Clinical management of combined tuberculosis and diabetes

Optimal management of combined tuberculosis (TB) and diabetes (DM) is important but challenging in terms of achieving good disease outcomes and avoiding toxicity, drug interactions and other challenges. DM management during anti-tuberculosis treatment, aimed at improving TB treatment outcomes and reducing DM-related morbidity and mortality, consists of glycaemic control and measures to reduce the risk of cardiovascular disease. Metformin, the glucose-lowering drug of choice for TB patients, has no meaningful interaction with rifampicin (RMP), and may reduce TB mortality. Insulin is effective for severe hyperglycaemia, but has several disadvantages that limit its use in TB patients. Cardiovascular risk assessment should be considered in TB-DM patients to guide management in terms of counselling and prescription of antihypertensive, lipid-lowering and anti-platelet treatment. With regard to anti-tuberculosis treatment, DM is associated with an increased risk of drug resistance, lower exposure to anti-tuberculosis drugs, treatment failure and recurrent TB. Patients therefore need careful assessment before, during and possibly after anti-tuberculosis treatment. Although no studies have been performed, anti-tuberculosis treatment may also have to be prolonged or intensified in terms of regimen or drug dosage if DM is present. With regard to service delivery, combined treatment should probably be administered, supervised and monitored as much as possible in a TB clinic. Local circumstances and severity of DM will guide the need for referral of patients to specialised DM care, and continuation of DM care after completion of anti-tuberculosis treatment. More data are also needed for the management of TB-DM patients with human immunodeficiency virus co-infection.