Summary
Background
Diabetes increases the risk of tuberculosis incidence and the risk of adverse treatment outcomes in patients with tuberculosis. Because prevalence of diabetes is increasing in low-income and middle-income countries where the burden of tuberculosis is high, prevention of diabetes carries the potential to improve tuberculosis control worldwide.
Methods
We used dynamic tuberculosis transmission models to analyse the potential effect of diabetes on tuberculosis epidemiology in 13 countries with high tuberculosis burden. We used data for previous diabetes prevalence in each country and constructed scenarios to represent the potential ranges of future diabetes prevalence. The country-specific model was calibrated to the estimated trend of tuberculosis incidence. We estimated the tuberculosis burden that can be reduced by alternative scenarios of diabetes prevention.
Findings
If the prevalence of diabetes continues to rise as it has been in the past decade in the 13 countries (base case scenario), by 2035, the cumulative reduction in tuberculosis incidence would be 8·8% (95% credible interval [CrI] 4·0–15·8) and mortality would be 34·0% (30·3–39·6). Lowering the prevalence of diabetes by an absolute level of 6·6–13·8% could accelerate the decline of tuberculosis incidence by an absolute level of 11·5–25·2% and tuberculosis mortality by 8·7–19·4%. Compared with the base case scenario, stopping the rise of diabetes would avoid 6·0 million (95% CrI 5·1–6·9) incident cases and 1·1 million (1·0–1·3) tuberculosis deaths in 13 countries during 20 years. If interventions reduce diabetes incidence by 35% by 2025, 7·8 million (6·7–9·0) tuberculosis cases and 1·5 million (1·3–1·7) tuberculosis deaths could be averted by 2035.
Interpretation
The diabetes epidemic could substantially affect tuberculosis epidemiology in high burden countries. The communicable disease and non-communicable disease sectors need to move beyond conventional boundaries and link with each other to form a joint response to diabetes and tuberculosis.