Taken together, the data available can be used to highlight a number implications for clinical practice, as well as suggest possible mechanisms of HIV-related growth failure. The data suggest that HIV infection is associated with profound and long-lasting defects in weight and height throughout infancy and childhood. The current evidence indicates that differences in growth patterns become apparent by 3 to 4 mo of age, persist and perhaps increase with time. Wasting associated with HIV infection was less common than stunting or underweight. It is possible that HIV-infected children experience nearly proportional declines in both height and weight such that normal weight-for-height is maintained7, 34
or that wasting in HIV-infected children may become apparent only as children become more sick. The data available also reveal no significant differences in the early growth of sero-reverters and healthy controls, suggesting that viral exposure without infection does not affect growth. These patterns of growth faltering were similar across developed and less developed country settings, despite differences in access to supplemental feeding and antiretroviral therapy and other factors including women’s routes of transmission, virus sub-types, and prevalence of STDs, drug use and nutritional deficiencies.
It was common for differences in weight-for-age to become apparent at the same time as differences in height-for-age in both developed and less developed country settings. As weight is more likely to fall off before height in conditions of protein-energy malnutrition, this pattern of concurrent impairment of weight and height could indicate that other mechanisms may underlie HIV-related growth failure. Possible mechanisms include HIV-related disturbances to energy balance,40, 43, 45–48
gastrointestinal disturbance and malabsorption,49–52
and nuero-endocrine changes.28, 53–58
Growth failure also may occur as a direct result of HIV infection, independent of the variety of secondary illnesses that accompany infection.30, 59–61
Understanding of the temporal course and mechanisms of growth impairment through future longitudinal study will continue to be important for the early intervention and care of HIV-infected children if impaired growth precedes and contributes to the onset of immune deficiency and opportunistic infection. Further research in a number of specific areas continues to be warranted to broaden and deepen our current understanding of the impact of HIV on postnatal growth. This includes development of evidence on the effect of HIV infection on body composition in children. As noted above, few studies have addressed the association between HIV infection and exposure and body composition in children. These limited studies suggest that HIV-infected children experience a preferential loss of lean body mass compared to fat, similar to that seen in adults.62
As changes in body composition may be an additional risk factor for disease progression, further study is needed to describe changes in body composition in HIV-infected children over time.
Evaluation of the effect of HIV infection on adolescent growth and development should also remain a research priority. Advances in the management of HIV means that many perinatally infected children reach adolescence. Only a small number of studies, however, have examined the effect of HIV on adolescent growth and pubertal development to date.41, 63, 64
Given the increasing survival of this population and the limited information on the effect of HIV on growth and development after 4 years of age, more information on how HIV infection may interact with adolescent growth and maturation is needed. Evaluation of the effect of nutritional intervention / supplementation on growth, immune status and disease progression in children is similarly important. The well-known interaction between nutrition and immune function suggests that nutritional interventions may have the potential to limit morbidity and mortality in HIV-infected individuals.65
The role of micronutrient status on HIV infection has been examined in several trials in adults and children,66
though more information on the effectiveness of various macronutrient interventions is still required. Finally, evidence on the effect of ARV therapy on growth and body composition in HIV-infected children must continue to be developed and summarized. ARV therapy has improved the virological, immunological and clinical outcomes of HIV-infected children, and studies on its effects on growth are now becoming available.61, 67, 68
Additional efforts to develop and consolidate information on the effects of such treatment on growth and body composition in the long-term and in less developed country settings are required.