The impact on large fibre function and small fibre function in patients with type 2 diabetes on benfotiamine therapy
Diabetes mellitus (DM) is the leading cause of neuropathy worldwide. Based on the data from several studies, sensorimotor polyneuropathy (diffuse and symmetric neuropathy) will develop within 10 years of the onset of DM in 40 % to 50 % of patients with type 1 and type 2 DM. In patients with type 2 DM, target blood glucose levels are associated with a reduced incidence of neuropathy. Objective - to study the correlation between the stage of diabetic peripheral polyneuropathy in type 2 diabetic patients, and the effects and efficacy of benfotiamine as transketolase activator. Materials and methods. In this study, 190 patients with type 2 DM were screened for DPN. DPN was confirmed in 105 patients displaying both clinical manifestations of neuropathy with a positive Diabetic Neuropathy Symptom (DNS) score and increased vibration perception threshold (VPT) on a biotensiometer. Based on the above stated criteria patients were divided into 4 groups: 1 - with positive DNS score, positive 10 g monofilament test score, VPT between 16-25 volts; 2 - with positive DNS score, positive 10 g monofilament test score, VPT between 26-35 volts; 3 - with positive DNS score, positive 10 g monofilament test score and VPT between 35-40 volts; 4 - control group with positive DNS score, negative 10 g monofilament test score and normal VPT value (n = 25 (23 %); 20 females and 5 males). The first 3 groups received benfotiamine 300 mg daily for 6 weeks, the control group was benfothiamine naïve. All the groups continued their antidiabetic medication. Results and discussion. The diabetic neuropathy score and vibration perception threshold was assessed in 105 patients (84 females and 21 males) with type 2 DM, before starting of benfotiamine 300 mg daily and after 6 weeks of therapy. Results of DNS: differences between group 3 and both group 1 and 2 were significant, but not between group 1 and 2. Patients in group 1 (n = 24), in females (n = 18) the DNS varied from 1-2, and in males (n = 6) the DNS varied from 1-3. After the 6 weeks,DNS score decreased in both females and males i.e. 1-1.25 and 1-2.5 correspondingly. Conclusions. The role of benfotiamine in clinical practice has been demonstrated in many clinical trials with variable trial design, patient groups and history of diabetes. In our study we found that patients with mild neuropathy and vibration perception threshold of 16-25 volts showed a reduction in VPT of up to 16 %, and the patients with moderate neuropathy and reduced vibration perception threshold of 26-35 volts were the ones who benefitted the most from benfotiamine therapy. Benfotiamine activates transketolase and thus helps in the reduction of AGEs formation and associated sugar induced metabolic stress.