. Experiments employing activator or inhibitor of adenosine monophosphate kinase (AMPK) as well as overexpression or silencing of sestrin2 indicated that high-glucose mediated monocyte polarization and adhesion of monocytes to the endothelial cells were appeared to be programmed via sestrin2-AMPK-mTOR nexus. Our results evidently suggest that sestrin2 plays a major role in regulating monocyte activation via the AMPK-mTOR-pathway under diabetic and dyslipidemic conditions and also AMPK regulates sestrin2 in a feedback mechanism.

Picroside II attenuates fatty acid accumulation in HepG2 cells via modulation of fatty acid uptake and synthesis.

BACKGROUND/AIMS: Hepatic steatosis is caused by an imbalance between free fatty acids (FFAs) uptake, utilization, storage, and disposal. Understanding the molecular mechanisms involved in FFAs accumulation and its modulation could drive the development of potential therapies for Nonalcoholic fatty liver disease. The aim of the current study was to explore the effects of picroside II, a phytoactive found in Picrorhiza kurroa, on fatty acid accumulation vis-à-vis silibinin, a known hepatoprotective phytoactive from Silybum marianum. METHODS: HepG2 cells were loaded with FFAs (oleic acid:palmitic acid/2:1) for 20 hours to mimic hepatic steatosis. The FFAs concentration achieving maximum fat accumulation and minimal cytotoxicity (500 µM) was standardized. HepG2 cells were exposed to the standardized FFAs concentration with and without picroside II pretreatment. RESULTS: Picroside II pretreatment inhibited FFAs-induced lipid accumulation by attenuating the expression of fatty acid transport protein 5, sterol regulatory element binding protein 1 and stearoyl CoA desaturase. Preatreatment with picroside II was also found to decrease the expression of forkhead box protein O1 and phosphoenolpyruvate carboxykinase. CONCLUSIONS: These findings suggest that picroside II effectively attenuated fatty acid accumulation by decreasing FFAs uptake and lipogenesis. Picroside II also decreased the expression of gluconeogenic genes.

Augmentation of histone deacetylase 3 (HDAC3) epigenetic signature at the interface of proinflammation and insulin resistance in patients with type 2 diabetes.

BACKGROUND: A role of proinflammation has been implicated in the pathogenesis of diabetes, but the up-stream regulatory signals and molecular signatures are poorly understood. While histone modifications such as changes in histone deacetylase (HDAC) are emerging as novel epigenetic biomarkers, there is lack of studies to demonstrate their clinical relevance in diabetes. Therefore, we investigated the extent of HDAC machinery and inflammatory signals in peripheral blood mononuclear cells (PBMCs) from patients with type 2 diabetes mellitus (T2DM) compared to control subjects. RESULTS: HDAC3 activity was significantly (p < 0.05) increased in patients with T2DM compared to control subjects. While subtypes of HDACs were differentially expressed at their transcriptional levels in patients with type 2 diabetes, the most prominent observation is the significantly (p < 0.05) elevated messenger RNA (mRNA) levels of HDAC3. Expression levels of Sirt1 which represents the class III HDAC were decreased significantly in T2DM (p < 0.05). Plasma levels of both TNF-α and IL-6 were significantly higher (p < 0.05) in patients with type 2 diabetes compared to control subjects. Among the proinflammatory mediators, the mRNA expression of MCP-1, IL1-ß, NFκB, TLR2, and TLR4 were also significantly (p < 0.05) increased in T2DM. Transcriptional levels of DBC1 (deleted in breast cancer 1, which is a negative regulator of HDAC3) were seen significantly reduced in PBMCs from T2DM. Interestingly, HDAC3 activity/HDAC3 mRNA levels positively correlated to proinflammation, poor glycemic control, and insulin resistance. CONCLUSIONS: Striking message from this study is that while looking for anti-inflammatory strategies and drugs with novel mode of action for T2DM, discovering and designing specific inhibitors targeted to HDAC3 appears promising.

Development of Diagnostic Fragment Ion Library for Glycated Peptides of Human Serum Albumin: Targeted Quantification in Prediabetic, Diabetic, and Microalbuminuria Plasma by Parallel Reaction Monitoring, SWATH, and MSE.

Human serum albumin is one of the most abundant plasma proteins that readily undergoes glycation, thus glycated albumin has been suggested as an additional marker for monitoring glycemic status. Hitherto, only Amadori-modified peptides of albumin were quantified. In this study, we report the construction of fragment ion library for Amadori-modified lysine (AML), N(ε)-(carboxymethyl)lysine (CML)-, and N(ε)-(carboxyethyl)lysine (CEL)-modified peptides of the corresponding synthetically modified albumin using high resolution accurate mass spectrometry (HR/AM). The glycated peptides were manually inspected and validated for their modification. Further, the fragment ion library was used for quantification of glycated peptides of albumin in the context of diabetes. Targeted Sequential Window Acquisition of all THeoretical Mass Spectra (SWATH) analysis in pooled plasma samples of control, prediabetes, diabetes, and microalbuminuria, has led to identification and quantification of 13 glycated peptides comprised of four AML, seven CML, and two CEL modifications, representing nine lysine sites of albumin. Five lysine sites namely K549, K438, K490, K88, and K375, were observed to be highly sensitive for glycation modification as their respective m/z showed maximum fold change and had both AML and CML modifications. Thus, peptides involving these lysine sites could be potential novel markers to assess the degree of glycation in diabetes.

Association of neutrophil-lymphocyte ratio with glucose intolerance: an indicator of systemic inflammation in patients with type 2 diabetes.

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) has been demonstrated to be a better risk factor than total white blood cell count in the prediction of adverse outcomes in various medical conditions. This study analyzed the association of NLR with different grades of glucose tolerance and insulin resistance in Asian Indians. SUBJECTS AND METHODS: Study subjects were recruited from Phase 3 of the Chennai Urban Rural Epidemiology Study (CURES). For this cross-sectional analysis, subjects with normal glucose tolerance (NGT) (n=237), impaired glucose tolerance (IGT) (n=63), and type 2 diabetes mellitus (DM) (n=286) were selected. The hemogram was done in all subjects using a five-part hematology analyzer (model SF-3000; Sysmex, Kobe, Japan). The NLR was calculated as the ratio between counts for neutrophils and total lymphocytes. Fasting insulin was measured by enzyme-linked immunosorbent assay, and insulin resistance was calculated using the homeostasis model assessment (HOMA-IR). RESULTS: Subjects with DM showed a significantly higher NLR (2.2 ± 1.12) compared with IGT subjects (1.82 ± 0.63), who in turn had a higher ratio than NGT subjects (1.5 ± 0.41) (P<0.01). Pearson correlation analysis showed a significant positive correlation of NLR with glycated hemoglobin (r=0.411), fasting plasma glucose (r=0.378), and HOMA-IR (r=0.233) (P<0.001). Regression analysis showed a linear increase in NLR with increasing severity of glucose intolerance even after adjusting for age, waist circumference, blood pressure, triglycerides, and smoking. CONCLUSIONS: This is the first report on the correlation of NLR with different grades of glucose intolerance and insulin resistance. NLR can be used as an adjuvant prognostic marker for macro- and microvascular complications in patients with glucose intolerance.

Convergence of innate immunity and insulin resistance as evidenced by increased nucleotide oligomerization domain (NOD) expression and signaling in monocytes from patients with type 2 diabetes.

Despite the well known role of nucleotide oligomerization domain (NOD) receptor proteins in innate immunity, their association with diabetes is less explored. Here we report the transcriptional level of NODs and their downstream molecular signatures in CD14(+) monocytes from subjects with different grades of glucose tolerance. NOD1 and NOD2 mRNA expression were significantly up-regulated in monocytes from patients with type 2 diabetes (T2DM) and positively correlated with HOMA-IR and poor glycemic control. Patients with T2DM also exhibited increased monocyte activation markers (CD11b and CD36) and proinflammatory signals downstream of NOD (RIPK2 and NFκB) along with the increased circulatory levels of TNF-α and IL-6. In vitro stimulation of monocytes with NOD specific ligands-i-EDAP and MDP significantly up regulated the mRNA expression of NOD1 and NOD2 respectively in T2DM. Our study exposes up regulation of NODs in monocytes as an important component of inflammation and insulin resistance in patients with T2DM.

Accelerated fat cell aging links oxidative stress and insulin resistance in adipocytes.

Telomere shortening is emerging as a biological indicator of accelerated aging and aging-related diseases including type 2 diabetes. While telomere length measurements were largely done in white blood cells, there is lack of studies on telomere length in relation to oxidative stress in target tissues affected in diabetes. Therefore, the aim of this study is to induct oxidative stress in adipocytes and to test whether these adipocytes exhibit shortened telomeres, senescence and functional impairment. 3T3-L1 adipocytes were subjected to oxidative stress and senescence induction by a variety of means for 2 weeks (exogenous application of H2O2, glucose oxidase, asymmetric dimethylarginine (ADMA) and glucose oscillations). Cells were probed for reactive oxygen species generation (ROS), DNA damage, mRNA and protein expression of senescent and pro-inflammatory markers, telomere length and glucose uptake. Compared to untreated cells, both ROS generation and DNA damage were significantly higher in cells subjected to oxidative stress and senescence. Adipocytes subjected to oxidative stress also showed shortened telomeres and increased mRNA and protein expression of p53, p21, TNF alpha and IL-6. Senescent cells were also characterized by decreased levels of adiponectin and impaired glucose uptake. Briefly, adipocytes under oxidative stress exhibited increased ROS generation, DNA damage, shortened telomeres and switched to senescent/pro-inflammatory phenotype with impaired glucose uptake.

Benefits of early glycemic control by insulin on sensory neuropathy and cataract in diabetic rats.

While there is an emphasis on the early glycemic control for its long-term benefits in preventing microvascular complications of diabetes, the biochemical mechanisms responsible for the long-lasting effects are not clearly understood. Therefore the impact of early insulin (EI) versus late insulin (LI) treatment on diabetic sensory neuropathy and cataract in streptozotocin-induced diabetic Wistar male rats were evaluated. EI group received insulin (2.5 IU/animal, once daily) treatment from day 1 to 90 while LI group received insulin from day 60 to 90. Early insulin treatment significantly reduced the biochemical markers like glucose, triglyceride, glycated hemoglobin, thiobarbituric acid reactive substances, advanced glycation end products and ratio of reduced glutathione and oxidized glutathione in diabetic rats. The late insulin treatment failed to resist the biochemical changes in diabetic rats. Diabetic rats developed sensory neuropathy as evidenced by mechanical and thermal hyperalgesia and showed a higher incidence and severity of cataract as revealed by slit lamp examination. Early insulin treatment protected the rats from the development of neuropathy and cataract, but late insulin administration failed to do so. The results demonstrate the benefits of early glycemic control in preventing neuropathy and cataract development in diabetic rats.

Hyperinsulinemia-induced vascular smooth muscle cell (VSMC) migration and proliferation is mediated by converging mechanisms of mitochondrial dysfunction and oxidative stress.

Atherosclerosis is one of the major complications of diabetes and involves endothelial dysfunction, matrix alteration, and most importantly migration and proliferation of vascular smooth muscle cells (VSMCs). Although hyperglycemia and hyperinsulinemia are known to contribute to atherosclerosis, little is known about the specific cellular signaling pathways that mediate the detrimental hyperinsulinemic effects in VSMCs. Therefore, we investigated the cellular mechanisms of hyperinsulinemia-induced migration and proliferation of VSMCs. VSMCs were treated with insulin (100 nM) for 6 days and subjected to various physiological and molecular investigations. VSMCs subjected to hyperinsulinemia exhibited increased migration and proliferation, and this is paralleled by oxidative stress [increased NADPH oxidase activity, NADPH oxidase 1 mRNA expression, and reactive oxygen species (ROS) generation], alterations in mitochondrial physiology (membrane depolarization, decreased mitochondrial mass, and increased mitochondrial ROS), changes in mitochondrial biogenesis-related genes (mitofusin 1, mitofusin 2, dynamin-related protein 1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, peroxisome proliferator-activated receptor gamma coactivator 1-beta, nuclear respiratory factor 1, and uncoupling protein 2), and increased Akt phosphorylation. Diphenyleneiodonium, a known NADPH oxidase inhibitor significantly inhibited migration and proliferation of VSMCs and normalized all the above physiological and molecular perturbations. This study suggests a plausible crosstalk between mitochondrial dysfunction and oxidative stress under hyperinsulinemia and emphasizes counteracting mitochondrial dysfunction and oxidative stress as a novel therapeutic strategy for atherosclerosis.

Noninvasive type 2 diabetes screening: clinical evaluation of SCOUT DS in an Asian Indian cohort.

OBJECTIVE: This study evaluated the noninvasive, point-of-care diabetes screening device, Scout DS (VeraLight Inc., Albuquerque, NM) (SCOUT), in a native Asian Indian cohort. RESEARCH DESIGN AND METHODS: SCOUT is a tabletop, skin fluorescence spectrometer that reports a risk score following a 3-4-min noninvasive measurement of a subject's left volar forearm. SCOUT, fasting plasma glucose (FPG), and hemoglobin A(1c) (A1C) were compared for detection of abnormal glucose tolerance (AGT) in a cohort of 256 subjects without previous diagnosis of diabetes or impaired glucose tolerance in Chennai, India. After an overnight fast, a 75-g, 2-h oral glucose tolerance test was administered, and AGT was defined as a plasma glucose value ≥ 140 mg/dL (7.8 mmol/dL). Sensitivity, false-positive rate (FPR), and receiver-operating characteristics area under the curve for AGT detection were computed for SCOUT, FPG, and A1C. Intra-day reproducibility of SCOUT was assessed. RESULTS: SCOUT, FPG, and A1C (at respective thresholds of 50, 110 mg/dL, and 5.7%) exhibited sensitivities of 87%, 32%, and 86%, respectively, and FPR of 52%, 3%, and 58%, respectively. For the 177 subjects receiving a valid SCOUT Diabetes Score on both measurement attempts, the coefficient of variation was 5.8%, and the Pearson correlation was 0.91. A SCOUT score could be obtained on 91% of subjects after two attempts. CONCLUSIONS: The performance of SCOUT is similar to that of A1C, whereas FPG had a much lower sensitivity. SCOUT is an effective tool for AGT screening in Asian Indians.

Convergence of adipocyte hypertrophy, telomere shortening and hypoadiponectinemia in obese subjects and in patients with type 2 diabetes.

OBJECTIVE: Although telomere shortening has been linked with type 2 diabetes and most variables of adiposity, a shortcoming of such studies is the measurement of telomere length in leukocytes. Therefore, we tested the association among adipocyte cell size, telomere length (both subcutaneous and visceral adipose tissue) and systemic levels of adiponectin in obese subjects and patients with type 2 diabetes compared to control subjects. METHODS: Human subcutaneous and visceral adipose tissues were obtained from the subjects who have undergone bariatric surgery or other abdominal surgeries. The study groups comprised: i) control subjects, ii) type 2 diabetes patients, iii) obese subjects without diabetes and iv) obese subjects with diabetes. Adipocyte cell size was measured by histological staining. Adiponectin levels were measured by ELISA. Telomere length was determined by Real-time PCR and lipid peroxidation was assessed by fluorimetry. RESULTS: Compared to control subjects, adipocyte size (both subcutaneous and visceral) from obese, diabetic and obese-diabetic subjects was significantly larger [p<0.001]. Individuals with adipose hypertrophy also exhibited shortened telomeres and hypoadiponectinemia. Pearson correlation analysis revealed that both visceral and subcutaneous fat cell size showed a positive correlation with FBS, HbA1c, HOMA-IR, LDL, total cholesterol, triglycerides and negatively correlated with HDL and adiponectin. Regression analysis revealed that the association between shortened telomeres and hypoadiponectinemia was lost when adjusted for adipocyte cell size. CONCLUSION: Adipocyte hypertrophy appears to be strongly associated with shortened telomeres, hypoadiponectinemia and poor glycemic and lipid control. Interestingly, these molecular alterations seen in lean diabetics reflect a state of 'metabolic obesity'.

Imbalanced levels of angiogenic and angiostatic factors in vitreous, plasma and postmortem retinal tissue of patients with proliferative diabetic retinopathy.

A role for vascular endothelial growth factor (VEGF) has been clearly implicated in the pathogenesis of proliferative diabetic retinopathy (PDR). However, other molecules and mechanisms may be operating independently, or in conjunction with VEGF in the pathogenesis of this disease. Therefore, we made an attempt to comparatively investigate the levels of angiogenic and angiostatic factors in vitreous, plasma and postmortem retinal tissue of subjects with Proliferative Diabetic Retinopathy (PDR) compared to control subjects. The vitreous and plasma concentrations of VEGF, EPO (Erythropoietin) and PEDF (Pigment Epithelium Derived Factor) were measured using Enzyme Linked Immunosorbent Assay (ELISA) and the postmortem retinal tissue was subjected to Western blot analysis. The mean vitreous and plasma levels of VEGF and EPO in patients with PDR were significantly (p<0.001) higher than those in subjects without diabetes. Conversely, the vitreous and plasma levels of PEDF were significantly (p<0.001) lower in the PDR patients compared to control subjects. Multivariate logistic-regression analyses indicated that EPO was more strongly associated with PDR than VEGF. The protein expression of the VEGF and EPO in the retinal tissue was significantly higher in PDR and diabetes without complication groups compared to controls. Compared to controls, the protein expression of PEDF was significantly lower in retinal tissues from diabetes patients without complications and in patients with PDR. The fact that the vitreous and plasma levels and the retinal tissue protein expression of EPO were strongly associated with PDR implies a definite role of 'hypererythropoietinemia' in neovascularization processes.

Oxidative stress is independently associated with non-alcoholic fatty liver disease (NAFLD) in subjects with and without type 2 diabetes.

OBJECTIVE: Our work is aimed at exploring the interrelationship of oxidative stress and insulin resistance in NAFLD subjects with and without type 2 diabetes in a population-based study. METHODS: Subjects [n=200] were recruited from the Chennai Urban Rural Epidemiology Study. 1: Normal glucose tolerance (NGT) subjects without NAFLD; 2: NGT with NAFLD; 3: type 2 diabetic subjects [T2DM] without NAFLD and 4: T2DM with NAFLD. Thiobarbituric acid reactive substances (TBARS), protein carbonyl (PCC) and glutathione levels were measured by standard methods. Ultrasound of the liver was used to diagnose NAFLD. RESULTS: TBARS and PCC levels were significantly elevated and GSH/GSSG ratio was significantly decreased in diabetic subjects with NAFLD compared to all other groups (p trend <0.001). Oxidative stress markers significantly associated with NAFLD even after adjusting for age, gender, BMI and glycemic status. CONCLUSIONS: Increased oxidative stress is independently associated with NAFLD in Asian Indians without and with T2DM.