Evaluation of Carnitine Acetyltransferase Levels and Oxidative Stress in Early- and Advanced-Stage Diabetic Nephropathy

AIM: Diabetic nephropathy (DN) is a leading cause of end-stage renal disease, with oxidative stress and mitochondrial dysfunction playing key roles in its progression. Carnitine acetyltransferase (CrAT) supports mitochondrial function by buffering excess acyl-CoA substrates, yet its role in DN remains unclear. This study aimed to evaluate changes in serum CrAT concentration across different DN stages and examine its relationship with oxidative stress.
MATRERIAL and METHOD: This cross-sectional study included patients with type 2 diabetes mellitus (T2DM) categorized into non-DN (n = 24), early-stage DN (n = 24), and advanced-stage DN (n = 32) based on clinical criteria. Serum CrAT levels, oxidative stress markers (total antioxidant status [TAS] and total oxidant status [TOS]), and renal function parameters were measured.
RESULTS: CrAT levels were significantly higher in early-stage DN compared to non-DN patients but markedly lower in advanced-stage DN (DN (-): 21.4 ± 2.1 vs. Early-stage DN: 29.2 ± 6.5 vs. Advanced-stage DN: 16.4 ± 2.0 ng/mL, p < 0.001). Oxidative stress worsened progressively with DN severity, and in early DN, CrAT was negatively correlated with TAS (r = -0.458, p < 0.001) and positively correlated with TOS (r = 0.526, p < 0.001). However, these correlations disappeared in advanced DN. Regression analyses revealed that higher CrAT levels were independently associated with early DN (OR = 2.39, 95% CI = 1.35–4.25, p = 0.004), while lower CrAT levels were linked to advanced DN (OR = 0.31, 95% CI = 0.13–0.74, p = 0.009). Diagnostic performance analysis indicated that CrAT levels were superior to oxidative stress markers in distinguishing DN stages.
CONCLUSION: CrAT levels showed stage-specific changes in DN, increasing in early disease and declining in advanced stages, while their association with oxidative stress was evident only in early DN.