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.

Study Overview

• Status: Recruiting
• Conditions: Sleep; Cardiometabolic Risk; Gut Microbiome
• Intervention / Treatment: Other: Dietary protein

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.

• Study Type: Interventional
• Enrollment (Estimated): 54
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Clarinda N Sutanto, PhD; Phone Number: 65 83787674; Email: cnsfst@nus.edu.sg
• Study Contact Backup: Name: Jung Eun Kim, PhD; Phone Number: 65 6516 1136; Email: fstkje@nus.edu.sg

Study Locations

• Singapore
  • Singapore, Singapore, 117546
    • Recruiting
    • National University of Singapore
    • Contact: Clarinda N Sutanto, PhD; Phone Number: 65 83787674; Email: cnsfst@nus.edu.sg
    • Principal Investigator: Ian Mak, B.Sc. (Hons)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Adults 60-85 years old
2. Not following HPB diet

Exclusion Criteria:

1. Weight change > 3kg in the past 3 months
2. Exercise vigorously over the past 3 months
3. Drinking more than 2 alcoholic drinks per day
4. (if applicable) Pre-menopausal women
5. 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
6. Taking dietary supplements which may impact the gut microbiota (e.g. antibiotics, prebiotics, probiotics) the past 2 months (a list of fermented foods)
7. 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)
8. Soy intolerance and/or allergy or any medical conditions that may be affected by consumption of soy products (e.g. gout)
9. 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
10. Diagnosed with gut/gastrointestinal issues such as lactose intolerance and irritable bowel syndrome (IBS)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Normal protein diet (control); Subjects 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.
Experimental: High protein diet (soy); Subjects 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.	Other: Dietary protein; 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).
Experimental: High protein diet (Micellar Casein); Subjects 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.	Other: Dietary protein; 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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
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.	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in blood amino acid concentration	Amino acid concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in blood serotonin concentration	Serotonin concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in urinary 6-sulfatoxymelatonin (aMT6s) concentration	6-sulfatoxymelatonin (aMT6s) concentration in the urine samples will be measured	Every 8 weeks (week 0 , week 8 and week 16)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fecal microbiome composition	High-throughput sequencing method (using Illumina MiSeq platforms) will be used to assess the changes in gut microbiome composition	Every 8 weeks (week 0 , week 8 and week 16)
Change in fecal short chain fatty acid (SCFA) concentration	SCFA concentration in fecal samples will be measured.	Every 8 weeks (week 0 , week 8 and week 16)
Change in serum lipopolysaccharide binding protein (LBP) concentration	LBP concentration in blood samples will be measured.	Every 8 weeks (week 0 , week 8 and week 16)
Change in blood short chain fatty acid (SCFA) concentration	SCFA concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in fecal bile acids	Bile acids concentration will be determined from fecal samples of the subjects	Every 8 weeks (week 0 , week 8 and week 16)
Change in fecal zonulin	Zonulin concentration will be determined from fecal samples of the subjects	Every 8 weeks (week 0 , week 8 and week 16)
Change in fecal calprotectin	Calprotectin concentration will be determined from fecal samples of the subjects	Every 8 weeks (week 0 , week 8 and week 16)
Change in urinary creatinine concentration	Creatinine concentration in the urine samples will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Estimated Glomerular Filtration Rate (eGFR)	The estimated Glomerular Filtration Rate (eGFR) of the subjects will be measured from the blood	Every 8 weeks (week 0 , week 8 and week 16)
Change in Trimethylamine N-oxide (TMAO)	Trimethylamine N-oxide (TMAO) concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Glucose	Glucose concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Triglyceride	Triglyceride concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Cholesterol	Total cholesterol concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Low-density Lipoprotein-cholesterol (LDL)	LDL concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood High-density Lipoprotein-cholesterol (LDL)	HDL concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Advanced Glycation End-product (AGEs)	AGEs concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Skin Advanced Glycation End-product (AGEs)	Using a scanner, the AGEs levels in the skin will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Blood Interleukin-6 (IL-6)	Interleukin-6 (IL-6) concentration in the blood will be measured	Every 8 weeks (week 0 , week 8 and week 16)
Change in Endothelial Function	Endothelial functions are determined by the function of endothelial progenitor cells	Baseline and Post-intervention (week 0 and week 16)
Change in Flow Mediate Dilation	Flow mediate dilation (%)	Baseline and Post-intervention (week 0 and week 16)
Change in weight and height	Weight (in kilograms) and height (in meters) will be combined to report BMI in kg/m^2	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in waist circumference	Waist circumference (in cm) will be measured	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in blood pressure	Systolic and diastolic blood pressure (in mmHg) will be measured by a blood pressure monitor.	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Dietary assessment	Dietary assessment will be assessed by 3-day dietary food record	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in mood (stress)	Perceived Stress Scale (PSS) will be used to assess the stress levels	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in mood (depression)	Geriatric Depression Scale (GDS) Assessment will be used to assess the depression status	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)
Change in mood (anxiety)	Geriatric Anxiety Inventory (GAI) Assessment will be used to assess the anxiety status.	Every 4 weeks (week 0, week 4, week 8, week 12 and week 16)

Collaborators and Investigators

• Sponsor: National University of Singapore
• Investigators: Principal Investigator: Jung Eun Kim, PhD, National University of Singapore

Publications and helpful links

General 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.
• 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.
• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2022
• Primary Completion (Estimated): August 31, 2024
• Study Completion (Estimated): March 31, 2025

Study Registration Dates

• First Submitted: May 27, 2022
• First Submitted That Met QC Criteria: May 27, 2022
• First Posted (Actual): June 1, 2022

Study Record Updates

• Last Update Posted (Actual): March 21, 2024
• Last Update Submitted That Met QC Criteria: March 19, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: Dietary protein
• Other Study ID Numbers: S19

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No