Consumption of Oral Artificial Sweeteners on Platelet Aggregation and Polyol Excretion
Phase: NA
Conditions: Cardiovascular Risk Factor
Sponsor: The Cleveland Clinic

Version Date: 06/29/2023 
 
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Consumption of Oral Artificial Sweeteners on Platelet Aggregation and Polyol 
Excretion (COSETTE) 
 
Principal Investigators: Marco Witkowski, MD & W.H. Wilson Tang, MD 
Date: 06/29/2023 
 
 
1.0 BACKGROUND AND SIGNIFICANCE 
The principal goals for the study are to examine 1) how long after ingestion of a single 
sweetened beverage are levels of that sweetener still elevated, and 2) whether 
ingestion of a beverage containing either an artificial sweetener or glucose alters in vitro 
platelet aggregation. 
 
Due to the growing number of cardiometabolic diseases like diabetes mellitus, the use 
of polyols (a.k.a. sugar alcohols) and other artificial sweeteners to replace free sugars 
has recently gained increasing appreciation. Two popular artificial sweeteners are 
erythritol and xylitol. 
  
Erythritol and xylitol are both naturally occurring polyols found in fruits and vegetables. 
They are potent artificial sweeteners with a higher sweetening intensity and lower 
calorie content than table sugar. This makes them attractive for the use as sugar 
substitutes or alternatives, particularly for patients with type 2 diabetes.  
 
All three mentioned sweeteners are generally considered safe and approved by the 
Food and Drug Administration (FDA) as food additives. Major side effects of excessive 
consumption comprise flatulence, laxation, and headache. Erythritol and xylitol are well 
tolerated up to an intake of 60g and 50g daily, respectively (1, 2). Major side effects of 
glucose are insulin resistance and type 2 diabetes following excessive chronic 
consumption.  
 
Up to now, there is no prospective data available about polyols with respect to their 
impact on event outcomes in cardiovascular patients, despite the extensive use in the 
food industry. Moreover, little is known about plasma levels and metabolic changes 
following food intake of artificial sweeteners, in particular polyols. 
 
We have measured fasting levels of various polyols in a large clinical cohort of 
cardiovascular patients and found that some candidate polyols are related to a higher 
risk of cardiovascular complications and death. In vitro data using human platelets 
revealed that the polyols xylitol and erythritol at the levels observed in fasting patients 

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induce platelet aggregation potential. Our data shows that erythritol and xylitol, impact 
platelet function and thereby may contribute to cardiovascular mortality.  
 
In preliminary studies we found that upon ingestion erythritol and xylitol levels in the 
plasma rise within the first hour. With this study we wish to examine whether the 
postprandial levels are capable of altering platelet function in vitro. We hypothesize that 
post prandial polyol concentrations following ingestion increase platelet aggregation in 
the blood.   
 
Glucose, as a naturally occurring sweetener, will serve as a control for this study. There 
is also evidence that glucose may increase platelet aggregation, allowing us to compare 
the degree of increased aggregation between the polyol sweeteners and glucose. (3)  
 
2.0 STUDY OBJECTIVES 
To assess platelet function before and after polyol exposure. 
 
3.0 STUDY DESIGN 
We will perform a prospective, non-blinded, 4-arm study. There will be up to 8 study 
visits depending on which arm the subject is assigned to. There will be three 
interventions: erythritol, xylitol, and glucose. Erythritol and glucose will each be used in 
one arm, xylitol will be used in two arms.  
 
At baseline, subjects will have fasting blood and urine samples collected. Subjects will 
then receive a drink (300mL of water containing either 30g of erythritol, 30g of xylitol, 5g 
of xylitol, or 30g of glucose) as a single oral dose. Blood and urine samples will be 
collected again on the same day at pre-determined intervals after ingestion of the 
sweetened water drink. Additional fasting blood and urine samples may be collected on 
subsequent days after drinking the artificially sweetened water as shown in the tables 
below. Subjects drinking xylitol (5g or 30g) may have 1 subsequent visit. Subjects 
consuming erythritol may have up to 7 subsequent visits. Subjects consuming glucose 
will have 1 study visit with blood and urine being collected about 30 minutes apart. All 
fasting collections will occur after an 8+ hour fast. 
 
Xylitol schedule (5g and 30g): 
  
Visit 1 
Day 1 
Visit 2 
Day 2 
Informed Consent 
X 
 
Brief Medical History Questionnaire 
X 
 
Vital Signs 
X 
 

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Baseline Fasting Blood Collection 
X 
X 
Baseline Fasting Urine Sample 
X 
X 
Drink Sweetened Water  
X 
 
30 minutes Post-drink Blood & Urine Collection* 
X 
 
1 hour Post-drink Blood & Urine Collection* 
X 
 
4 hours Post-drink Blood & Urine Collection* 
X 
 
6 hours Post-drink Blood & Urine Collection* 
X 
 
 
Erythritol schedule: 
 
Vital 
Signs 
Medical 
History 
Blood 
Draw 
Spot Urine 
Sample 
Baseline 
X 
X 
X 
X 
+ 30 minutes 
 
 
X 
X 
+ 2 hours* 
 
 
X 
X 
+ 6 hours* 
 
 
X 
X 
+ 24 hours (Day 2)* 
 
 
X 
X 
+ 48 hours (Day 3)* 
 
 
X 
X 
+ 72 hours (Day 4)* 
 
 
X 
X 
+ 96 hours (Day 5)* 
 
 
X 
X 
+ 168 hours (Day 8)* 
 
 
X 
X 
+ 216 hours (Day 10)* 
 
 
X 
X 
+ 264 hours (Day 12)* 
 
 
X 
X 
 
Glucose schedule: 
 
Vital 
Signs 
Medical 
History 
Blood 
Draw 
Spot Urine 
Sample 
Baseline 
X 
X 
X 
X 
+ 30 minutes 
 
 
X 
X 
* Laboratory schedules are subject to change as data is gathered. Subjects will be informed of lab 
schedule at time of consent. 
 
3.1 Study endpoints 
• Baseline plasma and urine fasting polyol or glucose 

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- Baseline and subsequent (after sweetener intake) changes in levels of 
polyol or glucose in plasma and urine as measured by established 
techniques by mass spectrometry.  
- Baseline and subsequent (after sweetener intake) changes in platelet 
function throughout the study using well established in vitro platelet 
assays. 
 
• Changes in markers of metabolism (e.g. lipid profile). 
 
 
4.0 SUBJECT SELECTION AND WITHDRAWAL  
There will be two study cohorts for the polyol arms. We will enroll healthy control 
subjects in the glucose arm. Subjects must meet the following inclusion/exclusion 
criteria to be eligible for the study. 
 
4.1 Cohort 1 Inclusion Criteria 
• Men and women age 18 years or above. 
• Able to provide informed consent and comply with study protocol. 
 
4.2 Cohort 1 Exclusion Criteria 
• Use of anti-platelet medications within 14 days of study enrollment. 
• Active infection or received antibiotics within 1 month of study enrollment. 
• Use of OTC probiotic within 1 month of study enrollment. 
• Diabetes Mellitus  
• Ulcerative colitis, Crohn’s disease, or other chronic gastrointestinal disorder. 
• Past history of bariatric procedures or surgeries (e.g. gastric banding or 
bypass). 
• Pregnancy. 
• Significant chronic illness. 
• Any condition that, in the judgment of the Investigator, would place a subject 
at undue risk by being enrolled in the trial or cause inability to comply with 
the trial. 
 
4.3 Cohort 2 Inclusion Criteria 

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• Men and women age 18 years or above. 
• Able to provide informed consent and comply with study protocol. 
• Diabetes Mellitus Type II 
 
4.4 Cohort 2 Exclusion Criteria 
• Use of anti-platelet medications within 14 days of study enrollment. 
• Active infection or received antibiotics within 1 month of study enrollment. 
• Use of OTC probiotic within 1 month of study enrollment. 
• Ulcerative colitis, Crohn’s disease, or other chronic gastrointestinal disorder. 
• Past history of bariatric procedures or surgeries (e.g. gastric banding or 
bypass). 
• Pregnancy. 
• Any condition that, in the judgment of the Investigator, would place a subject 
at undue risk by being enrolled in the trial or cause inability to comply with 
the trial. 
 
4.5 Subject Recruitment and Screening 
Subjects will be recruited from the Cleveland, OH area. Subjects will be 
recruited by several methods, including (but not limited to) posted 
advertisements, chart review, and personal interactions with patients in the 
cardiology outpatient departments at the Cleveland Clinic Foundation. All 
advertising materials used for this study will be approved by the Cleveland Clinic 
IRB prior to dissemination.  
 
4.6 Subject Consent 
Written consent will be obtained from all subjects prior to any study procedure 
being performed. Participants will be provided with a copy of the signed consent 
form.  Consent will also be documented in the subject’s medical record in EPIC. 
 
4.7 Early Withdrawal of Subjects 
Subjects may withdraw from the trial at any time and for any reason. Some 
possible reasons for early withdrawal include the following: 

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• Development of a medical condition or need for concomitant treatment that 
precludes further participation in the trial 
• Removal from the trial by the investigator in the best interests of the subject 
• Development of an active infection or starting an antibiotic treatment regimen 
• Study completion or discontinuation prior to participant completion 
• Subject withdraws consent to continued participation in the trial 
 
 
5.0 STUDY DRUG/FOOD ADDITIVE 
5.1 Description 
Erythritol and xylitol supplements:  The brand of supplements to be used is NOW 
Foods. These will be obtained from a commercial source, either Amazon.com or 
a pharmacy/store carrying this brand and stored as below. 
Glucose: The brand of glucose is NOW Foods. We will obtain from Amazon.com 
or a pharmacy/store carrying this brand. It will be stored at room temperature in a 
sealed bag. 
 
5.2 Treatment Regimen 
The study additive – erythritol, xylitol, or glucose – will be dissolved in 300mL of 
water and given to the subjects as a water solution to be taken all at once by 
mouth. The 300mL of water will contain either 30g of erythritol, 30g of xylitol, 5g 
of xylitol, or 30g of glucose depending on the intervention the subject is assigned 
to. 
 
5.3 Subject Compliance Monitoring 
Subjects will be observed taking their assigned intervention, either erythritol, xylitol, 
or glucose solution, by a study coordinator or other study personnel during their 
visit to ensure the subjects consume the entire beverage and are able to comply 
with the study procedures.  
 
5.4 Storage 
Erythritol, xylitol and glucose supplements will be stored at room temperature in a 
dry location. They will be kept locked in a secure location. Temperature will be 
monitored and recorded weekly to make sure that the temperature remains 
between 15° and 30° Celsius. 
 
 
6.0 STUDY PROCEDURES 

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This is a prospective pilot study. Up to 105 subjects will be enrolled in this pilot study, 
with a goal of having at least 12 subjects in each cohort of the polyol sweetener arms & 
12 subjects in the glucose arm complete the study. 
 
6.1 Study Visit Procedures 
• Blood Draws 
• Spot Urine collections 
• Medical History 
• Medication Review 
• Physical Exam including blood pressure, height, weight, and waist 
circumference 
 
 
7.0 STATISTICAL PLAN 
7.1 Sample Size Determination 
Based on previous research, we calculate that a sample size of 10 will provide us 
with a power of 0.9 to detect a significant difference between groups at a 
significance level of 0.05. However, we plan to enroll at least 15 subjects in each 
cohort in each arm in order to compensate for any unexpected occurrences or 
subject dropouts. 
 
7.2 Statistical Methods 
We plan to use standard descriptive statistics to characterize the overall study 
population of interest both at baseline and during follow-up. Summary statistics 
such as means, medians, standard deviations, and ranges will be produced for 
measured variables, and compared within and between groups with chi-square, 
Student t-test/Wilcoxon test, or ANOVA analysis as appropriate. Graphical 
methods will be used extensively to examine distributions, identify potential 
influential points, and guide in data transformations if warranted.  
 
 
8.0 SAFETY AND ADVERSE EVENTS 
8.1 Recording of Adverse Events  
At each contact with the subject, the investigator will seek information on adverse 
events by specific questioning and, as appropriate, by examination. Information 
on all adverse events will be recorded immediately in the source document. All 
clearly related signs, symptoms, and abnormal diagnostic procedures results will 
also be recorded in the source document.  

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All adverse events will be immediately reported to the primary investigators and 
to the IRB, per their procedures. The clinical course of each event will be 
followed until resolution, stabilization, or until it has been determined that the 
study treatment or participation is not the cause. Serious adverse events that are 
still ongoing at the end of the study period will be followed up to determine the 
final outcome. Any serious adverse event that occurs after the study period and 
is considered to be possibly related to the study treatment or study participation 
will be recorded and reported immediately. 
 
8.2 Serious/Unexpected Adverse Events 
Serious and unexpected adverse events will be reported to the Ethical 
Committee in accordance with institutional guidelines. In the case there would be 
any adverse events or unanticipated problems, an appropriate adverse event or 
unanticipated report form will be made and the Ethical Committee notified 
immediately. The study will also be stopped immediately if a subject would 
experience any unanticipated discomfort or adverse cardiac events (e.g. 
hospitalization). There will be no DMC and no interim analyses. 
 
 
9.0 DATA HANDLING AND RECORD KEEPING 
9.1 Confidentiality and Privacy 
Information about study subjects will be kept confidential and managed according 
to the Health Insurance Portability and Accountability Act of 1996 (HIPAA). 
Subjects will be informed of their rights and the privacy safeguards in place 
during the consent process. 
 
9.2 Data Management 
Study data will be collected and managed using REDCap (Research Electronic 
Data Capture).  REDCap is a secure, web application designed to support data 
capture for research studies, providing user-friendly web-based case report 
forms, real-time data entry validation (e.g. for data types and range checks), 
audit trails and a de-identified data export mechanism to common statistical 
packages (SPSS, SAS, Stata, R/S-Plus).   The system was developed by a multi-
institutional consortium which includes Cleveland Clinic and was initiated at 
Vanderbilt University.  The database is hosted at the Cleveland Clinic 
Datacenter.  The system is protected behind a login and Secure Sockets Layer 
(SSL) encryption. There is an audit trail tracking all logins and activities in the 
database. Data collection is customized for each study or clinical trial based on a 

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study-specific data dictionary defined by the research team with guidance from 
the REDCap administrator in Quantitative Health Sciences at the Cleveland 
Clinic.        
 
9.3 Records Retention 
All source documents, including the case report forms, will be kept for at least 6 
years following the completion of the study. Documents will be stored in a secure 
location with limited access.  
 
 
10.0 STUDY MONITORING, AUDITING AND INSPECTING 
10.1 Study Monitoring 
The Investigator will ensure that any monitor or other compliance or quality 
assurance reviewer is given access to all study-related documents and study 
related facilities, and that they have adequate space to conduct the monitoring 
visit. 
 
10.2  Auditing and Inspecting 
The investigator will permit study-related monitoring, audits, and inspections by 
the IRB, the sponsor, government regulatory bodies, and Institutional compliance 
and quality assurance groups of all study related documents (for example, 
source documents, regulatory documents, data collection instruments, study data 
etc.). The investigator will ensure the capability for inspections of applicable 
study-related facilities (for example, pharmacy, diagnostic laboratory, etc.). 
Participation as an investigator in this study implies acceptance of potential 
inspection by government regulatory authorities and applicable Institutional 
compliance and quality assurance offices. 
 
 
11.0 ETHICAL CONSIDERATIONS 
This study will be conducted according to US and international standards of Good 
Clinical Practice (FDA Title 21 part 312 and International Conference on Harmonization 
guidelines), applicable government regulations and Institutional research policies and 
procedures. 
 
This protocol and any amendments will be submitted to a properly constituted 
independent Institutional Review Board (IRB), in agreement with local legal 
prescriptions, for formal approval of the study conduct. The decision of the IRB 

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concerning the conduct of the study will be made in writing to the investigator before 
commencement of this study. 
 
 
12.0 REFERNCES 
 
1. Mäkinen KK. Gastrointestinal Disturbances Associated with the Consumption of Sugar 
Alcohols with Special Consideration of Xylitol: Scientific Review and Instructions for 
Dentists and Other Health-Care Professionals. Int J Dent. 2016;2016:5967907-. 
2. Oku T, Okazaki M. Laxative threshold of sugar alcohol erythritol in human subjects. Nutrition 
Research. 1996;16(4):577-89. 
3. Sudic D, Razmara M, Forslund M, Ji Q, Hjemdahl P, Li N. High glucose levels enhance 
platelet activation: involvement of multiple mechanisms. Br J Haematol. 2006 
May;133(3):315-22. doi: 10.1111/j.1365-2141.2006.06012.x. PMID: 16643434.