Association of polymorphic markers of the lipid metabolism genes with diabetic polyneuropathy in type 1 diabetes mellitus

Recent advances in exploring the genetic susceptibility to diabetic neuropathy

Diabetic polyneuropathy and cardiovascular autonomic neuropathy are common and disabling complications of diabetes. Although glycaemic control and cardiovascular risk factors are major contributory elements in its development, diabetic neuropathy recognizes a multifactorial influence and a multiplicity of pathogenetic mechanisms. Thus genetic and environmental factors may contribute to its susceptibility, each with a modest contribution, by targeting various metabolic and microvascular pathways whose alterations intervene in diabetic neuropathy pathogenesis. This review is aimed at describing major data from the available literature regarding genetic susceptibility to diabetic neuropathies. It provides an overview of the genes reported as associated with the development or progression of these complications, i.e. ACE, MTHFR, GST, GLO1, APOE, TCF7L2, VEGF, IL-4, GPX1, eNOS, ADRA2B, GFRA2, MIR146A, MIR128A. The identification of genetic susceptibility can help in both expanding the comprehension of the pathogenetic mechanisms of diabetic nerve damage and identifying biomarkers of risk prediction and response to therapeutic intervention.

The ε4 allele of the APOE gene is associated with more severe peripheral neuropathy in type 2 diabetic patients

We examined the association between the ε4 allele of the apolipoprotein E gene and severity of peripheral neuropathy in 234 patients with type 2 diabetes mellitus (T2DM). Based on the Neuropathy Disability Score (NDS), patients were divided into group A (NDS ≤ 6: mild or no neuropathy) and group B (NDS > 6: severe neuropathy). In each group, patients were further divided into ε4 carriers and non-ε4 carriers. In multivariate analysis, a more than 5-fold increased risk of severe neuropathy was associated with ε4 carrier status (adjusted odds ratio [aOR]: 5.26, 95% confidence interval [CI]: 2.24-12.31, P = .0001). The other significant risk factors for severe neuropathy included male gender (aOR: 2.08, 95% CI: 1.05-4.14, P = .036), diabetes duration (aOR: 1.05, 95% CI: 1.00-1.09, P = .039), and hemoglobin A1c (aOR: 1.32, 95% CI: 1.05-1.66, P = .020). In conclusion, the ε4 carrier status appears to be associated with severe peripheral neuropathy in T2DM.