A new method for monitoring hydration at high altitude by bioimpedance analysis

Piccoli, Antônio; Piazza, Paolo; Noventa, Donatella; Pillon, Luana; Zaccaria, Marco

doi:10.1097/00005768-199612000-00012

Cited by 48 publications

(41 citation statements)

References 11 publications

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“…A previous report indicated that, at HA, the loss of fat may account for up to 74% of mass loss (Westerterp et al 1994). In a later study (Piccoli et al 1996), we found a 5.6% loss in body mass after 3 weeks of HA exposure,which was widely reversed immediately after return to SL (from )5.6% to )2.0%), suggesting that water loss made a significant contribution to total body mass decrease. However, in a recent review, Westerterp (2001) concluded that water balance at altitude results were the same as at SL, even if an initial slight dehydration might be found as an adaptive mechanism.…”

Section: Discussionsupporting

confidence: 54%

Decreased serum leptin levels during prolonged high altitude exposure

et al. 2004

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Circulating leptin concentrations are shown to be influenced not only by hormones, but also by body weight and energy balance. High altitude (HA) exposure induces a daily negative energy balance and stress hormone activation. The aim of our study was to evaluate leptin concentration during both acute and prolonged HA exposure and its correlations with some metabolic and hormonal parameters. Twelve males were studied during a stay at HA (15-20 days at 5,050 m). Blood samples for serum leptin, plasma insulin and 24-h urinary epinephrine (E) and norepinephrine (NE) were collected at sea level (SL), at the arrival at HA (A) and after 12-16 days (C) of stay. Symptoms of Acute Mountain Sickness (AMS) were evaluated using the Lake Louise score and the results showed there was no relationship with leptin concentrations. During the stay, both body mass index and leptin levels significantly decreased in both groups [leptin from 1.88 (1.12) to 1.21 (1.04) ng/ml, P<0.008, in A; and to 1.06 (0.74) ng/ml, P<0.003, in C]. Acute HA exposure induced a clear-cut significant increase of NE ( P<0.001 in A, P<0.003 in C) while E and insulin levels were unchanged in both phases. Moreover, a significant correlation between leptin and NE absolute values, and leptin and insulin variations was found ( r 0.359, P<0.034 and r=0.560, P<0.007, respectively). Exposure to HA induces a decrease in fasting serum leptin concentrations in men. These changes are not linked to symptoms of AMS but to hormonal and energy balance variations, suggesting that leptin is involved in the endocrine and metabolic adaptations occurring during HA exposure.

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Section: Discussionsupporting

confidence: 54%

Decreased serum leptin levels during prolonged high altitude exposure

et al. 2004

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“…Similarly, a progressive lengthening and steepening of the vector was observed in lean uremic patients after hemodialysis (results not reported) and in lean healthy subjects after dehydration at high altitude. 31 We could not prove the reverse, since experiments with fat or¯uid overloading in obese subjects are unethical.…”

Section: Discussionmentioning

confidence: 97%

Discriminating between body fat and fluid changes in the obese adult using bioimpedance vector analysis

et al. 1998

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OBJECTIVE: Conventional body composition methods may produce biased quanti®cation of fat and fat-free mass in obese subjects, due to possible violation of the assumption of constant (73%) tissue hydration. We used an assumption-free, graphical method for interpreting body weight variation in obesity using bioelectrical measurements. DESIGN: 540 obese subjects with body mass index (BMI) b 31 kgam 2 without apparent edema were compared to 726 healthy subjects with BMI`31 kgam 2 and to 50 renal patients with apparent edema. A subgroup of 48 obese subjects were evaluated again after weight loss (8.6 kg, 3 BMI units) following one-month energy restriction (5 MJad, 1200 kcalad). 32 obese uremic patients were evaluated before and after a dialysis session (3.2 kg¯uid removed). Direct measurements obtained from standard 50 kHz frequency bioelectrical impedance analyzer were used as impedance vectors in the Resistance-Reactance Graph. RESULTS: 1) Impedance vectors of obese subjects could be discriminated from those of edematous patients with 91% correct allocation; 2) A signi®cant lengthening of vectors was observed after¯uid loss of 3 kg in obese subjects; but 3) A body weight loss of about 9 kg after energy restriction was associated with no vector displacement. CONCLUSION: A different impedance vector pattern was associated with body weight loss in obesity due to¯uid removal (vector lengthening) versus an energy-restricted diet (no vector displacement).

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“…El ligerísimo aumento no significativo de la MME podría ser debido a la asociación del ACT con la masa muscular y sus componentes tanto extra como intracelular que se observa tras el DT, habiéndose descrito modelos de regresión múltiple de los cambios del peso corporal a través de cambios del AEC que explicarían un 55% de la varianza en el cambio del peso corporal (13). La migración del vector de impedancia eléctrica (19,26) indica una doble dirección: hacia abajo y hacia la izquierda, lo cual denota un aumento del líquido corporal o rehidratación y un aumento de la masa grasa, que está en consonancia con los resultados encontrados en nuestras pruebas antropométricas y con la literatura (5). El análisis del vector de impedancia es considerado una buena herramienta para detectar cambios en la hidratación ya que no depende del peso del sujeto y permite la visualización gráfica de cambios tanto de la hidratación como de la masa celular activa (19,26,33,34).…”

Section: Discussionunclassified

“…Los cálculos del AEC fueron obtenidos con la aplicación de las ecuaciones de Deurenberg (25) y el AIC, por sustracción (AIC = ACT-AEC). Adicionalmente, se obtuvo el vector de impedancia a partir de las relaciones índice reactancia-altura (Xc/H) (ordenadas) e índice resistencia-altura (R/H) (abscisas), conformando el gráfico resistencia-reactancia (grá-fico RXc) con el objetivo de monitorizar los cambios de fluidos con independencia de la propia composición corporal (19,26).…”

Section: Análisis De Bioimpedancia Eléctricaunclassified

Cambios de la composición corporal tras un periodo de desentrenamiento deportivo

Cruz¹,

Ronconi

García-Romero

et al. 2017

Nutr Hosp

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Palabras clave:Composición corporal. Antropometría. Bioimpedancia eléctrica. Desentrenamiento. ResumenIntroducción: la infl uencia del ejercicio físico en sujetos entrenados tiene efectos benefi ciosos en la condición física y la composición corporal. Sin embargo, el desentrenamiento tiene un efecto desfavorable en todas ellas. Objetivo: el propósito del estudio fue analizar los cambios de la composición corporal después de un periodo de desentrenamiento de seis semanas de duración en dos grupos: uno de 43 jóvenes varones jugadores de fútbol (grupo experimental [GE], n = 43), y un grupo control de escolares no activos de la misma edad (grupo control [GC], n = 10). Métodos: las variables de composición corporal fueron evaluadas mediante antropometría, para estimar la masa grasa (MG) y la masa muscular esquelética (MME), y mediciones de bioimpedancia eléctrica, para estimar agua corporal total (ACT), agua extra (AEC) e intracelular (AIC). Las mediciones se realizaron tanto en situación de entrenamiento como de desentrenamiento. Resultados: tras el desentrenamiento, se encontraron diferencias signifi cativas en el ACT (35,5 ± 5,2 vs. 36,7 ± 4,9 kg), el AIC (14,2 ± 1,8 vs. 14,8 ± 1,6 kg) y el AEC (21,5 ± 3,6 vs. 22,0 ± 3,4 kg, p < 0,001 para todas las variables), sin existir diferencias en los ratios AEC/ACT (0,4 ± 0,02 vs. 0,4 ± 0,02) y AIC/ACT (0,6 ± 0,02 vs. 0,597 ± 0,02, ambos p > 0,05). La MG aumentó signifi cativamente (8,6 ± 3,2 vs. 8.95 ± 3,1 kg, p < 0,01); sin embargo, la MME no sufrió modifi caciones (21,2 ± 2,5 vs. 22,22 ± 2,8 kg, p > 0,05) Conclusiones: el principal resultado de este estudio fue que en un periodo de desentrenamiento de seis semanas se observaron aumentos del ACT y de su distribución en el grupo de jóvenes futbolistas. La importancia fi siológica de esta desadaptación en el rendimiento deportivo tiene que ser analizada en futuros estudios. Key words:Body composition. Anthropometry. Bioelectrical impedance analysis. Detraining. AbstractIntroduction: The infl uence of exercise in trained subjects has benefi cial effects in the physical fi tness and body composition; however, detraining has an unfavorable effect in all of them. Objective: The current study was designed to ascertain the infl uence of a six week-detraining period on body composition in both well-trained young soccer players (GE, n = 43) and sedentary male adolescents (GC, n = 10). Methods: Forty-three well-trained soccer players and ten sedentary adolescents accepted to participate in the study. Body composition measurements included fat mass and skeletal muscle mass (SMM), which were estimated by anthropometry. In addition, total body water (TBW), intracellular water (ICW) and extracellular water (ECW) were assessed by bioelectrical impedance analysis (BIA) at the end of training and after detraining periods. Results: After the six-week-detraining period, signifi cant increments were found in TBW (35.5 ± 5.2 vs. 36.7 ± 4.9 kg; p < 0.001), ICW (14.2 ± 1.8 vs. 14.8 ± 1.6 kg; p < 0.001) and ECW (21.5 ± 3.6 vs. 22.0 ± 3.4 kg; p <...

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A new method for monitoring hydration at high altitude by bioimpedance analysis

Cited by 48 publications

References 11 publications

Decreased serum leptin levels during prolonged high altitude exposure

Decreased serum leptin levels during prolonged high altitude exposure

Discriminating between body fat and fluid changes in the obese adult using bioimpedance vector analysis

Cambios de la composición corporal tras un periodo de desentrenamiento deportivo

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