The Impact of Diabetes and Prediabetes on Prevalence of Mycobacterium tuberculosis Infection Among Household Contacts of Active Tuberculosis Cases in Ethiopia
Authors: Smith Alison G C , Kempker Russell R , Wassie Liya , Bobosha Kidist , Nizam Azhar , Gandhi Neel R , Auld Sara C , Magee Matthew J , Blumberg Henry M ,   Tuberculosis Research Unit: Role of Antigen Specific Responses in the Control of TB (TBRU-ASTRa) Study Group, Ernst Joel , Ahmed Rafi , Sharling Lisa , Columbus Devin , Waller Lance , Elon Lisa , Knezevic Andrea , Jabbarzadeh Shirin , Wu Hao , Swanson Seegar , Chen Yunyun , Rengarajan Jyothi , Day Cheryl , Whatney Wendy , Quezada Melanie , Sasser Loren , Madan Lala Ranjna , Fergus Tawania , Ogongo Paul , Tran Anthony , Adekambi Toidi , Kaushal Deepak , Adekambi Toidi , Golden Nadia , Foreman Taylor , Bucsan Allison , Ibegbu Chris , Altman John , Contraras Alcantra Susanna , Sette Alessandro , Lindestam Arlehamn Cecilia , Allana Salim , Campbell Angela , Shah Sarita , Ray Susan , Brust James , Collins Jeffrey , Franczek Meghan , Daniel Jenna , Rao Anirudh , Goldstein Rebecca , Kabongo Madeleine , Oladele Alawode , Aseffa Abraham , Hamza Medina , Abebe Yonas , Mulate Fisseha , Wondiyfraw Mekdelawit , Degaga Firaol , Getachew Daniel , Tayachew Bere Dawit , Zewdu Meaza , Mussa Daniel , Tesfaye Bezalam , Jemberu Selam , Tarekegn Azeb , Assefa Gebeyehu , Jebessa Gutema , Solomon Zewdu , Neway Sebsibe , Hussein Jemal , Hailu Tsegaye , Geletu Alemayehu , Girma Edom , Legesse Million , Wendaferew Mitin , Solomon Hirut , Assefa Zenebech , Mekuria Mahlet , Kedir Misker , Zeleke Eleni , Zerihun Rediet , Dechasa Selam , Haile Emebet , Getachew Nahom , Wagari Firaol , Mekonnen Ruth , Bayu Samuel , Gebre-Medhin Melat , Kifle Alemayehu 
Published: June 2022

Abstract

Background
It is uncertain whether diabetes affects the risk of developing latent tuberculosis infection (LTBI) following exposure to Mycobacterium tuberculosis (Mtb). We assessed the relationship of diabetes or prediabetes and LTBI among close and household contacts (HHCs) of patients with active pulmonary tuberculosis (TB) disease in Addis Ababa, Ethiopia.

Methods
In this cross-sectional study, we performed interferon-γ release assays, TB symptom screening, and point-of-care glycolated hemoglobin (HbA1c) testing among HHCs of active TB cases. Diabetes status was classified into diabetes (HbA1c ≥6.5% or self-reported diagnosis), prediabetes (5.7%–6.4%), and euglycemia (≤5.6%). Multivariable logistic regression was used to determine the association of diabetes with LTBI.

Results
Among 597 study participants, 123 (21%) had dysglycemia including diabetes (n = 31) or prediabetes (n = 92); 423 (71%) participants were diagnosed with LTBI. Twelve of 31 (39%) HHCs with diabetes were previously undiagnosed with diabetes. The prevalence of LTBI among HHCs with diabetes, prediabetes, and euglycemia was 87% (27/31), 73% (67/92), and 69% (329/474), respectively. In multivariable analysis adjusted for age, sex, and HIV status, the odds of LTBI among HHCs with diabetes were 2.33 (95% confidence interval [CI], .76–7.08) times the odds of LTBI without diabetes. When assessing interaction with age, the association of diabetes and LTBI was robust among participants aged ≥40 years (adjusted odds ratio [aOR], 3.68 [95% CI, .77–17.6]) but not those &lt;40 years (aOR, 1.15 [95% CI, .22–6.1]).

Conclusions
HHCs with diabetes may be more likely to have LTBI than those with euglycemia. Further investigations are needed to assess mechanisms by which diabetes may increase risk of LTBI after Mtb exposure.