Effects of duration of stay in temperate area on thermoregulatory responses to passive heat exposure in tropical south-east Asian males residing in Japan

Table 2 Physiological responses to 60 minutes of leg immersion of subjects in the tropical Asian group (TR, TR-S, TR-L) and the Japanese group (JP) ¹

Variable	TR-S,²n = 5	TR-L, n = 7	TR. n = 12	JP, n = 12
Initial T_re,°C	37.02 ± 0.14^c	36.98 ± 0.06^c	37.00 ± 0.06^d	36.74 ± 0.04
Final T_re,°C	37.62 ± 0.12	37.49 ± 0.08	37.53 ± 0.08	37.46 ± 0.07
ΔT_re,°C	+0.60 ± 0.07^e	+0.51 ± 0.07^e	+0.53 ± 0.06^c	+0.72 ± 0.05
Initial ${\bar{T}}_{sk}$ ,°C	33.29 ± 0.12	33.37 ± 0.15	33.33 ± 0.10	33.43 ± 0.06
Final ${\bar{T}}_{sk}$ ,°C	35.09 ± 0.18	35.20 ± 0.33	35.15 ± 0.13	34.90 ± 0.22
HR, beats/min	76 ± 3	81 ± 4	79 ± 3	73 ± 3
ΔHR, beats/min	27 ± 3	20 ± 4	22 ± 3	22 ± 3
Baseline FBF, ml/100 ml	2.96 ± 0.25^e	3.75 ± 0.49^e	3.42 ± .32^e	2.61 ± 0.29
Final FBF, ml/100 ml	5.92 ± 0.53	6.87 ± 0.92	6.47 ± 0.43	7.14 ± 0.58
Relative change in FBF, %	99 ± 16^c	88 ± 20^c	92 ± 13^c	193 ± 24
Baseline FVC, ml/100 ml/mmHg	0.04 ± 0.01^e	0.047 ± 0.01^e	0.042 ± 0.00^c	0.03 ± 0.03
Final FVC, ml/100 ml/mmHg	0.07 ± 0.01	0.09 ± 0.01	0.08 ± 0.01	0.08 ± 0.01
Relative change in FVC, %	97 ± 16^c	93 ± 24^c	94 ± 15^d	185 ± 26
${\dot{M}}_{sw}$ , g/m²/h	63.1 ± 8.10^e	79.0 ± 6.1	71.64 ± 4.93^e	88.33 ± 6.99
OT on the forehead, minutes	17.9 ± 0.8^f,^c	11.2 ± 17.9	14.5 ± 1.37	11.7 ± 1.4
OT on the upper back, minutes	17.6 ± 0.8^f,³	11.3 ± 0.8	14.4 ± 1.45³	10.3 ± 1.2
OT on the forearm, minutes	13.0 ± 2.0^g	8.8 ± 1.4	10.9 ± 1.33	12.5 ± 1.4

^aData are presented as mean ± standard error.
^bAbbreviations: T_re, rectal temperature; ΔT_re, rise in rectal temperature after 60 minutes of leg immersion; ${\bar{T}}_{sk}$ , mean skin temperatures; FBF, forearm blood flow; FVC, forearm vascular conductance; HR, heart rate; ΔHR, change in heart rate after 60 minutes of leg immersion; ${\dot{M}}_{sw}$ , total sweat rate; OT, sweating onset time; TR-L, Tropical subjects who had stayed in Japan for > 23 months before the experiment; TR-S, Tropical subjects who had stayed in Japan for < 11 months before the experiment.
^cP < 0.05 compared with the JP group.
^dP < 0.01 compared with the JP group.
^eP < 0.1 compared with the JP group.
^fP < 0.05 between TR-S and TR-L.
^gP < 0.1 between TR-S and TR-L.

ISSN: 1880-6805