Association between nephrotic syndrome and tuberculosis in ICU patients: A cross-sectional study of the MIMIC-IV database

Background: This study investigated hospital mortality rates among patients with nephrotic syndrome (NS) and tuberculosis (TB) using data from the Medical Information Mart for Intensive Care IV version 2.2 (MIMIC-IV v2.2) database. The aim was to assess the impact of TB infection on in-hospital mortality risk in NS patients. Methods A total of 2167 NS patients were enrolled, among whom 1079 were co-infected with TB. Potential confounding factors included demographics, vital signs, laboratory values, acute physiology score, clinical treatments, and comorbidities. Univariate logistic regression was conduted to identify in-hospital mortality risk factors and multivariable multifactorial logistic regression was performed to explore the TB’s impact on in-hospital mortality. A restricted cubic spline regression analysis was carried out to investigate the linear relationship between hemoglobin, albumin, and in-hospital mortality. Stratified analyses were conducted for age, gender, sepsis, and acute kidney injury(AKI) stage to determine their effect on mortality of NS co-infected with TB. Results The prevalence of NS co-infected with TB was 49.8%, with a 14.6% in-hospital mortality rate, representing a 44% increased risk (P=0.005). The adjusted multivariable analysis revealed a mortality risk exceeding 20%. Among patients with sepsis, the incidence was 48.3% in those without TB and 46.7% in those co-infected with TB, with a 63% incidence of AKI within 7 days. Sepsis was associated with a 2.54-fold increase in mortality risk, and AKI stage 3 had an odds ratio (OR) of 9.03. Subgroup analyses suggested that both sepsis and AKI were independent risk factors for mortality. Hemoglobin and albumin exhibitedL-shaped linear relationships with in-hospital mortality, acting as protective factors below the inflection point. Only 1.8% received steroid treatments (NS 2.6%, NS and TB 0.9%), and 10.1% underwent continuous renal replacement therapy. Conclusions Our study results revealed significantly increased in-hospital mortality risk among NS patients with concurrent TB infection, alongside numerous complications. Sepsis and AKI independently increase mortality risk in NS patients co-infected with TB. These findings inform disease severity assessment and prognosis determination in adult NS patients with TB co-infection.