Protein Supplementation Intervention for Improving Muscle Mass and Physical Performance in Older People With Sarcopenia

Background: Sarcopenia is defined as an abnormal loss of muscle mass and strength. Declines in muscle mass and strength are expected with aging, but physical inactivity and low protein intake have been suggested as risk factors of sarcopenia. Recently, Taiwan is known as the fastest-aging nation in the world, and the prevalence of sarcopenia has been reported as 3.9-7.3%; even more 9-64% in Dr. Chen's study. So far, lifestyle interventions, especially exercise and nutritional supplementation, prevail as mainstays of treatment for sarcopenia.

Objective: To explore the effect and benefits of protein supplementation on the improvement of muscle mass and physical performance in older people with sarcopenia.

Study design: A randomized, double-blind, placebo-controlled clinical trial which will be conducted between September and November, 2020.

Participants: The study will be conducted in Keelung, Taiwan. A total of 9 day-care centers, including 180 over 65 years of residents, will be invited to participate the study via telephone calls.

Eligible participants will be invited to attend this randomized, double-blind, placebo-controlled, 2-parallel-groups trial, and will be randomly assigned to the experimental and control groups with 1:1 ratio.

Intervention: The intervention period will be 12 weeks. The control group will receive 150c.c placebo oat drink (1.5g protein, 0.5g fat, 0.1g carbohydrate each pack, Zhan Xuan Co. Ltd., Taiwan) per day, five days per week, while the experimental group will receive 150c.c protein supplementation drink (14g protein, 0.6g fat, 7g carbohydrate, 4.4 g BCAA , 2.4g glutamate, 0.5g arginine and 0.4g taurine each pack, Affix Health, Taiwan Branch) per day, five days per week.

Supplementation in the experimental group contains 90 kcal/d and the placebo oat drink contains 8.3kcal/d. Participants in the control group will be asked to maintain participants' usual diet and physical activity. There are 3 time-points to measure outcomes and observe other required information, at week 0(baseline), 6 and 12.

Sample size calculation: Referring to the setting in a published paper that gave a sample size of 30 participants/group, a sample size of 40 participants in each group is considered in the study, by considering potential dropouts.

Random assignment and blinding: An independent external researcher prepared a computer generated cluster random sampling. After random assignment, the external researcher newly assigned a subject ID to each participant. All other study personnel and participants remained blinded to the identity codes throughout the course of the study. When participants withdrew from or completed the study, researchers were provided with the participants' identities, and the participants were told what supplement participants had received.

Ethical approval: The study was approved by Taipei Hospital Human Trial Committee of the Ministry of Health and Welfare. All participants were assured that data collected from participants would be strictly confidential, and the physical condition and safety were given priority. Investigators conducted intervention only after obtaining participants ethical approval (registration number: TH-IRB-00190046). Anyone who feel uncomfortable during the study will be allowed to quit immediately with no any restriction.

Study measurement: Kihon Checklist, MNA, GDS-SF, SPPB, IADL, MMSE, handgrip, 6m gait speed, (SMI), SF-12 questionnaire and Tw-FROP-Com.

Statistical methods: Statistical analysis was conducted using the IBM SPSS software (version 22, IBM Corporation, New York, NY). An intention-to-treat analysis was performed. (1) Descriptive statistics: describe the distribution of category variables by number and percentage, and the mean and standard deviations describe the distribution of continuous variables. (2) Inference statistics: chi-square: to verify whether the pre-measured category variants between the experimental group and the control group are homogeneous. ANOVA: Check whether the continuous variables measured between the experimental group and the control group are homogeneous. Generalized estimating equations (GEE) with interactions of time and group in the models will be conducted to evaluate the intervention effect. A two-sided p-value < 0.05 is considered statistically significant.