Lack of Weight Gain During the First 2 Months of Treatment and Human Immunodeficiency Virus Independently Predict Unsuccessful Treatment Outcomes in Tuberculosis

Abstract

Background: Weight change may inform tuberculosis treatment response, but its predictive power may be confounded by human immunodeficiency virus (HIV).

Methods: We prospectively followed up adults with culture-confirmed, drug-susceptible, pulmonary tuberculosis receiving standard 4-drug therapy (isoniazid, rifampin, pyrazinamide, and ethambutol) in Brazil. We examined median weight change 2 months after treatment initiation by HIV status, using quantile regression, and unsuccessful tuberculosis treatment outcome (treatment failure, tuberculosis recurrence, or death) by HIV and weight change status, using Cox regression.

Results: Among 547 participants, 102 (19%) were HIV positive, and 35 (6%) had an unsuccessful outcome. After adjustment for confounders, persons living with HIV (PLWH) gained a median of 1.3 kg (95% confidence interval [CI], -2.8 to .1) less than HIV-negative individuals during the first 2 months of tuberculosis treatment. PLWH were at increased risk of an unsuccessful outcome (adjusted hazard ratio, 4.8; 95% CI, 2.1-10.9). Weight change was independently associated with outcome, with risk of unsuccessful outcome decreasing by 12% (95% CI, .81%-.95%) per 1-kg increase.

Conclusions: PLWH gained less weight during the first 2 months of tuberculosis treatment, and lack of weight gain and HIV independently predicted unsuccessful tuberculosis treatment outcomes. Weight, an easily collected biomarker, may identify patients who would benefit from alternative treatment strategies.

Keywords: HIV; Tuberculosis; body weight changes; observational study; treatment outcome.

Figure 1.

Directed acyclic graph for the primary and secondary analyses. The primary analysis examined the association between human immunodeficiency virus (HIV) and weight change, while adjusting for potential confounders. The secondary analysis examined the independent effect of HIV and weight change on tuberculosis treatment outcome and used mediation analysis to determine the total, direct, and indirect effects of HIV and weight change on tuberculosis treatment outcome.

Figure 2.

Crude and adjusted analysis of association between human immunodeficiency virus (HIV)–related characteristics and weight change during the first 2 months of tuberculosis treatment, using bootstrapped quantile regression Adjusted models control for baseline weight, age, sex, site, smear status, and hemoglobin level. Boldface indicates statistical significance (P < .05). Abbreviation: CI, confidence interval.