Does aging modify pulmonary tuberculosis? A meta-analytical review

To evaluate the differences in the clinical, radiologic, and laboratory features of pulmonary tuberculosis (TB) in older patients, as compared to younger patients. A meta-analysis (the Schmidt-Hunter method) of published works found in MEDLINE and other sources was performed. A total of 12 studies were collected, and each variable was submitted to meta-analysis. No differences were found between older (>/= 60 years old) and younger TB patients with respect to male predominance, evolution time before diagnosis, prevalence of cough, sputum production, weight loss, fatigue/malaise, radiographic upper lobes lesions, positive acid-fast bacilli in sputum, anemia or hemoglobin level, and serum aminotransferases. A lower prevalence of fever, sweating, hemoptysis, cavitary disease, and positive purified protein derivative, as well as lower levels of serum albumin and blood leukocytes were noticed among older patients. In addition, the older population had a greater prevalence of dyspnea and some concomitant conditions, such as cardiovascular disorders, COPD, diabetes, gastrectomy history, and malignancies. This meta-analytical review identified the main differences of older TB patients, as compared to younger TB patients, that should be considered during the diagnostic evaluation. Most of these differences are explained by the already known physiologic changes that occur during aging.