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Cardio Diabetes Medicine 2017 207

Diabetes Mellitus and

Tuberculosis - Double Jeopardy

Dr. Prof. Preetam Arthur, MD, FRCP
Professor and Head of General Medicine, Sri Ramachandra Medical University
&
Dr. Harshavardhan TS, MD.,
Senior Resident, General Medicine, Sri Ramachandra Medical University

Abstract hand we have reduced, by many folds, very many
This chapter attempts to throw light on the sinister infectious diseases that once were the scourge of
association between Diabetes mellitus and tubercu- mankind, but the resilient Mycobacterium tubercu-
losis and how they influence each other. Diabetes losis continues to plague us constantly in everyday
is a recognised risk factor to develop tuberculosis, medical practice. In fact many prior articles on this
and this correlates with poor glycemic control. This concurrence of diseases have called it the ‘double
has been attributed to a weakened immune response epidemic’ – signifying the paralleled rise in the diag-
to Mycobacterium tuberculosis among diabetics and nosis of both of these diseases in recent times. We
genetic factors have also been implicated. Clinical are deeming it ‘Double Jeopardy’. A national level,
presentation of tuberculosis in diabetics has been multi-centric study from the India Diabetes-TB study
described to be different from that in non-diabetics, group, in which our institute was a part, studied the
though various studies have differed in their find- prevalence of diabetes in patients with a diagnosis
ings. Multifocal, lower lobe predominant and cavi- of tuberculosis. Of the patients who were diagnosed
tatory disease has been described in some studies to have tuberculosis, 20% of south Indian patients
as more common in diabetics. Tuberculosis is also and 10% of patients from North India had diabetes
considered to influence diabetes. During acute dis- mellitus. This chapter attempts to throw light on the
ease, glycemic control is worsened in diabetics and sinister association between these two very common
can cause glucose intolerance in people with no pri- diseases and how they influence each other. A phy-
or diabetes. Concurrent diabetes and tuberculosis sician must be aware of how the occurrence of both
in a patient poses management issues that are im- tuberculosis and diabetes affects the clinical presen-
portant for the treating physician. Drug interactions tation and outcome of either disease process. We
between Rifampicin and oral glycemic agents are have also highlighted how the concurrence of both
significant. Rifampicin levels have also been shown of these diseases affects practical management. (1) (2)
to be reduced in diabetics probably due to reduced
absorption. Combined toxicities of drug therapy and 2. Diabetes as a risk for latent tuberculosis :
disease must also be considered in the treatment of Tuberculosis, as we know, is a two step process -
such a patient. It is therefore prudent to screen every infection and disease. The association between both
patient with tuberculosis for diabetes and engage in these entities and diabetes has been the subject of
strict glycemic control with heightened awareness on multiple observational studies. A recent meta-anal-
drug interactions and overlapping toxicities. Thus the ysis looking at the association between the occur-
double jeopardy of diabetes and tuberculosis is an rence of latent tuberculosis infection (LTBI) and dia-
entity that we have highlighted in this chapter. betes mellitus concludes that diabetes is associated
with a small but statistically significant risk for latent
1. Introduction: TB infection. However this risk is small and has not
Diabetes Mellitus is a ubiquitous disease that has prompted the World Health Organisation and other
taken centre stage in the realm of modern medicine, international societies to recommend routine LTBI
a disease that affects nearly every fifth patient that screening in all diabetics, unlike in HIV positive pa-
walks into a physician’s office in India. On the other tients. Though the association with LTBI risk is not

Cardio Diabetes Medicine