Essential Amino Acid and Tea Catechin Supplementation after Resistance Exercise Improves Skeletal Muscle Mass in Older Adults with Sarcopenia: An Open-Label, Pilot, Randomized Controlled Trial

Figures & data

Figure 1. A flow chart showing the study participants.

We randomly allocated participants with sarcopenia to one of the following three groups: completing the exercise intervention alone (RE group), completing the exercise intervention followed by amino acid ingestion (RE + EAA group), and completing the exercise intervention followed by amino acid and tea catechin supplementation (RE + EAA + TCC group)

Table 1. Pre-intervention clinical characteristics of participants.

	RE group (n = 15)	RE + EAA group (n = 15)	RE + EAA + TCC group (n = 16)	p value
Age (years)	79.0 (77.0, 80.0)	78.0 (77.0, 79.0)	79.0 (77.0, 80.3)	0.892
Male/Female (n)	2/13	2/13	2/14	0.997
BMI (kg/m^2)	20.3 (19.2, 20.6)	19.3 (19.1, 20.5)	20.2 (19.1, 20.8)	0.523
Calf circumference (cm)	28.0 (26.8, 28.8)	28.0 (26.9, 29.5)	28.6 (27.0, 29.5)	0.792
MNA-SF (score)	10.0 (8.5, 11.0)	11.0 (9.5, 12.0)	9.5 (8.5, 11.0)	0.663
Physical activity level	1.56 (1.54, 1.57)	1.55 (1.54, 1.57)	1.54 (1.51, 1.55)	0.364
SMM (kg)	18.0 (16.3, 18.2)	17.2 (16.4,17.7)	17.4 (16.3, 18.3)	0.885
Grip strength (kg)	15.1 (13.7, 15.9)	14.8 (12.6, 13.0)	13.9 (12.1, 16.1)	0.658
Knee extension strength (kg)	15.4 (13.2, 16.5)	14.5 (13.3, 15.2)	14.7 (12.4, 17.3)	0.845
Gait speed (m/sec)	0.98 (0.94, 1.07)	1.04 (0.94, 1.11)	0.99 (0.96, 1.01)	0.584
Physical QOL (score)	40.6 (38.3, 43.8)	43.1 (41.9, 45.6)	43.1 (38.4, 45.5)	0.296
Mental QOL (score)	48.5 (46.2, 51.2)	49.5 (46.4, 49.7)	51.2 (47.2, 54.6)	0.493
Total energy intake (kcal/kg IBW/day)	28.6 (27.8, 29.1)	28.0 (27.3, 29.6)	28.7 (27.6, 29.1)	0.911
Total protein intake (g/kg IBW/day)	1.01 (0.99, 1.05)	1.08 (1.03, 1.12)	0.99 (0.97, 1.05)	0.088

Median (25 percentile, 75 percentile), one-way repeated ANOVA and chi-square test.

RE, resistance exercise; EAA, essential amino acid; TCC, tea catechin; BMI, body mass index; MNA-SF, Mini Nutritional Assessment-Short Form; SMM, skeletal muscle mass; QOL, quality-of-life; IBW, ideal body weight.

Table 2. Pre- and post-intervention comparison of primary and secondary outcome.

	RE group (n = 15)		RE + EAA group (n = 15)		RE + EAA +TCC group (n = 16)		p value two-way repeated ANOVA
	Pre	Post	Pre	Post	Pre	Post	Interaction
SMM (kg)	18.0 (16.3, 18.2)	18.1 (16.3, 18.5)	17.2 (16.4, 17.7)	17.5 (16.6, 18.1)**	17.4 (16.3, 18.3)	18.0 (16.8, 18.7)**	0.010
Grip strength (kg)	15.1 (13.7, 15.9)	15.8 (14.2, 16.2)	14.8 (12.6, 13.0)	14.0 (13.0, 17.5)	13.9 (12.1, 16.1)	14.9 (12.4, 17.3)	0.732
Knee extension strength (kg)	15.4 (13.2, 16.5)	16.6 (14.5, 17.6)*	14.5 (13.3, 15.2)	15.6 (14.5, 17.0)*	14.7 (12.4, 17.3)	16.9 (13.0, 19.9)*	0.532
Gait speed (m/sec)	0.98 (0.94, 1.07)	0.98 (0.94, 1.06)	1.04 (0.94, 1.11)	1.03 (0.91, 1.11)	0.99 (0.96, 1.01)	1.00 (0.98, 1.05)*	0.270
Physical QOL (score)	40.6 (38.3, 43.8)	43.0 (40.8, 45.2)*	43.1 (41.9, 45.6)	45.6 (45.1, 46.3)***	43.1 (38.4, 45.5)	43.2 (42.6, 46.7)*	0.961
Mental QOL (score)	48.5 (46.2, 51.2)	47.8 (44.5, 50.5)	49.5 (46.4, 49.7)	48.3 (46.4, 49.5)	51.2 (47.2, 54.6)	52.4 (48.4, 53.5)	0.857
	RE group (n = 15)		RE + EAA group (n = 15)		RE + EAA +TCC group (n = 16)		p valueone-way repeated ANOVA
% Δ SMM	1.49 (0.59, 2.35)		1.53 (0.51, 2.25)		3.47 (1.72, 4.07)†		0.010
% Δ Grip strength	2.38 (0.00, 6.48)		2.25 (-0.17, 7.86)		7.18 (0.95, 9.47)		0.798
% Δ Knee extension strength	3.74 (2.27, 6.70)		10.1 (-1.88, 14.1)		12.5 (-6.46, 15.1)		0.680
% Δ Gait speed	−0.24 (-1.94, 0.00)		0.00 (-2.86, 4.66)		2.56 (-0.66, 3.74)		0.180
% Δ Physical QOL	8.68 (-3.01, 13.29)		5.94 (0.00, 9.02)		6.01 (-0.28, 11.30)		0.964
% Δ Mental QOL	−3.19 (-5.03, 0.90)		−2.27 (-7.40, 0.00)		−0.42 (-3.90, 3.33)		0.815

Median (25 percentile, 75 percentile). Pre vs. Post; Wilcoxon-signed-rank-test, *p < 0.05, **p < 0.01, ***p < 0.001.

Main effect × Interaction; two-way repeated ANOVA. vs between-group; Post hoc-test; RE vs RE + EAA + TCC, †<0.05.

RE, resistance exercise; EAA, essential amino acid; TCC, tea catechin; SMM, skeletal muscle mass; QOL, quality-of-life.

Data availability statement

All data sets generated during and/or analyzed during the current study are not publicly available. However, date sets are available from the corresponding author upon reasonable request.