New screening technologies for type 2 diabetes mellitus appropriate for use in tuberculosis patients [Review article]

Abstract

Type 2 diabetes mellitus (DM), which is epidemic in lowand middle-income countries (LMICs), may threaten gains made in tuberculosis (TB) control, as DM is both a major risk factor for developing active TB and it can lead to adverse TB treatment outcomes. Despite World Health Organization guidance that all TB patients should be screened for DM, most facilities in LMICs that manage TB patients do not currently perform screening for DM, due in part to the cost and complexity involved. DM screening is further complicated by the presentation of transient hyperglycemia in many TB patients, as well as differences in diabetes risk factors (e.g., body mass index) between TB patients and the general public. In this article, we review existing and new technologies for DM screening that may be more suitable for TB patients in LMICs. Such methods should be rapid, they should not require fasting, and they should allow the provider to differentiate between transient and longer-term hyperglycemia, using inexpensive tools that require little training and no specialized infrastructure. Several methods that are currently under development, such as point-of-care glycated hemoglobin and glycated albumin assays, non-invasive advanced glycation end-product readers, and sudomotor function-based screening devices, offer interesting performance characteristics and warrant evaluation in populations with TB.

Diabetes and pre-diabetes in tuberculosis patients in western Kenya using point-of-care glycated haemoglobin

“…6,12,15,16 Undiagnosed, inadequately treated and poorly controlled DM appears to be a much greater threat to TB prevention and control than has been realised previously. 17 Despite guidance from the World Health Organization (WHO), 18 most facilities in sub-Saharan Africa are still not screening TB patients for DM, partly due to cost, perceived complexities 19,20 and lack of a treatment infrastructure for those who screen positive. Transient hyperglycaemia caused by TB disease or medication, and similarities in symptom presentation, such as weight loss, further complicate the process.…”

“…Use of fasting blood glucose (FBG), the oral glucose tolerance test (OGTT) and random blood glucose (RBG) either require patients to fast for several hours before blood testing or have specific time-bound measurements and/or interpretations affected by transient hyperglycaemia, necessitating multiple measurements. 19,20 Use of glycated haemoglobin (HbA1c) does not require the patient to fast, is equally sensitive and, if offered at point of care (POC), minimises the time to diagnosis. 21,22 The devices are more expensive, however, and readings can be affected by anaemia and different haemoglobin variants.…”

“…21,22 The devices are more expensive, however, and readings can be affected by anaemia and different haemoglobin variants. 19,21,22 Kenya is heavily burdened by disease, with the principal challenges coming from communicable diseases such as malaria, human immunodeficiency virus (HIV) and TB, which accounted for 64% of deaths in 2014. 23,24 Non-communicable diseases were responsi-Public Health Action ble for 27% of all deaths in the same year, of which DM accounted for at least 1%, 24 although this rate is likely an underestimate due to the many undiagnosed cases in the country.…”

The impact of Diabetes Mellitus on epidemiological, clinical, radiological features of tuberculosis. Seven years experience in a Mexican teaching hospital

“…Therefore, it is essential to take as an example what happened in the 80's/90's, regarding the management of TB-HIV co-infection, when a slow and uncoordinated global response has allowed the increase of HIV-associated TB mortality (23). As for HIV, in fact, possible screening tests, such as the measurement of glycosuria, random blood glucose, fasting blood glucose, oral glucose tolerance test and HbA1c, would lead to early detection of DM at a primary healthcare level (24)(25)(26)(27). On the other hand, screening for DM in patients with tuberculosis could lead to early detection of DM cases and to an early connection between TB and DM, as indicated by the WHO in a context of cooperation with the International Union Against Tuberculosis and Lung Diseases in order to improve the joint management of the two diseases (28) in terms of treatment and outcome.…”

Taking on the diabetes-tuberculosis epidemic in India: paving the way through operational research [Editorial]

“…The second review article looks at existing and new technologies for screening and diagnosing type 2 DM that may be more suitable for TB patients in low-and middle-income countries. 6 As pointed out, these new technologies should be low cost, rapid, easy to use, non-invasive, requiring minimal additional infrastructure and able to differentiate between transient and longer term hyperglycaemia. Several tools in development, such as point-of-care glycated haemoglobin and glycated albumin assays, non-invasive advanced glycation end (AGE) product readers and sudomotor function-based screening devices, are discussed.…”