Association Between Food/Nutrient Intake and Sleep Quality in Middle Aged and Older Population
Conditions: Sleep
Sponsor: National University of Singapore

 
 
 
 
 
 
 
 
 
 
Study Title: 
Association between food/nutrient intake and 
sleep quality in middle aged and older population 
 
Study ID: NCT03554954 
 
 
 
 
 
Study Protocol 
31 October 2019 
 
 
 
 
 
 

 
 
STUDY PROTOCOL 
1. Specific Aims: 
The purpose of is research project is to assess the association between food/nutrient intake and 
pattern and sleep quality in middle-aged and older population.  
 
Specific aim 1: Will assess the associations among dietary protein intake, blood amino acid 
concentrations, and sleep quality  
Specific aim 2: Will assess the associations among fruit and vegetable intake, skin carotenoid status, 
and sleep quality 
 
2. Introduction: 
Sleep is essential to health and indexes of sleep including duration, quality, and patterning are related 
to the incidence of obesity, type 2 diabetes, cardiovascular disease, hypertension, and premature 
death. Changes in sleep patterns are a part of the aging process and as people age, they tend to have 
a harder time falling asleep and more trouble staying asleep than when they were younger. Certain 
cross-sectional studies have shown that food/nutrient intake may be associated with sleep duration, 
quality, and patterns. However, limited research examined the association between food/nutrient 
intake and indexes of sleep in middle-aged and older population. 
 
3. Preliminary Studies: 
Previously, Prof. Kim and colleagues found that the consumption of a greater proportion of energy 
from dietary protein while dieting may improve sleep quality in US overweight and obese adults. The 
results of the study suggest that the dietary protein intake may be associated with sleep quality in 
Singapore population.  
 
Ref: Zhou J, Kim JE, Armstrong CLH, Chen N, Campbell WW. Am J Clin Nutr. 103(3):766-74. 
 
4. Methodology: 
This is a cross-sectional study and participants require a 1-day visit. Generally healthy middle-aged 
and older population will be recruited and after the phone screening, validated participants will 
complete the medical history questionnaire and bring on the day of visit. During the visit, participants 
will stay approximately 3-h to complete the testing. After complete the consent form, fasting-state 
blood collection and general health assessment will be conducted. Then participants will be asked to 
complete the questionnaires to assess sleep quality dietary intake.  
 
On the testing day, participants will arrive at the NUHS Investigational Medicine Unit with 10-h 
overnight fast. After completing the consent form, fasting-state blood (20mL) will be collected by a 
certified phlebotomist and height, weight, waist circumference, blood pressure, and skin carotenoid 
status will be measured by trained research staffs. Once participants complete the health-related 
assessment, snack will be provided and trained research staffs will work with participants to complete 

 
 
the questionnaires including Pittsburgh Sleep Quality Index, lifestyle questionnaire, 3-day food record, 
and food frequency questionnaire to assess sleep quality dietary intake. The collected blood samples 
will be stored in -80°C, until they are ready to be analyzed.   
  
5. Subject Recruitment:  
This study will recruit 130 subjects from NUS and around Singapore over a period of 1.5 year. About 
103-130 subjects will be involved in this study. The following are the criteria of subjects that will be 
recruited for the study.  
 
Inclusion criteria 
 
1. Ability to give an informed consent 
2. Age ≥ 50 years 
3. Not taking dietary supplements which may impact the out of interests (i.e. dietary protein and 
vitamin supplements, and others)  
4. Did not have significant dietary changes for the past 1 year (i.e. weight loss, vegetarian diet, and 
others) 
5. Having sufficient venous access to allow the blood collection 
6. Willing to follow the study procedures  
 
Exclusion criteria 
 
1. Unable to give an informed consent 
2. Age < 50 years 
3. Taking dietary supplements which may impact the out of interests (i.e. dietary protein and vitamin 
supplements) 
4. Had significant dietary changes for the past 1 year 
5. Not having sufficient venous access to allow the blood collection 
6. Unwilling to follow the study procedures  
 
 

 
 
 
INFORMED CONSENT FORM 
 
1. Study Information 
 
Protocol Title: 
Association between food/nutrient intake and sleep quality in middle aged and older 
population 
 
Principal Investigator & Contact Details: 
Principal Investigator 
Dr. Khoo Chin Meng 
National University Hospital (S) Pte Ltd 
Department of Endocrinology 
5 Lower Kent Ridge Road 
Singapore 119074 
 
Email: mdckcm@nus.edu.sg   
 
Site Investigator (NUS) 
Dr. Gregory Chung Tsing Chan 
University Health Centre 
20 Lower Kent Ridge Rd. 
National University of Singapore 
Singapore 119080 
 
Email: gregchan@nus.edu.sg  
 
Co-Investigator (NUS) 
Assistant Professor Kim Jung Eun 
Food Science & Technology Programme 
c/o Department of Chemistry 
Block S14 level 6, S14-06-01 
3 Science Drive 3 
Lower Kent Ridge Road 
Singapore 117543 
 
Email: chmkje@nus.edu.sg 
 
 
 
 
 
 
 
 
 
 
 

 
 
Study Sponsor: 
NUS  
 
Sleep is essential to health.  Quality of sleep, measure through indexes of sleep, is related to 
the incidence of obesity, type 2 diabetes, cardiovascular disease, hypertension, and premature 
death. Sleep pattern changes as people age. They tend to have a harder time falling asleep 
and more trouble staying asleep than when they were younger. Studies have shown that 
food/nutrient intake may be associated with sleep duration, quality, and patterns. Singapore’s 
population is aging rapidly and improving their indexes of sleep may result in their health 
promotion.  
 
2. Purpose of the Research Study 
 
You are invited to participate in a research study.  It is important to us that you first take time 
to read through and understand the information provided in this sheet.  Nevertheless, before 
you take part in this research study, the study will be explained to you and you will be given 
the chance to ask questions. After you are properly satisfied that you understand this study, 
and that you wish to take part in the study, you must sign this informed consent form.  You will 
be given a copy of this consent form to take home with you. 
You are invited because we want to study the effect of nutrition on sleep quality. This study is 
carried out to find out the association between the food and nutrient intake and sleep quality 
in middle-aged and older adults. This study will recruit 130 subjects from NUS and around 
Singapore over a period of 1.5 year. About 103-130 subjects will be involved in this study.  
 
3. What procedures will be followed in this study  
 
If you take part in this study, you will be screened via phone according to the inclusion and 
exclusion criteria. Once your eligibility for the study is validated, you will send a medical history 
questionnaire by mail which will need to be completed and brought on the day of the visit. You 
will also be required to fast from 10pm the night before or from approximately 10-12hr prior to 
the study visit. During the visit the following procedures will be done: 
1. Sign the study consent form 
2. Fasting-state blood collection  
3. Anthropometric measurements: height, weight, waist circumference 
4. Blood pressure measurement 
5. Body composition measurement by measuring body impedance/electrical resistance.  
6. Skin scan by using a visible light scan (Raman Spectroscopy) to measure the level of 
carotenoid storage, indicator of fruits and vegetable intakes in the skin  
7. Dietary assessment via 24-hr recall and food frequency questionnaires (two additional 
24-hr dietary recall will be required after the study visit and sent back to our study 
team by either email or mail. Each 24-hr recall will take approximately 10 minutes to 
complete) 
Participants will be provided with a pre-paid envelope if they choose to send their two 
additional 24-hr dietary recall by mail. 
8. Sleep quality assessment via Pittsburgh Sleep Quality Index questionnaire and sleep 
evaluation questionnaire  
9. Perceived stress evaluation questionnaire 
In total, 20mL (4 teaspoons) of blood will be taken as part of this study. 

 
 
These procedures will be performed at the following address: 
Investigational Medical Unit (IMU) 
MD6 (Centre for Translational Medicine), level 7 
14 Medical Drive, Singapore 117599 
 
NUS Occupational Health Clinic 
20 Lower Kent Ridge Rd, Singapore 119080 
 
NUS Department of Chemistry 
6 Science Drive 2, Block 16, Singapore 117546 
 
With your consent, your research data and blood samples obtained during the course of this 
study will be stored for a minimum of 10 years in freezers owned by the research group in 
NUS, for use in this research study and general nutritional research. When the 10-year period 
ends, your blood sample and research data will be destroyed 
 
During the duration of the storage, your collected blood samples will NOT: 
1. Be used for future human biomedical research involving human-animal combinations 
2. Transferred outside of Singapore 
 
To ensure your privacy and confidentiality, your collected blood samples and research data 
will be coded and no subject identifiers will be attached to them Only the PI, Co-PI and 
assigned research staff of this study will have access to these codes identifying these research 
materials. Research data and biological samples will be used only for the current or future 
research.  
 
There will not be any incidental findings arising in this research. “Incidental findings” are 
findings that have potential health or reproductive importance to research participants like you 
and are discovered in the course of conducting the study, but are unrelated to the purposes, 
objectives or variables of the study. These findings may affect your current or future life and/or 
health insurance coverage  
 
However, there is a possibility that tests conducted in future research might unintentionally 
uncover new information about your health condition. These are considered as “incidental 
findings”. You will be asked to indicate whether you wish to be re-identified and notified in the 
case of a clinically significant incidental finding that is related to you.  
 
If you agree to be re-identified and notified, you will be advised to consult with a healthcare 
professional regarding this incidental finding. For this purpose, please inform the Principal 
Investigator or any of the study contact persons listed in this document whenever there are 
changes in your contact details. You may wish to do more tests and seek advice to confirm 
this incidental finding.  
 
The costs for any care that will be needed to diagnose or treat an incidental finding would not 
be paid for by this research study. These costs would be your responsibility. 
 
 
4. Your Responsibilities in This Study 
 
If you agree to participate in this study, you should follow the advice given to you by the study 
team.  You should be prepared to visit the hospital once and undergo all the procedures that 
are outlined above. 
 
 

 
 
5. What Is Not Standard Care or is Experimental in This Study 
 
The study is being conducted because the association of nutrition and sleep quality is not yet 
fully understood We hope that your participation will help us to assess the how nutrition may 
have the potential to improve a person’s sleep quality 
These procedure(s) are only being performed for the purposes of the research, and are not 
part of your routine care. 
 
6. Possible Risks and Side Effects 
 
As this is a cross-sectional study, no actual experimental procedure will be performed other 
than non-invasive measurements, filling out of questionnaires and blood collection. Although 
there may be potential human risks, they are minimal and the research group members will 
consistently pay attention to assure your safety. The risks of drawing blood include slight pain 
and bruising. Some people may also experience dizziness when drawing blood which will 
usually go away when the person lies down. In the unlikely event that you are injured, first aid 
and proper health treatment will be administered. In addition, the Raman Spectroscopy 
procedure used to scan the skin carotenoid status pose minimal risk as the scan is non-
invasive and done using visible light radiation for a short period of time (~30sec). Impedance 
measurements used for body composition measurement involves the application of alternating 
currents on the human body. As this is a commonly used method in health clinics and gyms to 
measure body composition and is non-invasive, it poses minimal risk.   
 
 
7. Possible Benefits from Participating in the Study 
 
 
There is no known benefit from participation in this study. However, your participation in this 
study may be used to design future research work targeted at improving the sleep quality for 
people aged 50 years and older 
 
8.. Costs & Payments if Participating in the Study 
 
You will be reimbursed $50 for your time, inconvenience and transportation costs by 
participating in this study. The participants will also be provided with a pre-paid envelope if 
they choose to send their two additional 24-hr dietary recall by mail. Research procedure will 
be performed at no cost to you as a participant.  
 
9. Voluntary Participation 
 
Your participation in this study is voluntary. You may stop participating in this study at any time. 
Your decision not to take part in this study or to stop your participation will not affect your 
medical care or any benefits to which you are entitled. If you decide to discontinue your 
participation in this study, you can notify us by calling (65) 6772 6174 and email 
mdckcm@nus.edu.sg, and we will, according to your request, terminate your further 
participation and/or destroy any data that has not been analyzed. However, you retain your 
right to ask the Principal Investigator to discard or destroy any remaining samples if the 
biological sample(s) is individually-identifiable and has not been used for the research/future 
research or it has been used for research but it is practicable to discontinue further use of the 
biological sample(s) for the research/future research. Withdrawal of participation in the study 
will prevent your collected information from contributing to further research and analysis, but it 
will not be possible to remove your data from analyses that has already been done. Your blood 
samples for this study will be considered to be gifted to NUS and will not be returned to you, 
however you may request us to destroy any unused samples that could identify you. You will 

 
 
also not have any right or claim to any share in the commercial gain derived from the research 
(if any). 
Your doctor, the Investigator and/or the Sponsor of this study may stop your participation in 
the study at any time if they decide that it is in your best interests. They may also do this if you 
do not follow instructions required to complete the study adequately. If you have other medical 
problems or side effects, the doctor and/or nurse will decide if you may continue in the research 
study.  
In the event of any new information becoming available that may be relevant to your willingness 
to continue in this study, you (or your legally acceptable representative, if relevant) will be 
informed in a timely manner by the Principal Investigator or his/her representative. 
 
 
10. Compensation for Injury 
 
In the unlikely event that you are physically injured during the process of this study, despite 
following the procedure carefully designed for this research, National University of Singapore 
(NUS) will pay the medical expenses for the treatment of the injury. By signing this consent 
form, you will not waive any of your legal rights or release the parties involved in this study 
from liability for negligence 
 
11. Confidentiality of Study and Medical Records 
 
The records of this study will be kept strictly confidential. Only the PI and authorized personnel 
will have immediate access to your identifiable information (e.g. names, contact, information, 
IC). Identifiable information will never be used in publication or presentation and all your 
identifiable health information and research data will be coded (i.e. only identified with a code 
number).  
All collected data will be kept in accordance to the University’s Research Data Management 
Policy. Research data used in the publication will be kept for a minimum of 10 years before 
being discarded.  
However, NUH, NUS and NHG Domain-Specific Review Board and Ministry of Health will be 
granted direct access to your original medical records to check study procedures and data, 
without making any of your information public. 
Any biological samples and/or information containing your “Personal Data” that is collected for 
the purposes described in this Informed Consent Form will not be transferred out of Singapore. 
“Personal Data” means data about you which makes you identifiable (i) from such data or (ii) 
from that data and other information which an organization has or likely to have access.  This 
includes medical conditions, medications, investigations and treatment history.  
Research arising in the future, based on this Personal Data, will be subject to review by the 
relevant institutional review board.  
Data collected and entered into the Case Report Forms are the property of NUS. In the event 
of any publication regarding this study, your identity will remain confidential. 
 
 
 
 
 

 
 
12. Who to Contact if You Have Questions 
If you have questions about this research study and/or in the case of any injuries during the 
course of this study, you may contact the following Principal Investigators: 
Principal Investigator 
Dr. Khoo Chin Meng 
National University Hospital (S) Pte Ltd 
Department of Endocrinology 
5 Lower Kent Ridge Road 
Singapore 119074 
 
Email: chin_meng_khoo@nuhs.edu.sg/ mdckcm@nus.edu.sg  
 
Site Investigator (NUS) 
Dr. Gregory Chung Tsing Chan 
University Health Centre 
20 Lower Kent Ridge Rd. 
National University of Singapore 
Singapore 119080 
 
Email: gregchan@nus.edu.sg  
Co- Investigator (NUS) 
Assistant Professor Kim Jung Eun 
Food Science & Technology Programme 
c/o Department of Chemistry 
Block S14 level 6, S14-06-01 
3 Science Drive 3 
Lower Kent Ridge Road 
Singapore 117543 
 
Email: chmkje@nus.edu.sg 
 
The study has been reviewed by the NHG Domain Specific Review Board (the central ethics 
committee) for ethics approval. 
If you want an independent opinion to discuss problems and questions, obtain information and 
offer inputs on your rights as a research subject, you may contact the NHG Domain Specific 
Review Board Secretariat at 6471-3266. You can also find more information about the NHG 
Domain Specific Review Board at www.research.nhg.com.sg.  
If you have any complaints or feedback about this research study, you may contact the 
Principal Investigator or the NHG Domain Specific Review Board Secretariat. 
 
 
 
 
 
 

 
 
13. Consent to be contacted for future research (Optional) 
You are being asked for permission to be contacted in the future for participation in research 
studies that you may be suitable for. If you agree to be contacted, your information and 
contact details will be entered and stored in a secured database in NUS. Your information 
and contact details will not be released to any parties outside NUS without your permission. 
When investigators from NUS identify you to be suitable for a particular research study, the 
investigators or authorised personnel from NUS will contact you to inform you about the 
research study. Your decision to be contacted for future research studies is completely 
voluntary and separate from your decision to participate in this study. Your decision will not 
affect your medical care or any benefits to which you are entitled. You may change your 
mind at any time by contacting Dr. Khoo Chin Meng at (65) 6772 6174 and email 
mdckcm@nus.edu.sg 

 
 
CONSENT FORM 
 
Protocol Title: 
Association between food/nutrient intake and sleep quality in middle aged and older 
population 
Principal Investigator & Contact Details: 
 
Principal Investigator 
Dr. Khoo Chin Meng 
National University Hospital (S) Pte Ltd 
Department of Endocrinology 
5 Lower Kent Ridge Road 
Singapore 119074 
 
Email: chin_meng_khoo@nuhs.edu.sg/ mdckcm@nus.edu.sg  
 
Site Investigator (NUS) 
Dr. Gregory Chung Tsing Chan 
University Health Centre 
20 Lower Kent Ridge Rd. 
National University of Singapore 
Singapore 119080 
 
Email: gregchan@nus.edu.sg  
 
Co-Investigator 
Assistant Professor Kim Jung Eun 
Food Science & Technology Programme 
c/o Department of Chemistry 
Block S14 level 6, S14-06-01 
3 Science Drive 3 
Lower Kent Ridge Road 
Singapore 117543 
 
Phone: (65) 6516 1136 
Email: chmkje@nus.edu.sg 
 
 
I voluntarily consent to take part in this research study.  I have fully discussed and 
understood the purpose and procedures of this study.  This study has been explained to me 
in a language that I understand. I have been given enough time to ask any questions that I 
have about the study, and all my questions have been answered to my satisfaction.  
 
By participating in this research study, I confirm that I have read, understood and consent to 
the NUS Data Protection Policy.  
 
 
 
 

 
 
I hereby acknowledge that: 
1. My signature is acknowledgement that I have agreed to take part in the above research 
2. I have received a study information sheet that explains the use of my blood and data in this 
research. I understand its contents and agreed to donate my blood and data for the purpose 
of this research.  
3. I can withdraw from the study at any point of time by informing the Principal Investigator 
and all my blood/tissue/data will be discarded if they have not been anonymized  
4. I will not have any financial benefits from participating in this study 
5. For the biological samples collected, please select any application options: 
  I agree to donate my coded biological samples collected for this research to be used 
in future research OR 
  I agree to donate my biological samples collected for this research to be used in future 
research. However, I would like all identifying information removed from my biological 
samples so that no one can link the sample to me OR 
  I agree to donate my biological samples collected for this research to be used in future 
research which may include testing and development by commercial firms. However, 
I would like all identifying information removed from my biological samples so that no 
one can link the sample to me OR 
 
  I do not agree consent to donate my biological samples collected for this research to 
be used in future research and would like to have my left-over biological samples 
destroyed after the completion of this research 
 
  I consent to have the coded data made available for future research 
 
6. Consent to be re-identified and notified in the case of an incidental finding. 
 
  I agree to be re-identified and notified in the case of an incidental finding from future 
research. In the event that I cannot be reached, please contact my next of kin.   
Name of next-of-kin: _______________________________________ 
 
Contact: _________________________________________________ 
  I do not agree to be re-identified and notified in the case of an incidental finding from 
future research  
 
 

 
 
7. Consent to be contacted for future research 
 
  I agree to be contacted for future research that I may be eligible for  
Phone: _______________________________________________ 
 
 
Mail: _________________________________________________ 
Email: ________________________________________________ 
Others: _______________________________________________ 
  I do not agree to be contacted for future research 
 
 
 
 
 ______________________  ____________________________   _________________  
Name of Participant 
Signature 
Date 
 
 
Witness Statement 
I, the undersigned, certify that: 
• 
I am 21 years of age or older 
• 
To the best of my knowledge, the participant/ the participant’s legally acceptable 
representative signing this informed consent form has the study fully explained in a 
language understood by him/ her and clearly understands the nature, risks and 
benefits of his/ her participation in the study. 
• 
I have taken reasonable steps to ascertain the identity of the participant/ the 
participant’s legally acceptable representative giving the consent. 
• 
I have taken steps to ascertain that the consent has been given voluntarily without 
any coercion or intimidation. 
 
 
 
 ______________________  ____________________________   _________________  
Name of Impartial Witness 
Signature 
Date 
 
 
Investigator Statement 
I, the undersigned, certify that I explained the study to the participant and to the best of my 
knowledge the participant signing this informed consent form clearly understands the nature, 
risks and benefits of his / her participation in the study. 
 
 
 
 ______________________  ____________________________   _________________  
Name of Investigator /  
Signature 
Date 
Person administering consent