Iron Deficiency and Anemia Predict Mortality in Patients with Tuberculosis3

Abstract

Many studies have documented a high prevalence of anemia among tuberculosis (TB) patients and anemia at TB diagnosis has been associated with an increased risk of death. However, little is known about the factors contributing to the development of TB-associated anemia and their importance in TB disease progression. Data from a randomized clinical trial of micronutrient supplementation in patients with pulmonary TB in Tanzania were analyzed. Repeated measures of anemia with iron deficiency, anemia without iron deficiency, and iron deficiency without anemia were assessed as risk factors for treatment failure, TB recurrence, and mortality. The prevalence of anemia (hemoglobin < 110 g/L) at baseline was 64%, more than one-half of which was related to iron deficiency (mean corpuscular volume , 80 fL). We found no evidence of an association between anemia (with or without iron deficiency) or iron deficiency without anemia at baseline and the risk of treatment failure at 1 mo after initiation. Anemia without iron deficiency was associated with an independent, 4-fold increased risk of TB recurrence [adjusted RR = 4.10 (95% CI = 1.88, 8.91); P < 0.001]. Iron deficiency and anemia (with and without iron deficiency) were associated with a 2- to nearly 3-fold independent increase in the risk of death [adjusted RR for iron deficiency without anemia = 2.89 (95% CI = 1.53, 5.47); P = 0.001; anemia without iron deficiency = 2.72 (95% CI = 1.50, 4.93); P = 0.001; iron deficiency anemia = 2.13 (95% CI = 1.10, 4.11); P = 0.02]. Efforts to identify and address the conditions contributing to TB-associated anemia, including iron deficiency, could play an important role in reducing morbidity and mortality in areas heavily affected by TB.

A systematic review of published literature describing factors associated with tuberculosis recurrence in people living with HIV in Africa

“…Following full text screening of the 9 manuscrip ts, 7,15,18,23,25,26,31,33,35 there were 5 manuscripts which were found not to specifically report risk factors for recurrent TB in people living with HIV/AIDS. 7,15,26,33,35 In addition, we screened the reference lists of the remaining 4 manuscripts 18,23,25,31 in order to identify other potentially eligible studies for inclusion in our systematic review, which did not yield any additional manuscripts.…”

“…Risk factors for recurrent TB in people living with HIV/AIDS were evaluated in participants from 4 studies conducted in 3 countries in Africa (Kenya, Malawi and Tanzania). 18,23,25,31 Three of the eligible manuscripts describe prospective observational studies. 18,23,31 One manuscript described the secondary analysis of data obtained from a randomized controlled trial.…”

“…Therefore, this systematic review was comprised of 4 eligible manuscripts. 18,23,25,31 A description of all eligible manuscripts evaluated in this systematic review is shown in Table 3. Risk factors for recurrent TB in people living with HIV/AIDS were evaluated in participants from 4 studies conducted in 3 countries in Africa (Kenya, Malawi and Tanzania).…”

“…18,23,31 One manuscript described the secondary analysis of data obtained from a randomized controlled trial. 25 Females comprised 38%, 18 54% 23 and 76% 31 of HIV-infected participants described in three of the eligible manuscripts. The remaining manuscript did not stratify results for gender by HIV status.…”

“…7,15,26,33,35 In addition, we screened the reference lists of the remaining 4 manuscripts 18,23,25,31 in order to identify other potentially eligible studies for inclusion in our systematic review, which did not yield any additional manuscripts. Therefore, this systematic review was comprised of 4 eligible manuscripts.…”