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.