Cumulative diabetes-related metabolic burden and the risk of hearing loss: A population-based study

Type 2 diabetes mellitus (T2DM) causes microvascular injury across multiple organs, but whether its cumulative microvascular burden contributes to sensory decline remains unclear. In this population-based cohort of 493,272 UK Biobank participants, including 43,332 with T2DM, we examined the association between diabetes-related microvascular complications (nephropathy, retinopathy, neuropathy) and incident hearing loss. Complications were identified from hospital records (ICD-10 E11.2/E11.3/E11.4) and categorized by count. Hearing loss (ICD-10 H90-H91) was ascertained from linked hospital records, death registries, and self-reports. Compared with participants without diabetes, adjusted hazard ratios (HRs; 95% CIs) for hearing loss were 1.28 (1.22-1.34) for T2DM without complications, 1.83 (1.65-2.02) for one complication, and 2.13 (1.75-2.59) for two or more. Within T2DM, risk increased stepwise with complication count (one vs none: 1.45 [1.31-1.60]; ≥2 vs none: 1.75 [1.44-2.13]). Associations were stronger in participants <60 years, those with glycated hemoglobin ≥6.5%, and insulin users. Mediation analyses showed partial indirect effects of estimated glomerular filtration rate and C-reactive protein, consistent with contributions of renal dysfunction and systemic inflammation. Findings were robust across demographic and clinical subgroups. These results indicate that the cumulative burden of microvascular complications is independently associated with higher risk of hearing loss, supporting integration of auditory evaluation into comprehensive diabetes care, particularly for individuals with multiple complications or poor glycemic control.