Amino Acids

Acute kidney injury (AKI) is a frequent complication of cardiac surgery, contributing to increased morbidity, longer hospital stays, and higher mortality. Evidence suggests amino acid (AA) supplementation may enhance renal blood flow and glomerular filtration rate (GFR), potentially reducing AKI risk; however, findings remain inconclusive. This study evaluated the efficacy of perioperative AA supplementation in preventing AKI and related complications post‐cardiac surgery.

PubMed, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing AA supplementation versus standard care in preventing cardiac surgery‐associated AKI. Main outcomes included AKI incidence (defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria), 30‐day mortality, and renal replacement therapy (RRT) requirement. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using random‐effects models. Statistical significance was set at p < 0.05. The certainty of the evidence (CoE) was assessed using the GRADE approach.

Six RCTs involving 4501 cardiac surgery patients were included. AA mixture interventions significantly reduced the risk of AKI stage 1 (RR: 0.56; 95% CI: 0.77–0.96; p = .009; CoE: Moderate) and Stage 3 (RR: 0.53; 95% CI: 0.34–0.83; p = .005; CoE: Moderate), but not stage 2 (RR: 1.24; 95% CI: 0.60–2.55; p = .568; CoE: Low). Preliminary findings from glutamic acid and glutamine (single AA interventions) showed potential benefits in reducing AKI incidence (CoE: Very low) and improving surrogate biomarkers, respectively. No significant effects were observed on mortality or RRT incidence for any intervention.

AA mixtures likely reduce AKI incidence following cardiac surgery but show limited effects on mortality and RRT. Further trials are needed to confirm the benefits of glutamic acid and glutamine supplementation.

Use of amino acid supplementation for the prevention of acute kidney injury after cardiac surgery may be effective, but more trial data and confidence in a beneficial effect is needed for this to be implemented in everyday clinical practice.

A healthy life depends on the availability and the synthesis of amino acids as they are building blocks of proteins and regulators of principal physiological processes in organisms. Contemporary investigations have elucidated amino acids' roles in biological processes, emphasizing their contributions to preventing and treating metabolic disorders. Their structural architecture and nutritional importance elucidate their diverse biological roles, including muscle protein synthesis, immune support, neurological functions, and energy metabolism. Type 2 diabetes mellitus (T2DM), a prevalent metabolic disorder marked by insulin resistance and hyperglycemia, exemplifies a pertinent case for examining the relevance of amino acids in pathological conditions. The alteration of the amino acid profile, particularly high levels of leucine, isoleucine, and valine, is connected with insulin resistance and oxidative stress, which contribute to the progression of T2DM. In contrast, the potential therapeutic benefit of branched chain amino acid (BCAA) has earlier been reported to influence insulin signaling pathways, promote glucose uptake, and decrease inflammatory responses. However, the dosage and combination of amino acid intake through dietary interventions and supplementation may offer promising benefits to improve the management of T2DM effectively. This review investigates the functions of amino acids in normal physiological states, their potential as a diagnostic biomarker, the probable risk of deficiency, and the therapeutic ability for managing and preventing T2DM. Conversely, there is a need to intensively investigate the controversial dual role of BCAA in T2DM, the mechanism of amino acid actions in insulin resistance, the effect of a combination of amino acids, and the dosage limit in diabetic conditions.