B NEUEN1, M JARDINE1, L SUKKAR1,2, A KANG1, C FOOTE3, K ROGERS1, A SCARIA1, A CASS4, M GALLAGHER1, M JUN
1The George Institute For Global Health, UNSW Sydney, Newtown, Australia, 2University of Sydney, Camperdown, Australia, 3Concord Repatriation General Hospital, Concord, Australia, 4Menzies School of Health Research, Darwin, Australia
Aim: To determine the risk of infection-related hospitalisation and mean hospital length of stay across different levels of kidney function in a community-based cohort study.
Background: The risk of infection associated with differing levels of kidney function is unclear.
Methods: Based on data from the EXTEND45 Study (the 45 and Up Study linked to hospital and community pathology datasets by the Centre for Health Record Linkage [CHeReL]), we identified a population-based cohort (2006-2014) of 41,099 people aged ≥45 years who had a measure of kidney function (estimated glomerular filtration rate [eGFR]). The risk of infection-related hospitalisation and mean hospital length of stay were assessed by eGFR categories (≥90, 60-89, 45-59, 30-44 and <30ml/min/1.73m2) using multivariable Cox regression.
Results: Of 41,099 participants, 18.6% had an eGFR <60 ml/min/1.73m2. Overall, 2,598 (6.3%) participants experienced ≥1 infection-related hospitalisation over a mean follow-up of 5.8 years. After adjusting for age and sex, risk of infection increased with declining eGFR in a graded and linear fashion (HR 0.91 [95% CI: 0.79-1.04], 1.16 [0.99-1.37], 1.48 [1.22-1.78], and 1.83 [1.44-2.31] for eGFR ≥90, 60-89, 45-59, 30-44, and <30 ml/min/1.73 respectively). Pneumonia, urinary tract infections, and cellulitis were the most common infections across all eGFR categories. Mean hospital length of stay similarly increased with declining eGFR categories (4.9, 6.5, 7.5, 7.8 and 7.9 days, respectively).
Conclusion: The risk of serious infection increases as kidney function declines, independent of age and sex, suggesting that susceptibility is likely related to other factors (e.g. alterations in immune function) and begins in mild-moderate renal impairment.
Dr Brendon Neuen is a PhD candidate at The George Institute for Global Health and Medical Registrar at Royal Prince Alfred Hospital. His primary interest is diabetes and CKD; he is leading several analyses of the CANVAS Clinical Trial Program to determine the potential cardiovascular and renoprotective effects of SGLT2 inhibitors. In 2018, he was awarded an Oxford Australia Clarendon Scholarship to undertake an MSc in Global Health at the University of Oxford. He has a keen interest in the role of social media in nephrology and is a member of the ISN Social Media Education Team. He can be found on Twitter as @brendonneuen