Serum glucose mediated association of serum lactate with acute kidney injury among AIS patients

Background

The serum lactate level has been confirmed to be an independent risk factor for the occurrence of acute kidney injury (AKI) in many diseases. However, the correlation between serum lactate level and AKI in critical patients with acute ischemic stroke (AIS) has not been clear. Moreover, limited studies have examined the mediating effect of serum glucose on the association between serum lactate and AKI.

Methods

We identified 1,435 AIS patients from the Medical Information Mart for Intensive Care (MIMIC-III) database and divided them into AKI or No-AKI groups. We used a propensity score matching method to reduce confounding factors. Linear regression, logistic regression, and restricted cubic splines (RCS) plots were used to evaluate relationships between serum lactate levels and AKI. Finally, the mediating role of serum glucose on the relationship between serum lactate and AKI was investigated utilizing the mediation analysis.

Results

In the present study, a total of 634 critical patients aged ≥ 18 years with AIS were included after propensity score matching (1:1). We used RCS plotting to reveal a linear association between serum lactate levels and AKI (P for nonlinearity < 0.001). After full adjustment for potential confounders (Model 3), high lactate levels increased the risk of AKI (odds ratio, 2.216; 95 % confidence interval, 1.559–3.271; P-value < 0.001). Serum glucose explained 14.9 % of the association between serum lactate and AKI among critical patients with AIS (P-value < 0.001), 16.4 % among patients with AIS and diabetes mellitus (DM) (P-value = 0.24), and 19.5 % among patients with AIS and without DM (P-value < 0.001).

Conclusion

Serum lactate was independently associated with increased risk-adjusted AKI in critical patients with AIS. The increase in serum glucose may have mediated this effect, especially in patients without DM.