Prevention of kidney injury after myocardial ischemia reperfusion is achievable with short-term protein restriction

Introduction: Kidney injury is a serious complication after cardiovascular surgery. Left ventricular dysfunction, pre-operative kidney dysfunction and inflammation can predict kidney injury after myocardial reperfusion. Objectives: We aimed to study whether short-term protein restriction (PR) would influence blood urea nitrogen (BUN) levels after myocardial reperfusion injury. Materials and Methods: Male Wistar rats fed with either AIN-93M or AIN-93M protein restricted diet one week before myocardial reperfusion injury. After surgery, feeding continued with AIN-93M for 1 week. Results: BUN levels increased significantly compared to the pre-operative level in the control group (P = 0.03) and decreased significantly in the protein-restricted group (P = 0.01). Multivariate analysis showed that PR through its effect on blood glucose (β = 1.2, 95% CI = 0.1-2.34), IL-6 (β = -2.22, 95% CI = -3.9 – -0.54) and left ventricular ejection fraction (LVEF) (β = -1.21, 95% CI = -2.34- 0.09) was able to protect the kidney from myocardial reperfusion. Conclusion: Short-term PR through modulating pre-operative IL-6, post-operative blood glucose levels and LVEF could prevent kidney injury after myocardial reperfusion injury.