Aslanoglu, NuriKeskek, Sakir OzgurNeselioglu, SalimEren, Funda2026-01-242026-01-2420252359-39972359-4292https://doi.org/10.20945/2359-4292-2025-0042https://hdl.handle.net/20.500.12868/5281Objective: To evaluate the effect of diabetes mellitus and its chronic complications on thiol/disulfide homeostasis. Methods: The study included 381 participants divided into six groups: healthy controls (Group 1; n = 91), patients with prediabetes (Group 2; n = 50), patients with diabetes mellitus without complications (Group 3; n = 70), patients with diabetic retinopathy (Group 4; n = 47), patients with diabetic nephropathy (Group 5; n = 70), and patients with diabetic foot (Group 6; n = 53). Thiol/disulfide homeostasis was determined by measuring the reduction reaction of oxidized thiols. Results: Native thiol levels were low in patients with diabetes mellitus complications (Group 4, 264.7 +/- 58.5 mu mol/L; Group 5, 246.6 +/- 67.5 mu mol/L; Group 6, 174.3 +/- 65.9 mu mol/L), as were total thiol levels. The highest and lowest disulfide levels were observed in Group 1(controls; 20.4 +/- 5.2 mu mol/L) and Group 6 (16.2 +/- 5.7 mu mol/L), respectively. The disulfide/native thiol ratio was increased in Groups 4, 5, and 6 compared with Groups 1, 2, and 3. Conclusion: The presence of diabetes mellitus complications substantially decreased native thiol, total thiol, and disulfide levels.eninfo:eu-repo/semantics/openAccessDisulfidesHomeostasisDiabetic angiopathiesPrediabetic stateBiomarkersArticle10.20945/2359-4292-2025-0042695410046642-s2.0-105017415008Q3WOS:001602231900001Q3