Patterns of First-Line Anti-Tuberculosis Drug Resistance and Multidrug-Resistant Tuberculosis and Their Association with Diabetes Co-Morbidity: A Cross-Sectional Study at the NTBLTC, Saye, Zaria, Northern Nigeria

Drug-resistant tuberculosis threatens global tuberculosis control, and diabetes mellitus is a plausible but incompletely characterised driver of both active and resistant disease in high-burden settings.This study characterised first-line anti-tuberculosis drug-resistance patterns, including multidrug-resistant tuberculosis, and examined their association with diabetes co-morbidity among presumptive tuberculosis patients at a national reference centre in northern Nigeria.A facility-based, descriptive cross-sectional study enrolled 200 consecutive presumptive-TB adults at the National Tuberculosis and Leprosy Training Centre, Saye, Zaria.Tuberculosis was diagnosed using Ziehl-Neelsen smear microscopy, the Xpert MTB/RIF assay, and Löwenstein-Jensen culture with first-line drug-susceptibility testing by the proportion method; a single fasting plasma glucose measurement classified diabetes status.Associations were assessed using chisquare or Fisher exact tests and logistic regression at a significance threshold of 0.05.Bacteriologically confirmed tuberculosis was identified in 26.0% of participants and diabetes in 17.0%.Among 48 culture-positive isolates with valid drug-susceptibility testing, isoniazid resistance was most frequent (22.9%), followed by rifampicin (16.7%), streptomycin (14.6%), and ethambutol (10.4%); across all 52 confirmed cases, rifampicin resistance was 17.3% (9/52) and multidrug-resistant tuberculosis 11.5% (6/52).Any first-line resistance and multidrug resistance were more than twice as frequent among the 13 tuberculosis patients with diabetes than among the 39 without (46.2%versus 20.5% and 23.1% versus 7.7%, respectively), although these differences did not reach statistical significance (Fisher exact p = 0.086 and p = 0.157).Diabetes independently predicted confirmed tuberculosis (adjusted odds ratio 2.34, 95% CI 1.08-5.05),alongside prior tuberculosis treatment and low body-mass index.Because diabetes was based on a single fasting plasma glucose measurement obtained during acute illness, stress hyperglycaemia cannot be excluded.These findings reveal a substantial resistance burden at referral level and a consistent but statistically unconfirmed resistance signal associated with diabetes.Routine drugsusceptibility testing and bidirectional tuberculosis-diabetes screening are warranted, and larger studies are needed to confirm the resistance association.