Rethinking the syndemic of tuberculosis and dysglycaemia: a Kenyan perspective on dysglycaemia as a neglected risk factor for tuberculosis

Abstract

Background: The END TB 2035 goal has a long way to go in low-income and low/middle-income countries (LICs and LMICs) from the perspective of a non-communicable disease (NCD) control interaction with tuberculosis (TB). The World Health Organization has identified diabetes as a determinant for, and an important yet neglected risk factor for tuberculosis. National guidelines have dictated testing time points, but these tend to be at an isolated time point rather than over a period of time. This article aims to give perspective on the syndemic interaction of tuberculosis and dysglycaemia and how the gaps in addressing the two may hamper progress towards END TB 2035.

Main text: Glycated haemoglobin (HbA1C) has a strong predictive association with the progression to subsequent diabetes. Therefore, screening using this measure could be a good way to screen at TB initiation therapy, in lieu of using the random blood sugar or fasting plasma glucose only. HbA1C has an observed gradient with mortality risk making it an informative predictor of outcomes. Determining the progression of dysglycaemia from diagnosis to end of treatment and shortly after may offer information on the best time point to screen and follow-up. Despite TB and Human Immunodeficiency Virus (HIV) disease care being free, hidden costs remain. These costs are additive if there is accompanying dysglycaemia. Regardless of receiving TB treatment, it is estimated that almost half of persons affected by pulmonary TB develop post-TB lung disease (PTLD) as an outcome and the contribution of dysglycaemia is not well described.

Conclusions: Establishing costs of treating TB with diabetes/prediabetes alone and in the additional context of HIV co-infection will inform policy makers on what it takes, financially, to treat these patients and subsidize dysglycaemia care. In Kenya, cardiovascular disease is only rivalled by infectious disease as a cause of mortality, and diabetes is a well-described risk factor for cardiac disease. In poor countries, communicable diseases are responsible for majority of the mortality burden, but societal shifts and rural-urban migration may have contributed to the observed increase of NCDs.

Keywords: Diabetes; Dysglycaemia; END TB 2035; HIV; NCDs; Prediabetes; Tuberculosis.