Body mass index at time of HIV diagnosis - A strong and independent predictor of survival

Background: Identification of basic prognostic indicators of HIV infection is essential before widespread antiretroviral therapy can be implemented in low-technology settings. This study assessed how well body mass index (BMI:kg/m(2)) predicts survival. Methods: BMI within 3 months of HIV diagnosis was obtained from 1657 patients aged greater than or equal to 15 years, recruited in a seroprevalent clinical cohort in The Garnbia since 1992 and followed up at least once. Baseline CD4(+) counts and clinical assessment at time of diagnosis were done. Results: The mortality hazard ratio (FIR) of those with a baseline BMI < 18 compared with those with a baseline BMI greater than or equal to 18 was 3.4 (95%, CI, 3.0-3.9). The median Survival time of those presenting with a BMI < 16 was 0.8 years, in contrast to a median survival of 8.9 years for those with a baseline BMI greater than or equal to 22. Baseline BMI < 18 remained a highly significant independent predictor of mortality after adjustment for age, sex, co-trimoxazole prophylaxis, tuberculosis, reported wasting at diagnosis, and baseline CD4(+) cell Count (aqjusted HR = 2.5 , 95% CI 2.0-3.0). Sensitivity and specificity of baseline BMI <18 was comparable to that of a CD4(+) Count < 200 in predicting mortality within 6 months of diagnosis. Discussion: BMI at diagnosis is a strong, independent predictor of survival in HIV-infected patients in West Africa. In the absence of sophisticated clinical and laboratory support, BMI may also prove a useful guide for deciding when to initiate antiretroviral therapy.