Coffee and Metabolic Health Outcomes (COMETH)

Influence of Coffee Consumption on Insulin Sensitivity in Overweight and Insulin Resistant Subjects.

The purpose of the study is to investigate the long-term (24 weeks) effects of coffee consumption on insulin sensitivity in insulin resistant individuals.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Coffee

Detailed Description

Coffee is a major source of the phenolic acid chlorogenic acid and a substantial source of trigonelline, niacin, lignans magnesium, and potassium. Several of these compounds have been shown to improve glucose metabolism in animal models. Consumption of coffee was inversely associated with the risk of type-2 diabetes in prospective cohort studies across the world. Consumption of 3 to 4 cups of coffee per day was associated with an approximately 25% lower risk of type-2 diabetes. However, direct evidence of the efficacy of coffee to reduce blood glucose and insulin resistance parameters in humans from randomized trials is still lacking. In recent small trials of short duration (up to 6 weeks) coffee consumption increased levels of the insulin-sensitizing hormone adiponectin, but did not significantly improve insulin sensitivity These results suggest that a larger longer-term trial of the effects of coffee consumption on directly measured insulin sensitivity is warranted.

• Study Type: Interventional
• Enrollment (Actual): 128
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 117597
    • Saw Swee Hock School of Public Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 69 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Subjects classified as being insulin-resistant in the screening visit. Subjects should have a non-diabetic fasting plasma glucose concentration (< 7.0 mM) and a HOMA-IR > 2.2. The HOMA-IR was demonstrated as a reliable indicator of insulin resistance strongly correlated with values obtained by clamp (4). The cut-off value of the HOMA-IR was defined according to data obtained in the Singapore cohort. It corresponds to the 75th percentile of the population. The HOMA-IR cut-off was subsequently revised to ≥ 1.3 to increase recruitment rates.
• Age: ≥ 35 to ≤ 69 years old
• Body mass index : ≥ 22.5 to ≤ 35.4 kg/m2
• Users of at least 1 cups of caffeinated coffee per day who are willing to be randomized to any of the interventions.
• Subjects should be willing to stop consuming caffeinated soft drinks or supplements during the study and to drink coffee with non-dairy creamer.
• Non-smokers (< 1 cigarette per week)
• Participants have been weight stable for at least -8 weeks pre-ceding the screening visit (± 2.5 kgs).
• Chinese, Malay and Indian ethnicity

Exclusion Criteria:

Subjects representing one or more of the following criteria are excluded from participation in the study:

• 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, GERD, a history of ulcer, clotting or bleeding disorders,allergy to the test beverage, allergy to insulin, according to a detailed medical history.
• Participants who are allergic to foods may be excluded based on the investigator's discretion.
• Participants consume > 2 alcoholic servings/day on a regular basis and > 8 caffeinated servings (based on tea and coffee)/day
• Present drug abuse or use of medications that could interfere with the treatment including bronchodilators, quinolone antibiotics, monoamine oxidase inhibitors, anxiolytics, ranitidine, corticosteroids, growth hormone, anti-hypertensives. These conditions will be screened based on subject reporting. Participants will be asked to bring in their current medications at the time of screening, and these will be checked by the study-staff.
• Subject is taking traditional medications, herbal or dietary supplements that may affect the study outcome in the opinion of the investigators.
• Subject who cannot be expected to comply with the study procedures in the opinion of the investigators.
• Currently participating or having participated in another clinical trial during the last 12 weeks prior to the beginning of this study.
• Premenopausal women with self-reported irregular menstrual cycles or peri-menopausal women (participants who stopped getting their menses for less than 48 weeks ).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Coffee; Subjects take 4 cups of coffee mix per day for 24 weeks	Dietary supplement: Coffee
Placebo Comparator: Placebo; Subjects take 4 cups of placebo per day for 24 weeks	Dietary supplement: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in insulin sensitivity when compared to baseline as measured using the euglycemic hyperinsulinemic clamp.	Baseline and 24 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in fasting plasma glucose concentration from baseline to 12 weeks	Baseline, 12 weeks
Change in fasting plasma glucose concentration from baseline to 24 weeks	Baseline, 24 weeks
Change in fasting plasma total adiponectin concentrations from baseline to 12 weeks	Baseline, 12 weeks
Change in fasting plasma total adiponectin concentrations from baseline to 24 weeks	Baseline, 24 weeks

Collaborators and Investigators

• Sponsor: National University Hospital, Singapore
• Collaborators: Société des Produits Nestlé (SPN)
• Investigators: Principal Investigator: Rob M van Dam, Saw Swee Hock School of Public Health, National University of Singapore

Publications and helpful links

General Publications

• Alperet DJ, Rebello SA, Khoo EY, Tay Z, Seah SS, Tai BC, Tai ES, Emady-Azar S, Chou CJ, Darimont C, van Dam RM. The effect of coffee consumption on insulin sensitivity and other biological risk factors for type 2 diabetes: a randomized placebo-controlled trial. Am J Clin Nutr. 2020 Feb 1;111(2):448-458. doi: 10.1093/ajcn/nqz306.
• Alperet DJ, Rebello SA, Khoo EY, Tay Z, Seah SS, Tai BC, Emady-Azar S, Chou CJ, Darimont C, van Dam RM. A randomized placebo-controlled trial of the effect of coffee consumption on insulin sensitivity: Design and baseline characteristics of the Coffee for METabolic Health (COMETH) study. Contemp Clin Trials Commun. 2016 Aug 2;4:105-117. doi: 10.1016/j.conctc.2016.06.013. eCollection 2016 Dec 15.

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (Actual): December 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: November 28, 2012
• First Submitted That Met QC Criteria: November 28, 2012
• First Posted (Estimate): November 30, 2012

Study Record Updates

• Last Update Posted (Estimate): April 23, 2015
• Last Update Submitted That Met QC Criteria: April 21, 2015
• Last Verified: March 1, 2012

More Information

Terms related to this study

• Keywords: Insulin resistance; Glucose metabolism; Coffee
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Insulin Resistance
• Other Study ID Numbers: 11.09.NRC