Endocrine and Metabolic Manifestations of Tuberculosis

Abstract

Tuberculosis (TB) is a communicable disease caused by Mycobacterium tuberculosis bacilli, and is a major health concern in low- and middle-income countries (LMICs). Though classically seen as pulmonary disease, extrapulmonary TB, affecting various organs and other systems, is not uncommon. Endocrine gland involvement in TB, as seen in the pre-antibiotic era, has markedly reduced in recent years with the availability of effective anti-TB therapy. Although rare, TB of endocrine glands, such as the adrenals, thyroid, and pituitary have pathophysiologic effects that are clinically significant. The thymus, parathyroid, pancreas, pineal gland, and gonads are other endocrine glands which may be affected by TB. The most commonly involved is the adrenal gland, and TB is an important cause of Addison’s disease in LMICs. The thyroid gland is rarely involved and thyroid dysfunction is uncommon. Hypothalamic—pituitary dysfunction due to intracranial tuberculoma or tuberculous meningitis has also been reported. Involvement of the endocrine glands can also be a part of severe disseminated or miliary TB. Diagnosis of endocrine gland involvement in TB is a great clinical challenge and therefore a high index of suspicion must prompt one to investigate the patient thoroughly. A high prevalence of diabetes mellitus among patients with TB and likewise an incidence of TB among patients with diabetes, are both matters of concern in developing countries. It is now known that, even in the absence of direct gland involvement, the tuberculous disease process and/or anti-TB treatment can result in endocrine and metabolic derangements. Metabolic abnormalities like hyponatremia and hypercalcemia are also seen with TB. Both tuberculous involvement of endocrine glands as well as secondary metabolic and endocrine complications due to the disease need to be identified appropriately, as they may need some early supportive care. Endocrine TB and its complications usually respond well to current anti-tuberculous therapy. Hormonal therapy or specific interventions may be necessary only occasionally for correction of endocrine dysfunction.