Experimental Studies of the Effects of Caffeine on Glucose Regulation

This study has been completed.
Information provided by:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
ClinicalTrials.gov Identifier:
First received: February 5, 2007
Last updated: March 1, 2010
Last verified: March 2010

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 Intervention Phase
Diabetes Mellitus, Type 2
Drug: caffeine administration
Phase 0

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacodynamics Study
Intervention Model: Crossover Assignment
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: Caffeine and Glucose Regulation

Resource links provided by NLM:

Further study details as provided by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK):

Primary Outcome Measures:
  • postprandial glucose and insulin
  • fasting glucose and insulin
  • insulin resistance
  • glucose tolerance

Secondary Outcome Measures:
  • epinephrine
  • norepinephrine
  • cortisol
  • blood pressure
  • plasma caffeine concentration

Estimated Enrollment: 150
Study Start Date: July 2004
Estimated Study Completion Date: February 2007
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.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
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
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00432887

Sponsors and Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: James D. Lane, Ph.D. Duke University
  More Information

ClinicalTrials.gov Identifier: NCT00432887     History of Changes
Other Study ID Numbers: DK67486 (completed) 
Study First Received: February 5, 2007
Last Updated: March 1, 2010
Health Authority: United States: Federal Government

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

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

ClinicalTrials.gov processed this record on May 24, 2016