Critical appraisal of the use of alpha lipoic acid (thioctic acid) in the treatment of symptomatic diabetic polyneuropathy

The efficacy of combining adjuvants with non-surgical periodontal therapy in individuals with type 2 diabetes: A Bayesian network meta-analysis

AIM

This Bayesian network meta-analysis of randomized controlled trials assessed the effect of adjuvant periodontal treatment in both periodontal and HbA1c outcomes in adult individuals with type 2 diabetes (T2DM).

MATERIALS AND METHODS

A systematic search was done up to February 2023 comparing sub-gingival debridement (SD) in combination with local or systemic adjuvant treatment with SD alone for individuals with T2DM. The primary outcomes were changes in absolute HbA1c levels and full-mouth probing depth reported at 3- to 6-month post-treatment.

RESULTS

Seventy-two eligible publications evaluating 27 adjuvant treatments were retrieved. The combination of SD and systemic antibiotic metronidazole or SD and antioxidant alpha lipoic acid provided, respectively, 1.4% (95% credible interval [CrI] 0.48; 2.20) and 2.4% (95% CrI 1.50; 3.30) more significant improvement on HbA1c levels, and 0.89 mm (95% CrI 0.23; 1.50) and 0.92 mm (95% CrI 0.02; 0.92) greater periodontal probing depth reductions. Other adjuvant treatments provided added benefit to the periodontal outcomes without discernible effects on HbA1c.

CONCLUSIONS

Adjuvant use of metronidazole or alpha lipoic acid was the best adjunct option to provide clinically meaningful HbA1c levels and probing depth reductions. However, no strong recommendation can be drawn due to the scarcity of studies for each adjuvant treatment and the low certainty of the resultant evidence.

The protective effect of chemical and natural compounds against vincristine-induced peripheral neuropathy (VIPN)

Vincristine, an alkaloid extracted from Catharanthus rosea, is a class of chemotherapy drugs that act by altering the function of the microtubules and by inhibiting mitosis. Despite its widespread application, a major adverse effect of vincristine that limits treatment duration is the occurrence of peripheral neuropathy (PN). PN presents with several symptoms including numbness, painful sensation, tingling, and muscle weakness. Vincristine-induced PN involves impaired calcium homeostasis, an increase of reactive oxygen species (ROS), and the upregulation of tumor necrosis factor-alpha (TNF-α), and interleukin 1 beta (IL-1β) expression. Several potential approaches to attenuate the vincristine-induced PN including the concomitant administration of chemicals with vincristine have been reported. These chemicals have a variety of pharmaceutical properties including anti-inflammation, antioxidant, and inhibition of calcium channels and calcineurin signaling pathways and increased expression of nerve growth factor (NGF). This review summarized several of these compounds and the mechanisms of action that could lead to effective options in improving vincristine-induced peripheral neuropathy (VIPN).

The role of biofactors in the prevention and treatment of age-related diseases

The present demographic changes toward an aging society caused a rise in the number of senior citizens and the incidence and burden of age-related diseases (such as cardiovascular diseases [CVD], cancer, nonalcoholic fatty liver disease [NAFLD], diabetes mellitus, and dementia), of which nearly half is attributable to the population ≥60 years of age. Deficiencies in individual nutrients have been associated with increased risks for age-related diseases and high intakes and/or blood concentrations with risk reduction. Nutrition in general and the dietary intake of essential and nonessential biofactors is a major determinant of human health, the risk to develop age-related diseases, and ultimately of mortality in the older population. These biofactors can be a cost-effective strategy to prevent or, in some cases, even treat age-related diseases. Examples reviewed herein include omega-3 fatty acids and dietary fiber for the prevention of CVD, α-tocopherol (vitamin E) for the treatment of biopsy-proven nonalcoholic steatohepatitis, vitamin D for the prevention of neurodegenerative diseases, thiamine and α-lipoic acid for the treatment of diabetic neuropathy, and the role of folate in cancer epigenetics. This list of potentially helpful biofactors in the prevention and treatment of age-related diseases, however, is not exhaustive and many more examples exist. Furthermore, since there is currently no generally accepted definition of the term biofactors, we here propose a definition that, when adopted by scientists, will enable a harmonization and consistent use of the term in the scientific literature.

Alpha-Lipoic Acid Can Overcome The Reduced Developmental Competency Induced by Alcohol Toxicity during Ovine Oocyte Maturation

Objective

Alpha-lipoic acid (ALA) as a strong antioxidant has a protective effect. This study was designed to assess whether supplementation of maturation medium with ALA during in vitro maturation (IVM) can attenuate the toxic effect of ethanol.

Materials and Methods

In this experimental study, to assess the antioxidant capacity of ALA challenged by 1% ethanol during in vitro maturation, immature ovine oocytes were exposed to 1% alcohol in the presence or absence of 25 µM ALA during oocyte maturation. The cumulus expansion index, intracellular reactive oxygen species (ROS), and thiol content levels were assessed in matured oocytes of various treatment groups. Consequently, the blastocyst formation rate of matured oocytes in various treatment groups were assessed. In addition, total cell number (TCN), cell allocation, DNA fragmentation, and relative gene expression of interested genes were assessed in resultant blastocysts.

Results

The results revealed that alcohol significantly reduced cumulus cells (CCs) expansion index and blastocyst yield and rate of apoptosis in resultant embryos. Addition of 25 µM ALA to 1% ethanol during oocyte maturation decreased ROS level and elevated Thiolcontent. Furthermore, supplementation of maturation medium with ALA attenuated the effect of 1% ethanol and significantly increased the blastocyst formation and hatching rate as compared to control and ethanol groups. In addition, the quality of blastocysts produced in ALA+ethanol was improved based on the low number of TUNEL positive cells, the increased expression level of mRNA for pluripotency, and anti-oxidant markers, and decreased expression of apoptotic genes.

Conclusion

The current findings demonstrate that ALA can diminish the effect of ethanol, possibly by decreasing the ROS level and increasing Thiolcontent during oocyte maturation. Using the ALA supplement may have implications in protecting oocytes from alcohol toxicity in affected patients.

Current concepts in the management of diabetic polyneuropathy

Diabetic sensorimotor polyneuropathy (DSPN) is encountered in approximately one-third of people with diabetes. This, in turn, might markedly impoverish their quality of life, mainly owing to neuropathic pain and foot ulcerations. Painful DSPN might be as frequent as 25% in diabetes patients. Symptoms as a result of DSPN typically comprise pain, paresthesia and numbness in the distal lower limbs. Asymptomatic DSPN might reach 50% among patients with this condition. Unfortunately, DSPN is still not adequately diagnosed and treated. Its management has three priorities: (i) lifestyle improvement, near-normoglycemia and multifactorial cardiovascular risk intervention; (ii) pathogenesis-oriented pharmacotherapy; and (iii) symptomatic alleviation of pain. Intensive diabetes therapy showed evidence for favorable effects on the incidence and deterioration of DSPN in type 1 diabetes, but not type 2 diabetes. Among pathogenesis-oriented treatments, α-lipoic acid, actovegin, benfotiamine and epalrestat are currently authorized to treat DSPN in several countries. Symptomatic therapy uses analgesics, notably antidepressants, opioids and anticonvulsants, reducing pain by ≥50% in approximately 50% of individuals, but might be limited, particularly by central nervous system-related adverse events. Local treatment with the capsaicin 8% patch might offer an alternative. In addition to pain relief, therapy should improve sleep, mobility and quality of life. In conclusion, multimodal treatment of DSPN should consider the individual risk profile, pathogenetic treatment and pain management using pharmacotherapy (combinations, if required), as well as non-pharmacological options.

The effect of alpha lipoic acid on passive avoidance and social interaction memory, pain perception, and locomotor activity in REM sleep-deprived rats

BACKGROUND

Evidence shows the vital role of sleep in the modulation of cognitive functions. Sleep deprivation (SD) can disrupt learning and memory processes. SD also affects pain perception and locomotor activity. Furthermore, alpha lipoic acid (ALA) may induce antioxidant and neuroprotective effects. ALA affects memory processes, pain subthreshold, and locomotor activity. The goal of the present study was to investigate the effect of REM (rapid-eye movement) SD and ALA on social and passive avoidance memory, locomotor activity, and pain perception.

METHODS

Multiple-platform apparatus was used to induce REM SD for 24 h. Three-chamber paradigm test, the shuttle box, locomotion apparatus, and hot plate were used to assess social interaction memory, passive avoidance memory, locomotor activity, and pain perception, respectively. ALA was injected intraperitoneally at the doses of 35 and 70 mg/kg.

RESULTS

24 h REM SD impaired both types of memory. In addition, ALA (35 mg/kg) reversed REM SD-induced memory impairments. However, ALA (70 mg/kg) impaired social memory with no effect on REM SD-induced memory impairments. ALA (70 mg/kg) also decreased pain subthreshold in REM SD rats.

CONCLUSION

REM SD impairs social interaction and passive avoidance memory. Furthermore, ALA may exhibit a dose-dependent manner in some cognitive tasks. ALA can induce a therapeutic effect at one dose, and an impairment effect at another dose (lower or higher), while the cognitive task and the conditions are equal.

The Neuroprotective Role of Alpha Thioctic Acid and Vitamin B Complex in Diabetic Neuropathy - an Experimental Study

Worldwide, approximately 463 million people are estimated to suffer from a form of diabetes mellitus, with diabetic neuropathy being one of its most common complication. Using streptozotocin to induce diabetes in C57BL/6J mice, we assess the neuroprotective role of alpha thioctic acid and vitamin B complex in diabetic neuropathy. In order to highlight the peripheral nerve changes produced by diabetes, we performed an electroneurographic recording of the animals and compared the amplitude of the compound muscle action potential (CMAP). Treatment with alpha thioctic acid (A), or vitamin B complex (B), or A+B caused a smaller decrease in CMAP amplitude than if these therapies had not been applied. On the other hand, we found that in group A+B a smaller decrease of CMAP amplitude was observed compared to the control group (6 weeks after the onset of diabetes p<0.0001). Also, separate treatment with alpha thioctic acid alone caused a smaller decrease in CMAP amplitude compared to the control group (6 weeks after the onset of diabetes mellitus p<0.0436), but also separate treatment with vitamin B complex alone resulted in a smaller decrease of CMAP amplitude compared to the Control group (6 weeks after the onset of diabetes p<0.0070). The combined therapy with alpha thioctic acid and vitamin B complex has a greater effect in preventing axonal degeneration in diabetic neuropathy than the single therapy only with alpha thioctic acid or only with vitamin B complex.

[Diabetic neuropathy and diabetic foot syndrome (Update 2019)]

These are the guidelines for diagnosis and treatment of diabetic neuropathy and diabetic foot. Diabetic neuropathy comprises a number of mono- and polyneuropathies, plexopathies, radiculopathies and autonomic neuropathy.The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy, including the complex situation of the diabetic foot syndrome. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensorimotor neuropathy, are provided. The needs to prevent and treat diabetic foot syndrome are summarized.

Effect of statins on oxidative DNA damage in diabetic polyneuropathy

Oxidative stress induces nerve damage in type 2 diabetes mellitus and leads to diabetic polyneuropathy (DPN) and can affect the DNA and antioxidant status. Statins have pleiotropic, protective effects on the peripheral nerves of patients with diabetes. The aim of this study was to determine the effects of ezetimibe/simvastatin and rosuvastatin on DNA damage in patients with DPN. This randomized, double-blind, placebo-controlled, clinical trial comprised outpatients from Guadalajara, Mexico. The inclusion criteria were either gender, age 35–80 years, type 2 diabetes, glycated hemoglobin ≤10%, diabetic polyneuropathy stage 1/2, and signed informed consent. Patients who were taking antioxidant therapy or statins, had hypersensitivity to drugs, experienced organ failure, were pregnant or breastfeeding, or had other types of neuropathy were excluded. We assigned patients to placebo, ezetimibe/simvastatin 10/20 mg, or rosuvastatin 20 mg, and the primary outcomes were 8-hydroxy-2′-deoxyguanosine (8-OHdG) for DNA damage, 8-oxoguanine-DNA-N-glycosilase (hOGG1) for DNA repair, and superoxide dismutase (SOD). Seventy-four patients were recruited. Nine patients were included as negative controls. There were no differences in 8-OHdG between the healthy subjects (4.68 [3.53–6.38] ng/mL) and the DPN patients (4.51 [1.22–9.84] ng/mL), whereas the hOGG1 level was 0.39 (0.37–0.42) ng/mL in the healthy subjects and 0.41 (0.38–0.54) ng/mL in patients with DPN at baseline (p = 0.01). SOD decreased significantly in patients with DPN (5.35 [0.01–17.90] U/mL) compared with the healthy subjects (9.81 [8.66–12.61] U/mL) at baseline (p < 0.001). No significant changes in DNA biomarkers were observed in any group between baseline and final levels. We noted a rise in hOGG1 in patients with DPN, without modifications after treatment. There was a slight, albeit insignificant, increase in SOD in patients who were on statins.

The Role of Advanced Glycation End Products in Aging and Metabolic Diseases: Bridging Association and Causality

Accumulation of advanced glycation end products (AGEs) on nucleotides, lipids, and peptides/proteins are an inevitable component of the aging process in all eukaryotic organisms, including humans. To date, a substantial body of evidence shows that AGEs and their functionally compromised adducts are linked to and perhaps responsible for changes seen during aging and for the development of many age-related morbidities. However, much remains to be learned about the biology of AGE formation, causal nature of these associations, and whether new interventions might be developed that will prevent or reduce the negative impact of AGEs-related damage. To facilitate achieving these latter ends, we show how invertebrate models, notably Drosophila melanogaster and Caenorhabditis elegans, can be used to explore AGE-related pathways in depth and to identify and assess drugs that will mitigate against the detrimental effects of AGE-adduct development.

A Possible Role for Singlet Oxygen in the Degradation of Various Antioxidants. A Meta-Analysis and Review of Literature Data

The thermodynamic parameters Eact, ΔH≠, ΔS≠, and ΔG≠ for various processes involving antioxidants were calculated using literature kinetic data (k, T). The ΔG≠ values of the antioxidants' processes vary in the range 91.27-116.46 kJmol-1 at 310 K. The similarity of the ΔG≠ values (for all of the antioxidants studied) is supported to be an indication that a common mechanism in the above antioxidant processes may be taking place. A value of about 10-30 kJmol-1 is the activation energy for the diffusion of reactants depending on the reaction and the medium. The energy 92 kJmol-1 is needed for the excitation of O₂ from the ground to the first excited state (¹Δg, singlet oxygen). We suggest the same role of the oxidative stress and specifically of singlet oxygen to the processes of antioxidants as in the processes of proteinaceous diseases. We therefore suggest a competition between the various antioxidants and the proteins of proteinaceous diseases in capturing singlet oxygen's empty π* orbital. The concentration of the antioxidants could be a crucial factor for the competition. Also, the structures of the antioxidant molecules play a significant role since the various structures have a different number of regions of high electron density.

Impaired Corneal Sensation and Nerve Loss in a Type 2 Rat Model of Chronic Diabetes Is Reversible With Combination Therapy of Menhaden Oil, α-Lipoic Acid, and Enalapril

PURPOSE

This study investigated the efficacy of monotherapy versus combination of menhaden oil, α-lipoic acid, and enalapril on corneal sensation and morphometry and other neuropathy-related endpoints in a rat model of type 2 diabetes.

METHODS

Male Sprague-Dawley rats (aged 12 weeks) were fed a high-fat diet for 8 weeks followed by 30 mg/kg streptozotocin. After 16 weeks of hyperglycemia, 12-week treatments consisting of menhaden oil, α-lipoic acid, enalapril, or their combination were initiated. Before and after treatments, we performed analyses of multiple neural and vascular endpoints including corneal sensitivity, corneal nerve density, vascular reactivity of epineurial arterioles, motor and sensory nerve conduction velocity, intraepidermal nerve fiber density, and thermal nociception.

RESULTS

Before treatment, all the neural and vascular endpoints in diabetic rats were impaired. Treating diabetic rats with monotherapy was effective in improving neural and vascular deficits with menhaden oil being most efficacious. However, the combination therapy provided the greatest benefit and improved/reversed all nerve and vascular deficits. The effect of combination therapy on corneal relative sensitivity and structure (in mm/mm), primary endpoints for this study, for control, diabetic, and diabetic treated rats was 4.2 ± 1.4 and 7.5 ± 0.5, 12.1 ± 1.3* and 3.8 ± 0.2*, and 6.6 ± 2.3 and 7.3 ± 0.5, respectively (*P < 0.05 compared with control rats; P < 0.05 compared with diabetic rats).

CONCLUSIONS

These studies suggest that a combination therapeutic approach may be most effective for treating vascular and neural complications of type 2 diabetes.

Protein Disulfide Levels and Lens Elasticity Modulation: Applications for Presbyopia

PURPOSE

The purpose of the experiments described here was to determine the effects of lipoic acid (LA)-dependent disulfide reduction on mouse lens elasticity, to synthesize the choline ester of LA (LACE), and to characterize the effects of topical ocular doses of LACE on mouse lens elasticity.

METHODS

Eight-month-old mouse lenses (C57BL/6J) were incubated for 12 hours in medium supplemented with selected levels (0-500 μM) of LA. Lens elasticity was measured using the coverslip method. After the elasticity measurements, P-SH and PSSP levels were determined in homogenates by differential alkylation before and after alkylation. Choline ester of LA was synthesized and characterized by mass spectrometry and HPLC. Eight-month-old C57BL/6J mice were treated with 2.5 μL of a formulation of 5% LACE three times per day at 8-hour intervals in the right eye (OD) for 5 weeks. After the final treatment, lenses were removed and placed in a cuvette containing buffer. Elasticity was determined with a computer-controlled instrument that provided Z-stage upward movements in 1-μm increments with concomitant force measurements with a Harvard Apparatus F10 isometric force transducer. The elasticity of lenses from 8-week-old C57BL/6J mice was determined for comparison.

RESULTS

Lipoic acid treatment led to a concentration-dependent decrease in lens protein disulfides concurrent with an increase in lens elasticity. The structure and purity of newly synthesized LACE was confirmed. Aqueous humor concentrations of LA were higher in eyes of mice following topical ocular treatment with LACE than in mice following topical ocular treatment with LA. The lenses of the treated eyes of the old mice were more elastic than the lenses of untreated eyes (i.e., the relative force required for similar Z displacements was higher in the lenses of untreated eyes). In most instances, the lenses of the treated eyes were even more elastic than the lenses of the 8-week-old mice.

CONCLUSIONS

As the elasticity of the human lens decreases with age, humans lose the ability to accommodate. The results, briefly described in this abstract, suggest a topical ocular treatment to increase lens elasticity through reduction of disulfides to restore accommodative amplitude.

[Polyneuropathy in the elderly]

The peripheral nervous system is subject to changes during the ageing process, e. g. deep tendon reflexes decrease, as does proprioception. Polyneuropathies, on the other hand, need to be distinguished from age-related changes as independent diseases with etiologies similar to those at younger ages. Etiologies includes metabolic disorders, primary inflammatory polyneuropathies, and systemic disorders. Neuropathies associated with diabetes, malignancy, and monoclonal gammopathies appear to be more common in older patients. Using a systematic approach, it is possible to establish a specific diagnosis in the majority of cases. Since polyneuropathies contribute to reduced mobility in the elderly, an assessment of functional skills is mandatory. Polyneuropathy therapy is primarily based on the treatment of underlying conditions and neuropathic pain management. Physiotherapy and rehabilitation target pain relief and maintaining activities of daily living.

Early vs. late intervention of high fat/low dose streptozotocin treated C57Bl/6J mice with enalapril, α-lipoic acid, menhaden oil or their combination: Effect on diabetic neuropathy related endpoints

We have previously demonstrated that enalapril, α-lipoic acid and menhaden (fish) oil has potential as a treatment for diabetic peripheral neuropathy. In this study we sought to determine the efficacy of these treatments individually or in combination on multiple neuropathic endpoints in a high fat fed low dose streptozotocin treated mouse, a model of type 2 diabetes, following early or late intervention. Four or twelve weeks after the onset of hyperglycemia, diabetic mice were treated with enalapril, α-lipoic acid, menhaden oil or their combination for 12 weeks. Afterwards, endpoints including glucose tolerance, motor and sensory nerve conduction velocity, thermal nociception, and intraepidermal and cornea nerve fiber density was determined. Glucose clearance was impaired in diabetic mice and significantly improved only with combination treatment and early intervention. Diabetes caused steatosis, slowing of motor and sensory nerve conduction velocity, thermal hypoalgesia and reduction in intraepidermal and cornea nerve fiber density. Treating diabetic mice with enalapril, α-lipoic acid or menhaden oil partially protected diabetic mice from these deficits, whereas the combination of these three treatments was more efficacious following early or late intervention. These studies suggest that a combination therapy may be more effective for treating neural complications of type 2 diabetes.

α-Lipoic acid as a triglyceride-lowering nutraceutical

Considering the current obesity epidemic in the United States (>100 million adults are overweight or obese), the prevalence of hypertriglyceridemia is likely to grow beyond present statistics of ∼30% of the population. Conventional therapies for managing hypertriglyceridemia include lifestyle modifications such as diet and exercise, pharmacological approaches, and nutritional supplements. It is critically important to identify new strategies that would be safe and effective in lowering hypertriglyceridemia. α-Lipoic acid (LA) is a naturally occurring enzyme cofactor found in the human body in small quantities. A growing body of evidence indicates a role of LA in ameliorating metabolic dysfunction and lipid anomalies primarily in animals. Limited human studies suggest LA is most efficacious in situations where blood triglycerides are markedly elevated. LA is commercially available as dietary supplements and is clinically shown to be safe and effective against diabetic polyneuropathies. LA is described as a potent biological antioxidant, a detoxification agent, and a diabetes medicine. Given its strong safety record, LA may be a useful nutraceutical, either alone or in combination with other lipid-lowering strategies, when treating severe hypertriglyceridemia and diabetic dyslipidemia. This review examines the current evidence regarding the use of LA as a means of normalizing blood triglycerides. Also presented are the leading mechanisms of action of LA on triglyceride metabolism.

Treatment with α-Lipoic Acid over 16 Weeks in Type 2 Diabetic Patients with Symptomatic Polyneuropathy Who Responded to Initial 4-Week High-Dose Loading

Effective treatment of diabetic sensorimotor polyneuropathy remains a challenge. To assess the efficacy and safety of α-lipoic acid (ALA) over 20 weeks, we conducted a multicenter randomized withdrawal open-label study, in which 45 patients with type 2 diabetes and symptomatic polyneuropathy were initially treated with ALA (600 mg tid) for 4 weeks (phase 1). Subsequently, responders were randomized to receive ALA (600 mg qd; n = 16) or to ALA withdrawal (n = 17) for 16 weeks (phase 2). During phase 1, the Total Symptom Score (TSS) decreased from 8.9 ± 1.8 points to 3.46 ± 2.0 points. During phase 2, TSS improved from 3.7 ± 1.9 points to 2.5 ± 2.5 points in the ALA treated group (p < 0.05) and remained unchanged in the ALA withdrawal group. The use of analgesic rescue medication was higher in the ALA withdrawal group than ALA treated group (p < 0.05). In conclusion, in type 2 diabetic patients with symptomatic polyneuropathy who responded to initial 4-week high-dose (600 mg tid) administration of ALA, subsequent treatment with ALA (600 mg qd) over 16 weeks improved neuropathic symptoms, whereas ALA withdrawal was associated with a higher use of rescue analgesic drugs. This trial is registered with ClinicalTrials.gov Identifier: NCT02439879.

Effect of rosuvastatin on diabetic polyneuropathy: a randomized, double-blind, placebo-controlled Phase IIa study

BACKGROUND

Diabetic neuropathy affects 50%-66% of patients with diabetes mellitus. Oxidative stress generates nerve dysfunction by causing segmental demyelinization and axonal degeneration. Antioxidants are considered to be the only etiologic management for diabetic polyneuropathy, and statins such as rosuvastatin increase nitric oxide bioavailability and reduce lipid peroxidation. The aim of this study was to evaluate the antioxidant effect of rosuvastatin in diabetic polyneuropathy.

METHODS

We conducted a randomized, double-blind, placebo-controlled Phase IIa clinical trial in patients with type 2 diabetes and diabetic polyneuropathy (DPN) stage ≥1b. We allocated subjects to two parallel groups (1:1) that received rosuvastatin 20 mg or placebo for 12 weeks. Primary outcomes were neuropathic symptom score, disability score, and nerve conduction studies, and secondary outcomes were glycemic control, lipid and hepatic profile, lipid peroxidation, and nerve growth factor beta (NGF-β) levels.

RESULTS

Both groups were of similar age and duration since diagnosis of diabetes and DPN. We observed improvement of DPN in the rosuvastatin group from stage 2a (88.2%) to stage 1b (41.2%), improvement of neuropathic symptom score from 4.5±2 to 2.4±1.8, and significant (P=0.001) reductions of peroneal nerve conduction velocity (from 40.8±2.2 to 42.1±1.6 seconds) and lipid peroxidation (from 25.4±2 to 12.2±4.0 nmol/mL), with no significant change in glycemic control or β-NGF.

CONCLUSION

The severity, symptoms, and nerve conduction parameters of DPN improved after 12 weeks of treatment with rosuvastatin. These beneficial effects appear to be attributable to reductions in lipid peroxidation and oxidative stress.

Lipoic Acid prevents the changes of intracellular lipid partitioning by free Fatty Acid

Background/Aims

It is suggested that the hepatic lipid composition is more important than lipid quantity in the pathogenesis of non-alcoholic steatohepatitis. We examined whether lipoic acid (LA) could alter intrahepatic lipid composition and free cholesterol distribution.

Methods

HepG2 cells were cultured with palmitic acid (PA) with and without LA. Apoptosis, changes of the mitochondrial structure, intracellular lipid partitioning, and reactive oxygen species (ROS) activity were measured.

Results

Free fatty acid (FA) increased apoptosis, and LA co-treatment prevented this lipotoxicity (apoptosis in controls vs PA vs PA+LA, 0.5% vs 19.5% vs 1.6%, p<0.05). LA also restored the intracellular mitochondrial DNA copy number (553±33.8 copies vs 291±14.55 copies vs 421±21.05 copies, p<0.05) and reversed the morphological changes induced by PA. In addition, ROS was increased in response to PA and was decreased in response to LA co-treatment (41,382 relative fluorescence unit [RFU] vs 43,646 RFU vs 41,935 RFU, p<0.05). LA co-treatment increased the monounsaturated and polyunsaturated FA concentrations and decreased the total saturated FA fraction. It also prevented the movement of intracellular free cholesterol from the cell membrane to the cytoplasm.

Conclusions

LA opposes free FA-generated lipotoxicity by altering the intracellular lipid composition and free cholesterol distribution.

Diabetic neuropathies: diagnosis and management

INTRODUCTION

Changes in human behaviour and lifestyle over the last century have resulted in a dramatic increase in the incidence of diabetes worldwide. Neuropathy is a common and costly complication of both type 1 and type 2 diabetes. The prevalence of neuropathy is estimated to be about 8% in newly diagnosed patients and greater than 50% in patients with long-standing disease. There are two main types of diabetic neuropathies, named as sensorimotor and autonomic neuropathies. Sensorimotor neuropathy is marked by pain, paraesthesia and sensory loss, and autonomic neuropathy may contribute to myocardial infarction, malignant arrhythmia and sudden death.

METHODS

In this article we reviewed the pathogenesis, clinical manifestations diagnosis and treatment of diabetic neuropathies.

CONCLUSION

Sensorimotor and autonomic neuropathies (cardiovascular, gastrointestinal and genitourinary autonomic neuropathies) are common in diabetic patients. Apart from strict glycaemic control, no further therapeutic approach exists in the prevention of this phenomenon. Intensive diabetes therapy, intensive multifactorial cardiovascular risk reduction and lifestyle intervention are recommended in patients with cardiovascular autonomic neuropathy. Gastroparesis is the most debilitating complication of gastrointestinal autonomic neuropathy and genitourinary autonomic neuropathy can cause sexual dysfunction and neurogenic bladder; these conditions are hard to manage. The symptomatic treatment of sensory symptoms includes tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors, gabapentin, pregabalin and opioids. Other treatment strategies are not so effective.

[Diabetic neuropathy]

These are the guidelines for diagnosis and treatment of diabetic neuropathy. This diabetic late complication comprises a number of mono- and polyneuropathies, plexopathies, radiculopathies and autonomic neuropathy. The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensomotoric neuropathy, are provided.