The increase in core body temperature in response to exertional-heat stress can predict exercise-induced gastrointestinal syndrome

Figures & data

Figure 1. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of I-FABP in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 2. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of sCD14 in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 3. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of IL-6 in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 4. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of IL-8 in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 5. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of IL-10 in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 6. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of IL-1ra in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 7. Association between M-T_re (a) and Δ T_re (b) with plasma concentrations of SIR-Profile in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Figure 8. Association between M-T_re (a) and Δ T_re (b) with total exercise-associated gastrointestinal symptoms in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

Table 1. Association between M-T_re and Δ T_re with plasma concentrations of EIGS epithelial integrity and systemic inflammatory biomarkers in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

		Mean	95% CI Lower	Upper	n	M-Tre rs	p	Δ Tre rs	p
I-FABP	(pg·mL^−1)	1083	881	1285	128	.430	<.001	.305	<.001
LBP	(ng·mL^−1)	1573	953	2194	83	.040	.720	.148	.183
sCD14	(ng·mL^−1)	400	213	586	87	.358	<.001	.362	<.001
IgM	(MMU·mL^−1)	26.0	11.4	40.6	88	.011	.921	.031	.776
TNFα	(pg·mL^−1)	3.3	1.9	4.6	117	.030	.746	.046	.625
IL-1β	(pg·mL^−1)	1.3	0.5	2.1	117	.002	.979	.007	.941
IL-6	(pg·mL^−1)	5.8	3.8	7.8	117	.242	.009	.233	.012
IL-8	(pg·mL^−1)	4.5	3.0	5.9	117	.200	.030	.112	.228
IL-10	(pg·mL^−1)	35.0	24.3	45.8	102	.629	<.001	.501	<.001
IL-1ra	(pg·mL^−1)	29.4	19.8	39.0	102	.374	<.001	.266	.007
SIR Profile	(arb.units)	76.7	59.2	99.9	102	.523	<.001	.418	<.001

Table 2. Association between M-T_re and Δ T_re with exercise-associated gastrointestinal symptoms (Ex-GIS) in response to 2 h of strenuous running exercise in temperate (20–30°C) and hot (~35°C) ambient conditions.

	Mean^#	Individual responses (lower and upper)^##		n	M-Tre rs	p	Δ Tre rs	p
Total-GIS	5	1	68	131	.261	.003	.197	.024
Upper-GIS	2	1	36	131	.384	<.001	.269	.002
Lower-GIS	1	1	31	131	.173	.048	.175	.046
Nausea	1	1	16	131	.105	.232	.037	.673

^#Summative accumulation of measured time points, ^## individual range of participants reporting incidence of GIS.

Table 3. Magnitude of prediction of change in plasma concentrations of EIGS epithelial integrity, systemic inflammatory biomarkers, and exercise-associated gastrointestinal symptoms (Ex-GIS) in response to 2 h of strenuous running exercise in temperature (20–30°C) and hot (~35°C) ambient conditions.

	Adjusted R^2	F	df	p
M-Tre
I-FABP	.164	12.0	2, 123^a	<.001
LBP	−.012	0.1	1, 78	.774
sCD14	.249	14.7	2, 81^b	<.001
IgM	−.012	0.0	1, 81	.925
TNFα	−.019	0.1	2, 97^a	.932
IL-1β	−.017	2.5	1, 83	.119
IL-10	.424	35.9	2, 93^a	<.001
IL-1ra	.126	14.2	1, 90	<.001
SIR Profile	.312	22.8	2, 94^a	<.001
Total-GIS	.124	11.6	1, 74	<.001
Upper-GIS	.118	7.0	1, 44	.011
Lower-GIS	−.032	0.1	1, 29	.787
Nausea	.191	2.9	2, 14^c	.089
Δ Tre
I-FABP	.058	4.7	2, 119^a	.011
LBP	−.001	1.0	1, 75	.310
sCD14	.214	11.8	2, 77^b	<.001
IgM	−.011	0.1	1, 81	.756
TNFα	−.020	0.1	2, 93^a	.947
IL-1β	−.019	2.5	1, 80	.116
IL-10	.263	17.1	2, 88^a	<.001
IL-1ra	.037	4.3	1, 85	.041
SIR Profile	.166	10.0	2, 89^a	<.001
Total-GIS	.104	9.4	1, 71	.003
Upper-GIS	.105	6.2	1, 43	.017
Lower-GIS	−.034	0.0	1, 29	.957
Nausea	.132	2.1	2, 13^c	.157

^amultiple regression analysis with variation in heart rate during exercise-confounding factor, ^bmultiple regression analysis with fitness status (VO₂max) confounding factor, and ^cmultiple regression analysis with hydration status (plasma osmolality) confounding factor.