This systematic review and meta-analysis quantified the pooled prevalence and comparative risk of moderate-to-severe hearing loss (≥40 dB HL) in adults with diabetes or prediabetes, with subgroup analyses by age (<60 vs. ≥60 years), national income level (LMICs vs. HICs), and diabetes duration (<10 vs. ≥10 years); 29 studies from 2000–2025 were included (PROSPERO: CRD42018100742).
Pooled prevalence of moderate-to-severe hearing loss in diabetes was **24%** (95% CI: 19%–30%; 23 studies, n=5,221; I²=94%). Diabetes more than doubled the odds vs. non-diabetic controls (OR=2.41, 95% CI: 1.62–3.60; 11 studies, n=17,051). Risk was highest in adults <60 years (OR=3.03, 95% CI: 2.17–4.22) and in low-/middle-income countries (OR=4.51, 95% CI: 2.43–8.40), but not significant in adults ≥60 years (OR=1.52, 95% CI: 0.72–3.22). Diabetes duration <10 years already conferred elevated risk (OR=2.68).
- Very high heterogeneity (I²=86.6–94%) driven by differences in study populations, audiometric definitions, and confounder adjustment (e.g., noise exposure, ototoxic medications). - Publication bias detected (Egger's p=0.019); small studies with null results may be underrepresented. - Predominantly cross-sectional designs preclude causal inference, and prediabetes data came from only one study, limiting conclusions for that group.
One in four adults with diabetes has clinically significant hearing loss—comparable in burden to retinopathy and nephropathy—supporting routine audiometric screening as part of standard diabetes care, especially for patients under 60 and those in resource-limited settings. Screening should begin at diagnosis rather than waiting for advanced disease, as elevated risk appears within the first 10 years.
