Mechanisms of Glucose Lowering Effect of Colesevelam HCl

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Carine Beysen, KineMed
ClinicalTrials.gov Identifier:
NCT00596427
First received: January 8, 2008
Last updated: October 10, 2012
Last verified: October 2012

January 8, 2008
October 10, 2012
November 2007
April 2009   (final data collection date for primary outcome measure)
  • Fasting Endogenous Glucose Production (EGP) [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Changes from baseline of fasting EGP after 12 weeks of placebo or colesevelam treatment.
  • Fasting Gluconeogenesis [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Change from baseline of fasting gluconeogenesis after 12 weeks of placebo or colesevelam treatment.
  • Fasting Glycogenolysis [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Change from baseline of fasting glycogenolysis after 12 weeks of placebo or colesevelam treatment.
  • Rate of Appearance of Exogenous Glucose (Glucose Absorption) [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Change from baseline of the rate of appearance of oral glucose after 12 weeks of placebo or colesevelam treatment. Mean of values obtained between 0 and 300 min is reported.
To evaluate the effects of 12 weeks of treatment with colesevelam HCl on hepatic glucose production, hepatic gluconeogenesis, hepatic glycogenolysis and glucose absorption [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
Complete list of historical versions of study NCT00596427 on ClinicalTrials.gov Archive Site
  • Total Glucagon-like Peptide (GLP-1) Area Under the Curve (AUC) [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]

    Changes from baseline of total GLP-1 AUC after 12 weeks of placebo or colesevelam treatment.

    AUC values were calculated by the trapezoid method using all results between 0 and 300 minutes

  • Total Glucose-dependent Insulinotropic Polypeptide (GIP) AUC [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]

    Changes from baseline of total GIP-1 AUC after 12 weeks of placebo or colesevelam treatment.

    AUC values were calculated by the trapezoid method using all results between 0 and 300 minutes

  • Fasting Fractional De Novo Lipogenesis (DNL) [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Changes from baseline in fasting fractional DNL after 12 weeks of colesevelam or placebo treatment were calculated. Fractional DNL represents the fraction of palmitate in very-low density lipoproteins-triglycerides (VLDL-TG) that was newly synthesized.
  • Fasting Fractional Cholesterol Synthesis [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Changes from baseline in fasting fractional cholesterol synthesis after 12 weeks of colesevelam or placebo treatment. Fractional Cholesterol synthesis represents the fraction of free cholesterol in plasma that was newly synthesised.
  • Postprandial Fractional Cholic Acid Synthesis [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Changes from baseline in fractional cholic acid synthesis after 12 weeks of colesevelam or placebo treatment were evaluated. Fractional cholic acid synthesis represents the relative amount of cholic acid that is made from newly synthesised cholesterol.
  • Glucagon AUC [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]

    Changes from baseline of glucagon AUC after 12 weeks of placebo or colesevelam treatment.

    AUC values were calculated by the trapezoid method using all results between 0 and 300 minutes

To evaluate the effects of 12 weeks of treatment with colesevelam HCl on de novo lipogenesis (DNL), de novo cholesterol synthesis (DNC), de novo bile acid synthesis, glucagon-like peptide (GLP-1), gastric inhibitory polypeptide (GIP) and glucagon [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  • Glycosylated Hemoglobin (HbAlc) [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]
    Changes from baseline of HbA1c after 12 weeks of placebo or colesevelam treatment.
  • Glucose AUC [ Time Frame: baseline and 12 weeks ] [ Designated as safety issue: No ]

    Changes from baseline of glucose AUC after 12 weeks of placebo or colesevelam treatment.

    AUC values were calculated by the trapezoid method using all results between 0 and 300 minutes

Not Provided
 
Mechanisms of Glucose Lowering Effect of Colesevelam HCl
Effects of Colesevelam HCl on Hepatic Insulin Sensitivity, Gluconeogenesis, Glucose Absorption and Lipid Synthesis in Subjects With Type 2 Diabetes Mellitus

The mechanism by which colesevelam HCl lowers glucose is not known. Knowledge of the potential mechanism of action is important for defining the role of the drug among oral antidiabetic agents available for use in subjects with diabetes. The objective of this study is to provide insight into the mechanisms of action of colesevelam HCl in T2DM. The mechanisms of interest include hepatic insulin sensitivity, rate of appearance of exogenous glucose and changes in incretin hormone concentrations.

Colesevelam HCl (marketed in the U.S. as WelChol®) is a non-absorbed polymer that binds bile acids in the intestine, impeding their reabsorption, and is indicated to lower low-density lipoprotein cholesterol (LDL-C) in subjects with hypercholesterolemia. As the bile acid pool becomes depleted, the hepatic enzyme cholesterol 7-(alpha)-hydroxylase is upregulated, increasing the conversion of cholesterol to bile acids. This causes an increased demand for cholesterol in the liver, resulting in the dual effect of increasing transcription and activity of the cholesterol biosynthetic enzyme, hydroxymethyl-glutaryl-coenzyme A (HMG CoA) reductase, and increasing the number of hepatic low-density lipoprotein (LDL) receptors. These compensatory effects increase the clearance of LDL-C from the blood, decreasing serum LDL C levels (1; 2).

Recently, it has been shown that colesevelam HCl also improves glycemic control in subjects with T2DM who are not controlled adequately on metformin, sulfonylurea or a combination of the two drugs (3). The mechanism of action for glucose lowering is not known. Improved glycemic control with colesevelam HCl treatment could be due to any of several mechanisms. Colesevelam HCl could reduce hepatic insulin resistance and lead to a decrease in hepatic glucose production (HGP). The observation by Schwartz et al (4) of significantly reduced fasting plasma glucose concentrations in colesevelam-treated T2DM patients suggests such a reduction in HGP, as fasting hyperglycemia is a direct function of HGP. Colesevelam HCl could also decrease post-prandial glucose absorption. Changes in glucose absorption with other bile acid sequestrants (BAS) (5) and bile acids (6) have been reported.

With regard to molecular mediators of the colesevelam effect on glucose metabolism, there is considerable evidence emerging about the role of bile acids and nuclear transcription factors, such as the farnesyl X receptor (FXR), in the regulation of glucose and lipid metabolism (7) (8) (9-15). Changes in cellular lipids or nuclear hormone receptors might directly alter HGP although mechanisms leading to changes in hepatic lipid and glucose metabolism by colesevelam HCl have not previously been investigated.

Significant changes in cholesterol and bile acid synthesis rates are expected with colesevelam treatment. BAS treatment can alter the transhepatic flux and compositional profile of the circulating bile acid pool (16), and thus its hydrophobicity, and this may effect the activation of nuclear receptors, including FXR (17; 18). Determination of the effect of colesevelam treatment on bile acid synthesis may provide evidence for its metabolic effects. The effects on hepatic fatty acid synthesis (de novo lipogenesis or DNL) have not been investigated and may provide further evidence for a metabolic effect of colesevelam.

Specific hypotheses about its mode of action will be tested, focusing on hepatic glucose metabolism and intestinal glucose absorption.

Interventional
Not Provided
Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
Diabetes
  • Drug: Colesevelam HCL
    Colesevelam HCL 625 mg: 3 tablets twice per day
    Other Name: WelChol
  • Drug: Placebo
    Placebo tablets: 3 tablets twice per day
  • Placebo Comparator: Placebo tablet 3 tablets 2x/day
    Type-2 diabetes mellitus patients
    Intervention: Drug: Placebo
  • Experimental: Colesevelam HCL 625 mg: 3 tablets 2x/day
    Type-2 diabetes mellitus patients
    Intervention: Drug: Colesevelam HCL

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
60
April 2009
April 2009   (final data collection date for primary outcome measure)

Inclusion Criteria:

Subjects meeting the following criteria at the Screening Visit will be eligible to participate in the trial:

  • Have given written informed consent
  • Male or Female

    1. Females of childbearing potential who are on approved birth control method:

      oral, injectable, or implantable hormonal contraceptives; intrauterine device; diaphragm plus spermicide or female condom plus spermicide

    2. Females of non-childbearing potential: hysterectomy, tubal ligation 6 months prior screening or post-menopausal for at least 1 year
  • Previously diagnosed or newly diagnosed with T2DM
  • Age 30 to 70 years, inclusive
  • BMI ≥ 18.5 kg/m2 and ≤ 40 kg/m2
  • HbA1C 7-10%, inclusive (exceptions between 6.7-7% may be enrolled with prior approval of SPONSOR)
  • Fasting plasma glucose < 300 mg/dL
  • Diet controlled or on stable dose of a sulfonylurea and/or meglitinides and/or metformin for ≥ 90 days before screening
  • No history of liver, biliary or intestinal disease (AST/ALT < 2X upper limit of normal value)
  • Normal TSH
  • Agrees to maintain their regular diet and exercise routine
  • Agrees to refrain from consumption of alcohol 48 hours prior to start of infusions (week 0 and week 12)

Exclusion Criteria:

Subjects are excluded from participation in the study if any of the following criteria apply:

  • Type 1 diabetes mellitus or history of diabetic ketoacidosis
  • Treatment with lipid lowering medication other than statins
  • Treatment with statins that have not been stable for 3 months before screening
  • Treatment with colesevelam HCl, cholestyramine or colestipol for hyperlipidemia within the last 3 months of screening
  • Treatment with a thiazolidinedione (TZD) at any time
  • Treatment with acarbose at any time
  • Treatment with insulin in the past 6 months
  • Treatment with antibiotics within the last 3 months
  • Treatment with any medication affecting liver or intestinal function within the last 3 months
  • Pregnant
  • Breastfeeding
  • Has had unstable weight within the last 3 months of screening (± 5 kg)
  • History of an allergic or toxic reaction to colesevelam HCl
  • History of dysphagia, swallowing disorders, or intestinal motility disorder
  • Serum triglycerides ≥ 350 mg/dL at screening visit (exceptions up to 500 mg/dl may be enrolled with prior approval of SPONSOR)
  • Serum LDL-C <60 mg/dL at screening visit
  • Any condition or therapy which, in the opinion of the investigator, poses a risk to the subject or makes participation not in the subject's best interest
  • Use of any investigational drug within 3 months of screening
  • Chronic treatment with oral corticosteroids at any time or acute treatment within the last 3 months
  • History of drug or alcohol abuse, is currently a user (including "recreational use") of any illicit drugs, or has a positive urine drug screen at screening
  • Donated a unit of blood within 30 days before screening
Both
30 Years to 70 Years
No
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT00596427
KM-11A
No
Carine Beysen, KineMed
Carine Beysen
Not Provided
Principal Investigator: Carine Beysen, PhD KineMed
KineMed
October 2012

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP