Body fluid status on induction, reinduction and prolonged stay at high altitude of human volunteers

Singh, Mrinalini; Rawal, S. B.; Tyagi, A. K.

doi:10.1007/bf01093454

Cited by 28 publications

(22 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand the inverse correlation (r = -0.689, P = 0.0138) between the increase in urine flow and the mean S a O 2 at 4500 m might point to a crucial role of the arterial hypoxaemia in determining the amount of high altitude diuresis. Assuming that the observed loss of body mass mainly reflects body fluid loss, the results would imply a negative water balance, a finding also reported in other high altitude studies, which, in particular, have demonstrated a reduction in interstitial fluid and plasma volume (Frayser et al 1975;Singh et al 1990). In our experiments, the mean renal fluid loss during the whole hypoxia exposure (484 ml) would suggest, that in addition there must have been an increase in the insensible water loss, i.e.…”

Section: Diuresismentioning

confidence: 72%

Volume changes in the forearm and lower limbs during 2 h of acute hypobaric hypoxia in nonacclimatized subjects

Schirlo

A²,

Reize

et al. 1997

European Journal of Applied Physiology

View full text Add to dashboard Cite

To investigate the role of fluid shifts during the short-term adjustment to acute hypobaric hypoxia (AHH), the changes in lower limb (LV) and forearm volumes (FV) were measured using a strain-gauge plethysmograph technique in ten healthy volunteers exposed to different altitudes (450 m, 2500 m, 3500 m, 4500 m) in a hypobaric chamber. Arterial blood pressure, heart rate, arterial oxygen saturation (SaO2), endtidal gases, minute ventilation and urine flow were also determined. A control experiment was performed with an analogous protocol under normobaric normoxic conditions. The results showed mean decreases both in LV and FV of 0.52 (SD 0.39) ml x 100 ml(-1) and -0.65 (SD 0.32) ml x 100 ml(-1), respectively, in the hypoxia experiments [controls: LV 0.28 (SD 0.37), FV 0.41 (SD 0.47) ml x 100 ml(-1)]. Descent to normoxia resulted in further small but not significant decreases in mean LV [-0.02 (SD 0.11) ml x 100 ml(-1)], whereas mean FV tended to increase slightly [ + 0.02 (SD 0.14) ml x 100 ml(-1)]; in the control experiments mean LV and FV decreased continuously during the corresponding times [-0.19 (SD 0.31), -0.18 (SD 0.10) ml x 100 ml(-1) , respectively]. During the whole AHH, mean urine flow increased significantly from 0.84 (SD 0.41) ml x min(-1) to 3.29 (SD 1.43) ml x min(-1) in contrast to the control conditions. We concluded that peripheral fluid volume shifts form a part of the hypoxia-induced acute cardiovascular changes at high altitude. In contrast to the often reported formation of peripheral oedema after prolonged exposure to hypobaric hypoxia, the results provided no evidence for the development of peripheral oedema during acute induction to high altitude. However, the marked increase in interindividual variance in SaO2 and urine flow points to the appearance of the first differences in the short-term adjustment even after 2 h of acute hypobaric hypoxia.

show abstract

Section: Diuresismentioning

confidence: 72%

Volume changes in the forearm and lower limbs during 2 h of acute hypobaric hypoxia in nonacclimatized subjects

Schirlo

A²,

Reize

et al. 1997

European Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…It is reported that about 3.5% of total body water decreases during first 3 days of HA (3500 m) exposure. But this body water loss is in proportion to the decrease in body weight (Jain et al 1980;Singh et al 1990). The decrease in food intake and loss in body mass in the present study is similar as reported earlier by several other workers.…”

Section: Discussionmentioning

confidence: 98%

High altitude induced anorexia: Effect of changes in leptin and oxidative stress levels

Vats

Singh

et al. 2007

Nutritional Neuroscience

View full text Add to dashboard Cite

High altitude (HA) exposure usually leads to a significant weight loss in non-acclimatized humans. Anorexia is believed to be the main cause of this body weight loss. Appetite regulatory peptides, i.e. leptin and neuropeptide Y play a key role in food intake and energy homeostasis. Recent studies suggests increased oxidative stress during HA exposure. In present study effect of HA exposure on levels of leptin and NPY was evaluated along with N-acetyl cysteine (NAC) and vitamin E supplementation in relation to food intake and body weight changes. The study was conducted on 30 healthy male volunteers (age 19-29 years). Subjects were divided randomly into three groups of 10 each. Group 1 (placebo) supplemented with 400 mg of calcium gluconate, group 2 and 3 were supplemented with 400 mg of NAC and 400 mg vitamin E, respectively per day. The study was conducted at low altitude (320 m, Phase I), at HA 3600 m (Phase II) and at an altitude of 4580 m (Phase III). On HA exposure significant reduction in plasma leptin levels was observed in all the groups on day 2 (Phase II) along with decrease in food intake and reduction in body weight. Statistically significant increase in blood malondialdehyde (MDA) levels was seen in all the groups on HA exposure (Phase II, Day 2), but the maximum increase was in case of placebo group (65.1%) on day 2 (Phase II) in comparison to low altitude values. The decrease in energy intake was almost same in all the groups indicating that antioxidant supplementation did not provide any protection against HA anorexia. From the study, it may be concluded that leptin and oxidative stress possibly are not the key players for HA anorexia.

show abstract

“…Lowlanders who sojourn to a high altitude often develop a transient increase in erythrocyte concentration, but this is caused by a reduced plasma volume because of high altitude dehydration, and not an increased rate of erythrocyte production [52].…”

Section: Role Of Quercetin In Modulating Hematological Changesmentioning

confidence: 99%

Quercetin as a prophylactic measure against high altitude cerebral edema

Patir

Sarada

Singh

et al. 2012

Free Radical Biology and Medicine

View full text Add to dashboard Cite

Body fluid status on induction, reinduction and prolonged stay at high altitude of human volunteers

Cited by 28 publications

References 20 publications

Volume changes in the forearm and lower limbs during 2 h of acute hypobaric hypoxia in nonacclimatized subjects

Volume changes in the forearm and lower limbs during 2 h of acute hypobaric hypoxia in nonacclimatized subjects

High altitude induced anorexia: Effect of changes in leptin and oxidative stress levels

Quercetin as a prophylactic measure against high altitude cerebral edema

Contact Info

Product

Resources

About