Prevalence and risk factors of diabetic peripheral neuropathy in a diabetics cohort: Register initiative “diabetes and nerves”

• The overall peripheral neuropathy prevalence among patients with diabetes is high (40.3%) and patients with type 2 diabetes (42.2%) are more often affected than those with type 1 diabetes (29.1%). • DPN prevalence increases with age and diabetes duration and is already high (35.0%) following type 2 diabetes diagnosis. • major DPN risk factors are “older age” and loss of consciousness due to severe hypoglycemia episodes among patients with type 1 diabetes as well as “older age” and an adverse cardiovascular-metabolic profile (obesity, hypertension, low HDL-c levels, elevated triglycerides, low physical activity and limited range of motion) among patients with type 2 diabetes. • diabetes micro- and macrovascular co-morbidities (diabetic nephropathy, retinopathy and peripheral artery disease) are strongly associated with the incidence of neuropathy. The aim of this study was to assess the prevalence of diabetic peripheral neuropathy (DPN) and associated risk factors among patients with type 1 (T1D) and type 2 diabetes (T2D). A total of 141 patients with T1D and 844 patients with T2D mostly from primary care practices were enrolled in our register initiative. DPN was assessed using the Neuropathy Symptom Score (NSS) and Neuropathy Deficit Score (NDS). Data were analyzed by bivariate and multivariate logistic regression. The overall prevalence of DPN in the cohort was 40.3% [95% CI: 37.3-43.3%], 29.1% [22.0-36.9%] among patients with T1D and 42.2% [38.9-45.6%] with T2D (p<0.005). DPN prevalence increased with age from 11.9% [4.5-20.9%] aged ≤40 years up to >50% [47.7-57.5%] aged >70 years (p<0.001). The diabetes duration subclassification revealed a high DPN-prevalence of 35% [15.0-55.0%] among patients with T2D at time of diagnosis. A significant increase of prevalence was present 5 and 25 years following T1D and 25 years following T2D diagnosis (p<0.001). DPN risk factors were “older age” (OR [95% CI]: 1.05 [1.02-1.08], p<0.005) and loss of consciousness due to severe hypoglycemia episodes (OR [95% CI]: 10.28 [1.70-62.01], p<0.05) for T1D and “older age” (OR [95% CI]: 1.02 [1.00-1.04], p=0.056) and the presence of a cardiovascular-metabolic profile (obesity, hypertension, low HDL-c levels, elevated triglycerides, low physical activity and limited range of motion) for T2D. Furthermore, co-morbidities such as diabetic nephropathy (OR [95% CI]: 1.92 [1.14-3.22]), retinopathy (OR [95% CI]: 1.87 [1.10-3.18]) and peripheral artery disease (OR [95% CI]: 1.81 [1.07-3.08]) were independently associated with DPN (p<0.05). High rates of DPN among outpatients with diabetes suggest the need for early screening, especially in individuals that present with a plethora of co-morbidities. Diabetes treatment regimens that preclude a cardiovascular-metabolic risk profile and episodes of severe hypoglycemia should be sought, given that such episodes are more common among patients suffering from DPN.