1. In 12 unselected outpatients with chronic obstructive pulmonary disease and six controls, arterial pH, PaO2, PaCO2 and oxygen saturation (SaO2), forced expiratory volume in 1.0 s (FEV1.0) and vital capacity were measured. Subjects were grouped into those with or without obstruction based on the Tiffenau index. The Baseline Dyspnoea Index was employed to objectify the severity of dyspnoea and the Borg index to evaluate the subjective sensation. Blood pressure was measured with a sphygmomanometer; calf arterial flow both at rest and during reactive hyperaemia with a plethysmograph. Basal and minimal resistance were calculated.2.FEV1.0 was 26% lower in patients with obstruction than in controls, and was also lower in patients with moderate-to-severe obstruction compared with those with mild or no obstruction. Arterial flow (75% greater in the patients with obstruction) progressively increased with increasing severity of obstruction, being 54% higher in those with mild obstruction than in those with no obstruction (P<0.001), and 28% higher in moderate-severe than in mild obstruction (P<0.005). In multiple regressions, F correlated inversely with FEV1.0, PaO2 and SaO2, and directly with PaCO2. Basal resistance correlated positively with FEV1.0, SaO2 and the Tiffenau index, and inversely with PaCO2 (r=-0.52, P=0.02). Minimal resistance was significantly lower in obstructed than in non-obstructed subjects. Both basal and minimal resistance progressively decreased, although insignificantly, with worsening bronchial obstruction. PaCO2 did not correlate with any haemodynamic parameter. Borg index correlated indirectly with FEV1.0 and basal resistance directly with arterial flow.3. Patients with chronic obstructive pulmonary disease therefore tend to show chronic vasodilatation depending on hypoxia rather than PaCO2. Other mechanisms could be involved in this phenomenon. The Borg index is a good indicator of oxygen desaturation and vasodilatation.

1. In 12 unselected outpatients with chronic obstructive pulmonary disease and six controls, arterial pH, PaO2, PaCO2 and oxygen saturation (SaO2), forced expiratory volume in 1.0 s (FEV1.0) and vital capacity were measured. Subjects were grouped into those with or without obstruction based on the Tiffenau index. The Baseline Dyspnoea Index was employed to objectify the severity of dyspnoea and the Borg index to evaluate the subjective sensation. Blood pressure was measured with a sphygmomanometer; calf arterial flow both at rest and during reactive hyperaemia with a plethysmograph. Basal and minimal resistance were calculated.2.FEV1.0 was 26% lower in patients with obstruction than in controls, and was also lower in patients with moderate-to-severe obstruction compared with those with mild or no obstruction. Arterial flow (75% greater in the patients with obstruction) progressively increased with increasing severity of obstruction, being 54% higher in those with mild obstruction than in those with no obstruction (P<0.001), and 28% higher in moderate-severe than in mild obstruction (P<0.005). In multiple regressions, F correlated inversely with FEV1.0, PaO2 and SaO2, and directly with PaCO2. Basal resistance correlated positively with FEV1.0, SaO2 and the Tiffenau index, and inversely with PaCO2 (r=-0.52, P=0.02). Minimal resistance was significantly lower in obstructed than in non-obstructed subjects. Both basal and minimal resistance progressively decreased, although insignificantly, with worsening bronchial obstruction. PaCO2 did not correlate with any haemodynamic parameter. Borg index correlated indirectly with FEV1.0 and basal resistance directly with arterial flow.3. Patients with chronic obstructive pulmonary disease therefore tend to show chronic vasodilatation depending on hypoxia rather than PaCO2. Other mechanisms could be involved in this phenomenon. The Borg index is a good indicator of oxygen desaturation and vasodilatation.

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It is unclear whether men and women perceive thermal stress differently when changes in intestinal temperature (ΔTin) and metabolic heat production (MHprod) are matched between sexes during exercise hyperthermia. This study tested the hypothesis that females have enhanced sensitivity to comfort and perception of thermal stress during exercise hyperthermia in these conditions. We had 22 healthy active adults (11 males, 11 females; M age = 22.4 years, SD = 4.9 ; M height = 169 cm, SD = 7.6; M weight = 68.3 kg, SD = 13) exercise in random order, separated by at least three days at similar MHprod ( M = 7.0 W/kg, SD = 1.5; p = 0.32) for 60 minutes on a cycle ergometer in cool ( M = 24.00C, SD = 0.0; M = 14.4%Rh, SD = 3.6) and hot ( M = 42.3°C, SD = 0.2; M = 10-60%Rh) environments with a progressive increase in humidity conditions. We measured ΔTin, and thermal stress indices for sensation (TS), comfort (TC), pleasantness (TP), and stickiness (S), feeling (FS scale), stress (visual analogue stress scale, VAS), focus (F) and felt arousal (FAS scale). We examined environmental conditions as wet bulb globe temperatures (WBGT). Males and females had similar increases in ΔTin (ME: WBGT; p < 0.0001), and both groups reported increased TS and TC and decreased TP (ME: WBGT, p ≤ 0.01). However, females reported that TS, TC, and TP, felt hotter overall, more uncomfortable, and more unpleasant, compared to males (ME: Sex; p < 0.04). Overall, females felt worse and were more stressed compared to males (ME: Sex; p ≤ 0.05). Females also reported greater internal focus as WBGT increased compared to males (I: WBGT × Sex; p < 0.003). Knowing that females perceive thermal stress during exercise hyperthermia to be hotter, more uncomfortable, more unpleasant, and more stressful compared to males can help coaches/trainers plan different exercise routines for exercisers of both sexes.

No abstract