Experimental Studies of the Effects of Caffeine on Glucose Regulation

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00432887
Recruitment Status : Completed
First Posted : February 8, 2007
Last Update Posted : March 2, 2010
Information provided by:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Brief Summary:

This project contains experimental studies of the effects of the drug caffeine on glucose regulation in adults who have Type 2 diabetes. In our experiments, we are testing the hypothesis that moderate amounts of caffeine exaggerate the abnormal increases in glucose and insulin observed after meals in patients with type 2 diabetes. On separate study days subjects receive standard meals after taking capsules containing either caffeine or an inactive placebo. We measure levels of glucose, insulin, and other chemicals in blood samples drawn over the next 3 hours. In a separate study, we use continuous glucose monitoring to measure glucose levels during everyday activities on days when subjects receive caffeine or placebo.

These studies do not involve clinical treatment or disease management. However, we hope to learn whether a very popular drug impairs the clinical management of a common disease.

Condition or disease Intervention/treatment Phase
Diabetes Mellitus, Type 2 Drug: caffeine administration Early Phase 1

Detailed Description:

Pilot results suggest that caffeine, the most commonly used drug in the world, may interfere with postprandial glucose metabolism by increasing insulin resistance and/or by stimulating hepatic glucose production. This effect could have serious clinical implications for coffee drinkers who have type 2 diabetes. Early results suggest caffeine exaggerates the postprandial hyperglycemia and hyperinsulinemia present in these patients.

The experimental (non-treatment) studies in this project include double-blind placebo-controlled cross-over laboratory tests of glucose tolerance in groups of type 2 diabetic patients and prediabetic volunteers who are coffee drinkers.

The lab studies test the hypothesis that caffeine (vs. placebo) increases postprandial insulin responses and results in a potentiation of glucose responses in the type 2 group.

An ambulatory study examines the effects of caffeine administration on glucose levels during everyday activities in the natural environment. This study uses a double-blind placebo-controlled cross-over design. Ambulatory glucose data are collected with a MiniMed CGMS sensor and recorder worn for 72 hours. Caffeine and placebo are administered on separate days. Average glucose levels and glucose responses to meals are compared across treatment days within subjects.

Study Type : Interventional  (Clinical Trial)
Enrollment : 150 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Caffeine and Glucose Regulation
Study Start Date : July 2004
Study Completion Date : February 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Caffeine

Primary Outcome Measures :
  1. postprandial glucose and insulin
  2. fasting glucose and insulin
  3. insulin resistance
  4. glucose tolerance

Secondary Outcome Measures :
  1. epinephrine
  2. norepinephrine
  3. cortisol
  4. blood pressure
  5. plasma caffeine concentration

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion criteria:

  • 6 months or longer history of type 2 diabetes
  • treatment by diet, exercise, or oral medication
  • current daily consumption of 2 or more cups of coffee
  • BMI >21kg/M2 and < 45kg/M2

Exclusion criteria:

  • Required use of insulin
  • Current cigarette smoking
  • Current use of medications that impact glucose metabolism
  • Pregnancy
  • Other major medical disorders

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00432887

Sponsors and Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: James D. Lane, Ph.D. Duke University Identifier: NCT00432887     History of Changes
Other Study ID Numbers: DK67486 (completed)
First Posted: February 8, 2007    Key Record Dates
Last Update Posted: March 2, 2010
Last Verified: March 2010

Keywords provided by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK):

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Central Nervous System Stimulants
Physiological Effects of Drugs
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Purinergic P1 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents