Achieving postprandial glucose control with lixisenatide improves glycemic control in patients with type 2 diabetes on basal insulin: a post-hoc analysis of pooled data.

BACKGROUND: To examine the impact on glycemic control of achieving postprandial glucose (PPG) target with lixisenatide, a once-daily glucagon-like peptide-1 receptor agonist approved in the US, in patients with uncontrolled type 2 diabetes (T2D) on basal insulin, an agent that primarily targets fasting plasma glucose. METHODS: A post hoc pooled analysis was conducted using clinical trial data extracted from the intent-to-treat subpopulation of patients with T2D who participated in the 24-week, phase 3, randomized, double-blind, placebo-controlled, 2-arm parallel-group, multicenter GetGoal-L (NCT00715624), GetGoal-Duo 1 (NCT00975286) and GetGoal-L Asia trials (NCT00866658). RESULTS: Data from 587 lixisenatide-treated patients and 484 placebo-treated patients were included. Patients on lixisenatide were more likely to achieve a PPG target of < 10 mmol/L (< 180 mg/dL) than placebo-treated patients (P < 0.001), regardless of baseline fasting plasma glucose (FPG) levels. More importantly, those who reached the PPG target experienced a significantly greater reduction in mean HbA1c, were more likely to achieve HbA1c target of < 53 mmol/mol (< 7.0%), and experienced weight loss. Those outcomes were achieved with no significant differences in the risk of symptomatic hypoglycemia compared with placebo. CONCLUSION: Compared with placebo, addition of lixisenatide to basal insulin improved HbA1c and reduced PPG, without increasing hypoglycemia risk. These findings highlight the importance of PPG control in the management of T2D, and provide evidence that adding an agent to basal insulin therapy that also impacts PPG has therapeutic value for patients who are not meeting glycemic targets. TRIAL REGISTRATION: NCT00715624. Registered 15 July 2008, NCT00975286. Registered 11 September 2009, NCT00866658. Registered 20 March 2009.

Adjunct Therapy in Type 1 Diabetes: A Survey to Uncover Unmet Needs and Patient Preferences Beyond HbA1c Measures.

Background: Adjunct therapy can help patients with type 1 diabetes achieve glycemic goals while potentially mitigating some of the side effects of insulin. In this study, we used a patient survey to identify the unmet needs in type 1 diabetes therapy, patient views of treatment benefit-risk trade-offs, and patient preferences for the use of an adjunct therapy. Methods: A quantitative survey was sent to 2084 adults with type 1 diabetes in November 2017. "Jobs-to-be-done" and conjoint analyses were performed on survey responses to identify unmet needs and the importance of treatment-associated benefits and risks to patients. A 5-point Likert scale measured the importance and satisfaction with patients' current therapy, and with gaps relating to unmet needs. In the conjoint analysis, patients were asked to choose between "packages" of attributes of two doses of adjunct therapy (200 and 400 mg) and placebo, based on established benefits and side effects. Results: A total of 1313 patients (63%) responded. The greatest unmet needs identified were simplifying treatment, lowering/maintaining glycated hemoglobin (HbA1c), reducing mental effort, and increasing time in range (TIR). Conjoint analysis showed that reductions in body weight and TIR had the highest attribute importance (25% and 18%, respectively). The majority (93%) of patients had a preference for the adjunct therapy (either dose) over placebo. Conclusions: This survey highlights the importance of measures beyond HbA1c, such as treatment simplification and TIR, and patient preference for adjunct therapies that help address unmet needs in type 1 diabetes treatment.

Predictive Modeling of Hypoglycemia Risk with Basal Insulin Use in Type 2 Diabetes: Use of Machine Learning in the LIGHTNING Study.

INTRODUCTION: Hypoglycemia remains a global burden and a limiting factor in the glycemic management of people with diabetes using basal insulins or oral antihyperglycemic drugs. Hypoglycemia data gleaned from randomized controlled trials (RCTs) have limited generalizability, as the strict RCT methodology and inclusion criteria do not fully reflect the real-world clinical picture. Therefore, real-world evidence, gathered from sources including electronic health records (EHR), is increasingly recognized as an important adjunct to RCTs. AIMS AND METHODS: The LIGHTNING study applied advanced analytical methods, including machine learning (ML), to EHR data. The study aimed to predict hypoglycemic event rates in patients with type 2 diabetes (T2DM) receiving different basal insulin treatments to identify potential subgroups of patients who are at lower risk of hypoglycemia when treated with one basal insulin compared with another and to predict hypoglycemia-related cost savings in these subgroups. Here we provide an overview of the objectives, study design and methods, and validation approaches used in the LIGHTNING study. CONCLUSION: It is hoped that results of the LIGHTNING study will help facilitate real-world clinical decision-making in addition to providing a clinically relevant predictive model of hypoglycemia risk. FUNDING: Sanofi.

Rates of Hypoglycemia Predicted in Patients with Type 2 Diabetes on Insulin Glargine 300 U/ml Versus First- and Second-Generation Basal Insulin Analogs: The Real-World LIGHTNING Study.

INTRODUCTION: The LIGHTNING study applied conventional and advanced analytic approaches to model, predict, and compare hypoglycemia rates of people with type 2 diabetes (T2DM) on insulin glargine 300 U/ml (Gla-300) with those on first-generation (insulin glargine 100 U/ml [Gla-100]; insulin detemir [IDet]) or second-generation (insulin degludec [IDeg]) basal-insulin (BI) analogs, utilizing a large real-world database. METHODS: Data were collected between 1 January 2007 and 31 March 2017 from the Optum Humedica US electronic health records [EHR] database. Patient-treatments, the period during which a patient used a specific BI, were analyzed for patients who switched from a prior BI or those who newly initiated BI therapy. Data were analyzed using two approaches: propensity score matching (PSM) and a predictive modeling approach using machine learning. RESULTS: A total of 831,456 patients with T2DM receiving BI were included from the EHR data set. Following selection, 198,198 patient-treatments were available for predictive modeling. The analysis showed that rates of severe hypoglycemia (using a modified definition) were approximately 50% lower with Gla-300 than with Gla-100 or IDet in insulin-naïve individuals, and 30% lower versus IDet in BI switchers (all p < 0.05). Similar rates of severe hypoglycemia were predicted for Gla-300 and IDeg, regardless of prior insulin experience. Similar results to those observed in the overall cohorts were seen in analyses across subgroups at a particularly high risk of hypoglycemia. PSM (performed on 157,573 patient-treatments) revealed comparable reductions in HbA1c with Gla-300 versus first- and second-generation BI analogs, alongside lower rates of severe hypoglycemia with Gla-300 versus first-generation BI analogs (p < 0.05) and similar rates versus IDeg in insulin-naïve and BI-switcher cohorts. CONCLUSIONS: Based on real-world data, predicted rates of severe hypoglycemia with Gla-300 tended to be lower versus first-generation BI analogs and similar versus IDeg in a wide spectrum of patients with T2DM. FUNDING: Sanofi, Paris, France.

Lixisenatide as add-on treatment among patients with different ß-cell function levels as assessed by HOMA-ß index.

BACKGROUND: The effect of lixisenatide-a prandial once-daily glucagon-like peptide-1 receptor agonist-on glycaemic control in patients with inadequately controlled type 2 diabetes mellitus (T2DM), stratified by baseline ß-cell function, was assessed. METHODS: The 24-week GetGoal-M, -P and -S trials evaluated the efficacy and safety of lixisenatide in combination with oral antidiabetic agents. This post hoc analysis used data from patients receiving lixisenatide in these trials, divided into matched cohorts by propensity scoring, and stratified according to baseline homeostasis model assessment of ß-cell function (HOMA-ß) index levels, high HOMA-ß: > median HOMA-ß (28.49%); low HOMA-ß: ≤ median. RESULTS: The matched "low" and "high" HOMA-ß index cohorts (N = 546 patients) had comparable baseline parameters. Mean change from baseline in glycated haemoglobin (HbA1c ) was -0.85% and -0.94% for low and high HOMA-ß cohorts, respectively (P = .2607). Reductions from baseline in fasting plasma glucose (FPG; -0.77 vs -1.04 mmol/L; P = .1496) and postprandial plasma glucose (PPG; -5.82 vs -5.61 mmol/L; P = .7511) were similar in the low versus high HOMA-ß index cohorts. Reduction in body weight was significantly greater in the low versus high HOMA-ß index cohort (-2.06 vs -1.13 kg, respectively; P = .0006). CONCLUSIONS: In patients with T2DM, lixisenatide was associated with reduction in HbA1c and improvements in both FPG and PPG, regardless of ß-cell function, indicating that lixisenatide is effective in reducing hyperglycaemia, even in patients with more advanced stages of T2DM and poor residual ß-cell function.

Lixisenatide treatment for older patients with type 2 diabetes mellitus uncontrolled on oral antidiabetics: meta-analysis of five randomized controlled trials.

AIM: Evaluate the efficacy and safety of lixisenatide, a once-daily prandial glucagon-like peptide-1 receptor agonist, in older patients with type 2 diabetes mellitus (T2DM) insufficiently controlled on oral antidiabetics (OADs). METHODS: A meta-analysis was conducted on data from older patients (≥65 years) from five of the GetGoal trials, in which patients with T2DM were treated with lixisenatide 20 µg once daily or placebo, as an add-on to OADs. The primary endpoint in all trials was change from baseline at week 24 in glycated hemoglobin (HbA1c). Other endpoints included changes in post-prandial plasma glucose (PPG), fasting plasma glucose (FPG) and weight. Composite and safety endpoints were also analyzed. RESULTS: A total of 501 patients aged ≥65 years were included in this meta-analysis: 304 received lixisenatide plus OADs and 197 received placebo as add-on to OADs. Lixisenatide as an add-on to OADs significantly reduced HbA1c, PPG, FPG and weight, with placebo-corrected treatment effects at week 24 of -0.54% (p<0.0001), -126 mg/dL (p<0.0001), -13 mg/dL (p=0.0005) and -0.90 kg (p=0.0021), respectively. Patients receiving lixisenatide plus OADs were significantly more likely to achieve composite (HbA1c levels<7%, HbA1c levels<7% and no symptomatic hypoglycemia, and HbA1c levels<7%, no weight gain and no symptomatic hypoglycemia) and safety endpoints than those receiving placebo plus OADs. Symptomatic hypoglycemia was experienced by 8.55% and 3.55% of patients in the lixisenatide plus OADs and placebo plus OADs groups, respectively (p=0.0276), although no serious hypoglycemic episodes were reported. CONCLUSIONS: Lixisenatide plus OADs improved glycemic control in older patients inadequately controlled on OADs compared with placebo plus OADs. Lixisenatide is well tailored to the pathophysiology of T2DM in older patients.

Insulin therapy in type 2 diabetes mellitus: a practical approach for primary care physicians and other health care professionals.

The responsibility of diabetes management and insulin therapy has definitively moved to primary care physicians. Within the primary care setting, there is a growing need for clear, evidence-based guidelines related to the management of insulin therapy. Straightforward algorithms regarding insulin initiation, titration, and follow-up management can help physicians effectively treat patients with type 2 diabetes mellitus. Once 2 oral diabetic drugs have failed in a patient whose disease duration is 7 to 10 years, use of insulin therapy with a basal insulin analog should be considered. For patients who receive maximal basal insulin doses without reaching fasting blood glucose and target glycated hemoglobin levels with basal insulin analogs, a mealtime-insulin intensification approach should be considered. The authors discuss how simplified insulin initiation and titration regimens allow primary care physicians and other health care professionals to care for patients with type 2 diabetes mellitus.

Weight loss, glycemic control, and changes in cardiovascular biomarkers in patients with type 2 diabetes receiving incretin therapies or insulin in a large cohort database.

OBJECTIVE: Weight loss in patients with type 2 diabetes can improve glycemic control, lower blood pressure, and improve dyslipidemia. Glucagon-like peptide (GLP-1) receptor agonists are associated with weight loss and have potentially beneficial effects on cardiovascular risk biomarkers; however, there is limited information to indicate whether these effects remain outside of clinical trials. RESEARCH DESIGN AND METHODS: Medical records from the General Electric Centricity research database were analyzed retrospectively to evaluate the relationship between weight loss and glycemic control and changes in blood pressure and lipids in patients with type 2 diabetes initiating therapy with exenatide, sitagliptin, or insulin. Baseline and follow-up (90-365 days after the index date) for weight, A1C, fasting blood glucose (FBG), blood pressure, triglycerides, and LDL, HDL, and total cholesterol were assessed. RESULTS: A total of 6,280, 5,861, and 32,398 patients receiving exenatide, sitagliptin, or insulin, respectively, were included in the analysis. Exenatide-treated patients lost a mean +/- SD of 3.0 +/- 7.33 kg, sitagliptin-treated patients lost 1.1 +/- 5.39 kg, and insulin-treated patients gained 0.6 +/- 9.49 kg. There was a significant association between weight loss and a reduction in A1C and FBG with exenatide only and a reduction in blood pressure for all therapies. Weight loss was associated with some improvements in lipids, primarily in the GLP-1 receptor agonist group, with little association in the insulin group. CONCLUSIONS: Weight reduction with GLP-1 receptor agonists was associated with a shift toward a more favorable cardiovascular risk profile. Outcome trials are needed to determine whether improvement in biomarkers translates into a reduction in cardiovascular events in patients with type 2 diabetes.

Pioglitazone improvement of fasting and postprandial hyperglycaemia in Mexican-American patients with Type 2 diabetes: a double tracer OGTT study.

OBJECTIVES: By using tracer techniques, we explored the metabolic mechanisms by which pioglitazone treatment for 16 weeks improves oral glucose tolerance in patients with type 2 diabetes when compared to subjects without diabetes. METHODS: In all subjects, before and after treatment, we measured rates of tissue glucose clearance (MCR), oral glucose appearance (RaO) and endogenous glucose production (EGP) during a (4-h) double tracer oral glucose tolerance test (OGTT) (1-(14)C-glucose orally and 3-(3)H-glucose intravenously). Basal hepatic insulin resistance index (HepIR) was calculated as EGPxFPI. beta-cell function was assessed as the incremental ratio of insulin to glucose (DeltaI/DeltaG) during the OGTT. RESULTS: Pioglitazone decreased fasting plasma glucose concentration (10.5 +/- 0.7 to 7.8 +/- 0.6 mM, P < 0.0003) and HbA1c (9.7 +/- 0.7 to 7.5 +/- 0.5%, P < 0.003) despite increased body weight and no change in plasma insulin concentrations. This was determined by a decrease both in fasting EGP (20.0 +/- 1.1 to 17.3 +/- 0.8 micromol/kg(ffm) min, P < 0.005) and HepIR (from 8194 declined by 49% to 3989, P < 0.002). During the OGTT, total glucose Ra during the 0- to 120-min time period following glucose ingestion decreased significantly because of a reduction in EGP. During the 0- to 240-min time period, pioglitazone caused only a modest increase in MCR (P < 0.07) but markedly increased DeltaI/DeltaG (P = 0.003). The decrease in 2h-postprandial hyperglycaemia correlated closely with the increase in DeltaI/DeltaG (r = -0.76, P = 0.004) and tissue clearance (r = -0.74, P = 0.006) and with the decrease in HepIR (r = 0.62, P = 0.006). CONCLUSIONS: In diabetic subjects with poor glycaemic control, pioglitazone improves oral glucose tolerance mainly by enhancing the suppression of EGP and improving beta-cell function.

Fenofibrate reduces systemic inflammation markers independent of its effects on lipid and glucose metabolism in patients with the metabolic syndrome.

CONTEXT: Fenofibrate is a peroxisome proliferator-activated receptor alpha agonist widely used in clinical practice, but its mechanism of action is incompletely understood. OBJECTIVE: The aim of the study was to assess whether improvement in subclinical inflammation or glucose metabolism contributes to its antiatherogenic effects in insulin-resistant subjects with the metabolic syndrome (MetS). DESIGN AND SETTING: We conducted a randomized, double-blind, placebo-controlled study in the research unit at an academic center. PATIENTS: We studied 25 nondiabetic insulin-resistant MetS subjects. INTERVENTION(S): We administered fenofibrate (200 mg/d) and placebo for 12 wk. MAIN OUTCOME MEASURES: Before and after treatment, we measured plasma lipids/apolipoproteins, inflammatory markers (high-sensitivity C-reactive protein, IL-6, intercellular adhesion molecule/vascular cell adhesion molecule), adipocytokines (adiponectin, TNFalpha, leptin), and insulin secretion (oral glucose tolerance test). We also assessed adipose tissue, hepatic and peripheral (muscle) insulin resistance fasting and during a euglycemic insulin clamp with (3)H glucose and (14)C palmitate infusion combined with indirect calorimetry. RESULTS: Subjects displayed severe insulin resistance and systemic inflammation. Fenofibrate significantly reduced plasma triglyceride, apolipoprotein (apo) CII, apo CIII, and apo E (all P < 0.01), with a modest increase in high-density lipoprotein-cholesterol (+12%; P = 0.06). Fenofibrate markedly decreased plasma high-sensitivity C-reactive protein by 49.5 +/- 8% (P = 0.005) and IL-6 by 29.8 +/- 7% (P = 0.03) vs. placebo. However, neither insulin secretion nor adipose tissue, hepatic or muscle insulin sensitivity or glucose/lipid oxidation improved with treatment. Adiponectin and TNF-alpha levels were also unchanged. Improvement in plasma markers of vascular/systemic inflammation was dissociated from changes in triglyceride/high-density lipoprotein-cholesterol, apo CII/CIII, or free fatty acid concentrations or insulin secretion/insulin sensitivity. CONCLUSIONS: In subjects with the MetS, fenofibrate reduces systemic inflammation independent of improvements in lipoprotein metabolism and without changing insulin sensitivity. This suggests a direct peroxisome proliferator-activated receptor alpha-mediated effect of fenofibrate on inflammatory pathways, which may be important for the prevention of CVD in high-risk patients.

Treatment with the human once-weekly glucagon-like peptide-1 analog taspoglutide in combination with metformin improves glycemic control and lowers body weight in patients with type 2 diabetes inadequately controlled with metformin alone: a double-blind placebo-controlled study.

OBJECTIVE: To evaluate the efficacy and safety of taspoglutide (R1583/BIM51077), a human once-weekly glucagon-like peptide-1 analog, in patients with type 2 diabetes inadequately controlled with metformin. RESEARCH DESIGN AND METHODS: Type 2 diabetic (n = 306) patients who failed to obtain glycemic control (A1C 7-9.5%) despite 1,500 mg metformin daily were randomly assigned to 8 weeks of double-blind subcutaneous treatment with placebo or taspoglutide, either 5, 10, or 20 mg once weekly or 10 or 20 mg once every 2 weeks, and followed for 4 additional weeks. All patients received their previously established dose of metformin throughout the study. Glycemic control was assessed by change in A1C (percent) from baseline. RESULTS: Significantly greater (P < 0.0001) reductions in A1C from a mean +/- SD baseline of 7.9 +/- 0.7% were observed in all taspoglutide groups compared with placebo after 8 weeks of treatment: -1.0 +/- 0.1% (5 mg once weekly), -1.2 +/- 0.1% (10 mg once weekly), -1.2 +/- 0.1% (20 mg once weekly), -0.9 +/- 0.1% (10 mg Q2W), and -1.0 +/- 0.1% (20 mg Q2W) vs. -0.2 +/- 0.1% with placebo. After 8 weeks, body weight loss was significantly greater in the 10 mg (-2.1 +/- 0.3 kg, P = 0.0035 vs. placebo) and 20 mg (-2.8 +/- 0.3 kg, P < 0.0001) once-weekly groups and the 20 mg once every 2 weeks (-1.9 +/- 0.3 kg, P = 0.0083) group than with placebo (-0.8 +/- 0.3 kg). The most common adverse event was dose-dependent, transient, mild-to-moderate nausea; the incidence of hypoglycemia was very low. CONCLUSIONS: Taspoglutide used in combination with metformin significantly improves fasting and postprandial glucose control and induces weight loss, with a favorable tolerability profile.

Risk assessment does not explain high prevalence of gestational diabetes mellitus in a large group of Sardinian women.

BACKGROUND: A very high prevalence (22.3%) of gestational diabetes mellitus (GDM) was recently reported following our study on a large group of Sardinian women. In order to explain such a high prevalence we sought to characterise our obstetric population through the analysis of risk factors and their association with the development of GDM. METHODS: The prevalence of risk factors and their association with the development of GDM were evaluated in 1103 pregnancies (247 GDM and 856 control women). The association of risk factors with GDM was calculated according to logistic regression. Sensitivity and specificity of risk assessment strategy were also calculated. RESULTS: None of the risk factors evaluated showed an elevated frequency in our population. The high risk patients were 231 (20.9%). Factors with a stronger association with GDM development were obesity (OR 3.7, 95% CI 2.08-6.8), prior GDM (OR 3.1, 95% CI 1.69-5.69), and family history of Type 2 diabetes (OR 2.6, 95% CI 1.81-3.86). Only patients over 35 years of age were more represented in the GDM group (38.2% vs 22.6% in the non-GDM cases, P < 0.001). Type 2 diabetes in second-degree relatives was equally represented in GDM and non-GDM subjects, while prior poor obstetrical outcomes mostly characterized non-GDM women (17.5% vs 10.6%, P < 0.001). The "average risk" assessment better characterized non-GDM patients (76.8% vs 57.8%, P < 0.001). The logistic regression analysis confirmed that Type 2 diabetes in second-degree relatives, prior poor obstetrical outcomes and the "average risk" definition did not predict the development of GDM. CONCLUSION: Such a high prevalence of GDM in our population does not seem to be related to the abnormal presence of some known risk factors, and appears in contrast with the prevalence of Type 2 diabetes in Sardinia. Further studies are needed to explain the cause such a high prevalence of GDM in Sardinia. The "average risk" definition is not adequate to predict GDM in our population.

Global relationship between the proteome and transcriptome of human skeletal muscle.

Skeletal muscle is one of the largest tissues in the human body. Changes in mRNA and protein abundance in this tissue are central to a large number of metabolic and other disorders, including, commonly, insulin resistance. Proteomic and microarray analyses are important approaches for gaining insight into the molecular and biochemical basis for normal and pathophysiological conditions. With the use of vastus lateralis muscle obtained from two groups of healthy, nonobese subjects, we performed a detailed comparison of the muscle proteome, obtained by HPLC-ESI-MS/MS, with the muscle transcriptome, obtained using oligonucleotide microarrays. HPLC-ESI-MS/MS analysis identified 507 unique proteins as present in four out of six subjects, while 5193 distinct transcripts were called present by oligonucleotide microarrays from four out of six subjects. The majority of the proteins identified by mass spectrometry also had their corresponding transcripts detected by microarray analysis, although 73 proteins were only identified in the proteomic analysis. Reflecting the high abundance of mitochondria in skeletal muscle, 30% of proteins detected were attributed to the mitochondrion, as compared to only 9% of transcripts. On the basis of Gene Ontology annotations, proteins assigned to mitochondrial inner membrane, mitochondrial envelope, structural molecule activity, electron transport, as well as generation of precursor metabolites and energy, had more corresponding transcripts detected than would be expected by chance. On the contrary, proteins assigned to Golgi apparatus, extracellular region, lyase activity, kinase activity, and protein modification process had fewer corresponding transcripts detected than would be expected by chance. In conclusion, these results provide the first global comparison of the human skeletal muscle proteome and transcriptome to date. These data show that a combination of proteomic and transcriptic analyses will provide data that can be used to test hypotheses regarding the pathogenesis of muscle disorders as well as to generate observational data that can be used to form novel hypotheses.

Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report.

BACKGROUND: We previously reported a high prevalence (22.3%) of gestational diabetes mellitus (GDM) in a large group of Sardinian women, in contrast with the prevalence of Type 2 diabetes. Sardinia has an unusual distribution of haplotypes and genotypes, with the highest population frequency of HLA DR3 in the world, and after Finland, the highest prevalence of Type 1 diabetes and Autoimmune-related Diseases. In this study we preliminarily tested the prevalence of serological markers of Type 1 diabetes in a group of Sardinian GDM patients. METHODS: We determined glutamic decarboxylase antibodies (anti-GAD65), protein tyrosine phosphatase ICA 512 (IA2) antibodies (anti-IA2), and IAA in 62 GDM patients, and in 56 controls with matching age, gestational age and parity. RESULTS: We found a high prevalence and very unusual distribution of antibodies in GDM patients (38.8%), the anti-IA2 being the most frequent antibody. Out of all our GDM patients, 38.8% (24 of 62) were positive for at least one antibody. Anti-IA2 was present in 29.0 % (18 out of 62) vs. 7.1% (4 out of 56) in the controls (P < 0.001). IAA was present in 14.5% (9 out of 62) of our GDM patients, and absent in the control subjects (P < 0.001). Anti-GAD65 was also present in GDM patients, with a prevalence of 3.2% (2 out of 62) while it was absent in the control group (P = NS). Pre-gestational weight was significantly lower (57.78 +/- 9.8 vs 65.9 +/- 17.3 P = 0.04) in auto-antibodies- positive GDM patients. CONCLUSION: These results are in contrast with the very low prevalence of all antibodies reported in Italy. If confirmed, they could indicate that a large proportion of GDM patients in Sardinia have an autoimmune origin, in accordance with the high prevalence of Type 1 diabetes.

Prolactin and insulin ultradian secretion and adipose tissue lipoprotein lipase expression in severely obese women after bariatric surgery.

BACKGROUND: Hyperprolactinemia is associated with obesity. Furthermore, in human adipose tissue cultured in vitro, prolactin (PRL) inhibited lipoprotein lipase (LPL) activity via functional PRL receptors. OBJECTIVE: To study PRL and insulin ultradian rhythm and subcutaneous adipose tissue LPL mRNA and protein expressions in severely obese women before and after malabsorptive bariatric surgery. METHODS AND PROCEDURES: Seven severely obese, fertile women were studied twice, once before and the second time 1 year after bilio-pancreatic diversion (BPD), when the weight was stable for at least 3 months. Metabolizable energy intake and 24-h energy expenditure (EE) were measured. Fourier and PULSEFIT analyses were applied to 24-h hormonal time-series to study daily fluctuations and hormonal clearance. Insulin sensitivity was assessed by euglycemic-hyperinsulinemic clamp. Quantitative-competitive reverse transcriptase-PCR and western blot analysis were used to measure LPL gene expression. RESULTS: Spontaneous 24-h PRL secretion was significantly reduced after BPD (mean-daily release, 128.4 +/- 28.1 microg/l vs. 67.2 +/- 9.2 microg/l distribution volume (Vd/l.24 h), P = 0.02); insulin secretion also was significantly reduced (499.9 +/- 204.0 microg/Vd/l.24 h vs. 85.6 +/- 21.0 microg/Vd/l.24 h, P = 0.0001). Metabolizable energy/kg(FFM) did not change significantly after BPD. Twenty-four-hour EE, but not 24-h EE/FFM, was significantly decreased after BPD (P < 0.05). Insulin sensitivity significantly (P < 0.0001) increased after BPD from 21.41 +/- 1.92 to 68.62 +/- 5.03 micromol/kg(FFM)/min. LPL mRNA concentration (from 42.63 +/- 4.21% to 19.00 +/- 2.74% of cyclophilin mRNA, P = 0.001) as well as LPL protein level (from 8.94 +/- 2.73 to 3.16 +/- 1.05 as ratios of protein of interest vs. housekeeping protein, P = 0.038) significantly decreased after BPD. The major determinant of PRL secretion was insulin secretion, whereas the best predictors of LPL expression were insulin and PRL secretion rates. DISCUSSION: The restriction of lipid metabolizable energy rather than weight loss seems to be responsible for both reduction in PRL circulating levels and normalization of its secretion rhythm after bariatric surgery. Furthermore, the reduced adipose tissue LPL expression, being significantly correlated with the decrease in insulin and PRL, suggests a role of hyperinsulinemia and hyperprolactinemia in inducing and sustaining obesity.

Insulin-resistant muscle is exercise resistant: evidence for reduced response of nuclear-encoded mitochondrial genes to exercise.

Mitochondrial dysfunction, associated with insulin resistance, is characterized by low expression of peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) and nuclear-encoded mitochondrial genes. This deficit could be due to decreased physical activity or a decreased response of gene expression to exercise. The objective of this study was to investigate whether a bout of exercise induces the same increase in nuclear-encoded mitochondrial gene expression in insulin-sensitive and insulin-resistant subjects matched for exercise capacity. Seven lean and nine obese subjects took part. Insulin sensitivity was assessed by an 80 mU.m(-2).min(-1) euglycemic clamp. Subjects were matched for aerobic capacity and underwent a single bout of exercise at 70 and 90% of maximum heart rate with muscle biopsies at 30 and 300 min postexercise. Quantitative RT-PCR and immunoblot analyses were used to determine the effect of exercise on gene expression and protein abundance and phosphorylation. In the postexercise period, lean subjects immediately increased PGC-1alpha mRNA level (reaching an eightfold increase by 300 min postexercise) and protein abundance and AMP-dependent protein kinase phosphorylation. Activation of PGC-1alpha was followed by increase of nuclear respiratory factor-1 and cytochrome c oxidase (subunit VIc). However, in insulin-resistant subjects, there was a delayed and reduced response in PGC-1alpha mRNA and protein, and phosphorylation of AMP-dependent protein kinase was transient. None of the genes downstream of PGC-1alpha was increased after exercise in insulin resistance. Insulin-resistant subjects have a reduced response of nuclear-encoded mitochondrial genes to exercise, and this could contribute to the origin and maintenance of mitochondrial dysfunction.

Model-based assessment of insulin sensitivity of glucose disposal and endogenous glucose production from double-tracer oral glucose tolerance test.

A new mathematical model of short-term glucose regulation by insulin is proposed to exploit the oral glucose tolerance test (OGTT), which is commonly used for clinical diagnosis of glucose intolerance and diabetes. Contributions of endogenous and exogenous sources to measured plasma glucose concentrations have been separated by means of additional oral administration and constant intravenous infusion of glucose labeled with two different tracers. Twelve type 2 diabetic patients (7 males and 5 females) and 10 control subjects (5 males and 5 females) with normal glucose tolerance and matched body mass index (BMI) participated in this study. Blood samples for measurement of concentrations/activity of unlabeled and double-tracer glucose and insulin were collected every 15 min for 3 h following the oral glucose load. A minimal model combined with non-linear mixed-effects population parameter estimation has been devised to characterize group-average and between-patient variability of: (i) gastrointestinal glucose absorption; (ii) endogenous glucose production (EGP), and (iii) glucose disposal rate. Results indicate that insulin-independent glucose clearance does not vary significantly with gender or diabetic state and that the latter strongly affects, as expected, insulin-dependent clearance (insulin sensitivity). Inhibition of EGP, interpreted in terms of variations from basal of insulin concentrations, does not appear to be affected by diabetes but rather by BMI, i.e. by the degree of obesity. This study supports the utility of a minimal modelling approach, combined with population parameter estimation, to characterize glucose absorption, production and disposition during double-tracer OGTT experiments. The model provides a means for planning further experiments to validate the new hypothesis on the influence of individual factors, such as BMI and diabetes, on glucose appearance and disappearance, and for designing new simplified clinical tests.

Relationship between hepatic/visceral fat and hepatic insulin resistance in nondiabetic and type 2 diabetic subjects.

BACKGROUND AND AIMS: Abdominal fat accumulation (visceral/hepatic) has been associated with hepatic insulin resistance (IR) in obesity and type 2 diabetes (T2DM). We examined the relationship between visceral/hepatic fat accumulation and hepatic IR/accelerated gluconeogenesis (GNG). METHODS: In 14 normal glucose tolerant (NGT) (body mass index [BMI] = 25 +/- 1 kg/m(2)) and 43 T2DM (24 nonobese, BMI = 26 +/- 1; 19 obese, BMI = 32 +/- 1 kg/m(2)) subjects, we measured endogenous (hepatic) glucose production (3-(3)H-glucose) and GNG ((2)H(2)O) in the basal state and during 240 pmol/m(2)/min euglycemic-hyperinsulinemic clamp, and liver (LF) subcutaneous (SAT)/visceral (VAT) fat content by magnetic resonance spectroscopy/magnetic resonance imaging. RESULTS: LF was increased in lean T2DM compared with lean NGT (18% +/- 3% vs 9% +/- 2%, P < .03), but was similar in lean T2DM and obese T2DM (18% +/- 3% vs 22% +/- 3%; P = NS). Both VAT and SAT increased progressively from lean NGT to lean T2DM to obese T2DM. T2DM had increased basal endogenous glucose production (EGP) (NGT, 15.1 +/- 0.5; lean T2DM, 16.3 +/- 0.4; obese T2DM, 17.2 +/- 0.6 micromol/min/kg(ffm); P = .02) and basal GNG flux (NGT, 8.6 +/- 0.4; lean T2DM, 9.6 +/- 0.4; obese T2DM, 11.1 +/- 0.6 micromol/min/kg(ffm); P = .02). Basal hepatic IR index (EGP x fasting plasma insulin) was increased in T2DM (NGT, 816 +/- 54; lean T2DM, 1252 +/- 164; obese T2DM, 1810 +/- 210; P = .007). In T2DM, after accounting for age, sex, and BMI, both LF and VAT, but not SAT, were correlated significantly (P < .05) with basal hepatic IR and residual EGP during insulin clamp. Basal percentage of GNG and GNG flux were correlated positively with VAT (P < .05), but not with LF. LF, but not VAT, was correlated with fasting insulin, insulin-stimulated glucose disposal, and impaired FFA suppression by insulin (all P < .05). CONCLUSIONS: Abdominal adiposity significantly affects both lipid (FFA) and glucose metabolism. Excess VAT primarily increases GNG flux. Both VAT and LF are associated with hepatic IR.

A placebo-controlled trial of pioglitazone in subjects with nonalcoholic steatohepatitis.

BACKGROUND: No pharmacologic therapy has conclusively proved to be effective for the treatment of nonalcoholic steatohepatitis, which is characterized by insulin resistance, steatosis, and necroinflammation with or without centrilobular fibrosis. Pioglitazone is a thiazolidinedione that ameliorates insulin resistance and improves glucose and lipid metabolism in type 2 diabetes mellitus. METHODS: We randomly assigned 55 patients with impaired glucose tolerance or type 2 diabetes and liver biopsy-confirmed nonalcoholic steatohepatitis to 6 months of treatment with a hypocaloric diet (a reduction of 500 kcal per day in relation to the calculated daily intake required to maintain body weight) plus pioglitazone (45 mg daily) or a hypocaloric diet plus placebo. Before and after treatment, we assessed hepatic histologic features, hepatic fat content by means of magnetic resonance spectroscopy, and glucose turnover during an oral glucose tolerance test ([14C]glucose given with the oral glucose load and [3H]glucose given by intravenous infusion). RESULTS: Diet plus pioglitazone, as compared with diet plus placebo, improved glycemic control and glucose tolerance (P<0.001), normalized liver aminotransferase levels as it decreased plasma aspartate aminotransferase levels (by 40% vs. 21%, P=0.04), decreased alanine aminotransferase levels (by 58% vs. 34%, P<0.001), decreased hepatic fat content (by 54% vs. 0%, P<0.001), and increased hepatic insulin sensitivity (by 48% vs. 14%, P=0.008). Administration of pioglitazone, as compared with placebo, was associated with improvement in histologic findings with regard to steatosis (P=0.003), ballooning necrosis (P=0.02), and inflammation (P=0.008). Subjects in the pioglitazone group had a greater reduction in necroinflammation (85% vs. 38%, P=0.001), but the reduction in fibrosis did not differ significantly from that in the placebo group (P=0.08). Fatigue and mild lower-extremity edema developed in one subject who received pioglitazone; no other adverse events were observed. CONCLUSIONS: In this proof-of-concept study, the administration of pioglitazone led to metabolic and histologic improvement in subjects with nonalcoholic steatohepatitis. Larger controlled trials of longer duration are warranted to assess the long-term clinical benefit of pioglitazone. (ClinicalTrials.gov number, NCT00227110 [ClinicalTrials.gov] .).

Exercise-induced improvement in vasodilatory function accompanies increased insulin sensitivity in obesity and type 2 diabetes mellitus.

OBJECTIVE: The present study was undertaken to determine whether improved vasodilatory function accompanies increased insulin sensitivity in overweight, insulin-resistant subjects (OW) and type 2 diabetic patients (T2DM) who participated in an 8-wk exercise training regimen. DESIGN: Before and after training, subjects had euglycemic clamps to determine insulin sensitivity. Brachial artery catheterization was done on another occasion for measurement of vasodilatory function. A lean, healthy, untrained group was studied as nonexercised controls. RESULTS: Training increased oxygen consumption (VO2) peak [OW, 29 +/- 1 to 37 +/- 4 ml/kg fat-free mass (FFM).min; T2DM, 33 +/- 2 to 43 +/- 3 ml/kg FFM.min; P < 0.05] and improved insulin-stimulated glucose disposal (OW, 6.5 +/- 0.5 to 7.2 +/- 0.4 mg/kg FFM.min; T2DM, 3.8 +/- 0.3 to 4.2 +/- 0.3 mg/kg FFM.min; P < 0.05) in insulin resistance. OW and T2DM, before training, had decreased acetylcholine chloride (ACh)- and sodium nitroprusside-mediated vasodilation and decreased reactive hyperemia compared with lean controls. Training increased the vasodilatory response to ACh [OW (30 microg ACh/min), 12.2 +/- 3.4 to 19 +/- 4.2 ml/100 g.min; T2DM (30 microg ACh/min), 10.1 +/- 1.5 to 14.2 +/- 2.1 ml/100 g.min; P < 0.05] in both groups without affecting nitroprusside response. CONCLUSION: Because vasodilatory dysfunction has been postulated to contribute to insulin resistance, the exercise-induced improvement in vasodilatory function may signify changes in the endothelium that could contribute to the improvement in insulin sensitivity observed after aerobic exercise training.