Prevalence and determinants of peripheral neuropathy among older Malaysians: Insights from a community-based cross-sectional study: Letter to editor

Sir We read with great interest the article by Huan et al.[1] the use of a biothesiometer adds value to the literature. Nevertheless, we would like to raise some methodological and interpretative concerns. The study used a convenience sample, so the claim of recruitment from multiple pharmacies enhances external validity appears overstated. Additionally, the markedly skewed ethnic distribution (74.8% Chinese, 12% Malay, and 11% Indian) may not reflect the broader demographic composition of older Malaysians. Furthermore, participants were neither randomly selected nor stratified by key variables such as sex or comorbidities, resulting in subgroup imbalances (e.g., few vegetarians or neurological cases). Exclusion of “mentally challenged or critically ill” individuals who are often at higher risk of PN due to multimorbidity and polypharmacy may further underestimate prevalence and limit applicability to vulnerable populations. Although the biothesiometer is sensitive for large-fiber neuropathy, the operational definition of PN required concordance between symptoms and abnormal vibration perception threshold (VPT) values. This approach likely excludes two clinically important groups: Individuals with asymptomatic neuropathy (elevated VPT but no symptoms), who are at high risk for ulceration. Patients with small fiber neuropathy (burning pain but normal VPT), since VPT assesses only large-fiber function. This restrictive definition may distort prevalence estimates and risk associations. Not report inter-rater reliability for VPT measurement. Variability in examiner technique could influence classification. Moreover, reliance solely on VPT without clinical foot examination (ulcers, deformities, trophic changes), or assessment of autonomic neuropathy narrows the diagnostic scope and may underestimate the true burden of neuropathy.[2] Importantly, lumbar spinal stenosis and radiculopathy common in this elderly population were not screened for or excluded. Sensory deficits from nerve root compression can elevate VPT and mimic distal symmetrical polyneuropathy, potentially inflating prevalence estimates.[3] Additionally, several important determinants of neuropathy were neither assessed nor adjusted for in the analysis. These include vitamin B12 deficiency particularly relevant among metformin users, renal insufficiency, thyroid dysfunction, prior chemotherapy or exposure to other neurotoxic medications, and long-term proton pump inhibitor use. This raises the possibility of residual confounding.[4,5] The study identified diabetes as a major risk factor (Adjusted Odds Ratio (AOR) = 3.216), yet did not account for diabetes duration, glycemic control (e.g., HbA1c), medication history, or comorbidity severity. Metformin-induced B12 deficiency is a well-established cause of neuropathy, and without adjusting for medication use or B12 levels, the study cannot distinguish disease-related from treatment-related neuropathy. Given the high outcome prevalence (60.9%), reporting Odds Ratios likely overestimates the true association strength. Prevalence Ratios would have provided a more appropriate and interpretable measure. The cross-sectional design precludes establishment of temporality. The observed diabetes–PN association may reflect reverse causality, survival bias, or residual confounding. Recommendations for sex-specific interventions appear premature without adjusting for lifestyle factors such as smoking or alcohol use. Data collection occurred during the COVID-19 pandemic (March 2021–May 2022), when healthcare access, physical activity, and metabolic control were disrupted. Potential seasonal or pandemic-related influences could have a role in thus. Overall, the authors are to be congratulated for shedding light on an important yet underdiagnosed condition in older adults. Their study meaningfully contributes to the growing body of evidence supporting improved community-based neuropathy screening and awareness. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.