Lack of weight gain and increased mortality during and after treatment among adults with drug-resistant tuberculosis: a retrospective cohort study in Georgia, 2009-2020.

BACKGROUND

While low body mass index (BMI) is associated with poor tuberculosis (TB) treatment outcomes, the impact of weight gain during TB treatment is unclear. To address this knowledge gap, we assessed whether a lack of weight gain is associated with all-cause mortality during and after TB treatment.

METHODS

We conducted a retrospective cohort study among adults with newly diagnosed multidrug or extensively drug-resistant (MDR/XDR) pulmonary TB in Georgia between 2009-2020. The exposure was a change in BMI during the first 3-6 months of TB treatment. All-cause mortality during and after TB treatment was assessed using the National Death Registry. We used competing-risk Cox proportional hazard models to estimate adjusted hazard ratios (aHRs) between BMI change and all-cause mortality.

RESULTS

Among 720 adult participants, 21% had low BMI (<18.5 kg·m) at treatment initiation and 9% died either during (n=16) or after treatment (n=50). During the first 3-6 months of TB treatment, 17% lost weight and 14% had no weight change. Among 479 adults with normal baseline BMI (≥18.5-<25 kg·m), weight loss was associated with an increased risk of death during TB treatment (aHR 5.25, 95% CI 1.31-21.10). Among 149 adults with a low baseline BMI, no change in BMI was associated with increased post-TB treatment mortality (aHR 4.99, 95% CI 1.25-19.94).

CONCLUSIONS

Weight loss during TB treatment (among those with normal baseline BMI) or no weight gain (among those with low baseline BMI) was associated with increased rates of all-cause mortality. Our findings suggest that scaling up weight management interventions among those with M/XDR TB may be beneficial.