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BACKGROUND: Insulin is a key regulator of metabolic function. The effects of excess adiposity, insulin resistance, and hepatic steatosis on the complex integration of insulin secretion and hepatic and extrahepatic tissue extraction are not clear. METHODS: A hyperinsulinemic-euglycemic clamp and a 3-hour oral glucose tolerance test were performed to evaluate insulin sensitivity and insulin kinetics after glucose ingestion in 3 groups: (a) lean subjects with normal intrahepatic triglyceride (IHTG) and glucose tolerance (lean-NL; n = 14), (b) obese subjects with normal IHTG and glucose tolerance (obese-NL; n = 24), and (c) obese subjects with nonalcoholic fatty liver disease (NAFLD) and prediabetes (obese-NAFLD; n = 22). RESULTS: Insulin sensitivity progressively decreased and insulin secretion progressively increased from the lean-NL to the obese-NL to the obese-NAFLD groups. Fractional hepatic insulin extraction progressively decreased from the lean-NL to the obese-NL to the obese-NAFLD groups, whereas total hepatic insulin extraction (molar amount removed) was greater in the obese-NL and obese-NAFLD subjects than in the lean-NL subjects. Insulin appearance in the systemic circulation and extrahepatic insulin extraction progressively increased from the lean-NL to the obese-NL to the obese-NAFLD groups. Total hepatic insulin extraction plateaued at high rates of insulin delivery, whereas the relationship between systemic insulin appearance and total extrahepatic extraction was linear. CONCLUSION: Hyperinsulinemia after glucose ingestion in obese-NL and obese-NAFLD is due to an increase in insulin secretion, without a decrease in total hepatic or extrahepatic insulin extraction. However, the liver’s maximum capacity to remove insulin is limited because of a saturable extraction process. The increase in insulin delivery to the liver and extrahepatic tissues in obese-NAFLD is unable to compensate for the increase in insulin resistance, resulting in impaired glucose homeostasis. TRIAL REGISTRATION: ClinicalTrials.gov NCT02706262. FUNDING: NIH grants DK56341 (Nutrition Obesity Research Center), DK052574 (Digestive Disease Research Center), RR024992 (Clinical and Translational Science Award), and T32 DK007120 (a T32 Ruth L. Kirschstein National Research Service Award); the American Diabetes Foundation (1-18-ICTS-119); Janssen Research & Development; and the Pershing Square Foundation.

Nonalcoholic fatty liver disease (NAFLD) ranges in severity from steatosis to NASH. NASH, which is characterized by steatosis, ballooning, inflammation (NAFLD Activity Score [NAS]), and frequently fibrosis, can progress to cirrhosis and hepatocellular carcinoma. Despite the unmet medical needs of NASH leading to end stage liver disease and increased risk for cardiovascular death, there are no approved treatments to date. In clinical trials, pioglitazone treatment (6-24 months) has led to NASH resolution and/or reduction in fibrosis. We developed a cynomolgus monkey (cyno) model of NASH by feeding a high fat/cholesterol diet for 2+ years and demonstrated accelerated disease progression by adding fructose to this diet. A total of 31 obese (mean±SD, 10.4±1.8 kg), insulin resistant (HOMA-IR: 29±32) cynos with NASH were used. Histological assessments of liver biopsies were used to characterize disease progression and response to therapy and compared to human studies. Baseline NAS of 5.6±0.9 was similar to those in NASH patients, whereas baseline fibrosis scores of 1.2±0.5 were slightly lower than values of ∼2 typically enrolled in Phase 2 trials. Cynos were treated daily with vehicle (n=10) or pioglitazone (3 mg/kg; n=21) for 6 months. Drug exposures 24 hours post-dose averaged 233±145 ng/mL, similar to that seen in humans (∼200 ng/mL) dosed with 45 mg. Adiponectin, a biomarker for PPARγ activation, increased ∼2-fold in treated cynos. NAS improvement (a decrease in NAS of ≥2 with changes in 2 or more components of NAS) was seen in 30% of treated cynos (p=0.08). No vehicle animals showed NAS improvement. Treated cynos showed significant decreases in ballooning, trends in decreases (p=0.07) in steatosis and inflammation, but no change in fibrosis whereas vehicle animals showed no changes or worsening. We have validated and benchmarked a novel cyno model for NASH that has characteristics similar to human pathology and responds to a treatment known to improve NASH in clinical trials. Disclosure R. Camacho: Employee; Self; Janssen Pharmaceuticals, Inc. D. Polidori: Employee; Self; Janssen Research and Development. Stock/Shareholder; Self; Janssen Research and Development. T. Chen: Employee; Self; Janssen Pharmaceuticals, Inc. B. Gao: Employee; Self; Janssen Pharmaceuticals, Inc. P. Wong: Employee; Self; Johnson & Johnson. Stock/Shareholder; Self; Merck & Co., Inc. J.A. Gabriel: Employee; Self; Kunming Biomed International (KBI). E. Zhu: None. T. Wang: None. A.R. Nawrocki: Employee; Self; Janssen Pharmaceuticals, Inc.

AIMS. Non-Alcoholic Fatty Liver Disease (NAFLD) has been associated with reduced endogenous insulin clearance (EIC) and hepatic insulin resistance (HIRI). These relationships, however, might be differentially affected by the ethnic background, as populations of African ancestry are typically featured with reduced intrahepatic fat content (HFF%) but impaired EIC. Therefore, we evaluated the influence of the ethnicity on the relationships between HFF%, EIC and HIRI. METHODS. The HFF% was quantified by magnetic resonance imaging in a multi-ethnic cohort of 632 obese youths from 7 to 18 years of age at baseline and after a 2-year follow-up. Insulin secretion rate (ISR), EIC and HIRI were estimated by modeling glucose, insulin, and C-peptide data during 9-point oral glucose tolerance tests. RESULTS. African American youths exhibited the lowest HFF% and a prevalence of NAFLD less than half of Caucasians and one-third of Hispanics. Furthermore, African Americans had lower EIC and glucose-stimulated ISR, despite similar HIRI and plasma insulin levels, compared with Caucasians and Hispanics. EIC and HIRI were markedly reduced in individuals with NAFLD and declined across group-specific HFF% tertiles in all ethnic groups. Consistently, the HFF% correlated with EIC and HIRI, irrespective of the ethnic background, after adjustment for age, sex, ethnicity, adiposity, waist-hip ratio, pubertal status, and plasma glucose levels. An increased HFF% at follow-up was associated with decreased EIC and increased HIRI across all groups. CONCLUSIONS. Intrahepatic lipid accumulation is associated with reduced insulin clearance and hepatic insulin sensitivity in obese youths, irrespective of their ethnic background.

The aims of this study were to 1. define the responses of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), glucagon, and peptide YY (PYY) to an oral meal and to intravenous L-arginine; and 2. examine correlation of enteroendocrine hormones with insulin secretion. We hypothesized a relationship between circulating incretin concentrations and insulin secretion.Subjects with normal glucose tolerance (NGT, n = 23), prediabetes (PDM, n = 17), or with type 2 diabetes (T2DM, n = 22) were studied twice, following a mixed test meal (470 kCal) (mixed meal tolerance test [MMTT]) or intravenous L-arginine (arginine maximal stimulation test [AST], 5 g). GLP-1 (total and active), PYY, GIP, glucagon, and β cell function were measured before and following each stimulus.Baseline enteroendocrine hormones differed across the glucose tolerance (GT) spectrum, T2DM generallyNGT and PDM. In response to MMTT, total and active GLP-1, GIP, glucagon, and PYY increased in all populations. The incremental area-under-the-curve (0-120 min) of analytes like total GLP-1 were often higher in T2DM compared with NGT and PDM (35-51%; P 0.05). At baseline glucose, L-arginine increased total and active GLP-1 and glucagon concentrations in all GT populations (all P 0.05). As expected, the MMTT and AST provoked differential glucose, insulin, and C-peptide responses across GT populations. Baseline or stimulated enteroendocrine hormone concentrations did not consistently correlate with either measure of β cell function.Both MMTT and AST resulted in insulin and enteroendocrine hormone responses across GT populations without consistent correlation between release of incretins and insulin, which is in line with other published research. If a defect is in the enteroendocrine/β cell axis, it is probably reduced response to rather than diminished secretion of enteroendocrine hormones.

AIMS: Adult African American (AA) women have one third of the hepatic insulin clearance of European American (EA) women. This lower hepatic (but not extra-hepatic) insulin clearance in AA individuals is associated with higher plasma insulin concentrations. This study aims to understand whether impairment of hepatic insulin clearance is seen in AA individuals since childhood, possibly suggesting that genetic/epigenetic factors, rather than lifestyle only, contribute to this. MATERIALS AND METHODS: A total of 203 children (105 male and 98 female (55 AA, 88 EA and 60 Hispanic American [HA]; ages, 7–13 years; mean BMI, 19 kg/m(2))) underwent the frequently-sampled intravenous glucose tolerance test (FSIGT) at the University of Alabama at Birmingham, General Clinical Research Center and Department of Nutrition Sciences. Glucose, insulin and C-peptide levels were measured and hepatic and extra-hepatic insulin clearances were calculated using mathematical modelling. RESULTS: Fractional hepatic insulin extraction (FE(L)) was lower in AA than in EA children (mean (SD), 19% (20%) vs 33% (20%); P = 0.0007). Adjusting for age, Tanner stage and body fat, FE(L) was lower in AA than in EA children (P = 0.0012), and there was a slight sex-related difference (FE(L), 24% (10%) vs 29% (10%) in boys vs girls; P = 0.04). Extra-hepatic insulin clearance did not differ with ethnicity (27 (12), 21 (12) and 24 (28) mL/kg/min for AA, HA and EA children, respectively; P > 0.05). CONCLUSIONS: At a young age, FE(L) is lower in AAs than in EAs, which does not rule out genetic/epigenetic factors. These differences are related to hyperinsulinaemia and, over time, could possibly contribute to metabolic disorders in AA individuals.

Diabetes is often thought of as one of two diseases: Type 1 diabetes (T1D), which is caused by immunological destruction of the beta-cells, and Type 2 diabetes (T2D), which is due to a combination of insulin resistance and relative failure of the beta-cells to compensate for the resistance. It is becoming clear, however, that even within these two definitions there may be considerable heterogeneity (1). There are several approaches to examine heterogeneity of T2D. Among these approaches are the use of biomarkers to categorize the disease, or the examination of variants in the genome. A third approach – the one we have been using in our laboratory – is to identify specific phenotypes which may contribute to failure to regulate the glucose level. We have identified a small group of such phenotypes which can be distinguished and measured using clinical protocols and/or mathematical modeling.

Sodium glucose co-transporter 2 (SGLT2) inhibitors have been associated with increased serum ketone body levels in patients with type 2 diabetes mellitus (T2DM). In the present analysis we evaluated serum ketone body levels and variability in 1278 Japanese patients with T2DM treated with canagliflozin 100 or 200 mg. Similar mean increases in ketone body concentrations of ~2-fold were seen with both canagliflozin doses. The median (interquartile range) percent change from baseline was 62% (0;180) for acetoacetate and 78% (2;236) for β-hydroxybutyrate. Approximately two-thirds of the variability in each ketone measure was attributed to intra-subject variability. Intra-subject variability was higher for serum ketones than other metabolites. Patients in the lowest response tertile exhibited no increase in ketones. Those in the highest response tertile tended to be male and have higher fasting plasma glucose levels, lower insulin levels, and longer T2DM duration at baseline. Moreover, changes in serum ketones were not fully explained by changes in plasma fatty acids, suggesting downstream effects of SGLT2 inhibition on hepatic metabolism that favour ketogenesis. In summary, increases in serum ketone bodies with canagliflozin were greater and more variable than changes in other metabolic measures in Japanese patients with T2DM.

African Americans (AAs) tend to have higher plasma insulin concentrations than European Americans (EAs); the increased insulin concentrations have been attributed to increased secretion and/or decreased insulin clearance by liver or other tissues. This work characterizes the contributions of hepatic versus extrahepatic insulin degradation related to ethnic differences between AAs and EAs. By using a recently developed mathematical model that uses insulin and C-peptide measurements from the insulin-modified, frequently sampled intravenous glucose tolerance test (FSIGT), we estimated hepatic versus extrahepatic insulin clearance in 29 EA and 18 AA healthy women. During the first 20 min of the FSIGT, plasma insulin was approximately twice as high in AAs as in EAs. In contrast, insulin was similar in AAs and EAs after the 20–25 min intravenous insulin infusion. Hepatic insulin first-pass extraction was two-thirds lower in AAs versus EAs in the overnight-fasted state. In contrast, extrahepatic insulin clearance was not lower in AAs than in EAs. The difference in insulin degradation between AAs and EAs can be attributed totally to liver clearance. The mechanism underlying reduced insulin degradation in AAs remains to be clarified, as does the relative importance of reduced liver clearance to increased risk for type 2 diabetes.

Aim Canagliflozin is an SGLT2 inhibitor approved for the treatment of type-2 diabetes. A dynamic population pharmacokinetic–pharmacodynamic (PK/PD) model relating 24-h canagliflozin exposure profiles to effects on glycosylated haemoglobin was developed to compare the efficacy of once-daily and twice-daily dosing. Methods Data from two clinical studies, one with once-daily, and the other with twice-daily dosing of canagliflozin as add-on to metformin were used (n = 1347). An established population PK model was used to predict full 24-h profiles from measured trough concentrations and/or baseline covariates. The dynamic PK/PD model incorporated an Emax relationship between 24-h canagliflozin exposure and HbA1c-lowering with baseline HbA1c affecting the efficacy. Results Internal and external model validation demonstrated that the model adequately predicted HbA1c-lowering for canagliflozin once-daily and twice-daily dosing regimens. The differences in HbA1c reduction between the twice-daily and daily mean profiles were minimal (at most 0.023% for 100 mg total daily dose [TDD] and 0.011% for 300 mg TDD, up to week 26, increasing with time and decreasing with TDD) and not considered clinically meaningful. Conclusions Simulations using this model demonstrated the absence of clinically meaningful between-regimen differences in efficacy, supported the regulatory approval of a canagliflozin-metformin immediate release fixed-dose combination tablet and alleviated the need for an additional clinical study.

Objective To quantify the feedback control of energy intake in response to long-term covert manipulation of energy balance in free-living humans. Methods A validated mathematical method was used to calculate energy intake changes during a 52-week placebo-controlled trial in 153 patients treated with canagliflozin, a sodium glucose co-transporter inhibitor that increases urinary glucose excretion, thereby resulting in weight loss without patients being directly aware of the energy deficit. The relationship between the body weight time course and the calculated energy intake changes was analyzed using principles from engineering control theory. Results It was discovered that weight loss leads to a proportional increase in appetite resulting in eating above baseline by ∼100 kcal/day per kilogram of lost weight—an amount more than threefold larger than the corresponding energy expenditure adaptations. Conclusions While energy expenditure adaptations have often been considered the main reason for slowing of weight loss and subsequent regain, feedback control of energy intake plays an even larger role and helps explain why long-term maintenance of a reduced body weight is so difficult.

We examined the relationship between insulin clearance, insulin sensitivity, and β-cell function and the longitudinal effect of insulin clearance on β-cell function in lean and obese insulin-sensitive and insulin-resistant adolescents. A hyperinsulinemic-euglycemic and a hyperglycemic clamp were performed in 110 youths to quantify hepatic and peripheral clearance, insulin sensitivity, and β-cell function (disposition index, DIh-clamp). Participants underwent an oral glucose tolerance test at baseline and after 2 years to assess glucose tolerance and oral β-cell function (oDIcpep) and were sorted into four groups (lean and obese normal glucose tolerance, insulin sensitive, insulin resistant, and impaired glucose tolerance). Insulin sensitivity was defined based on the median of insulin stimulated glucose disposal (M) measured during the hyperinsulinemic-euglycemic clamp. Lean and obese insulin-sensitive participants did not differ with respect to hepatic and peripheral clearance or for insulin sensitivity. Insulin sensitivity was linearly correlated with whole-body insulin clearance. Hepatic insulin extraction at baseline acted as an independent determinant of β-cell function at follow-up. The decline in insulin sensitivity, even in the absence of an impairment of glucose tolerance, is associated with lowering of hepatic insulin clearance in obese youth, which in turn may contribute to the decline in β-cell function over time.

OBJECTIVE Standardized, reproducible, and feasible quantification of β-cell function (BCF) is necessary for the evaluation of interventions to improve insulin secretion and important for comparison across studies. We therefore characterized the responses to, and reproducibility of, standardized methods of in vivo BCF across different glucose tolerance states. RESEARCH DESIGN AND METHODS Participants classified as having normal glucose tolerance (NGT; n = 23), prediabetes (PDM; n = 17), and type 2 diabetes mellitus (T2DM; n = 22) underwent two standardized mixed-meal tolerance tests (MMTT) and two standardized arginine stimulation tests (AST) in a test-retest paradigm and one frequently sampled intravenous glucose tolerance test (FSIGT). RESULTS From the MMTT, insulin secretion in T2DM was >86% lower compared with NGT or PDM (P < 0.001). Insulin sensitivity (Si) decreased from NGT to PDM (∼50%) to T2DM (93% lower [P < 0.001]). In the AST, insulin secretory response to arginine at basal glucose and during hyperglycemia was lower in T2DM compared with NGT and PDM (>58%; all P < 0.001). FSIGT showed decreases in both insulin secretion and Si across populations (P < 0.001), although Si did not differ significantly between PDM and T2DM populations. Reproducibility was generally good for the MMTT, with intraclass correlation coefficients (ICCs) ranging from ∼0.3 to ∼0.8 depending on population and variable. Reproducibility for the AST was very good, with ICC values >0.8 across all variables and populations. CONCLUSIONS Standardized MMTT and AST provide reproducible and complementary measures of BCF with characteristics favorable for longitudinal interventional trials use.

Insulin clearance is a highly variable and important factor that affects circulating insulin concentrations. We developed a novel model-based method to estimate both hepatic and extrahepatic insulin clearance using plasma insulin and C-peptide profiles obtained from the insulin-modified frequently sampled intravenous glucose tolerance test. Data from 100 African immigrants without diabetes (mean age 38 years, body weight 81.7 kg, fasting plasma glucose concentration 83 mg/dL, and fasting insulin concentration 37 pmol/L) were used. Endogenous insulin secretion (calculated by C-peptide deconvolution) and insulin infusion rates were used as inputs to a new two-compartment model of insulin kinetics and hepatic and extrahepatic clearance parameters were estimated. Good agreement between modeled and measured plasma insulin profiles was observed (mean normalized root mean square error 6.8%), and considerable intersubject variability in parameters of insulin clearance among individuals was identified (the mean [interquartile range] for hepatic extraction was 25.8% [32.7%], and for extrahepatic insulin clearance was 20.7 mL/kg/min [11.7 mL/kg/min]). Parameters of insulin clearance were correlated with measures of insulin sensitivity and acute insulin response to glucose. The method described appears promising for future research aimed at characterizing variability in insulin clearance and the mechanisms involved in the regulation of insulin clearance.

Type 2 diabetes is a chronic disease with disabling micro- and macrovascular complications that lead to excessive morbidity and premature mortality. It affects hundreds of millions of people and imposes an undue economic burden on populations across the world. Although insulin resistance and insulin secretory defects play a major role in the pathogenesis of hyperglycemia, several other metabolic defects contribute to the initiation/worsening of the diabetic state. Prominent among these is increased renal glucose reabsorption, which is maladaptive in patients with diabetes. Instead of an increase in renal glucose excretion, which could ameliorate hyperglycemia, there is an increase in renal glucose reabsorption, which helps sustain hyperglycemia in patients with diabetes. The sodium–glucose cotransporter (SGLT) 2 inhibitors are novel antidiabetes agents that inhibit renal glucose reabsorption and promote glucosuria, thereby leading to reductions in plasma glucose concentrations. In this article, we review the long journey from the discovery of the glucosuric agent phlorizin in the bark of the apple tree through the animal and human studies that led to the development of the current generation of SGLT2 inhibitors.

Diabetes is often thought of as one of two diseases: Type 1 diabetes (T1D), which is caused by immunological destruction of the beta-cells, and Type 2 diabetes (T2D), which is due to a combination of insulin resistance and relative failure of the beta-cells to compensate for the resistance. It is becoming clear, however, that even within these two definitions there may be considerable heterogeneity (1). There are several approaches to examine heterogeneity of T2D. Among these approaches are the use of biomarkers to categorize the disease, or the examination of variants in the genome. A third approach – the one we have been using in our laboratory – is to identify specific phenotypes which may contribute to failure to regulate the glucose level. We have identified a small group of such phenotypes which can be distinguished and measured using clinical protocols and/or mathematical modeling.

African American (AA) adult women (AAw) have 1/3 the hepatic insulin extraction as European American adult women (EAw). Lower hepatic (but not extrahepatic) insulin clearance in AAw contributes to hyperinsulinemia. Our aim was to examine whether hepatic insulin clearance impairment exists in AA since childhood. If so, genetic factors might explain ethnic differences in insulin clearance. The FSIGT was performed on 203 children [55 AAc, 88 EAc, 60 HAc (Hispanic American), ages 7-13 years, mean BMI = 19 kg/m2, basal plasma glucose = 99 mg/dL, insulin = 78 pM, C-peptide = 511 pM]. Data were analyzed with a recent mathematical model providing individual estimates of both hepatic fractional insulin extraction (FEL) and extrahepatic insulin clearance (CLP). Results are presented as mean (SD). Two-way ANOVA and ANCOVA were done: sex and ethnicity were used as groups for both the analysis, while age, Tanner stage and body fat from DXA were the covariates. FEL is lower in AAc (19% (20%)) than EAc (33% (20%)), p = 0.0007). Adjusting for the covariates, ethnicity was still associated with lower FEL in AAc vs. EAc (p = 0.0012); sex had a slight but significant effect (FEL=24% (10%) in boys vs. 29% (10%) in girls, p = 0.04). FEL in HAc (28% (21%)) was not significantly different than either AAc or EAc (p>0.05), with or without covariates correction. No correlation between FEL and age was found in these children. Unlike FEL, CLP was not impacted by ethnicity or sex; similar values were observed among the three groups [27 (12), 21 (12), and 24 (28) mL/kg/min for AAc, HAc, and EAc, respectively; p > 0.05]. As the between-group differences in FEL are seen early in childhood, this suggests genetic factors likely contribute to those, rather than lifestyle, that might have a less evident effect at that age, instead. Playing a more important role than previously realized, the reduced insulin degradation would lead to hyperinsulinemia, insulin resistance, and possibly greater risk for type 2 diabetes in AA, compared to other ethnic groups. Disclosure F. Piccinini: None. D. Polidori: Employee; Self; Janssen Research & Development. Stock/Shareholder; Self; Janssen Research & Development. B. Gower: None. J.R. Fernandez: None. R.N. Bergman: Advisory Panel; Self; Ingredion, Inc.. Research Support; Self; AstraZeneca. Consultant; Self; GI Dynamics Inc.. Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases. Consultant; Self; Novo Nordisk A/S.

The sodium/glucose cotransporters (SGLT1 and SGLT2) transport glucose across the intestinal brush border and kidney tubule. Dual SGLT1/2 inhibition could reduce hyperglycemia more than SGLT2-selective inhibition in patients with type 2 diabetes. However, questions remain about altered gastrointestinal (GI) luminal glucose and tolerability, and this was evaluated in slc5a1−/− mice or with a potent dual inhibitor (compound 8; SGLT1 Ki = 1.5 ± 0.5 nM 100-fold greater potency than phlorizin; SGLT2 Ki = 0.4 ± 0.2 nM). 13C6-glucose uptake was quantified in slc5a1−/− mice and in isolated rat jejunum. Urinary glucose excretion (UGE), blood glucose (Sprague-Dawley rats), glucagon-like peptide 1 (GLP-1), and hemoglobin A1c (HbA1c) levels (Zucker diabetic fatty rats) were measured. Intestinal adaptation and rRNA gene sequencing was analyzed in C57Bl/6 mice. The blood 13C6-glucose area under the curve (AUC) was reduced in the absence of SGLT1 by 75% (245 ± 6 vs. 64 ± 6 mg/dl⋅h in wild-type vs. slc5a1−/− mice) and compound 8 inhibited its transport up to 50% in isolated rat jejunum. Compound 8 reduced glucose excursion more than SGLT2-selective inhibition (e.g., AUC = 129 ± 3 vs. 249 ± 5 mg/dl⋅h for 1 mg/kg compound 8 vs. dapagliflozin) with similar UGE but a lower renal glucose excretion threshold. In Zucker diabetic fatty rats, compound 8 decreased HbA1c and increased total GLP-1 without changes in jejunum SGLT1 expression, mucosal weight, or villus length. Overall, compound 8 (1 mg/kg for 6 days) did not increase cecal glucose concentrations or bacterial diversity in C57BL/6 mice. In conclusion, potent dual SGLT1/2 inhibition lowers blood glucose by reducing intestinal glucose absorption and the renal glucose threshold but minimally impacts the intestinal mucosa or luminal microbiota in chow-fed rodents.

OBJECTIVE This study assessed the efficacy and safety of canagliflozin, a sodium–glucose cotransporter 2 inhibitor, as add-on to insulin in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS This 18-week, double-blind, phase 2 study randomized 351 patients (HbA1c 7.0–9.0% [53–75 mmol/mol]) on multiple daily insulin injections or continuous subcutaneous insulin infusion to canagliflozin 100 or 300 mg or placebo. The primary end point was the proportion of patients achieving at week 18 both HbA1c reduction from baseline of ≥0.4% (≥4.4 mmol/mol) and no increase in body weight. Other end points included changes in HbA1c, body weight, and insulin dose, as well as hypoglycemia incidence. Safety was assessed by adverse event (AE) reports. RESULTS More patients had both HbA1c reduction ≥0.4% and no increase in body weight with canagliflozin 100 and 300 mg versus placebo at week 18 (36.9%, 41.4%, 14.5%, respectively; P < 0.001). Both canagliflozin doses provided reductions in HbA1c, body weight, and insulin dose versus placebo over 18 weeks. The incidence of hypoglycemia was similar across groups; severe hypoglycemia rates were low (1.7–6.8%). Overall incidence of AEs was 55.6%, 67.5%, and 54.7% with canagliflozin 100 and 300 mg and placebo; discontinuation rates were low (0.9–1.3%). Increased incidence of ketone-related AEs (5.1%, 9.4%, 0%), including the specific AE of diabetic ketoacidosis (DKA) (4.3%, 6.0%, 0%), was seen with canagliflozin 100 and 300 mg versus placebo. CONCLUSIONS Canagliflozin provided reductions in HbA1c, body weight, and insulin dose with no increase in hypoglycemia, but increased rates of ketone-related AEs, including DKA, in adults with type 1 diabetes inadequately controlled with insulin.

SUMMARY Canagliflozin is an SGLT2 inhibitor approved for the treatment of adults with Type 2 diabetes mellitus (T2DM). A comprehensive Phase III program evaluated canagliflozin in a broad range of patients with T2DM on various background therapies; studies were also conducted in special populations, including older patients and those with moderate renal impairment. Canagliflozin provided clinically meaningful reductions in HbA1c, bodyweight and blood pressure versus placebo and active comparators in studies up to 104 weeks. Canagliflozin was generally well tolerated, with increased incidences of adverse events related to the mechanism of action, including genital mycotic infections and osmotic diuresis-related adverse events. Overall, canagliflozin appears to be a useful treatment option for patients with inadequately controlled T2DM.

Canagliflozin, a sodium glucose co-transporter 2 inhibitor, reduces HbA1c, body weight and systolic BP (SBP) in patients with type 2 diabetes. As weight loss is known to reduce both HbA1c and SBP, these analyses were performed to evaluate the contribution of weight loss resulting from treatment with canagliflozin to HbA1c and SBP reductions in patients with type 2 diabetes.Pooled data from four placebo-controlled Phase 3 studies (N = 2,250) in patients with type 2 diabetes were used in the analyses. In each study, patients were treated with placebo, canagliflozin 100 mg or canagliflozin 300 mg, once daily for 26 weeks. Changes from baseline in body weight, HbA1c and SBP were measured at week 26, and the contribution of weight loss to the lowering of HbA1c and SBP was obtained using ANCOVA.Canagliflozin 100 and 300 mg reduced mean body weight, HbA1c and SBP compared with placebo (p 0.001 for each), and more patients had body-weight reductions0%, ≥5% and ≥10% with canagliflozin treatment than with placebo. Weight-loss-independent and weight-loss-associated mechanisms contributed to HbA1c and SBP lowering with canagliflozin: ~85% of HbA1c lowering and ~60% of SBP lowering was independent of weight loss.In patients with type 2 diabetes, canagliflozin provided clinically meaningful body-weight reductions, and the weight loss contributed to reductions in HbA1c and SBP.

Objective Canagliflozin is a sodium glucose co-transporter 2 inhibitor approved for treating patients with type 2 diabetes. This study evaluated renal and non-renal effects of canagliflozin on postprandial plasma glucose (PG) excursion in patients with type 2 diabetes inadequately controlled with metformin. Materials/Methods Patients (N=37) were randomized to a four-period crossover study with 3-day inpatient stays in each period and 2-week wash-outs between periods. Patients received Treatments (A) placebo/placebo, (B) canagliflozin 300mg/placebo, (C) canagliflozin 300mg/canagliflozin 300mg, or (D) canagliflozin 300mg/canagliflozin 150mg on Day 2/Day 3 in one of four treatment sequences (similar urinary glucose excretion [UGE] expected for Treatments B–D). A mixed-meal tolerance test (MMTT) was given 20minutes post-dose on Day 3 of each period. Results A single dose of canagliflozin 300mg reduced both fasting and postprandial PG compared with placebo, with generally similar effects on fasting PG and UGE observed for Treatments B–D. An additional dose of canagliflozin 300mg (Treatment C), but not 150mg (Treatment D), prior to the MMTT on Day 3 provided greater postprandial PG reduction versus placebo (difference in incremental glucose AUC 0–2h , −7.5% for B vs A; −18.5% for C vs A; −12.0% [ P =0.012] for C vs B), leading to modestly greater reductions in total glucose AUC 0–2h with Treatment C versus Treatment B or D. Canagliflozin was generally well tolerated. Conclusions These findings suggest that a non-renal mechanism (ie, beyond UGE) contributes to glucose lowering for canagliflozin 300mg, but not 150mg.

GPR40 (FFAR1) and GPR120 (FFAR4) are G-protein-coupled receptors (GPCRs) that are activated by long chain fatty acids (LCFAs). GPR40 is expressed at high levels in islets and mediates the ability of LCFAs to potentiate glucose-stimulated insulin secretion (GSIS). GPR120 is expressed at high levels in colon, adipose, and pituitary, and at more modest levels in pancreatic islets. The role of GPR120 in islets has not been explored extensively. Here, we confirm that saturated (e.g. palmitic acid) and unsaturated (e.g. docosahexaenoic acid (DHA)) LCFAs engage GPR120 and demonstrate that palmitate- and DHA-potentiated glucagon secretion are greatly reduced in isolated GPR120 KO islets. Remarkably, LCFA potentiated glucagon secretion is similarly reduced in GPR40 KO islets. Compensatory changes in mRNA expression of GPR120 in GPR40 KO islets, and vice versa, do not explain that LCFA potentiated glucagon secretion seemingly involves both receptors. LCFA-potentiated GSIS remains intact in GPR120 KO islets. Consistent with previous reports, GPR120 KO mice are hyperglycemic and glucose intolerant; however, our KO mice display evidence of a hyperactive counter-regulatory response rather than insulin resistance during insulin tolerance tests. An arginine stimulation test and a glucagon challenge confirmed both increases in glucagon secretion and liver glucagon sensitivity in GPR120 KO mice relative to WT mice. Our findings demonstrate that GPR120 is a nutrient sensor that is activated endogenously by both saturated and unsaturated long chain fatty acids and that an altered glucagon axis likely contributes to the impaired glucose homeostasis observed in GPR120 KO mice.

Background Many patients with type 2 diabetes mellitus (T2DM) also have hypertension, which is commonly treated with thiazide diuretics, including hydrochlorothiazide (HCTZ). Canagliflozin, a sodium glucose cotransporter 2 inhibitor developed for the treatment of T2DM, lowers plasma glucose by inhibiting renal glucose reabsorption, thereby increasing urinary glucose excretion and mild osmotic diuresis. Because patients with T2DM are likely to receive concurrent canagliflozin and HCTZ, potential interactions were evaluated. Objective This study evaluated the effects of HCTZ on the pharmacokinetic and pharmacodynamic properties and tolerability of canagliflozin in healthy participants. Methods This Phase I, single-center, open-label, fixed-sequence, 2-period study was conducted in healthy participants. During period 1, participants received canagliflozin 300 mg once daily for 7 days, followed by a 14-day washout period. During period 2, participants received HCTZ 25 mg once daily for 28 days, followed by canagliflozin 300 mg + HCTZ 25 mg once daily for 7 days. Blood samples were taken before and several times after administration on day 7 of period 1 and on days 28 and 35 of period 2 for canagliflozin and HCTZ pharmacokinetic analyses using LC-MS/MS. Blood and urine samples were collected for up to 24 hours after canagliflozin administration on day 1 of period 1 and day 35 of period 2 for pharmacodynamic glucose assessment. Tolerability was also evaluated. Results Thirty participants were enrolled (16 men, 14 women; all white; mean age, 43.7 years). Canagliflozin AUC during a dosing interval (T) at steady state (AUC τ,ss ) and C max at steady state (C max,ss ) were increased when canagliflozin was coadministered with HCTZ, with geometric mean ratios (90% CI) of 1.12 (1.08–1.17) and 1.15 (1.06–1.25), respectively. AUC τ,ss and C max,ss for HCTZ were similar with and without canagliflozin coadministration. The 24-hour mean renal threshold for glucose and mean plasma glucose were comparable for canagliflozin alone and coadministered with HCTZ. The change in 24-hour urine volume from baseline was −0.1 L with canagliflozin alone and 0.4 L with HCTZ alone and with canagliflozin + HCTZ. The overall incidence of adverse events (AEs) was higher with canagliflozin + HCTZ (69%) than with canagliflozin (47%) or HCTZ (50%) alone; most AEs were of mild severity. Overall, minimal changes in serum electrolytes (eg, sodium, potassium) were observed after coadministration of canagliflozin + HCTZ compared with individual treatments. Conclusions Adding canagliflozin treatment to healthy participants on HCTZ treatment had no notable pharmacokinetic or pharmacodynamic effects; canagliflozin coadministered with HCTZ was generally well tolerated, with no unexpected tolerability concerns. ClinicalTrials.gov identifier: NCT01294631.

OBJECTIVE Canagliflozin, a sodium glucose cotransporter (SGLT) 2 inhibitor, is also a low-potency SGLT1 inhibitor. This study tested the hypothesis that intestinal canagliflozin levels postdose are sufficiently high to transiently inhibit intestinal SGLT1, thereby delaying intestinal glucose absorption. RESEARCH DESIGN AND METHODS This two-period, crossover study evaluated effects of canagliflozin on intestinal glucose absorption in 20 healthy subjects using a dual-tracer method. Placebo or canagliflozin 300 mg was given 20 min before a 600-kcal mixed-meal tolerance test. Plasma glucose, 3H-glucose, 14C-glucose, and insulin were measured frequently for 6 h to calculate rates of appearance of oral glucose (RaO) in plasma, endogenous glucose production, and glucose disposal. RESULTS Compared with placebo, canagliflozin treatment reduced postprandial plasma glucose and insulin excursions (incremental 0- to 2-h area under the curve [AUC0–2h] reductions of 35% and 43%, respectively; P < 0.001 for both), increased 0- to 6-h urinary glucose excretion (UGE0–6h, 18.2 ± 5.6 vs. CONCLUSIONS Canagliflozin reduces postprandial plasma glucose and insulin by increasing UGE (via renal SGLT2 inhibition) and delaying RaO, likely due to intestinal SGLT1 inhibition.

Context: The stepwise hyperglycemic clamp procedure (SHCP) is the gold standard for measuring the renal threshold for glucose excretion (RTG), but its use is limited to small studies in specialized laboratories. Objective: The objective of the study was to validate a new method for determining RTG using data obtained during a mixed-meal tolerance test (MMTT) in untreated and canagliflozin-treated subjects with type 2 diabetes mellitus (T2DM). Design: This was an open-label study with 2 sequential parts. Setting: The study was performed at a single center in Germany. Patients: Twenty-eight subjects with T2DM were studied. Interventions: No treatment intervention was given in part 1. In part 2, subjects were treated with canagliflozin 100 mg/d for 8 days. In each part, subjects underwent an MMTT and a 5-step SHCP on consecutive days. Main Outcome Measures: For both methods, RTG was estimated using measured blood glucose (BG) and urinary glucose excretion (UGE); estimated glomerular filtration rates were also used to determine RTG during the MMTT. The methods were compared using the concordance correlation coefficient and geometric mean ratios. Results: In untreated and canagliflozin-treated subjects, the relationship between UGE rate and BG was well described by a threshold relationship. Good agreement was obtained between the MMTT-based and SHCP-derived RTG values. The concordance correlation coefficient (for all subjects) was 0.94; geometric mean ratios (90% confidence intervals) for RTG values (MMTT/SHCP) were 0.93 (0.89–0.96) in untreated subjects and 1.03 (0.78–1.37) in canagliflozin-treated subjects. Study procedures and treatments were generally well tolerated in untreated and canagliflozin-treated subjects. Conclusions: In both untreated and canagliflozin-treated subjects with T2DM, RTG can be accurately estimated from measured BG, UGE, and estimated glomerular filtration rates using an MMTT-based method.

ObjectiveTo quantify the homeostatic feedback control of energy intake in response to long-term covert manipulation of energy balance in free-living humans.MethodsWe used a validated mathematical method to calculate energy intake changes during a 52 week placebo-controlled trial in 153 patients treated with canagliflozin, a sodium glucose co-transporter inhibitor that increases urinary glucose excretion thereby resulting in weight loss without patients being directly aware of the energy deficit. We analyzed the relationship between the body weight time course and the calculated energy intake changes using principles from engineering control theory.ResultsWe discovered that weight loss leads to a proportional homeostatic drive to increase energy intake above baseline by ~100 kcal/day per kg of lost weight – an amount more than 3-fold larger than the corresponding energy expenditure adaptations.ConclusionsWhile energy expenditure adaptations are often thought to be the main reason for slowing of weight loss and subsequent regain, feedback control of energy intake plays an even larger role and helps explain why long-term maintenance of a reduced body weight is so difficult.FundingThis research was supported by the Intramural Research Program of the NIH, National Institute of Diabetes & Digestive & Kidney Diseases, using data from a study sponsored by Janssen Research & Development, LLC.DisclosureD.P. is a full-time employee of Janssen Research & Development, LLC. K.D.H. reports patent pending on a method of personalized dynamic feedback control of body weight (US Patent Application No. 13/754,058; assigned to the NIH) and has received funding from the Nutrition Science Initiative to investigate the effects of ketogenic diets on human energy expenditure. R.S. is a paid consultant for Janssen, Novo Nordisk, Takeda, Daichii Sankyo, Novartis, Pfizer, Nestle, Circuit Therapeutics and Ethicon. R.S., also has received research support from Novo Nordisk, Ethicon, Sanofiand Boehringer Ingelheim. A.S. reports no conflicts of interest.What is already known about this subject?Human body weight is believed to be regulated by homeostatic feedback control of both energy intake and energy expenditure.Adaptations of energy expenditure to weight loss have been well-established, but the homeostatic control of energy intake has yet to be quantified.What this study addsWe provide the first quantification of the homeostatic control of energy intake in free-living humans.The increase in energy intake per kg of weight lost is several-fold larger than the known energy expenditure adaptations.Homeostatic control of energy intake is likely the primary reason why it is difficult to achieve and sustain large weight losses.

To quantify the feedback control of energy intake in response to long-term covert manipulation of energy balance in free-living humans.A validated mathematical method was used to calculate energy intake changes during a 52-week placebo-controlled trial in 153 patients treated with canagliflozin, a sodium glucose co-transporter inhibitor that increases urinary glucose excretion, thereby resulting in weight loss without patients being directly aware of the energy deficit. The relationship between the body weight time course and the calculated energy intake changes was analyzed using principles from engineering control theory.It was discovered that weight loss leads to a proportional increase in appetite resulting in eating above baseline by ∼100 kcal/day per kilogram of lost weight-an amount more than threefold larger than the corresponding energy expenditure adaptations.While energy expenditure adaptations have often been considered the main reason for slowing of weight loss and subsequent regain, feedback control of energy intake plays an even larger role and helps explain why long-term maintenance of a reduced body weight is so difficult.

OBJECTIVE To evaluate the effects of canagliflozin, a sodium-glucose cotransporter 2 inhibitor, in type 2 diabetes mellitus inadequately controlled with metformin monotherapy. RESEARCH DESIGN AND METHODS This was a double-blind, placebo-controlled, parallel-group, multicenter, dose-ranging study in 451 subjects randomized to canagliflozin 50, 100, 200, or 300 mg once daily (QD) or 300 mg twice daily (BID), sitagliptin 100 mg QD, or placebo. Primary end point was change in A1C from baseline through week 12. Secondary end points included change in fasting plasma glucose (FPG), body weight, and overnight urinary glucose-to-creatinine ratio. Safety and tolerability were also assessed. RESULTS Canagliflozin was associated with significant reductions in A1C from baseline (7.6–8.0%) to week 12: −0.79, −0.76, −0.70, −0.92, and −0.95% for canagliflozin 50, 100, 200, 300 mg QD and 300 mg BID, respectively, versus −0.22% for placebo (all P < 0.001) and −0.74% for sitagliptin. FPG was reduced by −16 to −27 mg/dL, and body weight was reduced by −2.3 to −3.4%, with significant increases in urinary glucose-to-creatinine ratio. Adverse events were transient, mild to moderate, and balanced across arms except for a non–dose-dependent increase in symptomatic genital infections with canagliflozin (3–8%) versus placebo and sitagliptin (2%). Urinary tract infections were reported without dose dependency in 3–9% of canagliflozin, 6% of placebo, and 2% of sitagliptin arms. Overall incidence of hypoglycemia was low. CONCLUSIONS Canagliflozin added onto metformin significantly improved glycemic control in type 2 diabetes and was associated with low incidence of hypoglycemia and significant weight loss. The safety/tolerability profile of canagliflozin was favorable except for increased frequency of genital infections in females.

Type 2 diabetes is a chronic disease with disabling micro- and macrovascular complications that lead to excessive morbidity and premature mortality. It affects hundreds of millions of people and imposes an undue economic burden on populations across the world. Although insulin resistance and insulin secretory defects play a major role in the pathogenesis of hyperglycemia, several other metabolic defects contribute to the initiation/worsening of the diabetic state. Prominent among these is increased renal glucose reabsorption, which is maladaptive in patients with diabetes. Instead of an increase in renal glucose excretion, which could ameliorate hyperglycemia, there is an increase in renal glucose reabsorption, which helps sustain hyperglycemia in patients with diabetes. The sodium-glucose cotransporter (SGLT) 2 inhibitors are novel antidiabetes agents that inhibit renal glucose reabsorption and promote glucosuria, thereby leading to reductions in plasma glucose concentrations. In this article, we review the long journey from the discovery of the glucosuric agent phlorizin in the bark of the apple tree through the animal and human studies that led to the development of the current generation of SGLT2 inhibitors.

Canagliflozin is a sodium glucose cotransporter 2 inhibitor developed to treat type 2 diabetes mellitus (T2DM).Our objective is to describe the effects of canagliflozin on bone mineral density (BMD) and bone biomarkers in patients with T2DM.This was a randomized study, consisting of a 26-week, double-blind, placebo-controlled period and a 78-week, double-blind, placebo-controlled extension.This study was undertaken in 90 centers in 17 countries.Patients were aged 55-80 years (N = 716) and whose T2DM was inadequately controlled on a stable antihyperglycemic regimen.Canagliflozin 100 or 300 mg or placebo were administered once daily.BMD was assessed using dual-energy x-ray absorptiometry at weeks 26, 52, and 104. Bone strength was assessed using quantitative computed tomography and finite element analysis at week 52. Serum collagen type 1 β-carboxy-telopeptide, osteocalcin, and estradiol were assessed at weeks 26 and 52.Canagliflozin doses of 100 and 300 mg were associated with a decrease in total hip BMD over 104 weeks, (placebo-subtracted changes: -0.9% and -1.2%, respectively), but not at other sites measured (femoral neck, lumbar spine, or distal forearm). No meaningful changes in bone strength were observed. At week 52, canagliflozin was associated with an increase in collagen type 1 β-carboxy-telopeptide that was significantly correlated with a reduction in body weight, an increase in osteocalcin, and, in women, a decrease in estradiol.In older patients with T2DM, canagliflozin showed small but significant reductions in total hip BMD and increases in bone formation and resorption biomarkers, due at least in part to weight loss.

Roux-en-Y gastric bypass (RYGB) has been shown to induce rapid and durable reversal of type 2 diabetes.The aim of the study was to investigate a possible mechanism for the remission of type 2 diabetes after RYGB.A cross-sectional, nonrandomized, controlled study was conducted. Surgery patients were studied before RYGB and 1 wk and 3 months after surgery.This study was conducted at East Carolina University.Subjects were recruited into three groups: 1) lean controls with no surgery [body mass index (BMI)25 kg/m²; n = 9], 2) severely obese type 2 diabetic patients (BMI35 kg/m²; n = 9), and 3) severely obese nondiabetic patients (BMI35 kg/m²; n = 9).Intervention was RYGB.One week after RYGB, diabetes was resolved despite continued insulin resistance (insulin sensitivity index was approximately 50% of lean controls) and reduced insulin secretion during an iv glucose tolerance test (acute insulin response to glucose was approximately 50% of lean controls). Fasting insulin decreased and was no different from lean control despite continued elevated glucose in the type 2 diabetic patients compared with lean.After RYGB, fasting insulin decreases to levels like those of lean control subjects and diabetes is reversed (fasting blood glucose125 mg/dl). This leads us to propose that 1) exclusion of food from the foregut corrects hyperinsulinemia and 2) fasting insulin is dissociated from the influence of fasting glucose, insulin resistance, and BMI. The mechanisms for reversal of diabetes in the face of reduced insulin remain a paradox.

Aim To explain the subadditive efficacy typically observed with initial combination treatments for type 2 diabetes. Methods Individual subject data from 1186 patients with type 2 diabetes [mean glycated haemoglobin (HbA1c) = 8.8%] treated with metformin, canagliflozin or canagliflozin + metformin were used. The baseline HbA1c versus ΔHbA1c relationships for monotherapy arms were determined using analysis of covariance and then used to predict efficacy in the combination arms by modelling how applying one treatment lowers the ‘effective baseline HbA1c’ for a second treatment. The model was further tested using data from several published combination studies. Results The mean ΔHbA1c levels were −1.25, −1.33, −1.37, −1.77 and −1.81% with metformin, canagliflozin 100 mg, canagliflozin 300 mg, canagliflozin 100 mg/metformin and canagliflozin 300 mg/metformin, respectively. Using the monotherapy results, the predicted efficacy for the canagliflozin/metformin arms was within 10% of the observed values using the new model, whereas assuming simple additivity overpredicted efficacy in the combination arms by nearly 50%. For 10 other published initial combination studies, predictions from the new model [mean (standard error) predicted ΔHbA1c = 1.67% (0.14)] were much more consistent with observed values [ΔHbA1c = 1.72% (0.12)] than predictions based on assuming additivity [predicted ΔHbA1c = 2.19% (0.21)]. Conclusions The less-than-additive efficacy commonly seen with initial combination treatments for type 2 diabetes can be largely explained by the impact of baseline HbA1c on the efficacy of individual treatments. Novel formulas have been developed for predicting the efficacy of combination treatments based on the efficacy of individual treatments and the baseline HbA1c of the target patients.

The sodium glucose co-transporter 2 (SGLT2) inhibitor canagliflozin is a novel treatment option for adults with type 2 diabetes mellitus (T2DM). In patients with hyperglycemia, SGLT2 inhibition lowers plasma glucose levels by reducing the renal threshold for glucose (RTG ) and increasing urinary glucose excretion (UGE). Increased UGE is also associated with a mild osmotic diuresis and net caloric loss, which can lead to reductions in body weight and blood pressure (BP). After promising results from preclinical and phase I/II studies, the efficacy and safety of canagliflozin was evaluated in a comprehensive phase III development program in over 10,000 patients with T2DM on various background therapies. Canagliflozin improved glycemic control and provided reductions in body weight and BP versus placebo and active comparators in studies of up to 2 years' duration. Canagliflozin was generally well tolerated, with higher incidences of adverse events (AEs) related to the mechanism of action, including genital mycotic infections and AEs related to osmotic diuresis. Results from the preclinical and clinical studies led canagliflozin to be the first-in-class SGLT2 inhibitor approved in the United States, and support canagliflozin as a safe and effective therapeutic option across a broad range of patients with T2DM.

Aims To compare the pharmacodynamic effects of the highest approved doses of the sodium glucose co-transporter 2 (SGLT2) inhibitors canagliflozin and dapagliflozin on urinary glucose excretion (UGE), renal threshold for glucose excretion (RTG) and postprandial plasma glucose (PPG) excursion in healthy participants in a randomized, double-blind, two-period crossover study. Methods In each treatment period, participants (n = 54) received canagliflozin 300 mg or dapagliflozin 10 mg for 4 days (20 min before breakfast). A mixed-meal tolerance test (600 kcal; 75 g glucose) was performed at baseline and on day 4 of each treatment period to assess changes in incremental PPG (PPGΔAUC0–2 h). We measured 24-h UGE and plasma glucose on day 4 to determine 24-h mean RTG. Results Canagliflozin 300 mg and dapagliflozin 10 mg had similar effects on UGE and RTG for 4 h after dosing, but canagliflozin was associated with higher UGE and greater RTG reductions for the remainder of the day. Mean 24-h UGE was ∼25% higher with canagliflozin than with dapagliflozin (51.4 vs. 40.8 g), and 24-h mean RTG was ∼0.4 mmol/l (7 mg/dl) lower with canagliflozin than with dapagliflozin (3.79 vs. 4.17 mmol/l; p

Background The indocyanine green dilution method is one of the methods available to estimate plasma volume, although some researchers have questioned the accuracy of this method. Methods We developed a new, physiologically based mathematical model of indocyanine green kinetics that more accurately represents indocyanine green kinetics during the first few minutes postinjection than what is assumed when using the traditional mono-exponential back-extrapolation method. The mathematical model is used to develop an optimal back-extrapolation method for estimating plasma volume based on simulated indocyanine green kinetics obtained from the physiological model. Results Results from a clinical study using the indocyanine green dilution method in 36 subjects with type 2 diabetes indicate that the estimated plasma volumes are considerably lower when using the traditional back-extrapolation method than when using the proposed back-extrapolation method (mean (standard deviation) plasma volume = 26.8 (5.4) mL/kg for the traditional method vs 35.1 (7.0) mL/kg for the proposed method). The results obtained using the proposed method are more consistent with previously reported plasma volume values. Conclusions Based on the more physiological representation of indocyanine green kinetics and greater consistency with previously reported plasma volume values, the new back-extrapolation method is proposed for use when estimating plasma volume using the indocyanine green dilution method.

Aims/hypothesis In rodent models of diabetes, treatment with sodium glucose co-transporter 2 (SGLT2) inhibitors improves beta cell function. This analysis assessed the effects of the SGLT2 inhibitor, canagliflozin, on model-based measures of beta cell function in patients with type 2 diabetes. Methods Data from three Phase 3 studies were analysed, in which: (Study 1) canagliflozin 100 and 300 mg were compared with placebo as monotherapy for 26 weeks; (Study 2) canagliflozin 100 and 300 mg were compared with placebo as add-on to metformin + sulfonylurea for 26 weeks; or (Study 3) canagliflozin 300 mg was compared with sitagliptin 100 mg as add-on to metformin + sulfonylurea for 52 weeks. In each study, a subset of patients was given mixed-meal tolerance tests at baseline and study endpoint, and model-based beta cell function parameters were calculated from plasma glucose and C-peptide. Results In Studies 1 and 2, both canagliflozin doses increased beta cell glucose sensitivity compared with placebo. Placebo-subtracted least squares mean (LSM) (SEM) changes were 23 (9) and 18 (9) pmol min−1 m−2 (mmol/l)−1 with canagliflozin 100 and 300 mg, respectively (p

A new method is presented for approximating the stationary probability density function of the response of a general class of non-linear single-degree-of-freedom dynamical systems subjected to additive stochastic white noise excitation. The method is based on finding the best probability density function (PDF) from a parameterized class of trial non-Gaussian PDFs by minimizing a weighted norm of the Fokker–Planck–Kolmogorov equation error. The proposed procedure yields simple expressions in terms of one-dimensional integrals for determining desired probabilistic characteristics of the system response, such as moments and mean outcrossing rates. Examples illustrating the applicability and accuracy of the method include a system modeling the rolling motion of a ship and a Duffing oscillator with non-linear damping. Comparisons are made with some other approximate methods, including equivalent linearization, partial linearization, equivalent non-linearization, and dissipation energy balancing methods, that show that the new method yields substantially improved estimates for the expected outcrossing rates of the response. These outcrossing rates are crucial for evaluating the reliability of the system. In contrast, the equivalent non-linearization and the dissipation energy balancing methods, known to provide the most accurate estimates for the mean-square response, give very poor estimates of the mean outcrossing rates as the number of level outcrossings decreases.

This study characterized single- and multiple-dose pharmacokinetics of canagliflozin and its O-glucuronide metabolites (M5 and M7) and pharmacodynamics (renal threshold for glucose [RTG ], urinary glucose excretion [UGE0-24h ], and 24-hour mean plasma glucose [MPG0-24h ]) of canagliflozin in subjects with type 2 diabetes. Thirty-six randomized subjects received canagliflozin 50, 100, or 300 mg/day or placebo for 7 days. On Days 1 and 7, area under the plasma concentration-time curve and maximum observed plasma concentration (Cmax ) for canagliflozin and its metabolites increased dose-dependently. Half-life and time at which Cmax was observed were dose-independent. Systemic molar M5 exposure was half that of canagliflozin; M7 exposure was similar to canagliflozin. Steady-state plasma canagliflozin concentrations were reached by Day 4 in all active treatment groups. Pharmacodynamic effects were dose- and exposure-dependent. All canagliflozin doses decreased RTG , increased UGE0-24h , and reduced MPG0-24h versus placebo on Days 1 and 7. On Day 7, placebo-subtracted least-squares mean decreases in MPG0-24h ranged from 42-57 mg/dL with canagliflozin treatment. Adverse events (AEs) were balanced between treatments; no treatment-related serious AEs, AE-related discontinuations, or clinically meaningful adverse changes in routine safety evaluations occurred. The observed pharmacokinetic/pharmacodynamic profile of canagliflozin in subjects with type 2 diabetes supports a once-daily dosing regimen.

Introduction This randomized, double-blind, placebo-controlled, single and multiple ascending-dose study evaluated the pharmacodynamic effects and safety/tolerability of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in patients with type 2 diabetes. Methods Patients (N = 116) discontinued their antihyperglycemic medications 2 weeks before randomization. Patients received canagliflozin 30, 100, 200, or 400 mg once daily or 300 mg twice daily, or placebo at 2 study centers in the United States and Germany, or canagliflozin 30 mg once daily or placebo at 1 study center in Korea, while maintaining an isocaloric diet for 2 weeks. On Days –1, 1, and 16, urinary glucose excretion (UGE), plasma glucose (PG), fasting PG (FPG), and insulin were measured. The renal threshold for glucose (RTG) was calculated from UGE, PG, and estimated glomerular filtration rate. Safety was evaluated based on adverse event (AE) reports, vital signs, electrocardiograms, clinical laboratory tests, and physical examinations. Results Canagliflozin increased UGE dose-dependently (∼80–120 g/day with canagliflozin ≥100 mg), with increases maintained over the 14-day dosing period with each dose. Canagliflozin dose-dependently decreased RTG, with maximal reductions to ∼4–5 mM (72–90 mg/dL). Canagliflozin also reduced FPG and 24-hour mean PG; glucose reductions were seen on Day 1 and maintained over 2 weeks. Plasma insulin reductions with canagliflozin were consistent with observed PG reductions. Canagliflozin also reduced body weight. AEs were transient, mild to moderate in intensity, and balanced across groups; 1 canagliflozin-treated female reported an episode of vaginal candidiasis. Canagliflozin did not cause hypoglycemia, consistent with the RTG values remaining above the hypoglycemia threshold. At Day 16, there were no clinically meaningful changes in urine volume, urine electrolyte excretion, renal function, or routine laboratory test values. Conclusions Canagliflozin increased UGE and decreased RTG, leading to reductions in PG, insulin, and body weight, and was generally well tolerated in patients with type 2 diabetes. Trial Registration ClinicalTrials.gov NCT00963768