Effects of WB-EMS and protein supplementation on body composition, physical function, metabolism and inflammatory biomarkers in middle-aged and elderly patients with sarcopenic obesity: A meta-analysis of randomized controlled trials

BACKGROUND The patients with sarcopenic obesity (SO) have the characteristics of both sarcopenia and obesity, that is, less muscle mass and increased fat mass, and their morbidity, disability and mortality are higher than patients with sarcopenia or obesity alone. OBJECTIVES To investigate the effects of whole-body electromyostimulation (WB-EMS) training and protein supplementation intervention on body composition, physical function, metabolism and inflammatory biomarkers in middle-aged and elderly patients with SO. METHODS We searched for randomized controlled trials in seven databases, including PubMed, Web of Science, Embase, Cochrane Library, Scopus, SinoMed, and CNKI as of July 3, 2021. The methodological quality of each included study was assessed using the Physiotherapy Evidence Database (PEDro) scale. The Cochrane Risk of Bias Tool was used to assess the risk of bias. Statistical analysis was performed using Review Manager 5.3. RESULTS Eleven randomized controlled studies with a total of 779 participants were included in this meta-analysis. WB-EMS training improved sarcopenia Z-score (MD = -1.52, 95 % CI: -2.27, -0.77, P < 0.0001) and waist circumference (WC) (MD = -1.41, 95 % CI: -2.62, -0.20, P = 0.02), and increased skeletal muscle mass index (SMI) (MD = 1.27, 95 % CI: 0.66,1.88, P < 0.0001) and appendicular skeletal muscle mass (ASMM) (MD = 0.68, 95 % CI: 0.08, 1.27, P = 0.03). Protein supplementation intervention reduced body fat rate (BF%) (MD = -1.28, 95 % CI: -1.88, -0.68, P < 0.0001, I2 = 0 %), total body fat (TBF) (MD = -0.98, 95 % CI: -1.65, -0.31, P = 0.004, I2 = 0 %) and trunk body fat mass (TBFM) (MD = -0.50, 95 % CI: -0.94, -0.06, P = 0.03, I2 = 0 %), and increased grip strength (GS) (MD = 1.13, 95 % CI: 0.06, 2.21, P = 0.04, I2 = 0 %). The combination of WB-EMS and protein supplements is beneficial to most body components and physical functions, such as SMI (MD = 1.21, 95 % CI: 0.73, 1.51, P < 0.00001, I2 = 0 %), GS (MD = 1.60, 95 % CI: 0.80, 2.40, P < 0.0001, I2 = 45 %) and walking speed (WS) (MD = 0.04, 95 % CI: 0.02, 0.06, P < 0.0001, I2 = 49 %). Compared with protein supplementation alone, WB-EMS could have an additional beneficial effect on BF% (MD = -0.92, 95 % CI: -1.80, -0.04, P = 0.04) and WC (MD = -1.03, 95 % CI: -1.70, -0.36, P = 0.003). Nevertheless, the addition of protein supplements did not provide any additional benefit compared with WB-EMS alone. In addition, there was almost no positive effect of WB-EMS and protein supplements on metabolic and inflammatory biomarkers. CONCLUSIONS As things stand, protein supplementation intervention can effectively reduce body fat percentage, fat mass, and increase grip strength in SO patients. Both WB-EMS and protein supplementation intervention had no significant effects on metabolic and inflammatory biomarkers. WB-EMS combined with protein supplementation intervention was beneficial for SO patients in many ways. Due to the small number of studies, further studies are needed to confirm the efficacy of WB-EMS alone or in combination with protein supplementation intervention in SO patients. REGISTRATION NUMBER INPLASY202190096 DOI:10.37766/inplasy2021.9.0096.