Association between albumin to Globulin ratio and pneumonia in patients with aneurysmal subarachnoid hemorrhage

The albumin-to-globulin ratio (AGR) has been associated with infectious diseases; however, its association with pneumonia in patients with aneurysmal subarachnoid hemorrhage (aSAH) is unclear. This research aims to investigate the connection between AGR and hospital-acquired pneumonia (HAP). This retrospective analysis included 4,813 patients with aSAH from West China Hospital, Sichuan University. Serum samples were collected within seven days after admission. Logistic regression analysis was conducted to assess the association between AGR and HAP. Among the 4,813 patients, 1,249 (26.0%) developed HAP. The patients were classified into quartiles according to their AGR levels. Significant differences in odds ratios (ORs) were found in admission AGR: 0.76 (95% CI 0.63-0.93, p = 0.007) for Q2, 0.78 (95% CI 0.64-0.94, p = 0.016) for Q3, and 0.77 (95% CI 0.63-0.94, p = 0.012) for Q4 versus Q1. ORs of minimum AGR were: 0.67 (95% CI 0.57-0.80, p < 0.001) for Q2, 0.45(95% CI 0.37-0.54, p < 0.001) for Q3, and 0.24 (95% CI 0.20-0.30, p < 0.001) for Q4. ORs for AGR drift: 1.19 (95% CI 0.93-1.52, p = 0.18) for Q2, 1.35 (95% CI 1.06-1.73, p = 0.015) for Q3, and 2.00 (95% CI 1.57-2.55, p < 0.001) for Q4. Furthermore, admission AGR (< 1.21) and minimum AGR (< 0.99) were linked to elevated CURB-65 scores^3-5 in HAP patients, yielding ORs of 0.46 (95% CI 0.27-0.77, p = 0.003) and 0.44 (95% CI 0.27-0.69, p < 0.001). AGR was associated with an increased risk of HAP. Furthermore, lower minimum AGR was associated with increased severity of HAP among aSAH patients. Further research is necessary to confirm this finding and investigate the underlying mechanisms.