PEDIATRIC AIDS PROGNOSIS USING SOMATIC GROWTH VELOCITY

Objective: To describe the natural history of somatic growth in HIV in fection by constructing age-specific growth velocity norms and to asse ss specific prognostic information available using these norms. Design : Observations on 1338 HIV-infected children aged 3 months to 15 years who participated in one of four US clinical trials of pediatric anti- HIV therapies were pooled; baseline growth velocity data were obtained using the first 6 months of observation for each child. Methods: Dist ributions of physical growth velocities in HIV-infected children in th e Pediatric AIDS Clinical Trials Group were computed. Statistical smoo thing of growth histories was employed to derive velocity estimates, a nd quantile regression analysis of growth velocities was performed to allow comparisons of growth rates in age- and gender-heterogeneous coh orts in the context of HIV infection. The quantile regressions provide corrected z-scores for growth velocity that appropriately compare HIV -infected children with one another for the purpose of distinguishing more from less favorable prognoses. Results: Consistent deficits in gr owth velocity amongst HIV-infected children were revealed when compare d with the Fels Institute velocity standards. Approximately 33% of hei ght land 20% of weight) age- and sex-corrected velocity measurements o btained in the first 6 months of clinical trial participation lay bene ath the corresponding third percentiles of the Fels reference distribu tions, which are commonly regarded as critical indicators of growth fa ilure. Proportional hazards regression tests indicated that both weigh t and height velocity contributed significant information on the risk of death among children with AIDS after adjusting for antiretroviral t herapy received, CD4 cell counts, and age at trial enrollment. Compari ng subjects who differ in initial weight velocity by one age- and sex- corrected SD, the relative hazard of death was 0.63 (95% confidence in terval, 0.55-0.72; P less than or equal to 0.0001) in favor of the chi ld with greater weight velocity, controlling for antiretroviral therap y received, age and CD4 cell count at baseline. The analogous hazard r atio for height velocity was 0.68 (95% confidence interval, 0.57-0.79; P less than or equal to 0.0001). Conclusions: Suitably normalized gro wth velocities are informative and inexpensive criteria for pediatric AIDS prognosis; the growth velocity distributions presented will be us eful for comparing growth effects of new therapeutic strategies to tho se of single and combination antiretrovirals employed for maintenance of pediatric HIV infection in the mid-1990s. (C) 1998 Lippincott-Raven Publishers.