Effect of Multiple-Nutrient Supplement on Muscle Damage, Liver, and Kidney Function After Exercising Under Heat: Based on a Pilot Study and a Randomised Controlled Trial

Abstract

Objective: This study explored the effect of multiple-nutrient supplementation on muscle damage and liver and kidney function after vigorous exercise under heat. Methods: After an initial pilot trial comprising 89 male participants, 85 participants were recruited and assigned into three groups: a multiple-nutrient (M) group, a glucose (G) group, and a water (W) group. Multiple-nutrient supplements contain glucose, fructose, maltose, sodium, potassium, vitamin B₁, vitamin B₂, vitamin C, vitamin K, and taurine. Participants were organised to take a 3-km running test (wet-bulb globe temperature 32°C) after a short-term (7 days) supplement. Blood samples were obtained to detect biochemical parameters [glucose (GLU), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), uric acid (UA), creatinine (Cr), creatine kinase (CK), lactate dehydrogenase (LDH), and lactic acid], inflammation factors [interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)], and oxidative stress biomarkers [superoxide dismutase (SOD) and 8-iso-prostaglandin F (2alpha) (8-iso-PGF2α)]. Results: In the pilot trial, BUN decreased significantly in the M and G groups immediately after the running test. AST, Cr, and UA were significantly reduced 24 h after the running test with single-shot multiple-nutrient supplementation. In the short-term trial, multiple nutrients further prevented the elevation of CK (p = 0.045) and LDH (p = 0.033) levels 24 h after strenuous exercise. Moreover, we found that multiple nutrients significantly reduced IL-6 (p = 0.001) and TNF-α (p = 0.015) elevation immediately after exercise. Simultaneously, SOD elevation was significantly higher in the M group immediately after exercising than in the other two groups (p = 0.033). 8-iso-PGF2α was reduced in the M group 24 h after exercise (p = 0.036). Conclusions: This study found that multiple-nutrient supplementation promoted the recovery of muscle damage and decreased liver and kidney function caused by strenuous exercise in a hot environment, probably through the inhibition of secondary damage induced by increased inflammatory reactions and oxidative stress. In this respect, the current study has important implications for the strategy of nutritional support to accelerate recovery and potentially prevent heat-related illness. This study was prospectively registered on clinicaltrials.gov on June 21, 2019 (ID: ChiCTR1900023988).

Keywords: hot environment; inflammatory reaction; multiple nutrients; oxidative stress; recovery.

Figure 1

Time scheme of the single-shot supplement trial (pilot trial) (A) and short-term supplement trial (B).

Figure 2

Fatigue-related parameters of each group in the short-term supplement trial. Glucose levels before and after running test (A). Individual response of each group (B). Change in lactic acid levels at different time points (C). Values are mean ± SEM. PRE, prior running test; POST, immediately after running test. **Indicates p < 0.01. ++Indicates difference compared with PRE, p < 0.01.

Figure 3

Changes in biochemical parameters in the short-term supplement trial. Changes in AST (A), BUN (B), Cr (C), UA (D), CK (E), and LDH (F) levels in different experimental groups. Values are mean ± SEM. PRE, prior running test; POST, immediately after running test; REC, 24 h after running test. Change at POST equals POST minus PRE, change at REC equals REC minus PRE. *Indicates difference compared with water, p < 0.05. ^#Indicates a difference compared with glucose, p < 0.05. +Indicates difference compared with PRE, p < 0.05.

Figure 4

Changes in inflammatory factors and oxidative stress parameters in the short-term supplement trial. Changes in (interleukin 6) IL-6 (A), tumour necrosis factor-α (TNF-α) (B), 8-iso-prostaglandin F (2alpha) (8-iso-PGF2α) (C) and superoxide dismutase (SOD) (D) levels in different experimental groups. Values are mean ± SEM. PRE, prior running test; POST, immediately after running test; REC, 24 h after running test. Change at POST equals POST minus PRE, change at REC equals REC minus PRE. *Indicates difference compared with water, p < 0.05. ^#Indicates a difference compared with glucose, p < 0.05, ^##Indicates a difference compared with glucose, p < 0.01.

Figure 5

Elevation of running time after 7 days of supplementation in the short-term supplement trial. Values are mean ± SEM.