Effects of Caffeinated and Decaffeinated Coffee on Body Weight and Glucose Tolerance

Overweight Clinical Trial

Official title:

Effects of Caffeinated and Decaffeinated Coffee on Body Weight and Glucose Tolerance

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00305097
• Other study ID #: DK46200 (completed)
• Secondary ID: P30DK046200
• Status: Completed
• Phase: N/A
• First received: March 20, 2006
• Last updated: March 2, 2018
• Start date: May 2006
• Est. completion date: September 2008

Study information

• Verified date: March 2018
• Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Habitual consumption of coffee may have substantial beneficial effects on glucose metabolism according to recent findings of epidemiological studies in the U.S., Europe, and Japan. However, data from longer-term human intervention studies with appropriate outcome measures are lacking. We will study the effects of caffeinated and decaffeinated coffee consumption on body fatness, insulin sensitivity and glucose tolerance that may underlie the observed associations with a lower risk of type 2 diabetes in a randomized controlled trial. We hypothesize that both caffeinated and decaffeinated coffee will improve insulin sensitivity and glucose tolerance. Before starting a larger, long-term intervention study, we will conduct a pilot study to test the feasibility of such a trial. The pilot study will be an 8-week parallel trial in 45 overweight individuals, who will be randomized to drinking 5 cups per day of 1) caffeinated coffee (n=15), 2) decaffeinated coffee (n=15), or 3) water (n=15). Body fatness (weight, waist circumference, bioelectrical impedance), insulin sensitivity (HOMA model), and glucose tolerance (oral glucose tolerance test) will be the primary outcomes. We will assess the adherence of participants to their assigned treatment by measuring serum caffeine concentrations, documentation of coffee use in diaries by the participants, and counting unused coffee packets. We will also obtain feedback from participants on how to improve compliance in a future trial. If successful, this study will form the basis for a definitive trial of coffee consumption, body fatness, and glucose tolerance. Given the extensive use of coffee and the rapidly increasing health burden of type 2 diabetes, such a trial would have important public health implications.

Description:

Habitual consumption of coffee may have substantial beneficial effects on glucose metabolism according to recent findings of epidemiological studies in the U.S., Europe, and Japan. However, data from longer-term human intervention studies with appropriate outcome measures are lacking. We will study the effects of caffeinated and decaffeinated coffee consumption on body fatness, insulin sensitivity and glucose tolerance that may underlie the observed associations with a lower risk of type 2 diabetes in a randomized controlled trial. We hypothesize that both caffeinated and decaffeinated coffee will improve insulin sensitivity and glucose tolerance. Before starting a larger, long-term intervention study, we will conduct a pilot study to test the feasibility of such a trial. The pilot study will be an 8-week parallel trial in 45 overweight individuals, who will be randomized to drinking 5 cups per day of 1) caffeinated coffee (n=15), 2) decaffeinated coffee (n=15), or 3) water (n=15). Body fatness (weight, waist circumference, bioelectrical impedance), insulin sensitivity (HOMA model), and glucose tolerance (oral glucose tolerance test) will be the primary outcomes. We will assess the adherence of participants to their assigned treatment by measuring serum caffeine concentrations, documentation of coffee use in diaries by the participants, and counting unused coffee packets. We will also obtain feedback from participants on how to improve compliance in a future trial. If successful, this study will form the basis for a definitive trial of coffee consumption, body fatness, and glucose tolerance. Given the extensive use of coffee and the rapidly increasing health burden of type 2 diabetes, such a trial would have important public health implications.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 45
• Est. completion date: September 2008
• Est. primary completion date: September 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Aged at least 18 years with an ability and willingness to give written informed consent.

• Body mass index 25-35 kg/m2

• Users of at least 2 cups of caffeinated coffee per day who are willing to be randomized to any of the interventions.

• Non-smoking

Exclusion Criteria:

• Any condition/illness that may affect the study outcomes or would make participation potentially harmful such as pregnancy or breastfeeding, diabetes mellitus, heart disease, stroke, hypertension, malabsorption syndromes, Gastroesophageal reflux disease GERD, a history of ulcer, according to a detailed medical history.

• Abnormal hepatic function (liver function test > twice the normal range), abnormal renal function (creatinine > 1.1 mg/dl), fasting plasma glucose in the diabetic range (>/= 126 mg/dl), or blood pressure > 140/90 mmHg.

• Present alcoholism or drug abuse or use of medications that could interfere with the treatment including bronchodilators, quinolone antibiotics, monoamine oxidase inhibitors, anxiolytics, ranitidine, corticosteroids, growth hormone, antihypertensives.

Related Conditions & MeSH terms

• Body Weight
• Overweight

Intervention

Dietary Supplement:
• Decaffeinated coffee
5 cups per day for 8 weeks
• Caffeinated coffee
5 cups per day for 8 weeks
• No coffee

Locations

Country	Name	City	State
United States	Beth Israel Deaconess Medical Center	Boston	Massachusetts

Sponsors (3)

Lead Sponsor	Collaborator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Beth Israel Deaconess Medical Center, Harvard School of Public Health

Country where clinical trial is conducted

United States, 

References & Publications (1)

Wedick NM, Brennan AM, Sun Q, Hu FB, Mantzoros CS, van Dam RM. Effects of caffeinated and decaffeinated coffee on biological risk factors for type 2 diabetes: a randomized controlled trial. Nutr J. 2011 Sep 13;10:93. doi: 10.1186/1475-2891-10-93. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	glucose tolerance / insulin sensitivity		4 and 8 weeks
Secondary	body weight/fatness, blood pressure, concentrations of blood lipids, adipokines, inflammatory markers		4 and 8 weeks