Please note that the ANZCTR will be unattended from Friday the 17th of July to Monday the 20th of July 2020 inclusive. Thank you and apologies for any inconvenience caused.

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 endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12617000201370
Ethics application status
Approved
Date submitted
19/01/2017
Date registered
6/02/2017
Date last updated
4/06/2019
Date data sharing statement initially provided
11/02/2019
Date results information initially provided
11/02/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Comparison of effects on blood glucose and lipid levels upon consumption of different types of coffee
Scientific title
Comparison of effects on blood glucose and lipid levels upon consumption of different types of coffee in healthy adults
Secondary ID [1] 290979 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Postprandial blood glucose and lipid levels. 301729 0
Condition category
Condition code
Metabolic and Endocrine 301425 301425 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The following test drinks are tested: espresso-, instant, boiled and decaffeinated coffee, both with and without sugar and milk added, as well as water and sugar-sweetened milk. The details of the test drinks are listed below:

Espresso-coffee: 35ml of the beverage is made from 7g of grounded coffee powder using an espresso machine (Delonghi 680). Caffeine content in one serve of espresso drink is 115mg.

Instant coffee: made by adding 2g of instant coffee powder into 140ml of near-boiling water. Caffeine content in one serve of instant coffee drink is 110mg.

Boiled coffee: made by adding 9g of grounded coffee powder into 175ml boiled water. Simmer for 10 minutes and cool in room temperature for 3 minutes. 150ml of the coffee beverage is served. Caffeine content in one serve of boiled coffee drink is 170mg.

Decaffeinated coffee: made by adding 2g of decaffeinated coffee powder into 140ml of near-boiling water. Caffeine content in one serve of decaffeinated coffee drink is 3mg.

All beverages listed above are tested in two versions: one with 50g low-fat cow's milk and 7.5 g white sugar added, while the other with nothing but black coffee.

Control: 140ml of near-boiling water.

Sweetened-milk: 50g of low-fat cow's milk and 7,5g of white sugar is added into 140ml of near-boiling water.

The participant arrives in the morning with an empty stomach. He/she will give the first blood sample, then drink the test drink within 10 minutes. After 60 minutes, another blood sample will be taken. Then he/she will have to consume a standard breakfast made up of rice cereal, rice milk and glucose powder in 10 minutes. Investigators will make sure that the participant finishes the test drink and the standard breakfast.

With a total of 10 test drinks and each of them being tested in two sessions, each participant will take part in a total of 20 sessions. A washout period of three days is given between each session.
Intervention code [1] 296928 0
Lifestyle
Comparator / control treatment
Water and the sugar-sweetened milk will also be provided as test drinks to the participants in 4 of the study sessions (2 each).
Control group
Active

Outcomes
Primary outcome [1] 300814 0
Plasma glucose level in 3 hours during the session
Timepoint [1] 300814 0
1 sample will be taken before consuming the test drink. 60 minutes later, another blood sample will be taken and the participant will consume the standard breakfast. After that another 6 samples will be taken at the following time after breakfast consumption: 15, 30, 45, 60, 90 and 120 minutes. The plasma glucose level will be measured using glucose oxidase commercial kits (Stanbio).

Whenever a study session is conducted using decaffeinated coffee, the glucose level will also be monitored using the FreeStyle Libre Flash Glucose Monitoring System (Berkshire, UK). A sensor will be inserted into participants' upper arm before the start of the experiment. A reading will be obtained by scanning the sensor, before collecting blood samples at each timepoint.
Primary outcome [2] 300880 0
Plasma insulin levels for 3 hours during the sessions
Timepoint [2] 300880 0
1 sample will be taken before consuming the test drink. 60 minutes later, another blood sample will be taken and the participant will consume the standard breakfast. After that another 6 samples will be taken at the following time after breakfast consumption: 15, 30, 45, 60, 90 and 120 minutes.

The insulin level will be measured using enzyme-linked immunosorbent assay (ELISA).
Secondary outcome [1] 330953 0
Changes of the total and active GLP-1 levels in 3 hours during the session (composite).
Timepoint [1] 330953 0
1 sample will be taken before consuming the test drink. 60 minutes later, another blood sample will be taken and the participant will consume the standard breakfast. After that another 6 samples will be taken at the following time after breakfast consumption: 15, 30, 45, 60, 90 and 120 minutes. Heparin-treated tubes are used to collect blood samples, which are then centrifuged to collect the plasma. Separate tubes with DPPIV-inhibitor added will be used to collect blood samples for active GLP-1 measurement.

Both total and active GLP-1 levels will be measured using ELISA.
Secondary outcome [2] 331105 0
Plasma triglyceride levels for 3 hours during the session
Timepoint [2] 331105 0
1 sample will be taken before consuming the test drink. 60 minutes later, another blood sample will be taken and the participant will consume the standard breakfast. After that another 6 samples will be taken at the following time after breakfast consumption: 15, 30, 45, 60, 90 and 120 minutes. Heparin-treated tubes are used to collect blood samples, which are then centrifuged to collect the plasma.

The plasma triglyceride level will be measured using glycerol phosphate oxidase commercial kit (Stanbio).
Secondary outcome [3] 331106 0
Plasma total cholesterol level for 3 hours during the session
Timepoint [3] 331106 0
1 sample will be taken before consuming the test drink. 60 minutes later, another blood sample will be taken and the participant will consume the standard breakfast. After that another 6 samples will be taken at the following time after breakfast consumption: 15, 30, 45, 60, 90 and 120 minutes. Heparin-treated tubes are used to collect blood samples, which are then centrifuged to collect the plasma.

The plasma total cholesterol levels will be determined using cholesterol oxidase commercial kits (Stanbio).

Eligibility
Key inclusion criteria
1. Aged between 18-40 years old
2. Body mass index (BMI) WITHIN the range of 18.0-23.0
3. Consume at least 2 cups of coffee on a weekly basis in the past 3 months
4. Have never smoked before
5. Not a vegetarian
6. Able to tolerate cow’s milk
7. Able to tolerate caffeine or coffee
8. Not on regular medication, except oral contraceptives
9. Women who are not pregnant or does not plan to be pregnant during the study
10. Without high blood lipid or cholesterol
11. Without diagnosed type 1 or type 2 diabetes
12. Without current or history of cardiovascular diseases
13. Without current or history of liver diseases
14. Without current or history of gastrointestinal diseases
15. Without haemophobia
Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Aged out of 18-40 years old
2. Body mass index (BMI) not within the range of 18.0-23.0
3. Consume less than 2 cups of coffee on a weekly basis in the past 3 months
4. Ex- or current smoker
5. Vegetarian
6. Unable to tolerate cow’s milk
7. Unable to tolerate caffeine or coffee
8. On regular medication, except oral contraceptives
9. Women who are pregnant or plan to be pregnant during the study
10. With high blood lipid or cholesterol
11. Diagnosed with type 1 or type 2 diabetes
12. With current or history of cardiovascular diseases
13. With current or history of liver diseases
14. With current or history of gastrointestinal diseases
15. Haemophobia

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 8597 0
Hong Kong
State/province [1] 8597 0

Funding & Sponsors
Funding source category [1] 295393 0
University
Name [1] 295393 0
The University of Hong Kong
Address [1] 295393 0
1 Pokfulam Road, Pokfulam
Country [1] 295393 0
Hong Kong
Primary sponsor type
University
Name
The University of Hong Kong
Address
1 Pokfulam Road, Pokfulam
Country
Hong Kong
Secondary sponsor category [1] 294215 0
None
Name [1] 294215 0
Address [1] 294215 0
Country [1] 294215 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296727 0
Human Research Ethics Committee - University of Hong Kong Research Services
Ethics committee address [1] 296727 0
9/F, Knowles Building, University of Hong Kong,
1 Pokfulam Road, Pokfulam,
Hong Kong Special Administrative Region.
Ethics committee country [1] 296727 0
Hong Kong
Date submitted for ethics approval [1] 296727 0
01/03/2016
Approval date [1] 296727 0
15/04/2016
Ethics approval number [1] 296727 0
EA1604004

Summary
Brief summary
Coffee is a staple drink around the world and is mainly consumed for its arousing effect. Available in different types, including espresso, boiled and instant, coffee is becoming increasingly popular in Hong Kong. The protective effects of habitual coffee consumption towards several chronic diseases related to unhealthy lifestyles, such as type 2 diabetes mellitus (T2DM), cardiovascular diseases (CVD) and metabolic syndrome, have been demonstrated. However these findings contradict with the results of acute feeding studies, which found that coffee is capable of impairing the body's own ability to control blood sugar level. This project aims at investigating the acute effect of consuming different kinds of coffee on the different biomarkers in blood. This project will be able to demonstrate the difference in effects upon consuming different types of coffee, which can lead to further investigation of the biological mechanisms involved. Long term consumption studies may also be carried out so that a comparison between the short-term and long-term effects is possible.

Four types of coffee will be studied, including espresso, boiled, instant and decaffeinated coffee. After overnight fasting, each participant will consume a cup of test drink and consume a standard breakfast 60 minutes later. Blood samples will be taken to track the changes of the different metabolites during the session.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 71906 0
Dr Jimmy Chun Yu Louie
Address 71906 0
5S-14, Kadoorie Biological Sciences Building,
The University of Hong Kong,
1 Pokfulam Road, Pokfulam,
Country 71906 0
Hong Kong
Phone 71906 0
+852 22990677
Fax 71906 0
Email 71906 0
jimmyl@hku.hk
Contact person for public queries
Name 71907 0
Mr Tommy Hon Ting Wong
Address 71907 0
5S-01, Kadoorie Biological Sciences Building,
The University of Hong Kong,
1 Pokfulam Road, Pokfulam
Country 71907 0
Hong Kong
Phone 71907 0
+852 22990832
Fax 71907 0
Email 71907 0
tommywht@hku.hk
Contact person for scientific queries
Name 71908 0
Mr Tommy Hon Ting Wong
Address 71908 0
5S-01, Kadoorie Biological Sciences Building,
The University of Hong Kong,
1 Pokfulam Road, Pokfulam
Country 71908 0
Hong Kong
Phone 71908 0
+852 22990832
Fax 71908 0
Email 71908 0
tommywht@hku.hk

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
To protect the privacy of participants
What supporting documents are/will be available?
Ethical approval
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary