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SleepNCT05400005

Impact of Different Types of Higher Dietary Protein Intake on Sleep Quality in Singapore Older Adults

A study testing Dietary protein in people with Sleep and Gut Microbiome, run by National University of Singapore at 1 site in Singapore.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Today, insufficient sleep has become a growing global problem. Sleep is essential to health and changes in sleep patterns are a part of the aging process. Inadequate and low-quality sleep also increases the risk for age-related cognitive decline and disease conditions. Read more about this study

Who is it for?
Ages 60 to 85 yearsHealthy volunteers can take part
Conditions the study is for
Sleep, Gut Microbiome, Cardiometabolic Risk
What is being tested?
Dietary protein
Could I receive a placebo?
No, everyone receives an active treatment
How many people
54 participants
Where
1 siteSingapore
Study dates
1 Feb 2023to Dec 2025
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 60 to 85 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Adults 60-85 years old
  • Not following HPB diet

Who cannot join

  • Weight change > 3kg in the past 3 months
  • Exercise vigorously over the past 3 months
  • Drinking more than 2 alcoholic drinks per day
  • (if applicable) Pre-menopausal women
  • Taking dietary supplements or medications which may impact sleep outcomes (e.g. Nutritional Shakes (e.g. Ensure), Trp, 5-HTP or melatonin supplementations) the past 1 month
  • Taking dietary supplements which may impact the gut microbiota (e.g. antibiotics, prebiotics, probiotics) the past 2 months (a list of fermented foods)
Show all 10Show fewer
  • Impaired renal function (normal values: estimated glomerular filtration rate ≥ 90 mL/min/1.73 m2 calculated by chronic kidney disease epidemiology collaboration equation; CKD EPI)
  • Soy intolerance and/or allergy or any medical conditions that may be affected by consumption of soy products (e.g. gout)
  • Prescribed and taking antihypertensive/cholesterol-lowering/ type-2 diabetic medication or Chinese medicine herb which started less than 3 years prior to the intervention participation
  • Diagnosed with gut/gastrointestinal issues such as lactose intolerance and irritable bowel syndrome (IBS)

Trial locations and contacts

1 site in 1 country.

Singapore1 site
  • National University of Singapore

    Singapore, 117546

Other trials in Singapore

About this study

Today, insufficient sleep has become a growing global problem. Sleep is essential to health and changes in sleep patterns are a part of the aging process. Inadequate and low-quality sleep also increases the risk for age-related cognitive decline and disease conditions. More importantly, due to COVID-19 health emergency, there is a significant increase of psychological distress and symptoms of mental illness and a worsening of quality of sleep. Therefore, there is an urgent need to investigate the way of improving sleep quality, in particular during and post COVID-19 period, in older adults.

One of the possible strategies in improving sleep quality with lifestyle modification is having higher-protein diet. However, this effect has not been fully elucidated in older adults. In addition, the effect of type of dietary protein on sleep quality is inconclusive and there is no clinical trial which assessed the differential response in sleep quality between animal-sourced protein vs. plant-sourced protein. Therefore, the purpose of this research project is to assess the impact of different types of higher dietary protein intake on sleep quality in Singapore older adults.

Findings from the proposed research will provide the scientific evidence of the beneficial effects of regularly consuming higher-protein diet on sleep quality in Singapore older adults. In addition, this research may validate the differential effect of different type of dietary protein on sleep quality. The results from the proposed research will also assist a practical guidance of nutritional behaviour changes providing sleep promoting effects to a large proportion of the Singapore population.

Read the detailed description

During the 16-week intervention, subjects will be randomly assigned to 1 of 3 groups including consuming normal-protein diet, higher-protein diet supplemented with micellar casein protein or higher-protein diet supplemented with soy protein. Recommended Dietary Allowances for healthy Singaporean. Normal-protein diet will be designed following a healthy eating pattern diet, referred to as the "My Healthy Plate" launched by Health Promotion Board and subjects will consume 3 servings of dietary protein. Higher-protein diet will also follow a healthy eating pattern diet while subjects will additionally take either 20 g micellar casein protein isolate or 20 g soy protein isolate. One-on-one dietary counselling and written instructions for each subject will be provided by a research dietitian and trained research staff. Compliance with the diet interventions will be promoted by frequent online and in-person contact and dietary assessment. Blood amino acid concentration will also be assessed as an indicator of compliance to the protein intake.

Being tested
Dietary protein
Keywords
Dietary protein

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Dietary proteinOther

    Intervention of the study include consuming a higher protein diet. Depending on the group allocation, this is done by asking the subjects to follow "My Healthy Plate" diet and consumption of 20g of protein isolates (casein or soy).

Study groups in NCT05400005
Study groupRoleWhat they receive
Normal protein diet (control)No interventionSubjects are to consume normal-protein diet based on the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) for the duration of the 16-week study.
High protein diet (soy)ExperimentalSubjects are to consume higher-protein diet by following the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) and 20g of soy protein isolate for the duration of the 16-week study.
Receives: Other: Dietary protein
High protein diet (Micellar Casein)ExperimentalSubjects are to consume higher-protein diet by following the "My Healthy Plate" diet (launched by Health Promotion Board of Singapore) and 20g of micellar casein isolate for the duration of the 16-week study.
Receives: Other: Dietary protein

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in sleep quality assessed by validated sleep questionnaires

    Pittsburgh Sleep Quality Index Questionnaire (PSQI) will be used to assess the sleep quality. Overall score ranging from 0 to 21 points, where lower scores denote a healthier sleep quality.

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  2. Change in sleep quality assessed by electronic equipment

    An electronic equipment, actigraphy, will be used to assess the sleep quality, including sleep timing and wake up timing.

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  3. Change in blood amino acid concentration

    Amino acid concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  4. Change in blood serotonin concentration

    Serotonin concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  5. Change in urinary 6-sulfatoxymelatonin (aMT6s) concentration

    6-sulfatoxymelatonin (aMT6s) concentration in the urine samples will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

Secondary outcomes (27)
  1. Change in fecal microbiome composition

    High-throughput sequencing method (using Illumina MiSeq platforms) will be used to assess the changes in gut microbiome composition

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  2. Change in fecal short chain fatty acid (SCFA) concentration

    SCFA concentration in fecal samples will be measured.

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  3. Change in serum lipopolysaccharide binding protein (LBP) concentration

    LBP concentration in blood samples will be measured.

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  4. Change in blood short chain fatty acid (SCFA) concentration

    SCFA concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  5. Change in fecal bile acids

    Bile acids concentration will be determined from fecal samples of the subjects

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  6. Change in fecal zonulin

    Zonulin concentration will be determined from fecal samples of the subjects

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  7. Change in fecal calprotectin

    Calprotectin concentration will be determined from fecal samples of the subjects

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  8. Change in urinary creatinine concentration

    Creatinine concentration in the urine samples will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  9. Change in Estimated Glomerular Filtration Rate (eGFR)

    The estimated Glomerular Filtration Rate (eGFR) of the subjects will be measured from the blood

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  10. Change in Trimethylamine N-oxide (TMAO)

    Trimethylamine N-oxide (TMAO) concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  11. Change in Blood Glucose

    Glucose concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  12. Change in Blood Triglyceride

    Triglyceride concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  13. Change in Blood Cholesterol

    Total cholesterol concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  14. Change in Blood Low-density Lipoprotein-cholesterol (LDL)

    LDL concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  15. Change in Blood High-density Lipoprotein-cholesterol (LDL)

    HDL concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  16. Change in Blood Advanced Glycation End-product (AGEs)

    AGEs concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  17. Change in Skin Advanced Glycation End-product (AGEs)

    Using a scanner, the AGEs levels in the skin will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  18. Change in Blood Interleukin-6 (IL-6)

    Interleukin-6 (IL-6) concentration in the blood will be measured

    Measured: Every 8 weeks (week 0 , week 8 and week 16)

  19. Change in Endothelial Function

    Endothelial functions are determined by the function of endothelial progenitor cells

    Measured: Baseline and Post-intervention (week 0 and week 16)

  20. Change in Flow Mediate Dilation

    Flow mediate dilation (%)

    Measured: Baseline and Post-intervention (week 0 and week 16)

  21. Change in weight and height

    Weight (in kilograms) and height (in meters) will be combined to report BMI in kg/m^2

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  22. Change in waist circumference

    Waist circumference (in cm) will be measured

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  23. Change in blood pressure

    Systolic and diastolic blood pressure (in mmHg) will be measured by a blood pressure monitor.

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  24. Dietary assessment

    Dietary assessment will be assessed by 3-day dietary food record

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  25. Change in mood (stress)

    Perceived Stress Scale (PSS) will be used to assess the stress levels

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  26. Change in mood (depression)

    Geriatric Depression Scale (GDS) Assessment will be used to assess the depression status

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

  27. Change in mood (anxiety)

    Geriatric Anxiety Inventory (GAI) Assessment will be used to assess the anxiety status.

    Measured: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 Jun 2022
  2. Study start1 Feb 2023
  3. Primary completion22 Oct 2024
  4. Study completionDec 2025 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Factorial
Model description
This is a 16-week factorial study design with subjects randomly assigned to consume normal-protein diet, higher-protein diet with micellar casein protein isolates or higher-protein diet with soy protein isolates. Subjects' sleep quality will also be evaluated and screened using the PSQI questionnaire (GSS ≤5 \[good sleepers\] vs. GSS \>5 \[poor sleepers\]). Sixty-eight older men and women (aged 60-85y, approximately half men and half women) will be recruited with the expectation that ≥ 54 subjects (≥ 18 subjects per group) will complete the study (≤ 20% dropout rate). The 18 subjects recruited for each of the intervention group were further classified into poor (n=9) and good sleepers (n=9).
Masking
Double blind
Who is masked
Investigator, Outcomes assessor
Enrolment
54 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05400005
Sponsor's protocol ID
S19
Status last verified
Sep 2025
First submitted
27 May 2022
Last updated
10 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Electronic copies of the data with identifiable participant information will be kept on a secure website with access limited to Dr. Kim and her research staff. All data will be de-identified prior to statistical analyses.

Publications

  • Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010 May;33(5):585-92. doi: 10.1093/sleep/33.5.585.

    PubMed 20469800
  • Sutanto CN, Wang MX, Tan D, Kim JE. Association of Sleep Quality and Macronutrient Distribution: A Systematic Review and Meta-Regression. Nutrients. 2020 Jan 2;12(1):126. doi: 10.3390/nu12010126.

    PubMed 31906452
  • Zhou J, Kim JE, Armstrong CL, Chen N, Campbell WW. Higher-protein diets improve indexes of sleep in energy-restricted overweight and obese adults: results from 2 randomized controlled trials. Am J Clin Nutr. 2016 Mar;103(3):766-74. doi: 10.3945/ajcn.115.124669. Epub 2016 Feb 10.

    PubMed 26864362
  • Saidi O, Rochette E, Dore E, Maso F, Raoux J, Andrieux F, Fantini ML, Merlin E, Pereira B, Walrand S, Duche P. Randomized Double-Blind Controlled Trial on the Effect of Proteins with Different Tryptophan/Large Neutral Amino Acid Ratios on Sleep in Adolescents: The PROTMORPHEUS Study. Nutrients. 2020 Jun 24;12(6):1885. doi: 10.3390/nu12061885.

    PubMed 32599773
  • St-Onge MP, Crawford A, Aggarwal B. Plant-based diets: Reducing cardiovascular risk by improving sleep quality? Curr Sleep Med Rep. 2018 Mar;4(1):74-78. Epub 2018 Feb 5.

    PubMed 29910998
  • Ting M, Mak IEK, Yao Y, Chng ASM, Khoo CM, Kim JE. Investigating the Impact of Protein Supplementation from Different Sources on Advanced Glycation End Products in Older Adults in Singapore Following a Healthy Dietary Pattern. Nutrients. 2026 Sep 7;18(17):2925. doi: 10.3390/nu18172925.

    PubMed 42739097
  • Yao Y, Mak IE, Sutanto CN, Leong ZN, He Q, Pahwa U, Ling LH, Khoo CM, Ackers-Johnson MA, Foo RS, Kim JE. Impact of quantity and source of dietary protein intake within a healthy dietary pattern on cardiovascular disease risk factors in Singapore older adults: a randomized controlled trial. Food Funct. 2025 Dec 8;16(24):9533-9544. doi: 10.1039/d5fo03817k.

    PubMed 41284351

Questions about this trial

What is this clinical trial studying?

A study testing Dietary protein in people with Sleep and Gut Microbiome, run by National University of Singapore at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 10 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in sleep quality assessed by validated sleep questionnaires (time frame: Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05400005, which also lists 7 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Sep 2025.

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