Serum phosphate predicts early mortality in adults starting antiretroviral therapy in Lusaka, Zambia: a prospective cohort study.
BACKGROUND
Patients starting antiretroviral therapy (ART) for acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa have high rates of mortality in the initial weeks of treatment. We assessed the association of serum phosphate with early mortality among HIV-infected adults with severe malnutrition and/or advanced immunosuppression.


RESULTS
An observational cohort of 142 HIV-infected adults initiating ART in Lusaka, Zambia with body mass index (BMI) <16 kg/m(2) or CD4(+) lymphocyte count <50 cells/microL, or both, was followed prospectively during the first 12 weeks of ART. Detailed health and dietary intake history, review of systems, physical examination, serum metabolic panel including phosphate, and serum ferritin and high-sensitivity C-reactive protein (hsCRP) were monitored. The primary outcome was mortality. Baseline serum phosphate was a significant predictor of mortality; participants alive at 12 weeks had a median value of 1.30 mmol/L (interquartile range [IQR]: 1.04, 1.43), compared to 1.06 mmol/L (IQR: 0.89, 1.27) among those who died (p<0.01). Each 0.1 mmol/L increase in baseline phosphate was associated with an incremental decrease in mortality (AHR 0.83; 95% CI 0.72 to 0.95). The association was independent of other metabolic parameters and known risk factors for early ART-associated mortality in sub-Saharan Africa. While participant attrition represented a limitation, it was consistent with local program experience.


CONCLUSIONS
Low serum phosphate at ART initiation was an independent predictor of early mortality among HIV patients starting ART with severe malnutrition or advanced immunosuppression. This may represent a physiologic phenomenon similar to refeeding syndrome, and may lead to therapeutic interventions that could reduce mortality.
Heimburger
Douglas C
DC
Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. douglas.heimburger@vanderbilt.edu
Koethe
John R
JR
Nyirenda
Christopher
C
Bosire
Claire
C
Chiasera
Janelle M
JM
Blevins
Meridith
M
Munoz
Andres Julian
AJ
Shepherd
Bryan E
BE
Potter
Dara
D
Zulu
Isaac
I
Chisembele-Taylor
Angela
A
Chi
Benjamin H
BH
Stringer
Jeffrey S A
JS
Kabagambe
Edmond K
EK
D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000097:blood* / Q000188:drug therapy / Q000401:mortality*; D006801:Humans; D008297:Male; D010710:Phosphates / Q000097:blood*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D016019:Survival Analysis; D015024:Zambia
D010710:Phosphates