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Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology, 1995; 9:20-25.

Bioelectrical impedance analysis as a predictor of survival in patients with human immunodeficiency virus infection.

Michael Ott, Harald Fischer, Hatice Polat, Eike Brigitte Helm (1), Marcus Frenz (2), Wolfgang F. Caspary, and Bernard Lembcke.

Division of Gastroenterology, Center of Internal Medicine, Laboratory of Infectious Diseases (1), and Department of Biostatistics (2), University Hospital, Johann Wolfgang Goethe University, Frankfurt, Germany.

Summary: In patients with AIDS, short-term survival has been related to body weight, body composition, and serum nutritional parameters, but their prognostic impact at earlier stages of the HIV infection is not known. With an individual follow-up period of 1,000 days, we investigated the prognostic relevance of electrical tissue conductivity [resistance R, reactance Xc, phase angle α, extracellular mass (ECM), body cell mass (BCM)] measured by bioelectrical impedance analysis), of the CD4+ cell count, and of serum parameters indicating malnutrition in 75 HIV-infected male patients at Walter Reed stages 3-5. After initial recording, 29 patients (38.7%) died from AIDS during this period. Among 12 parameters estimated with a semiparametric Cox regression model adjusted for therapy (pentamidine, azidothymidine), the phase angle α (parameter estimate: 1.043, 95% confidence interval of -0.61 to -1.47) p <= 0.0001 the ECM/BCM ratio, Xc, BCM, serum cholesterol, number of CD4+ cells, and serum albumin had significant prognostic influence on survival, whereas age, body weight, body mass index, resistance, serum protein, and serum triglycerides did not. In a model with four covariates CD4+ cells, phase angle, pentamidine, azidothymidine, the prognostic impact of the CD4+ cell count (parameter estimate: -0.549) was lower compared with the phase angle α (parameter estimate: -0.799; p <= 0.0001) and did not gain statistical significance (p = 0.0626). The phase angle α was the best single predictive factor for survival among all 12 parameters (comparison of the respective Cox models with the likelihood ratio test). Body composition as reflected by the phase angle α is a major determinant of long term survival in HIV infection, thereby representing an important parameter for monitoring disease progression.
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