Association of Serum Lactate Dehydrogenase With Sepsis-Associated Acute Kidney Injury: A Large-Scale Analysis Based...

Sepsis-associated acute kidney injury (SA-AKI) frequently occurs during critical illness and represents a serious complication of sepsis. Although serum lactate dehydrogenase (LDH) may reflect tissue injury and metabolic derangement, large-cohort evidence relating LDH to SA-AKI remains limited.

We analyzed a retrospective cohort of adults with sepsis identified in Medical Information Mart for Intensive Care IV (MIMIC-IV). The exposure was serum LDH recorded during the first 24 h after ICU admission, grouped by quartile. Associations with SA-AKI were estimated using logistic regression models with stepwise covariate adjustment for demographics, comorbid disease, illness severity, and selected metabolic and inflammatory laboratory variables. Restricted cubic splines were fitted to assess possible nonlinearity.

The final cohort comprised 9461 patients. The incidence of SA-AKI increased from 44.2% in the lowest LDH quartile to 70.6% in the highest quartile (p < 0.001). In the expanded model including demographics, comorbidities, illness severity, lactate, white blood cell count, and glucose, higher LDH levels retained a statistically significant association with SA-AKI (adjusted OR: 1.033 per 100 U/L, 95% CI: 1.025-1.042, p < 0.001). Spline modeling indicated nonlinearity, with the curve becoming steeper in the higher LDH range.

In this MIMIC-IV cohort, LDH values obtained during the first 24 h after ICU admission were positively associated with SA-AKI. Because the analysis was observational, the results should be viewed as associative rather than causal.