Prevalence, Length of Stay, and Hospitalization of Acute Kidney Injury in Patients With and Without Sjogren’s Syndrome

BACKGROUND: Literature on the outcome of acute kidney injury (AKI) in Sjogren’s syndrome (SJS) is quite scanty. Acute kidney injury has emerged as a significant cause of morbidity and mortality in patients with autoimmune diseases such as systemic lupus erythematosus. OBJECTIVE: To examine the outcome of AKI with and without SJS. To achieve this, we examined the prevalence, mortality, outcomes, length of stay (LOS), and hospital charges in patients with AKI with SJS compared with patients without SJS from a National Inpatient Sample (NIS) database in the period 2010 to 2013. DESIGN: A retrospective cohort study using NIS. SETTING: United States. SAMPLE: Cohort of 97 055 weighted patient discharges with AKI from the NIS. MEASUREMENTS: Not applicable. METHODS: Data were retrieved from the NIS for adult patients admitted with a principal diagnosis of AKI between 2010 and 2013, using the respective International Classification of Diseases, Ninth Revision (ICD-9) codes. The study population divided into 2 groups, with and without Sjogren’s disease. Multivariate and linear regression analysis conducted to adjust for covariates. We omitted patients with systemic sclerosis and rheumatoid arthritis from the analysis to avoid any discrepancy as they were not meant to be a primary outcome in our study. RESULTS: The study population represented 97 055 weighted patient discharges with AKI. Analysis revealed AKI patients with Sjogren’s compared with patients without Sjogren’s had statistically significant lower hyperkalemia rates (adjusted odds ratio: 0.65, confidence interval: 0.46-0.92; P = .017. There was no statistically significant difference in mortality, LOS, hospital charges, and other outcomes. LIMITATIONS: Study is not up to date as data are from ICD-9 which are testing data from 2010 to 2013, and data were obtained through SJS codes, which have their limitations. Also, limitations included lack of data on metabolic acidosis, hypokalemia, and not including all causes of AKI. CONCLUSIONS: At present, our study is unique as it has examined prevalence, mortality, and outcomes of Sjogren’s in patients with AKI. Patients with Sjogren’s had significantly lower hyperkalemia during the hospitalization. Further research is needed to identify the underlying protective mechanisms associated with Sjogren’s that resulted in lower hyperkalemia. TRIAL REGISTRATION: Not applicable.