Correlation between hba1c variability and diabetic neuropathy in type 2 diabetes mellitus

Abstract

Background: Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of type 2 diabetes mellitus (T2DM). Emerging evidence suggests that long-term glycaemic variability, in addition to mean glycated haemoglobin (HbA1c), may contribute to the development of neuropathy.

Methods: This prospective observational study included 120 patients with T2DM attending a tertiary care centre. Clinical characteristics, glycaemic profile, and serial HbA1c measurements were recorded. HbA1c variability was assessed using standard deviation (SD) and coefficient of variation (CV). DPN was evaluated using clinical neurological examination together with the Michigan Neuropathy Screening Instrument (MNSI), Neuropathy Symptom Score (NSS), and Neuropathy Disability Score (NDS). Correlation analysis and multivariable logistic regression were performed to identify factors independently associated with DPN.

Results: DPN was present in 54 (45.0%) patients. Patients with DPN had significantly higher mean HbA1c (8.94 ± 1.18% vs. 7.89 ± 1.08%), HbA1c SD (1.02 ± 0.34% vs. 0.58 ± 0.24%), and HbA1c CV (11.56 ± 4.12% vs. 7.67 ± 3.62%) than those without DPN (all p<0.001). HbA1c SD demonstrated the strongest positive correlation with MNSI (r=0.624), NSS (r=0.587), and NDS (r=0.608). Multivariable analysis identified longer diabetes duration (adjusted OR 1.16, 95% CI 1.07–1.26), higher mean HbA1c (adjusted OR 1.42, 95% CI 1.03–1.97), HbA1c SD (adjusted OR 1.31, 95% CI 1.16–1.48), and HbA1c CV (adjusted OR 1.12, 95% CI 1.03–1.22) as independent predictors of DPN.

Conclusion: Greater long-term HbA1c variability is independently associated with the presence and severity of diabetic peripheral neuropathy. Assessment of HbA1c variability alongside mean HbA1c may improve risk stratification and facilitate earlier identification and prevention of diabetic neuropathy in patients with T2DM.