title: Impact of diabetes and smoking on mortality in tuberculosis.
abstract: BACKGROUND
  Diabetes mellitus is a risk factor for tuberculosis (TB) disease. There is evidence that diabetes also influences TB severity and treatment outcomes but information is incomplete and some published results have been inconsistent.
  
  
  METHODS
  A longitudinal cohort study was conducted at the National Masan Tuberculosis Hospital in the Republic of Korea. Subjects presenting with a first episode of TB or for retreatment of TB were followed from enrollment through completion of treatment. Demographic, clinical, and microbiological variables were recorded, along with assessment of outcomes. Results were compared in TB patients with and without diabetes or smoking history. Data were adjusted for gender, age, cohort, educational level and alcohol consumption.
  
  
  RESULTS
  The combined cohorts comprised 657 subjects. Diabetes was present in 25% and was associated with greater radiographic severity and with recurrent or relapsed TB. Diabetes and cigarette smoking independently increased the risk of death in the first 12 months after enrollment. Estimating the combined impact of diabetes and smoking yielded a hazard ratio of 5.78. Only 20% of diabetic subjects were non-smokers; 54% smoked ≥1 pack daily. In this cohort, the impact of diabetes on mortality was greater in patients younger than 50 years, compared to older patients.
  
  
  CONCLUSIONS
  In this cohort of Korean patients, diabetes exacerbated the severity of TB disease. Diabetic subjects who smoked ≥1 pack of cigarettes daily were at particularly high risk of death from TB. Strategies to improve TB outcomes could productively focus resources for patient education and TB prevention on the vulnerable population of younger diabetics, particularly those who also smoke.
authors.affiliation: Department of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: George W
authors.initials: GW
authors.lastname: Reed
authors.forename: Hongjo
authors.initials: H
authors.lastname: Choi
authors.forename: So Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Myungsun
authors.initials: M
authors.lastname: Lee
authors.forename: Youngran
authors.initials: Y
authors.lastname: Kim
authors.forename: Hyemi
authors.initials: H
authors.lastname: Park
authors.forename: Jongseok
authors.initials: J
authors.lastname: Lee
authors.forename: Xin
authors.initials: X
authors.lastname: Zhan
authors.forename: Hyeungseok
authors.initials: H
authors.lastname: Kang
authors.forename: SooHee
authors.initials: S
authors.lastname: Hwang
authors.forename: Matthew
authors.initials: M
authors.lastname: Carroll
authors.forename: Ying
authors.initials: Y
authors.lastname: Cai
authors.forename: Sang-Nae
authors.initials: SN
authors.lastname: Cho
authors.forename: Clifton E
authors.initials: CE
authors.lastname: Barry
authors.forename: Laura E
authors.initials: LE
authors.lastname: Via
authors.forename: Hardy
authors.initials: H
authors.lastname: Kornfeld
mesh_terms: D000368:Aged; D000995:Antitubercular Agents / Q000627:therapeutic use; D015331:Cohort Studies; D048909:Diabetes Complications / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000401:mortality*
chemical_list: D000995:Antitubercular Agents