The influence of nutritional and metabolic status on progression from asymptomatic HIV infection to AIDS-defining diagnosis

Background: Changes in body weight and lean tissue increase morbidity and mortality during AIDS; however there are few data on the effect of alterations in nutrition and metabolism on disease progression at earlier stages of HIV infection. Objectives: To assess whether change in weight, lean tissue or skeletal muscle affects progression to AIDS; to assess prospectively the effects of recognized alterations in nutrition and metabolism in asymptomatic HIV-seropositive men on disease progression; and to examine prospectively changes in nutrition and metabolism at AIDS-defining diagnosis. Methods: A group of 104 asymptomatic HIV-seropositive men were recruited and prospectively examined at 3-monthly intervals between April 1993 and September 1995. Nutritional status and metabolism were examined using indirect calorimetry, dual energy X-ray absorptiometry and urine excretion of simple sugars. Time-fixed and time-dependent Cox's proportional hazard models were fitted to calculate risks of developing a first AIDS diagnosis, weight loss or death. Results: During the study period, 31 subjects had a first AIDS diagnosis of whom 26 were fully assessed. Changes in nutrition and metabolism do not affect disease progression in asymptomatic HIV infection. However, subjects with a reduction in body weight and basal metabolic index tend to have a higher risk of progression to AIDS-defining diagnosis, independent of CD4 count. There is a significant decrease in all body tissue compartments, a decrease in excretion of urinary sugars and significant increase in resting energy expenditure and fat oxidation associated with a first AIDS diagnosis. Conclusion: Change in metabolic and nutritional status at the asymptomatic stage of HIV infection does not influence disease progression significantly, although there is a trend suggesting weight loss has an independent effect on outcome. There is a cachectic response to AIDS-defining opportunistic infection or tumour.