title: Serum Phosphate Predicts Early Mortality among Underweight Adults Starting ART in Zambia: A Novel Context for Refeeding Syndrome?
abstract: Background. Low body mass index (BMI) at antiretroviral therapy (ART) initiation is associated with early mortality, but the etiology is not well understood. We hypothesized that low pretreatment serum phosphate, a critical cellular metabolism intermediate primarily stored in skeletal muscle, may predict mortality within the first 12 weeks of ART. Methods. We prospectively studied 352 HIV-infected adults initiating ART in Lusaka, Zambia to estimate the odds of death for each 0.1 mmol/L decrease in baseline phosphate after adjusting for established predictors of mortality. Results. The distribution of phosphate values was similar across BMI categories (median value 1.2 mmol/L). Among the 145 participants with BMI <18.5 kg/m(2), 28 (19%) died within 12 weeks. Lower pretreatment serum phosphate was associated with increased mortality (odds ratio (OR) 1.24 per 0.1 mmol/L decrement, 95% CI: 1.05 to 1.47; P = 0.01) after adjusting for sex, age, and CD4(+) lymphocyte count. A similar relationship was not observed among participants with BMI ≥18.5 kg/m(2) (OR 0.96, 95% CI: 0.76 to 1.21; P = 0.74). Conclusions. The association of low pretreatment serum phosphate level and early ART mortality among undernourished individuals may represent a variant of the refeeding syndrome. Further studies of cellular metabolism in this population are needed.
authors.affiliation: Centre for Infectious Diseases Research in Zambia, Plot 1275 Lubuto Road, P.O. Box 34681, Lusaka 10101, Zambia ; Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, A2200-MCN, 1161 21st Avenue South, Nashville, TN 37232-2582, USA ; Vanderbilt Institute for Global Health, 2525 West End Avenue, Suite 750, Nashville, TN 37203, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Koethe
authors.forename: Meridith
authors.initials: M
authors.lastname: Blevins
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Nyirenda
authors.forename: Edmond K
authors.initials: EK
authors.lastname: Kabagambe
authors.forename: Janelle M
authors.initials: JM
authors.lastname: Chiasera
authors.forename: Bryan E
authors.initials: BE
authors.lastname: Shepherd
authors.forename: Isaac
authors.initials: I
authors.lastname: Zulu
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Heimburger