A study measured several blood proteins, including the antimicrobial peptide LL‑37, in people with diabetes‑related urinary leakage, people with leakage but no diabetes, and healthy volunteers. Only one marker, a lipid‑peroxidation product called 4‑HNE, was lower in the diabetic group; LL‑37 and the other proteins showed no meaningful differences.

Diabetic urinary incontinence is a multifactorial condition involving neuropathy, oxidative stress, and epithelial dysfunction. Serum biomarkers-cathelicidin (LL-37), elafin, vitamin D receptor (VDR), 4-hydroxynonenal (4-HNE), and amyloid-β1-42 (Aβ1-42) may provide insight into underlying mechanisms. We conducted a cross-sectional, single-centre observational study including 120 adults: type II diabetes with urinary incontinence (DI; n = 40), non-diabetic urinary incontinence (Non-DI; n = 40), and healthy controls (n = 40). Serum biomarker levels were measured by ELISA. Group differences were analysed using Kruskal-Wallis, with pairwise Mann-Whitney U tests and Bonferroni adjustment (m = 3) where appropriate. Among profiled biomarkers, 4-HNE was lower in DI than in both Non-DI and controls, while LL-37, elafin, VDR, and Aβ1-42 showed no Bonferroni-corrected pairwise differences. In diabetic urinary incontinence, 4-HNE showed the most consistent group-level separation-lower in DI compared with both Non-DI and healthy controls-whereas LL-37, elafin, VDR, and Aβ1-42 did not demonstrate Bonferroni-corrected pairwise differences. These preliminary findings highlight oxidative and neuroimmune alterations in diabetic incontinence and warrant validation in larger longitudinal studies.