You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
A benfotiamine-vitamin B combination in treatment of diabetic polyneuropathy.
Abstract 1:
In a double-blind, randomized, controlled study, the effectiveness of treatment with a combination of Benfotiamine (an Allithiamine, a lipid-soluble derivative of vitamin B1 with high bioavailability) plus vitamin B6/B12 on objective parameters of neuropathy was studied over a period of 12 weeks on 24 diabetic patients with diabetic polyneuropathy. The results showed a significant improvement (p = 0.006) of nerve conduction velocity in the peroneal nerve and a statistical trend toward improvement of the vibration perception threshold. Long-term observation of 9 patients with verum over a period of 9 months support the results. Therapy-specific adverse effects were not seen. The results of this double-blind investigation, of the long-term observation and of the reports in the literature support the contention that the neurotropic benfotiamine-vitamin B combination represents a starting point in the treatment of diabetic polyneuropathy.


Title 2:
Benfotiamine in treatment of alcoholic polyneuropathy: an 8-week randomized controlled study (BAP I Study).
Abstract 2:
A three-armed, randomized, multicentre, placebo-controlled double-blind study was used to examine the efficacy of benfotiamine vs a combination containing benfotiamine and vitamins B6 and B12 in out-patients with severe symptoms of alcoholic polyneuropathy (Benfotiamine in treatment of Alcoholic Polyneuropathy, BAP I). The study period was 8 weeks and 84 patients fulfilled all the prerequisite criteria and completed the study as planned. Benfotiamine led to significant improvement of alcoholic polyneuropathy. Vibration perception (measured at the tip of the great toe) significantly improved in the course of the study, as did motor function. and the overall score reflecting the entire range of symptoms of alcoholic polyneuropathy. A tendency toward improvement was evident for pain and co-ordination; no therapy-specific adverse effects were seen.


Title 3:
[The efficacy of the intravenous administration of the trometamol salt of thioctic (alpha-lipoic) acid in diabetic neuropathy].
Abstract 3:
A two-central randomised single-blind placebo-controlled study was conducted to assess efficacy of intravenous administration of trometamol salt of thioctic (alpha-lipoic) acid (Thioctacid 600, "ASTA Medica", Germany) in 200 ml of physiological solution in 40 non-insulin dependent diabetic patients with symptomatic diabetic neuropathy. 10 patients of the control group received a physiological solution stained with 1% solution of riboflavin mononucleate (B2 vitamin) as placebo. Intravenous infusion was administered once daily during a period of 3 weeks. Diabetic neuropathy score was assessed at the entry as well as on days 7, 14 and 21 of therapy. Indicators of lipid peroxidation (oxidative stress)--malonic dialdehyde levels in plasma and membranes of erythrocytes. Electroneuromyography were performed. Most of the patients (29) noted symptomatic improvement after 7-10 infusions and on day 14 a significant reduction of the diabetic neuropathy score was noted in comparison to a baseline (p < 0.05). The further improvement of clinical picture had been pronounced by day 21 (p < 0.001). Improvement of symptom score was obtained in 39 patients (97.5%). The response rate in the control group was 40%. Parameters of oxidative stress and electroneuromyography improved significantly in the main group of patients, while these in placebo group remained without changes.


Title 4:
Effectiveness of different benfotiamine dosage regimens in the treatment of painful diabetic neuropathy.
Abstract 4:
The therapeutic effectiveness of a benfotiamine (CAS 22457-89-2)-vitamin B combination (Milgamma-N), administered in high (4 x 2 capsules/day, = 320 mg benfotiamine/day) and medium doses (3 x 1 capsules/day), was compared to a monotherapy with benfotiamine (Benfogamma) (3 x 1 tablets/day, = 150 mg benfotiamine/day) in diabetic patients suffering from painful peripheral diabetic neuropathy (DNP). In a 6-week open clinical trial, 36 patients (aged 40 to 70 yrs) having acceptable metabolic control (HbA1c < 8.0%) were randomly assigned to three groups, each of them comprising 12 participants. Neuropathy was assessed by five parameters: the pain sensation (evaluated by a modified analogue visual scale), the vibration sensation (measured with a tuning fork using the Riedel-Seyfert method) and the current perception threshold (CPT) on the peroneal nerve at 3 frequencies: 5, 250 and 2000 Hz). Parameters were registered at the beginning of the study and at the end of the 3rd and 6th week of therapy. An overall bneneficial therapeutic effect on the neuropathy status was observed in all three groups during the study, and a significant improvement in most of the parameters studied appeared already at the 3rd week of therapy (p < 0.01). The greatest change occurred in the group of patients receiving the high dose of benfotiamine (p < 0.01 and 0.05, resp., compared to the othr groups). Metabolic control did not change over the study. It is concluded that benfotiamine is most effective in large doses, although even in smaller daily dosages, either in combination or in monotherapy, it is effective.


Title 5:
Evaluation of the efficacy of thiamine and pyridoxine in the treatment of symptomatic diabetic peripheral neuropathy.
Abstract 5:
The clinical response to therapeutic doses of two vitamins were determined in diabetic patients with symptomatic peripheral neuropathy. Of 200 consecutive patients, 100 were randomly allocated to treatment with both thiamine (25 mg/day) and pyridoxine (50 mg/day) group A and the rest group B to treatment with an identical tablet containing 1 mg/day each of thiamine and pyridoxine. Pain, numbness, paraesthesia and impairment of sensation and ankle in the legs were graded into none, mild, moderate or severe. Blood thiamine levels were measured using HPLC fluorimetry. Four weeks after starting treatment the grade was less than on the first visit in 88.9%, 82.5% and 89.7% of those whose worst symptoms were pain, numbness and paraesthesia respectively for group A compared with 11.1%, 40.5% and 39.4% respectively for group B. The severity of signs of peripheral neuropathy decreased in 48.9% of patients in group A compared with 11.4% in group B. The mean (s.e.) pre-treatment whole blood thiamine levels decreased with increasing severity of symptoms: 64.2 (2.81), 57.7 (3.25) and 52.2 (2.14) micrograms/l for those with mild, moderate and severe symptoms respectively (analysis of variance, p = 0.03). Diabetic peripheral neuropathy in Dar es Salaam is associated with thiamine deficiency. Dietary guidelines for diabetic patients should emphasize a balanced diet.


Title 6:
The influence of pyridoxine in diabetic peripheral neuropathy.
Abstract 6:
To determine the role of pyridoxine in the treatment of diabetic peripheral neuropathy, 18 symptomatic diabetic patients were treated with vitamin B6 or placebo in a double-blind controlled study. Only one patient had a low plasma pyridoxal phosphate level at the start of the study. After 4 mo of treatment with pyridoxine hydrochloride (50 mg three times daily) 6 of 9 pyridoxine-treated and 4 of 9 placebo-treated patients noted significant relief from their neuropathic symptoms. There was no difference between the two groups with regard to fasting plasma glucose, motor nerve conduction velocity, or ophthalmologic examination at the beginning or at the conclusion of the study. Our results suggest that vitamin B6 deficiency is not a factor in the etiology of diabetic peripheral neuropathy. Furthermore, treating diabetic peripheral neuropathy with high dose vitamin B6 or placebo results in a similar frequency of symptomatic improvement.


Title 7:
Effects of methylcobalamin on diabetic neuropathy.
Abstract 7:
We studied the clinical and neurophysiological effects of methylcobalamin on patients with diabetic neuropathy. In a double-blind study, the active group showed statistical improvement in the somatic and autonomic symptoms with regression of signs of diabetic neuropathy. Motor and sensory nerve conduction studies showed no statistical improvement after 4 months. The drug was easily tolerated by the patients and no side effects were encountered.
There are only limited data in randomised trials testing the efficacy of vitamin B for treating peripheral neuropathy and the evidence is insufficient to determine whether vitamin B is beneficial or harmful. One small trial in alcoholic peripheral neuropathy reported slightly greater improvement in vibration perception threshold with oral benfotiamine for eight weeks than placebo. In another small study, a higher dose of oral vitamin B complex for four weeks was more efficacious than a lower dose in reducing symptoms and signs. Vitamin B administered by various routes for two to eight weeks was less efficacious than alpha-lipoic acid, cilostazol or cytidine triphosphate in short-term improvement of clinical and nerve conduction study outcomes. Vitamin B is generally well-tolerated.