Bioelectrical impedance phase angle as a prognostic indicator in advanced pancreatic cancer

Abstract

Bioelectrical impedance analysis (BIA) is an easy-to-use, non-invasive and reproducible technique to evaluate changes in body composition and nutritional status. Phase angle, determined by BIA, has been found to be a prognostic indicator in several chronic conditions, such as HIV, liver cirrhosis, chronic obstructive pulmonary disease and lung cancer, and in patients undergoing dialysis. The present study investigated the prognostic role of phase angle in advanced pancreatic cancer. We evaluated a case series of fifty-eight stage IV pancreatic cancer patients treated at Cancer Treatment Centers of America w at Midwestern Regional Medical Center (Zion, IL, USA) between January 2000 and July 2003. BIA was conducted on all patients using a bioelectrical impedance analyser that operated at 50 kHz. The phase angle was calculated as capacitance (Xc)/resistance (R) and expressed in degrees. The Kaplan-Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle independent of other clinical and nutritional variables. The correlations between phase angle and traditional nutritional measures were evaluated using Pearson and Spearman coefficients. Patients with phase angle ,5·08 had a median survival time of 6·3 (95 % CI 3·5, 9·2) months (n 29), while those with phase angle .5·08 had a median survival time of 10·2 (95 % CI 9·6, 10·8) months (n 29); this difference was statistically significant (P¼ 0·02). The present study demonstrates that phase angle is a strong prognostic indicator in advanced pancreatic cancer. Similar studies in other cancer settings with larger sample sizes are needed to further validate the prognostic significance of the phase angle.

Longitudinal follow-up of nutritional status and its influencing factors in adults undergoing allogeneic hematopoietic cell transplantation

“…This reveals that the phase angle, which is a valid nutritional marker and independent indicator of survival for patients receiving chemotherapy, 16,[18][19][20]31 was extremely low in this cohort. Within this cohort, we also investigated the validity of these nutritional markers as risk factors for outcomes after alloHCT and found that the pre-transplant phase angle is an independent predictor for 2-year overall survival, relapse mortality and progression-free survival (Urbain, unpublished data).…”

“…16 It is an established parameter for diagnosing malnutrition, and a useful prognostic marker in many clinical conditions 17 including several types of cancer. [18][19][20][21] The Subjective Global Assessment (SGA) questionnaire according to Detsky et al 22 is another means of demonstrating the best combination of sensitivity and specificity in identifying complications related to malnutrition, 23 making the SGA questionnaire a validated tool in cancer patients with which to evaluate nutritional status. 24 The main objective of this prospective study was to evaluate the nutritional status in patients before alloHCT and its course during the early post-transplant period until day þ 100 via weight change before admission, BMI normalized for gender and age, the SGA questionnaire, the phase angle normalized for gender, age, and BMI, and height-normalized fat-free mass and body fat mass.…”

Avaliação dos indicadores nutricionais e da composição corporal em hepatopatas crônicos e a relação com a etiologia e gravidade da doença

“…A R é a restrição pura ao fluxo de uma corrente elétrica através do corpo (45) , relacionada aos líquidos extra e intracelulares (41,44,47,48) , contidos primariamente na massa magra (46) . A R é inversamente proporcional a quantidade de água corporal (42,49) .…”

“…A reactância significa a oposição do fluxo elétrico causado pela capacitância produzida pelas interfaces teciduais e membranas celulares (41,45,47) , ou seja, reflete a habilidade das membranas de atuar como capacitadores oferencendo reactância (50) . A Xc está relacionada à estrutura e função das membranas celulares (46,49) , isto é, se relaciona com o balanço hídrico extra e intracelular, dependente da normalidade da membrana celular (42) .…”

“…O AF depende tanto do comportamento capacitativo dos tecidos (associado com a celularidade tecidual e tamanho celular, isto é, massa celular corpórea) quanto do seu comportamento resistivo absoluto (primariamente relacionado à hidratação tecidual) e permeabilidade das membranas. (47,(49)(50)(51) Por definição, o AF está positivamente associado com a Xc e negativamente associado com R. No ser humano o ângulo de fase varia entre 4 e 15°.…”