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Active, Not Recruiting

NCT Number: NCT05400005

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

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Sleep Cardiometabolic Risk Gut Microbiome

Age range

60 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

National University of Singapore

Singapore, 117546

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

  • 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)
  • 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)

Treatment and study plan

Dietary Protein

Other

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).

Primary outcomes

  1. 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)

    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.

  2. Change in sleep quality assessed by electronic equipment

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

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

  3. Change in blood amino acid concentration

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Amino acid concentration in the blood will be measured

  4. Change in blood serotonin concentration

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Serotonin concentration in the blood will be measured

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

Secondary outcomes

  1. Change in fecal microbiome composition

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    SCFA concentration in fecal samples will be measured.

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    LBP concentration in blood samples will be measured.

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    SCFA concentration in the blood will be measured

  5. Change in fecal bile acids

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

  6. Change in fecal zonulin

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Zonulin concentration will be determined from fecal samples of the subjects

  7. Change in fecal calprotectin

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Calprotectin concentration will be determined from fecal samples of the subjects

  8. Change in urinary creatinine concentration

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Creatinine concentration in the urine samples will be measured

  9. Change in Estimated Glomerular Filtration Rate (eGFR)

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

  10. Change in Trimethylamine N-oxide (TMAO)

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

  11. Change in Blood Glucose

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Glucose concentration in the blood will be measured

  12. Change in Blood Triglyceride

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Triglyceride concentration in the blood will be measured

  13. Change in Blood Cholesterol

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    Total cholesterol concentration in the blood will be measured

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    LDL concentration in the blood will be measured

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    HDL concentration in the blood will be measured

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

    AGEs concentration in the blood will be measured

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

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

    Time frame: Every 8 weeks (week 0 , week 8 and week 16)

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

  19. Change in Endothelial Function

    Time frame: Baseline and Post-intervention (week 0 and week 16)

    Endothelial functions are determined by the function of endothelial progenitor cells

  20. Change in Flow Mediate Dilation

    Time frame: Baseline and Post-intervention (week 0 and week 16)

    Flow mediate dilation (%)

  21. Change in weight and height

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

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

  22. Change in waist circumference

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

    Waist circumference (in cm) will be measured

  23. Change in blood pressure

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

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

  24. Dietary assessment

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

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

  25. Change in mood (stress)

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

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

  26. Change in mood (depression)

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

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

  27. Change in mood (anxiety)

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

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

Sponsors and collaborators

Lead sponsor

National University of Singapore

Other

Registry information

Important dates

Study start
2023
Primary completion
2024
Study completion
2025
First posted
Jun 1, 2022
Registry last updated
Sep 10, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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