Background/Objectives: Vitamin B12 deficiency can cause variable symptoms, which may be irreversible if not diagnosed and treated in a timely manner. We aimed to develop a widely accepted expert consensus to guide the practice of diagnosing and treating B12 deficiency. Methods: We conducted a scoping review of the literature published in PubMed since January 2003. Data were used to design a two-round Delphi survey to study the level of consensus among 42 experts. Results: The panelists agreed on the need for educational and organizational changes in the current medical practices for diagnosing and treating B12 deficiency. Recognition of clinical symptoms should receive the highest priority in establishing the diagnosis. There is agreement that the serum B12 concentration is useful as a screening marker and methylmalonic acid or homocysteine can support the diagnosis. Patient lifestyle, disease history, and medications can provide clues to the cause of B12 deficiency. Regardless of the cause of the deficiency, initial treatment with parenteral B12 was regarded as the first choice for patients with acute and severe manifestations of B12 deficiency. The use of high-dose oral B12 at different frequencies may be considered for long-term treatment. Prophylactic B12 supplementation should be considered for specific high-risk groups. Conclusions: There is a consensus that clinical symptoms need to receive more attention in establishing the diagnosis of B12 deficiency. B12 laboratory markers can support the diagnosis. The severity of clinical symptoms, the causes of B12 deficiency, and the treatment goals govern decisions regarding the route and dose of B12 therapy.

Introduction: The oxidative stress associated with glucose variability might be responsible for neuronal damage while autonomic neuropathy (AN) has a detrimental effect on metabolism. The aim of the study was to find relationship between AN and GV in type 1 diabetic patients and to identify further factors that affect GV. Patients and methods: Twenty type 1 diabetic patients were involved (age: 39.5 ± 3.4 years, duration of diabetes: 17.5 ± 2.5 years; HbA1c: 8.1 ± 0.2%, mean ± SE). AN was assessed by the cardiovascular reflex tests. The interstitial glucose levels were determined following insertion of a subcutaneous electrode during the continuous glucose monitoring (CGM) method on six consecutive days. GV was characterized by calculation of four parameters. Results: SD of interstitial glucose values correlated positively with the overall AN score and the degree of the orthostatic reduction of systolic blood pressure (AN-score-SD ρ = 0.47, p < 0.05; orthostasis-SD: ρ = 0.51, p < 0.05). Mean absolute glucose (MAG) correlated with three parameters of AN (AN-score-MAG: ρ = 0.62, p < 0.01; 30/15 ratio-MAG: ρ = −0.50, p < 0.05; orthostasis-MAG: ρ = 0.59, p < 0.01). The HbA1c also correlated with two parameters of GV (HbA1c-continuous overlapping net glycemic action: ρ = 0.56, p < 0.05; HbA1c-MAG: ρ = 0.45, p < 0.05). The frequency of hypoglycemia did not exhibit any correlation with measures of GV. Conclusion: Severity of glucose variability but not overall glucose load correlates with both parasympathetic and sympathetic dysfunctions in type 1 diabetes. Higher HbA1c is associated with more severe glucose variability. The observed correlation between increased glucose variability and the severity of AN necessitates the further exploration of this relationship.

The authors review current advances in the therapy of diabetic neuropathy. The role of glycemic control and management of cardiovascular risk factors in the prevention and treatment of neuropathic complications are discussed. As further options of pathogenetically oriented treatment, recent knowledge on benfotiamine and alpha-lipoic acid is comprehensively reviewed. Alpha-lipoic acid is a powerful antioxidant and clinical trials have proven its efficacy in ameliorating neuropathic signs and symptoms. Benfotiamine acts via the activation of transketolase and thereby inhibits alternative pathways triggered by uncontrolled glucose influx in the cells comprising polyol, hexosamine, protein-kinase-C pathways and formation of advanced glycation end products. Beyond additional forms of causal treatment, choices of symptomatic treatment will be summarized. The latter is mostly represented by the anticonvulsive agents pregabalin and gabapentin as well as duloxetine widely acknowledged as antidepressant. Finally, non-pharmacological therapeutic alternatives are summarized. The authors conclude that combination therapy should be more often suggested to our patients; especially the combination of pathogenetic and symptomatic agents.

We aimed to summarise recent advances in the therapy of diabetic neuropathy. Although all therapeutic choices in the treatment of diabetes mellitus itself are based on clear pathophysiological basis, this approach is less present in the treatment of the “forgotten complication”, diabetic neuropathy. As part of pathogenetic oriented treatment, the role of glycemic control and cardiovascular risk factors are reviewed. The mode of action of benfotiamine is based on inhibition of key alternative pathways, including the polyol, hexosamine, protein-kinase-C pathways, and inhibition of advanced glycation end products formation, just as on activation of transketolase. Alpha- lipoic-acid is considered as the most potent antioxidant. Other forms of pathogenetic oriented treatment, including actovegin, will be summarised. The anticonvulsants gabapentin and pregabalin, as well as the antidepressant duloxetine represent the most important new drugs among agents for symptomatic relief. Most likely, we should offer combination treatment to our patients much more often, first of all combination of pathogenetic and symptomatic drugs. Finally, the broad spectrum of non-pharmacological treatment will be reviewed.