Nonlinear relationship between blood glucose and 30-day mortality in critical patients with acute kidney injury: A retrospective cohort study

Abstract

Background: Acute kidney injury (AKI) is a major health problem affecting millions of people worldwide. Effective preventative and therapeutic treatments remain to be produced. We aim to determine the association between blood glucose and mortality in critical patients with AKI. Method: This cohort study included 18,703 patients with AKI. The exposure of interest was baseline blood glucose. The outcome was 30-day mortality. Multivariable Cox regression analyses and smooth curve fitting were adopted to assess the independent association between blood glucose and 30-day mortality. Results: We identified 18,703 consecutive individuals with AKI. The average age of the participants was 66.8 ± 16.0 years, and about 42.7% of them were female. The overall 30-day mortality was 16.9%. Through the multivariate COX regression model and smooth curve fitting, we observed that the correlation between blood glucose and 30-day mortality is nonlinear. An inflection point was found at about 5.93 mmol/L. On the left side of inflection point, the effect size was 0.81 (HR: 0.81, 95% CI 0.74-0.89, p < 0.001). On the right side of inflection point, the effect size was 1.02 (HR: 1.02,95% CI 1.01-1.03, p < 0.001). Conclusion: Our study suggested that, among patients with AKI, there was a nonlinearity relationship between blood glucose and mortality in patients with AKI. The optimal of blood glucose associated with the lowest risk of 30-day mortality was around 5.93 mmol/L.