Abstract
BACKGROUND: Diabetes is a risk factor for mortality during rifampicin-resistant tuberculosis (RR-TB) treatment, but whether its impact differs by nutritional status is unknown. We estimated the effect of diabetes and its interaction with low body mass index (BMI) (ie, <18.5 kg/m(2)) on all-cause mortality during treatment of RR-TB. METHODS: We used medical record data of adults treated for RR-TB in Indonesia between March 2020 and May 2022. Diabetes was defined as glycated hemoglobin ≥6.5% or prior diabetes diagnosis by healthcare providers. Cox proportional hazards regression was used to estimate the hazard rates of mortality during treatment comparing those with and without diabetes. Multiplicative and additive interactions were evaluated to determine if the effect of diabetes on mortality during treatment was moderated by BMI status. RESULTS: Among 345 individuals (57% male, 1.7% with human immunodeficiency virus, 59% with BMI <18.5 kg/m(2)), 96 (28%) had diabetes and 62 (18%) died. Adjusting for confounders, the hazard rates of mortality during treatment were higher among those with diabetes (adjusted hazard rate ratio [aHR], 2.05 [95% CI, 1.17-3.58]) or those with BMI <18.5 kg/m(2) (aHR, 2.33 [95% CI, 1.28-4.21]). No significant multiplicative nor additive interaction was detected, but the hazard rates of mortality were highest among those with diabetes and BMI <18.5 kg/m(2) (aHR, 7.14 [95% CI, 2.71-18.82]) compared to those without diabetes and BMI ≥18.5 kg/m(2). CONCLUSIONS: Having diabetes doubled the risk of mortality during RR-TB treatment. Highest mortality rates were observed among individuals with combined diabetes and low BMI.