Homeostasis Model Assessment Beta-cell Research Articles

Low dose tacrolimus exposure and early steroid withdrawal with strict body weight control can improve post kidney transplant glucose tolerance in Japanese patients.

The development of diabetes mellitus (DM) after living donor kidney transplantation (KT) is a risk factor for worsening transplant kidney function, cardiac disease, and cerebrovascular disease, which may affect prognosis after KT. At our institution, all patients' glucose tolerance is evaluated perioperatively by oral glucose tolerance tests (OGTTs) at pre-KT, and 3, 6, and 12 month (mo.) after KT. We analyzed the insulinogenic index (ISI) and homeostasis model assessment beta cell (HOMA-β) based on the immunoreactive insulin (IRI) levels to determine how glucose tolerance changed after KT in 214 patients who had not been diagnosed with DM before KT. In addition, we analyzed the body mass index (BMI) which may also influence glucose tolerance after KT. The concentration of tacrolimus (TAC) in blood was also measured as the area under the curve (AUC) to examine its effects at each sampling point. The preoperative-OGTTs showed that DM was newly diagnosed in 22 of 214 patients (10.3%) who had not been given a diagnosis of DM by the pre-KT fasting blood sugar (FBS) tests. The glucose tolerance was improved in 15 of 22 DM patients at 12 mo. after KT. ISI and IRI deteriorated only at 3 mo. after KT but improved over time. There was a trend of an inverse correlation between HOMA-β and TAC-AUC. We also found inverse correlations between IRI and an increase in BMI from 3 to 12 mo. after KT. Early corticosteroid withdrawal or the steroid minimization protocol with tacrolimus to maintain a low level of diabetogenic tacrolimus and BMI decrease after KT used by our hospital individualizes lifestyle interventions for each patient might contribute to an improvement in post-KT glucose tolerance.

Factors Associated with Relapse of Type 2 Diabetes Mellitus after Laparoscopic Sleeve Gastrectomy in Japanese Subjects: A Subgroup Analysis of J-SMART Study

Introduction: Laparoscopic sleeve gastrectomy (LSG) for morbidly obese patients often results in remission of type 2 diabetes (T2DM), but diabetes relapses in some of those patients. The frequency of T2DM relapse in Asians and the factors involved have not been adequately investigated. Methods: The J-SMART study was conducted on 322 Japanese subjects with body mass index (BMI) ≥32 kg/m² who underwent LSG at 10 accredited centers in Japan between 2011 and 2014. Of these, 82 T2DM subjects with diabetes in complete or partial remission at 1 year after LSG and followed postoperatively for 5 years were included in the subgroup analysis and classified into two groups: diabetes remission-maintained and diabetes relapse. Results: The mean age of all included subjects was 49.2 years, median BMI was 41.5 kg/m², and median HbA1c was 6.7%. Compared with the diabetes remission-maintained group, the diabetes relapse group at 5 years after LSG had significantly higher preoperative HbA1c, number of antidiabetic medications, and high-density lipoprotein cholesterol level; and lower BMI and homeostasis model assessment-beta cell function (HOMA-β). As many as 83.0% of the subjects were able to achieve HbA1c <7% at 5 years after LSG, but 26.8% of the subjects had diabetes relapse. Preoperative HbA1c significantly contributed to diabetes relapse (odds ratio 1.54, p = 0.049). In addition, the diabetes relapse group tended to have lower percentage total weight loss (%TWL) at 1 year after LSG and higher percentage weight regain (%WR) from postoperative nadir weight, compared with the diabetes remission-maintained group. The hazard ratio for diabetes relapse was 3.14-fold higher in subjects with %TWL ≥20% and %WR ≥25%, and 5.46-fold higher in those with %TWL <20% and %WR ≥25%, compared with %TWL ≥20% and %WR <25%. Conclusion: While LSG provides a high remission rate for T2DM, relapse is not uncommon. Preoperative HbA1c, poor weight loss, and excess weight regain after LSG contribute to diabetes relapse, suggesting the importance of treatment strategies focusing on these factors.

The effect of omega-3 and vitamin D co-supplementation on glycemic control and lipid profiles in reproductive-aged women with pre-diabetes and hypovitaminosis D: a randomized controlled trial

BackgroundPrediabetes can predispose the individual to type 2 diabetes in the long-term. The present study was conducted to determine the effectiveness of vitamin D and omega-3 co-supplementation on glycemic control and serum lipid profiles in women of reproductive age with prediabetes and hypovitaminosis D.MethodsThe present factorial, triple-blind, clinical trial was conducted on 168 women of reproductive age with prediabetes and hypovitaminosis D. The participants were assigned to four groups based on block randomization method: the placebo group received omega-3 and vitamin D placebos; the omega-3 group took omega-3 supplements and vitamin D placebos; the vitamin D group received omega-3 placebos and vitamin D supplements and the co-supplementation group. The groups received every 2 weeks 50,000 IU pearls of vitamin D and twice-daily doses of 1000-mg omega-3 tablets or placebos for 8 weeks. Dietary intake, physical activity, anthropometric indices and blood biochemical tests were measured at the beginning and end of the study. Analysis was performed using two-way mixed ANOVA.ResultsA significant reduction was observed in fasting glucose, insulin, homeostasis model assessment-beta cell function, weight and waist circumference in the co-supplementation group compared to the other three groups (P < 0.05). Moreover, high-density lipoprotein-cholesterol levels increased significantly in the co-supplementation group compared to the other three groups (P < 0.05). Despite the fact that homeostasis model assessment-insulin resistance, total cholesterol, triglyceride and low-density lipoprotein-cholesterol levels decreased after intervention in the co-supplementation group, there was no significant difference between the groups in these outcomes.ConclusionVitamin D and omega-3 co-supplementation improved fasting serum glucose, insulin, high-density lipoprotein-cholesterol level, homeostasis model assessment-beta cell function, weight and waist circumference in women of reproductive age with prediabetes and hypovitaminosis D. This co-supplementation can therefore be recommended for glycemic control in these women.Trial registration Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on 9 Feb. 2019

EFFECT OF SPEXIN TREATMENT ON CARDIOMETABOLIC CHANGES IN OBESE TYPE 2 DIABETIC RATS

Background: Spexin is a peptide hormone that was expressed in brain regions and peripheral tissues of many species including human and rat. Several studies investigated its blood level changes with obesity and type 2 diabetes, but few studies assessed its effect on cardiometabolic, histological and morphometric changes in diabetes with some controversies in their results. Objective: To explore the effect of spexin treatment on cardiometabolic, histological and morphometric changes of pancreas and heart tissue in obese type 2 diabetic rats, and the possible mechanisms involved. Materials and Methods: Thirty adult male albino rats were divided randomly into 5 equal groups; control (fed ordinary laboratory chow along this 8 weeks’ study), diabetic [fed high fat diet along this 8 weeks’ study, but at the start of the 4th week, overnight fasted rats were injected with a single streptozotocin injection intraperitoneally (40 mg/kg body weight, dissolved in 0.01M citrate buffer, pH 4.5) to induce diabetes], diabetic metformin-treated [rats were managed as in diabetic group and in addition to that, metformin was given orally (300 mg/kg/day) by oral gavage to rats for 4 weeks from the start of 5th week to the end of 8th week], diabetic vildagliptin treated [rats were manipulated as in diabetic group and in addition to that, vildagliptin was given orally (10 mg/kg/day) using oral gavage to rats for 4 weeks from the start of 5th week to the end of 8th week], and diabetic spexin treated [rats were managed as in diabetic group and in addition to that, spexin dissolved in normal saline was injected intraperitoneally (35 μg/kg/day) for 4 weeks from the start of 5th week to the end of 8th week] groups. For histological, immunohistochemical and morphometric examinations, fresh heart and pancreatic specimens were collected from rats that were sacrificed. Results: In diabetic group, a significant increase was detected in final body mass index, serum glucose, serum insulin, homeostasis model assessment-insulin resistance, serum total cholesterol, serum triglycerides, serum low density lipoprotein, atherogenic index, serum dipeptidyl peptidase-IV, serum tumor necrosis factor alpha serum interleukin-1 beta, serum malondialdehyde, serum lactate dehydrogenase, serum creatine kinase-myoglobin binding and mean arterial blood pressure, with a significant decrease in homeostasis model assessment-beta cell functionserum high density lipoprotein, serum superoxide dismutase and serum spexin in comparison to that in the control group. With spexin treatment (as well as with the administration of standard drugs metformin and vildagliptin), all these changes were reversed significantly in comparison with those in the diabetic group. Diabetes induced histopathological changes in cardiac muscle and pancreatic structure which were ameliorated by treatment with spexin as well as with the standard anti-diabetic drugs (metformin and vildagliptin). The morphometric analysis confirmed the histopathological results, as a statistically significant difference was detected in area percent of collagen deposition, area percent of insulin immune-reaction in pancreas and cardiac muscle Bax expression between both diabetic group and all other groups, with no statistically significant difference between diabetic metformin treated, diabetic vildagliptin treated and diabetic spexin treated groups. Conclusion: Spexin ameliorated diabetes induced deleterious cardiometabolic, histopathological and morphometric disturbances. The anti-obesity, dipeptidyl peptidase-IV inhibitory, hypoglycemic, hypolipidemic, antioxidant, anti-inflammatory and cardio-protective properties of spexin may contribute to its useful effects.

EFFECT OF SPEXIN TREATMENT ON CARDIOMETABOLIC CHANGES IN OBESE TYPE 2 DIABETIC RATS

Background: Spexin is a peptide hormone that was expressed in brain regions and peripheral tissues of many species including human and rat. Several studies investigated its blood level changes with obesity and type 2 diabetes, but few studies assessed its effect on cardiometabolic, histological and morphometric changes in diabetes with some controversies in their results. Objective: To explore the effect of spexin treatment on cardiometabolic, histological and morphometric changes of pancreas and heart tissue in obese type 2 diabetic rats, and the possible mechanisms involved. Materials and Methods: Thirty adult male albino rats were divided randomly into 5 equal groups; control (fed ordinary laboratory chow along this 8 weeks’ study), diabetic [fed high fat diet along this 8 weeks’ study, but at the start of the 4th week, overnight fasted rats were injected with a single streptozotocin injection intraperitoneally (40 mg/kg body weight, dissolved in 0.01M citrate buffer, pH 4.5) to induce diabetes], diabetic metformin-treated [rats were managed as in diabetic group and in addition to that, metformin was given orally (300 mg/kg/day) by oral gavage to rats for 4 weeks from the start of 5th week to the end of 8th week], diabetic vildagliptin treated [rats were manipulated as in diabetic group and in addition to that, vildagliptin was given orally (10 mg/kg/day) using oral gavage to rats for 4 weeks from the start of 5th week to the end of 8th week], and diabetic spexin treated [rats were managed as in diabetic group and in addition to that, spexin dissolved in normal saline was injected intraperitoneally (35 μg/kg/day) for 4 weeks from the start of 5th week to the end of 8th week] groups. For histological, immunohistochemical and morphometric examinations, fresh heart and pancreatic specimens were collected from rats that were sacrificed. Results: In diabetic group, a significant increase was detected in final body mass index, serum glucose, serum insulin, homeostasis model assessment-insulin resistance, serum total cholesterol, serum triglycerides, serum low density lipoprotein, atherogenic index, serum dipeptidyl peptidase-IV, serum tumor necrosis factor alpha serum interleukin-1 beta, serum malondialdehyde, serum lactate dehydrogenase, serum creatine kinase-myoglobin binding and mean arterial blood pressure, with a significant decrease in homeostasis model assessment-beta cell functionserum high density lipoprotein, serum superoxide dismutase and serum spexin in comparison to that in the control group. With spexin treatment (as well as with the administration of standard drugs metformin and vildagliptin), all these changes were reversed significantly in comparison with those in the diabetic group. Diabetes induced histopathological changes in cardiac muscle and pancreatic structure which were ameliorated by treatment with spexin as well as with the standard anti-diabetic drugs (metformin and vildagliptin). The morphometric analysis confirmed the histopathological results, as a statistically significant difference was detected in area percent of collagen deposition, area percent of insulin immune-reaction in pancreas and cardiac muscle Bax expression between both diabetic group and all other groups, with no statistically significant difference between diabetic metformin treated, diabetic vildagliptin treated and diabetic spexin treated groups. Conclusion: Spexin ameliorated diabetes induced deleterious cardiometabolic, histopathological and morphometric disturbances. The anti-obesity, dipeptidyl peptidase-IV inhibitory, hypoglycemic, hypolipidemic, antioxidant, anti-inflammatory and cardio-protective properties of spexin may contribute to its useful effects.

Long-Term Efficacy and Safety of Add-On Therapy of Sitagliptin to a Very Small Dose of Glimepiride Versus a Small Dose of Glimepiride Over Eighteen Months

Background: In patients associated with type 2 diabetes mellitus, sulfonylureas (SUs) are being prescribed less frequently, and in smaller doses, to avoid hypoglycemia and body weight gain. On the other hand, since dipeptidyl peptidase-4 (DPP-4) inhibitors only infrequently induce hypoglycemia and weight gain, more than 60% or 70% of Japanese patients associated with type 2 diabetes mellitus are currently being treated with DPP-4 inhibitors. However, the long-term effects of DPP-4 inhibitors on glycemic control and beta-cell function have not been thoroughly elucidated. Methods: The present study was designed to compare the long-term efficacy and safety of a daily administration of 50 mg sitagliptin added to a very small dose of glimepiride, SUs, of 1.1 mg (SIT group), versus a small dose of glimepiride added by 1 mg to its basal dosage, i.e., 2.1 mg (SU group) up to 18 months in Japanese patients with type 2 diabetes mellitus. Sixty patients, aged 20 to 75 years with hemoglobin A1c (HbA1c) between 7.4% and 9.0% on glimepiride with or without metformin, were randomized into two groups. If the target (HbA1c is less and equall than 6.9% or fasting plasma glucose level is less and equall than 130 mg/dL) was not achieved, sitagliptin or glimepiride, respectively, was increased. Results: After 18 months, HbA1c had significantly decreased to 7.1-7.2% in both groups (P < 0.01). Plasma levels of insulin and proinsulin remained unchanged during the study. However, the proinsulin/insulin ratio was significantly lower after 6 months and thereafter only in the SU group. Homeostasis model assessment-beta cell (HOMA- beta ) demonstrated a significant augmentation at some points during the study in both groups. No severe hypoglycemic episodes or body weight gain were seen in either group. Conclusions: Add-on therapy of 50 mg of sitagliptin to a very small dose of glimepiride at 1.1 to 1.2 mg/day, or a small dose of glimepiride at 2.1 mg/day, proved effective for improving or maintaining glycemic control without deterioration of beta -cell function over 18 months. J Endocrinol Metab. 2019;9(6):171-179 doi: https://doi.org/10.14740/jem621

Factors That Influence Pancreatic Beta Cell Function and Insulin Resistance in Newly Diagnosed Type 2 Diabetes Patients: A Sub-Analysis of the MARCH Trial.

IntroductionThe Metformin and Acarbose in Chinese as the initial Hypoglycemic treatment (MARCH) trial has demonstrated a similar efficacy in HbA1c reduction between acarbose and metformin treatments in newly diagnosed type 2 diabetes mellitus (T2DM) patients. The current sub-analysis of the MARCH trail aims to evaluate the baseline characteristics that may influence the improvement of pancreatic β-cell function and insulin resistance after acarbose therapy in Chinese patients with newly diagnosed T2DM.MethodsOf the 784 patients who entered the MARCH trail, 391 were assigned to the acarbose therapy group; 304 of these completed 48 weeks of follow-up of acarbose therapy. At 48 weeks, on the basis of the tertiles of change in homeostasis model assessment–beta cell function (∆HOMA-β) and homeostasis model assessment–insulin resistance (∆HOMA-IR), the subjects were divided into lowly, mediumly, and highly improved groups.ResultsIn the highly improved HOMA-β group, patients had higher systolic blood pressure (SBP), 2-h postprandial blood glucose (PBG), hemoglobin A1c (HbA1c), and lower high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) concentration, and HOMA-IR in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between HbA1c, SBP, and highly improved ∆HOMA-β (p < 0.05), while an inverse correlation was evident between HDL-c and highly improved ∆HOMA-β (p < 0.05). The highly improved HOMA-IR group had a significantly higher body mass index (BMI), fasting blood glucose (FBG), FINS concentration, and HOMA-β in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between FBG, waist circumference, and highly improved HOMA-IR (p < 0.05).ConclusionNewly diagnosed T2DM Chinese patients with lower baseline HDL-c and higher HbA1c and SBP values are more likely to achieve improvement in beta cell function whereas baseline fasting blood glucose and waist circumference were the significant factors associated with improvement in insulin resistance with acarbose therapy.Trial RegistrationThe clinical trial registry number was ChiCTR-TRC-08000231.

Bone remodelling markers in hypertensive patients with and without diabetes mellitus: link between bone and glucose metabolism.

Growing evidence suggests the presence of a complex interplay between hypertension as well as type 2 diabetes mellitus (DM) and osteoporosis. The present study was designed to investigate a possible effect of type 2 DM on bone remodelling markers such as osteoprotegerin and N-terminal propeptide of type 1 collagen (P1NP) in hypertensive patients. The 100 study participants were divided into three groups according to the presence of DM and hypertension: group one included diabetic hypertensive subjects, group 2 included hypertensive subjects without diabetes and group 3 included subjects without hypertension and without DM (controls). Blood sampling for metabolic parameters, including osteoprotegerin, P1NP, adiponectin, fasting glucose, HbA1c , CRP, homeostasis model assessment-insulin resistance, homeostasis model assessment-beta function was performed. Circulating P1NP increased from group 1 to group 3 in a continuous fashion. P1NP was significantly lower in hypertensive subjects with DM (group 1), than in groups 2 and 3 (p < 0.0001). P1NP, was marginally lower in diabetic hypertensive subjects as compared with nondiabetic subjects with hypertension (p = 0.079). Circulating osteoprotegerin did not differ significantly between groups (p = 0.593). In the present study, bone formation marker, P1NP, was significantly lower in diabetic hypertensive subjects as compared with nondiabetic subjects with and without hypertension. P1NP was inversely associated with parameters of glucose homeostasis such as fasting glucose, HbA1c and positively with homeostasis model assessment-beta cell function. Type 2 DM was associated with an adverse effect on bone formation independently of age, sex and exposure to anti-diabetic drugs.

A multicenter, randomized, placebo‐controlled, double‐blind phase II trial evaluating the optimal dose, efficacy and safety of LC 15‐0444 in patients with type 2 diabetes

The objective of this study was to evaluate the optimal dose, efficacy and safety of a novel dipeptidyl peptidase-4 (DPP-IV) inhibitor, LC15-0444, in Korean subjects with type 2 diabetes mellitus treated by diet and exercise. This study was a double-blind, randomized, multicenter and parallel-group, dose-range finding study. We enrolled 145 patients (91 men and 54 women) with a median age of 53 years and a median body mass index of 25.1 kg/m(2) . The median baseline fasting plasma glucose (FPG) was 8.1 mmol/l, the median HbA1c was 7.9% and the median time since the diagnosis of diabetes was 3 years. After 2 weeks of an exercise/diet programme followed by 2 weeks of a placebo period, the subjects were randomized to one of the four following groups for a 12-week active treatment period: placebo and 50, 100 or 200 mg of LC15-0444. All three doses of LC15-0444 significantly reduced the HbA1c from baseline compared to the placebo group (-0.06 vs. -0.98, -0.74 and -0.78% in the placebo and 50, 100 and 200 mg groups, respectively), without a significant difference between the doses. Subjects with a higher baseline HbA1c (≥8.5%) had a greater reduction in HbA1c. Insulin secretory function, as assessed using homeostasis model assessment-beta cell, C-peptide and the insulinogenic index, improved significantly with LC15-0444 treatment. Insulin sensitivity, as assessed using homeostasis model assessment-insulin resistance, also improved significantly after 12 weeks of treatment. The 50 and 200 mg groups had significantly reduced total cholesterol and low-density lipoprotein cholesterol levels at 12 weeks compared to the placebo group. No dosage of LC15-0444 affected weight or waist circumference. The incidences of adverse events were similar in all study subjects. LC15-0444 monotherapy (50 mg for 12 weeks) improved the HbA1c, FPG level, oral glucose tolerance test results, β-cell function and insulin sensitivity measures, and was well tolerated in Korean subjects with type 2 diabetes.

Effects of One Year Treatment of Vildagliptin Added to Pioglitazone or Glimepiride in Poorly Controlled Type 2 Diabetic Patients

The aim of the study was to compare the effects of vildagliptin added to pioglitazone or glimepiride on metabolic and insulin resistance related-indices in poorly controlled type 2 diabetic patients (T2DM). 168 patients with T2DM were randomized to take either pioglitazone 30 mg once a day plus vildagliptin 50 mg twice a day or glimepiride 2 mg 3 times a day plus vildagliptin 50 mg twice a day. We evaluated body weight, body mass index (BMI), glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), homeostasis model assessment beta-cell function index (HOMA-beta), fasting plasma proinsulin (FPPr), proinsulin/fasting plasma insulin ratio (Pr/FPI ratio), adiponectin (ADN), resistin (R), tumor necrosis factor-alpha (TNF-alpha), and high sensitivity C-reactive protein (Hs-CRP) at their baseline values, and after 3, 6, 9, and 12 months of treatment. We observed a similar improvement of HbA1c, FPG, PPG, and Hs-CRP compared to baseline in the 2 groups. Fasting plasma insulin, FPPr, Pr/FPI ratio, R, and TNF-alpha were significantly decreased and ADN was significantly increased with pioglitazone plus vildagliptin, but not with glimepiride plus vildagliptin. HOMA-IR, and HOMA-beta values obtained with pioglitazone plus vildagliptin were significantly better than the values obtained with glimepiride plus vildagliptin. Pioglitazone plus vildagliptin were found to be more effective in preserving beta-cell function, and in reducing insulin resistance, and inflammatory state parameters.

Serum visfatin in Asian women with polycystic ovary syndrome

Objective. To determine serum visfatin levels in Asian polycystic ovary syndrome (PCOS) women and its correlations with various parameters.Study design. Case–control study.Setting. University hospital.Subjects. Eighty women were enrolled in this study. Of these, 40 women were PCOS and 40 age-matched subjects with regular menstrual cycles were controls.Intervention. Seventy-five gram oral glucose tolerance tests were performed in all women. Fasting venous blood samples for serum visfatin, insulin and androgen levels were obtained both from the PCOS and the control women.Main outcome measures. Serum concentrations of visfatin, fasting insulin (FI), fasting glucose, 2-h post-load glucose (2hPG), homeostasis model assessment insulin resistance, homeostasis model assessment beta cell function, total testosterone, free testosterone, androstenedione and dehydroepiandrosterone sulfate were measured in both groups.Results. Women with PCOS had significantly higher serum visfatin levels than the healthy controls [100.39 ± 41.90 vs. 45.09 ± 28.24 mg/ml, p < 0.01]. PCOS women also had significantly higher concentrations of all androgens (p < 0.01). Insulin resistance seemed to be greater in the PCOS than the control groups, but did not reach a statistically significant level. In the PCOS group, serum visfatin levels were positively correlated with 2hPG, and systolic blood pressure and diastolic blood pressure. Serum visfatin levels were negatively associated with FI (r = −0.80, p = 0.03) and positively associated with systolic and diastolic blood pressure (r = 0.77, p = 0.04, r = 0.79, p = 0.03, respectively) in the sub-group of PCOS women with abnormal glucose tolerance (AGT).Conclusions. Asian PCOS women had significantly higher serum visfatin levels than age-matched healthy controls. Their levels were significantly correlated with 2hPG and blood pressure in PCOS women, and with FI and blood pressure in PCOS women with AGT.

Efficacy and safety of the dipeptidyl peptidase‐4 inhibitor alogliptin in patients with type 2 diabetes inadequately controlled by glyburide monotherapy

To evaluate the efficacy and safety of alogliptin, a potent and highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, in combination with glyburide in patients with type 2 diabetes inadequately controlled by sulphonylurea monotherapy. After a 2-week screening period, adult patients 18-80 years of age entered a 4-week run-in/stabilization period in which they were switched from their own sulphonylurea medication to an equivalent dose of glyburide (open label) plus placebo (single blind). After the run-in period, patients were randomly assigned to double-blind treatment with alogliptin 12.5 mg (n = 203), alogliptin 25 mg (n = 198), or placebo (n = 99) for 26 weeks. The primary end-point was change from baseline to week 26 in glycosylated haemoglobin (HbA1c). Secondary end-points included clinical response rates and changes in fasting plasma glucose, beta-cell function (fasting proinsulin, insulin, proinsulin/insulin ratio, and C-peptide, and homeostasis model assessment beta-cell function), body weight, and safety end-points [adverse events (AEs), clinical laboratory tests, vital signs and electrocardiographic readings]. The study population had a mean age of 57 years and a mean disease duration of 8 years; it was well balanced for gender (52% women) and was mainly white (71%). The mean baseline HbA1c was approximately 8.1% in each group. Significantly greater least squares (LS) mean reductions in HbA1c were seen at week 26 with alogliptin 12.5 mg (-0.38%) and 25 mg (-0.52%) vs. placebo (+0.01%; p < 0.001), and more patients in the alogliptin 25-mg group had HbA1c levels < or =7.0% at week 26 (34.8%, p = 0.002) vs. placebo (18.2%). Proportionately more patients in the alogliptin 12.5 mg (47.3%) and 25 mg (50.5%) groups had an HbA1c reduction > or =0.5% from baseline compared with patients in the placebo group (26.3%; p < 0.001). Minor improvements in individual markers of beta-cell function were seen with alogliptin, but no significant treatment group differences were noted relative to placebo. Minor LS mean changes in body weight were noted across groups (placebo, -0.20 kg; alogliptin 12.5 mg, +0.60 kg; alogliptin 25 mg, +0.68 kg). AEs were reported for 63-64% of patients receiving alogliptin and 54% of patients receiving placebo. Few AEs were treatment limiting (2.0-2.5% across groups), and serious AEs (2.0-5.6%) were infrequent, similar across groups, and generally considered not related to treatment. The incidences of hypoglycaemia for placebo, alogliptin 12.5 mg and alogliptin 25 mg groups were 11.1, 15.8 and 9.6% respectively. In patients with type 2 diabetes inadequately controlled by glyburide monotherapy, the addition of alogliptin resulted in clinically significant reductions in HbA1c without increased incidence of hypoglycaemia.

Elevation of fasting insulin and its association with cardiovascular disease risk in women with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis. We previously showed that SLE patients have a higher risk of insulin resistance (IR) and abnormal insulin secretion. The present study was to further investigate the relationship between fasting insulin levels and both classic and novel cardiovascular risk factors in patients with SLE. Body mass index (BMI), fasting glucose and insulin, lipid profile, oxidation markers, fibrinolytic factors, vascular function factors, and disease-specific variables were determined in a total of 87 female SLE patients. The homeostasis model assessment (HOMA) was used to evaluate the IR and secretion. SLE patients had significantly higher fasting insulin, HOMA IR, HOMA beta-cell, titers of autoantibodies against oxidized low density lipoprotein, systolic blood pressure, homocysteine, and brachial-ankle pulse wave velocity (baPWV) than age-matched healthy controls. There were no statistical differences in disease duration, anti-dsDNA, C3, C4, disease activity, and medication dosage between SLE patients stratified by fasting insulin levels. However, mean values for BMI, insulin, HOMA IR, HOMA beta-cell, triglyceride (TG), homocysteine, and baPWV were significantly higher in the SLE patients with hyperinsulinemia when compared with those SLE controls. In addition, fasting insulin levels were positively correlated with TG, homocysteine, blood pressure, plasminogen activator inhibitor 1, and baPWV in SLE patients. The elevation of fasting insulin levels in SLE patients is not only associated with IR, but is related to classic and novel cardiovascular risk factors. This study concludes that there is an insulin-related cardiovascular disease risk in SLE.

Homeostasis Model Assessment (HOMA) as Surrogate Insulinization Criteria in Patients With Type 2 Diabetes

Type 2 diabetes mellitus is a metabolic disorder that results from defects in both insulin secretion and insulin action. Questions remain about when insulin therapy is indicated; thus, the aim of this study was to evaluate homeostasis model assessment beta-cell (HOMAbetacell) values as surrogate criteria for insulin therapy indication in patients with type 2 diabetes. A prospective study was performed involving 189 type 2 diabetic patients with deficient metabolic control assessed by clinical and laboratory parameters. All patients received nutritional intervention and combination therapy with metformin and glimepiride. Patients who did not respond were admitted to the next phase, which consisted of glimepiride + metformin + rosiglitazone oral therapy and revaluation after 3 months. Comparisons between responders and nonresponders in this phase were made in order to achieve differences in metabolic parameters and beta cell function. Of 189 patients studied, 150 (79.36%) were considered full responders in the first phase of this study. The remaining 39 patients were admitted in the second trial phase, in which 20 patients (51.28%) responded to triple oral therapy, while the other 19 (49.72%) required insulin therapy. Significant differences were found in fasting and postprandial glycemia (P < 0.001; P < 0.004) between the non-insulin-requiring group (200 +/- 12.0 mg/dL; 266.05 +/- 17,67 mg/dL) and the insulin-requiring group (291.5 +/- 17.6 mg/dL; 361.6 +/- 26.1 mg/dL). Likewise, significant differences were observed in homeostasis model assessment insulin resistance (HOMAIR) and HOMAbetacell values (P < 0.002; P < 0.04) between non-insulin-requiring patients (7.7 +/- 0.8; 24.5 +/- 1.3%) and insulin-requiring patients (12.6 +/- 1.2; 19.4 +/- 2.4%). Finally, significant differences were observed when comparing body mass index (non-insulin-requiring group, 29.2 +/- 0.4 kg/m, versus insulin-requiring group, 27.1 +/- 0.9 kg/m; P < 0.05). HOMAbetacell determination in clinical practice is a useful tool to determine when insulin therapy should be started for type 2 diabetic patients.

Aldosterone as a key mediator of the cardiometabolic syndrome in primary aldosteronism: an observational study

Primary aldosteronism (PA) is characterized by the onset of both cardiac and gluco-metabolic alterations. The aim of this study was to evaluate the impact of aldosterone excess on the development of such complications, and the effects of surgical and pharmacological treatment on their long-term outcome. We prospectively re-examined 61 patients: 25 with aldosterone-producing adenoma (APA), after surgery, and 36 patients with idiopathic hyperaldosteronism (IHA) on pharmacological treatment. The lipid, fasting and dynamic glucose profiles and the echocardiographic parameters were evaluated at diagnosis and at follow-up. After adrenalectomy all patients had normalization of aldosterone levels and were cured of hypokalaemia, and a resolution of hypertension was achieved in 12 of 25 patients. APA patients showed a significant reduction of both plasma glucose (P=0.017) and insulin levels (P=0.001) after 75 g oral glucose tolerance test. Stabilization of glucose metabolism complications was observed in IHA patients. Multiple regression analysis at diagnosis showed a positive correlation between homeostasis model assessment (HOMA) insulin resistance index and HOMA beta cell and serum aldosterone levels in both APA and IHA. Echocardiographic parameters were improved in both APA and IHA at follow-up and the difference was statistically significant for left ventricular mass index (P=0.017) and interventricular septum thickness (P=0.007) in APA patients. The removal of aldosterone excess in APA patients induces the regression of both cardiac and gluco-metabolic complications, indicating aldosterone as a main determinant of such alterations. In IHA patients the medical treatment seems to avoid the possible progression of the these alterations that appear to be stable.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor sitagliptin as monotherapy in patients with type 2 diabetes mellitus

The aim of this study was to assess the efficacy and safety of sitagliptin (MK-0431) as monotherapy in patients with type 2 diabetes mellitus and inadequate glycaemic control (HbA(1c) > or =7% and < or =10%) on exercise and diet. A total of 521 patients aged 27-76 years with a mean baseline HbA(1c) of 8.1% were randomised in a 1:2:2 ratio to treatment with placebo, sitagliptin 100 mg once daily, or sitagliptin 200 mg once daily, for 18 weeks. The efficacy analysis was based on an all-patients-treated population using an analysis of covariance, excluding data obtained after glycaemic rescue. After 18 weeks, HbA(1c) was significantly reduced with sitagliptin 100 mg and 200 mg compared with placebo (placebo-subtracted HbA(1c) reduction: -0.60% and -0.48%, respectively). Sitagliptin also significantly decreased fasting plasma glucose relative to placebo. Patients with higher baseline HbA(1c) (> or =9%) experienced greater placebo-subtracted HbA(1c) reductions with sitagliptin (-1.20% for 100 mg and -1.04% for 200 mg) than those with HbA(1c) <8% (-0.44% and -0.33%, respectively) or > or =8% to 8.9% (-0.61% and -0.39%, respectively). Homeostasis model assessment beta cell function index and fasting proinsulin:insulin ratio, markers of insulin secretion and beta cell function, were significantly improved with sitagliptin. The incidence of hypoglycaemia and gastrointestinal adverse experiences was not significantly different between sitagliptin and placebo. Sitagliptin had a neutral effect on body weight. Sitagliptin significantly improved glycaemic control and was well tolerated in patients with type 2 diabetes mellitus who had inadequate glycaemic control on exercise and diet.

Characteristics of dysfunction of islet beta-cell in newly diagnosed type 2 diabetic patients

To investigate the characteristics of the dysfunction of islet beta-cell in newly diagnosed type 2 diabetic patients. Intravenous glucose tolerance test (IVGTT) was carried out on 352 newly diagnosed type 2 diabetic patients and 48 subjects with normal glucose tolerance (NGT) and then blood samples were collected 1, 2, 4, 6, and 10 minutes later to measure the plasma glucose and insulin to calculate the acute insulin response (AIR) and the area under the curve of insulin (AUC of insulin), homeostasis model assessment beta-cell (Homabeta), and Homa IR (insulin resistance). The median AIR of the type 2 diabetic patients was -33.7 pmol/L, significantly lower than that of the NGT subjects (6962.0 pmol/L, P < 0.001). The median AUC of the type 2 diabetic patients was 834.2 pmol/L, significantly lower than that of the NGT subjects (7934.7 pmol/L, P < 0.001). When the fasting plasma glucose (FPG) of the type 2 diabetic patients was above 7.0 mmol/L, the AIR value was remarkably reduced with a median level of 317.3 pmol/L, and then subsequently disappeared when the FPG was above 9.0 mmol/L. After adjustment of the insulin resistance assessed by HOMA IR, the Homabeta of the type 2 diabetic patients was reduced to be 30% that of the NGT subjects (3.7 +/- 0.9 vs 5.9 +/- 0.9, P < 0.001). Both the fasting proinsulin concentration and the ratio of fasting proinsulin to fasting insulin of the type 2 diabetic patients were significantly higher those of the NGT subjects (22.6 pmol/L +/- 14.7 pmol/L vs 11.5 pmol/L +/- 7.1 pmol/L, P < 0.001; and 30.1% +/- 20.5% vs. 12.1% +/- 9.6%, P < 0.001). The dysfunction of islet beta-cell in newly diagnosed type 2 diabetic patients is mainly represented by the disappearance of AIR and the evident decline of AUC and HOMA B, and the decrease of quality of insulin secretion.

The central issue? Visceral fat mass is a good marker of insulin resistance and metabolic disturbance in women with polycystic ovary syndrome

To establish whether visceral fat mass is the most significant variable correlating with insulin resistance and other metabolic parameters in women with polycystic ovary syndrome (PCOS). Prospective cross-sectional trial. Reproductive medicine clinic. Forty women with anovulatory PCOS. Measurements were taken at recruitment, and analysis was performed to define correlations between the outcome measures and the explanatory variables. Visceral and subcutaneous fat by computed tomography scan, insulin resistance, anthropometric measures, markers of the metabolic syndrome and androgens. Strong linear correlation of visceral fat to insulin resistance (r = 0.68, P < 0.001) was observed. There were also statistically significant correlations with fasting insulin (r = 0.73, P < 0.001), homeostasis model assessment beta-cell function (r = 0.50, P = 0.007), triglycerides (r = 0.45, P = 0.003), high-density lipoprotein cholesterol (r = -0.42, P = 0.007), urate (r = 0.47, P = 0.002), Sex hormone binding globulin (r = -0.39, P = 0.01) and luteinising hormone (r = -0.32, P = 0.02). There were no significant correlations of testosterone with fat distribution or metabolic parameters. Insulin resistance showed closest correlation to visceral fat mass (r = 0.68, P < 0.001), then to waist circumference (r = 0.62, P < 0.001), with the weakest correlation being waist:hip ratio (r = 0.36, P = 0.01). The best regression model for predicting insulin resistance is with visceral fat mass and triglycerides as the explanatory variables (r = 0.72, P < 0.001). Visceral fat is the most significant variable correlating with metabolic dysfunction in women with PCOS. Our data support the hypothesis that visceral fat either causes insulin resistance or is a very early effect of it. It also implies that reducing visceral fat should reduce insulin resistance which may account for the observations that exercise and weight loss appear to be more effective interventions than pharmacological treatments. The best anthropometric measure of insulin resistance is waist circumference.

Contribution of insulin-stimulated glucose uptake and basal hepatic insulin sensitivity to surrogate measures of insulin sensitivity.

The goal of this study was to evaluate the performance of surrogate measures of insulin sensitivity and insulin secretion. The homeostasis model assessment (HOMA) of insulin resistance (IR) and the insulin sensitivity index (S(i)) from oral glucose tolerance test (OGTT) were compared with the M value from a hyperinsulinemic-euglycemic clamp in 467 subjects with various degrees of glucose tolerance. Endogenous glucose production (EGP) and hepatic insulin sensitivity were determined in a subset (n = 143). Insulin secretion was estimated as the HOMA beta-cell index and as the insulinogenic index from the first 30 min of the OGTT (I/G30) and compared with the first-phase insulin response (FPIR) to an intravenous glucose tolerance test (n = 218). The M value correlated with the HOMA-IR (r = -0.591, P < 0.0001) and the S(i) (r = 0.533, P < 0.0001) indexes in the total study group. HOMA-IR correlated with basal EGP in the total study group (r = 0.378, P < 0.0005) and in subjects with diabetes (r = 0.330, P = 0.01). However, neither HOMA-IR nor S(i) correlated significantly with the M value in subjects with impaired fasting glucose (IFG) (r = -0.108, P = 0.5; r = 0.01, P = 0.9) or IFG/impaired glucose tolerance (IGT) (r = -0.167, P = 0.4; r = 0.09, P = 0.6). The HOMA-IR correlated with hepatic insulin sensitivity in the whole study group (r = -0.395, P < 0.005) as well as in the IFG/IGT subgroup (r = -0.634, P = 0.002) and in the diabetic subgroup (r = -0.348, P = 0.008). In subjects with IFG/IGT, hepatic insulin sensitivity was the most important determinant of HOMA-IR, explaining 40% of its variation. The HOMA beta-cell index showed a weak correlation with FPIR in the whole study group (r = 0.294, P = 0.001) but not in the subgroups. In contrast, the I/G30 correlated with FPIR in the whole study group (r = 0.472, P < 0.0005) and in the IFG/IGT subgroup (r = 0.493, P < 0.005). HOMA-IR is dependent upon both peripheral and hepatic insulin sensitivity, the contribution of which differs between subjects with normal and elevated fasting glucose concentrations. These discrepancies develop as a consequence of a nonparallel deterioration of the variables included in the equations with worsening of glucose tolerance.

Clinical evaluation of insulin resistance and beta-cell function by the homeostasis model assessment in patients with systemic lupus erythematosus.

The aim of this preliminary study was to evaluate insulin resistance and secretion using homeostasis model assessment (HOMA) in patients with systemic lupus erythematosus (SLE). The fasting glucose and insulin concentrations, HOMA insulin resistance (IR), HOMA beta-cell, antidouble-stranded DNA antibodies (anti-dsDNA), C3, C4, and SLE disease activity index (SLEDAI) were determined in a total of 58 female SLE patients. All patients were classified into subgroups according to the presence of anticardiolipin antibodies (aCL+ vs. aCL-) and SLEDAI scores (SLEDAI < 3 vs. SLEDAI > 3). Results showed that SLE patients with and without aCL had significantly higher fasting insulin levels, HOMA IR, and HOMA beta-cells than controls. Similar results were also found in SLE patients with different disease activities. Pearson's correlation analysis showed that there was a highly significant correlation of HOMA IR with fasting insulin concentration in the SLE patients and SLE subgroups overall. However, HOMA beta-cells were positively correlated with HOMA IR and fasting insulin level, but negatively correlated with fasting glucose concentration in SLE patients overall. In conclusion, SLE patients, regardless of the presence of aCL and different disease activities, had a higher risk of insulin resistance and abnormal insulin secretion than age-matched healthy controls, based on fasting insulin concentration, HOMA IR, and HOMA beta-cells.