Minding blood sugar: how misperceptions of sugar consumption influence patients with type 2 diabetes

ISRCTN	ISRCTN81937091
DOI	https://doi.org/10.1186/ISRCTN81937091

Submission date: 03/06/2019
Registration date: 09/07/2019
Last edited: 07/09/2021

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
This study investigates whether expectations affect diabetic metabolism. To determine whether cognition affects glucose levels, the study examines study participants who have type 2 diabetes in which the body fails to generate sufficient insulin or use it properly. The researchers’ previous work found that the subjective perception of time exerts a stronger influence on blood glucose level changes in people with type 2 diabetes than the objective passage of time. In this study, the researchers targeted the amount of sugar believed to be consumed by diabetics. Sugar consumption is perhaps the most widely accepted factor in explaining blood glucose fluctuations.

Who can participate?
Patients aged 18 and over who have insulin-independent type 2 diabetes mellitus

What does the study involve?
Participants are instructed to come to the laboratory twice at three-day intervals. At each session, participants sample one of the two beverages which are actually identical but had labels indicating different sugar levels. Blood glucose levels are measured at the start and after 20, 40 and 60 minutes.

What are the possible benefits and risks of participating?
Possible benefits to participants may include improved understanding of their experience. Participants may experience minimal discomfort associated with participation, but there were no adverse events associated with this trial.

Where is the study run from?
Harvard University (USA)

When is the study starting and how long is it expected to run for?
April 2017 to April 2018

Who is funding the study?
National Science Foundation (USA)

Who is the main contact?
Mr Chanmo Park
Chanmo_Park@mail.harvard.edu

Contact information

Mr Chanmo Park
Scientific

33 Kirkland St
Cambridge
02138
United States of America

ORCID ID	0000-0001-5865-0354
Phone	+1 (0)617 495 3932
Email	Chanmo_Park@mail.harvard.edu

Study information

Study design	Randomised cross over trial
Primary study design	Interventional
Secondary study design	Randomised cross over trial
Study setting(s)	Other
Study type	Other
Participant information sheet	Psychology Study Pool at Harvard (https://studypool.psychology.fas.harvard.edu)
Scientific title	Minding blood sugar: how misperceptions of sugar consumption influence patients with type 2 diabetes
Study objectives	Perceived rather than actual sugar consumption would influence blood glucose levels.
Ethics approval(s)	Approved 20/04/2017, Harvard University-Area Committee on the Use of Human Subjects (Smith Campus Center, Suite 935, 1350 Massachusetts Ave., Cambridge, MA 02138, USA; IRB Registration- IRB00000109; Federal Wide Assurance - FWA00004837), ref: IRB16-1833
Health condition(s) or problem(s) studied	Insulin-independent type 2 diabetes mellitus
Intervention	Participants were instructed to come to the laboratory twice, at three-day intervals. At each session, participants sampled one of the two beverages, which were actually identical but had labels indicating different sugar levels. The researchers counterbalanced order of presentation based on a block randomization procedure, creating two equally sized group samples. They controlled for consumption speed by instructing participants to completely consume the beverage in 3 minutes.
Intervention type	Other
Primary outcome measure	Blood glucose levels (mg/dL) measured at baseline, 20, 40 and 60 minutes
Secondary outcome measures	1. Perceived stress measured using Perceived Stress Scale (PSS, 10-item version) at baseline during the first session 2. Eating behaviors measured using Dutch Eating Behavior Questionnaire (DEBQ) at 60 minutes during the post-intervention of the first session 3. Affectivity measured using Positive Affect and Negative Affect Scale (PANAS) at baseline, 20, and 60 minutes 4. Hunger measured using Satiety Labeled Intensity Magnitude (SLIM) at baseline, 20, and 60 minutes
Overall study start date	20/04/2017
Completion date	19/04/2018

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	30
Total final enrolment	34
Key inclusion criteria	1. Individuals (≥ age 18) who have insulin-independent type 2 diabetes mellitus 2. Individuals who hold a minimum of 12 months duration from diagnosis 3. Individuals who do not have any serious illnesses other than type 2 diabetes and who do not have diabetes-related complications 4. Individuals with a text-enabled phone for the duration of the study
Key exclusion criteria	1. Individuals under the age 18 2. Individuals who do not have insulin-independent type 2 diabetes mellitus 2. Individuals who do not hold a duration of 12 months from diagnosis 3. Individuals who have any serious illnesses other than type 2 diabetes and who do not have diabetes-related complications 4. Individuals without access to a text-enabled phone for the duration of the study
Date of first enrolment	20/04/2017
Date of final enrolment	19/04/2018

Locations

Countries of recruitment

United States of America

Study participating centre

Harvard University

33 Kirkland Street
Cambridge
02138
United States of America

Sponsor information

National Science Foundation
Government

2415 Eisenhower Avenue
Alexandria
22314
United States of America

Phone	+1 (0)703 292 5111
Email	info@nsf.gov
Website	https://www.nsf.gov
"ROR"	https://ror.org/021nxhr62

Funders

Funder type

Government

National Science Foundation GRFP under Grant No. (NSF 16-588).
Government organisation / National government

Alternative name(s): U.S. National Science Foundation, NSF, US NSF, USA NSF
Location: United States of America

Results and Publications

Intention to publish date	01/09/2019
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Stored in repository
Publication and dissemination plan	The researchers will present their findings to scientific conferences in the United States. They are also currently preparing to disseminate their findings via journal publication.
IPD sharing plan	The data that support the findings of this study have been deposited in Harvard Dataverse with the identifier (https://doi.org/10.7910/DVN/2WC8LC) and will be made publically available at a later date.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article		24/09/2020	07/09/2021	Yes	No

Editorial Notes

07/09/2021: The following changes have been made:
1. Publication reference added.
2. The final enrolment number has been added from the reference.
24/06/2019: Trial's existence confirmed by ethics committee.