Patients with stage 5 chronic kidney disease (CKD5) are at greater risk of developing tuberculosis (TB) than the general population, especially if they are male or receiving dialysis, suggests a Singapore study.
“Clinicians should maintain a high degree of suspicion for TB in CKD5 patients with compatible clinical symptoms,” the researchers said.
This retrospective cohort study included all CKD5 patients registered in Singapore’s renal registry who developed active pulmonary and extra-pulmonary TB between 2012 and 2021, following their CKD5 diagnosis. [Ann Acad Med Singap 2026;55:64-73]
The incidence of TB was significantly higher among patients with CKD5 than the general population in Singapore. From 2012 to 2021, TB incidence ranged from 279 to 630 per 100,000 CKD5 population compared with 32.6 to 41.1 per 100,000 general population.
Univariable comparisons showed that male sex (odds ratio [OR], 1.66, 95 percent confidence interval [CI], 1.3‒2.12; p<0.001), Malay ethnicity (OR, 1.33, 95 percent CI, 1.02‒1.72; p=0.03), and reported history of “ever smoking” (OR, 2.93, 95 percent CI, 2.15‒4.03; p<0.001) significantly increased the risk of developing TB disease in CKD5 patients.
Patients with CKD5 who were on any type of dialysis also showed an increased risk of TB development relative to those who had not been initiated on dialysis: haemodialysis (OR, 2.31, 95 percent CI, 1.69‒3.23; p<0.001), peritoneal dialysis (OR, 2.53, 95 percent CI, 1.46‒4.23; p=0.001), or a combination of haemodialysis and peritoneal dialysis (OR, 2.55, 95 percent CI, 1.63‒3.95; p<0.001).
These factors persisted in multivariable models, except ethnicity.
“The findings strengthen the evidence on the increased risk among CKD5 patients of developing TB disease, compared to the general population, especially in a moderate TB incidence country with a growing CKD5 population such as Singapore,” the researchers said.
Cigarette smoking
Furthermore, previous studies have shown significant associations between smoking and TB, including one on latent TB infection in CKD patients in Indonesia, which found Interferon-gamma Release Assay positivity to be more frequent in smokers. [J Clin Tuberc Other Mycobact Dis 2022;27:100302]
“Cigarette smoke contains harmful components which lead to peribronchial inflammation and fibrosis, disruption of mucociliary clearance and subsequently increase susceptibility to pulmonary infections including TB progression,” the researchers said. “However, they did not observe significant association between age and sex otherwise.”
Older age
The current study also found that older CKD5 patients (≥80 years) were less likely to develop TB than those aged <50 years. Notably, nearly three in four (74 percent) CKD5 patients who were not on dialysis were >70 years of age.
“This is likely a reflection of an individualized clinical decision-making process made between the managing renal physician with the patient after weighing risks and benefits of dialysis initiation including the impact on quality of life and expected survival outcomes,” the researchers said. [J Clin Med 2019;8:5]
“[T]he seemingly lower risk for TB disease in CKD5 patients aged 80 years and above may be due to the shorter time and lower chance they have of developing TB prior to death from other causes, rather than a protective effect of older age,” they added.
Moreover, older patients tend to have increased social isolation and frailty, which can potentially protect them from getting infected. [Lancet Healthy Longev 2021;2:e70-77]
“This hypothesis may be borne out in another study where most TB-dialysis patients were also in the age range 55–74 years,” the researchers said. [J Clin Tuberc Other Mycobact Dis 2022;27:100302]
“These findings would suggest that patients of advanced age may benefit the least from TB screening, as compared to younger patients, given the high competing risk of death,” they added.