Tuberculosis risk among people with diabetes mellitus in Sub‐Saharan Africa: A systematic review

Abstract

Objectives People with diabetes mellitus (DM) have a higher tuberculosis (TB) risk, but the evidence from sub‐Saharan Africa (SSA) was scarce until recently and not included in earlier global summaries. Therefore, this systematic review aims to determine the risk of active TB disease among people with DM in SSA and whether HIV alters this association. Methods Medline, Embase, CINAHL, Web of Science, Global Health and African Index Medicus were searched between January 1980 and February 2021. Cohort, case‐control and cross‐sectional studies from SSA, which assessed the association between DM and active TB, were included if adjusted for age. Two researchers independently assessed titles, abstracts, full texts, extracted data and assessed the risk of bias. Estimates for the association between DM and TB were summarised using a random effects meta‐analysis. PROSPERO: CRD42021241743. Results Nine eligible studies were identified, which reported on 110,905 people from 5 countries. Individual study odds ratios (OR) of the TB–DM association ranged from 0.88 (95% CI 0.17–4.58) to 10.7 (95% CI 4.5–26). The pooled OR was 2.77 (95% CI 1.90–4.05). High heterogeneity was reduced in sensitivity analysis (from I2 = 57% to I2 = 6.9%), by excluding one study which ascertained DM by HbA1c. Risk of bias varied widely between studies, especially concerning the way in which DM status was determined. Conclusions There is a strong positive association between DM and active TB in SSA. More research is needed to determine whether HIV, a key risk factor for TB in SSA, modifies this relationship.

Undernutrition as a risk factor for tuberculosis disease

“…To identify relevant studies, we developed an empirically derived search strategy for MEDLINE. First, we sourced relevant cohort studies from five known systematic reviews on 'tuberculosis and diabetes' (= 4) [ 6 , 23 , 24 , 25 ] and 'tuberculosis and undernutrition' (= 1) [ 8 ]. This yielded a set of 25 relevant references as a study pool for diabetes and five relevant studies for undernutrition.…”

Immunologic, metabolic and genetic impact of diabetes on tuberculosis susceptibility

“…Correspondingly, the clinical presentation and prognosis of T2DM show considerable heterogeneity, with the clustering of 32 phenotypes identifying 4 archetypes with different dysfunctional patterns across T2DM etiological processes ( 125 ). Moreover, in the context of Africa, there is a relative scarcity of epidemiological data compared to Asia, with a 2.77 TB disease risk previously reported ( 126 ). The influence of HIV and COVID-19, major risk factors in the TB-T2DM comorbidity need to be assessed.…”

How can tuberculosis services better support patients with a diabetes co-morbidity? A mixed methods study in the Philippines

“…People with diabetes mellitus (DM) have an estimated two- to three-times greater risk of poor tuberculosis (TB) treatment outcomes compared to those without DM [ 1 – 9 ]. Improving the management of DM among persons with TB could optimise TB treatment outcomes [ 10 – 14 ].…”