Dyslipidemia as a contributory factor in etiopathogenesis of diabetic neuropathy

Alternative therapeutic strategies in diabetes management

Diabetes is a heterogeneous metabolic disease characterized by elevated blood glucose levels resulting from the destruction or malfunction of pancreatic β cells, insulin resistance in peripheral tissues, or both, and results in a non-sufficient production of insulin. To adjust blood glucose levels, diabetic patients need exogenous insulin administration together with medical nutrition therapy and physical activity. With the aim of improving insulin availability in diabetic patients as well as ameliorating diabetes comorbidities, different strategies have been investigated. The first approaches included enhancing endogenous β cell activity or transplanting new islets. The protocol for this kind of intervention has recently been optimized, leading to standardized procedures. It is indicated for diabetic patients with severe hypoglycemia, complicated by impaired hypoglycemia awareness or exacerbated glycemic lability. Transplantation has been associated with improvement in all comorbidities associated with diabetes, quality of life, and survival. However, different trials are ongoing to further improve the beneficial effects of transplantation. Furthermore, to overcome some limitations associated with the availability of islets/pancreas, alternative therapeutic strategies are under evaluation, such as the use of mesenchymal stem cells (MSCs) or induced pluripotent stem cells for transplantation. The cotransplantation of MSCs with islets has been successful, thus providing protection against proinflammatory cytokines and hypoxia through different mechanisms, including exosome release. The use of induced pluripotent stem cells is recent and requires further investigation. The advantages of MSC implantation have also included the improvement of diabetes-related comorbidities, such as wound healing. Despite the number of advantages of the direct injection of MSCs, new strategies involving biomaterials and scaffolds have been developed to improve the efficacy of mesenchymal cell delivery with promising results. In conclusion, this paper offered an overview of new alternative strategies for diabetes management while highlighting some limitations that will need to be overcome by future approaches.

Effect of Ruzu Herbal Bitters on the Liver Function and Lipid Profile Parameters of Alloxan-Induced Diabetic Rats

Background

Ruzu herbal bitters (RHB) is a polyherbal mixture produced in Nigeria indicated for diabetes and other ailments. The consumers of the product testify of its efficacy, but there are not much scientific information on RHB. The study determined the effect of RHB on the liver function and lipid profile parameters of alloxan-induced diabetic rats.

Method

Fifty-four adult albino rats were divided into nine groups of six rats each. Group 1 was the normal control, while groups 2-6 were diabetic. Group 2 was not treated, while groups 3-6 were respectively treated with 5 mg/kg b.w of glibenclamide, 0.14, 0.29, and 0.57 ml/kg b.w of RHB. Groups 7-9 were not diabetic but treated as groups 4-6. Diabetes was induced by intraperitoneal injection of freshly prepared alloxan into adult male albino Wister rats with a single dose of 120 mg/kg body weight. The blood sugar level, weight, liver function, and lipid profile of the rats were tested using standard methods.

Result

The results showed a significant (P < 0.05) increase in the blood glucose level and decrease in weight in the diabetic-untreated group compared to the normal group. The liver function and lipid profile tests showed significant (P<0.05) increases in the activities of gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST); increases in the levels of total bilirubin, total cholesterol (T.CHOL), triglycerides (TG), very low-density lipoprotein (VLDL) and lowdensity lipoprotein (LDL); decreases in the levels of total protein, albumin and high-density lipoproteins (HDL), in the diabetic-untreated group compared to the normal group. However, treatment of the diabetic rats with different doses of RHB caused the reversal of these effects to near-normal levels in a dose-dependent manner.

Conclusions

Our study reveals that RHB has antidiabetic, hepatoprotective, and antihyperlipidemic effects.

Lipid variability and risk of microvascular complications in patients with diabetes: a systematic review and meta-analysis

BACKGROUND AND AIMS

The current systematic review aimed to elucidate the effects of lipid variability on microvascular complication risk in diabetic patients. The lipid components studied were as follows: High-density lipoprotein (HDL), High-density lipoprotein (LDL), Triglyceride (TG), Total Cholesterol (TC), and Remnant Cholesterol (RC).

METHOD

We carried out a systematic search in multiple databases, including PubMed, Web of Science, and SCOPUS, up to October 2nd, 2023. After omitting the duplicates, we screened the title and abstract of the studies. Next, we retrieved and reviewed the full text of the remaining articles and included the ones that met our inclusion criteria in the study.

RESULT

In this research, we examined seven studies, comprising six cohort studies and one cross-sectional study. This research was conducted in Hong Kong, China, Japan, Taiwan, Finland, and Italy. The publication years of these articles ranged from 2012 to 2022, and the duration of each study ranged from 5 to 14.3 years. The study group consisted of patients with type 2 diabetes aged between 45 and 84 years, with a diabetes history of 7 to 12 years. These studies have demonstrated that higher levels of LDL, HDL, and TG variability can have adverse effects on microvascular complications, especially nephropathy and neuropathic complications. TG and LDL variability were associated with the development of albuminuria and GFR decline. Additionally, reducing HDL levels showed a protective effect against microalbuminuria. However, other studies did not reveal an apparent relationship between lipid variations and microvascular complications, such as retinopathy. Current research lacks geographic and demographic diversity. Increased HDL, TG, and RC variability have been associated with several microvascular difficulties. Still, the pathogenic mechanism is not entirely known, and understanding how lipid variability affects microvascular disorders may lead to novel treatments. Furthermore, the current body of this research is restricted in its coverage. This field's lack of thorough investigations required a more extensive study and comprehensive effort.

CONCLUSION

The relationship between lipid variation (LDL, HDL, and TG) (adverse effects) on microvascular complications, especially nephropathy and neuropathic (and maybe not retinopathy), is proven. Physicians and health policymakers should be highly vigilant to lipid variation in a general population.

Do Serum Nesfatin-1 Levels have A Predictive Role in Type-2 Diabetes Mellitus and its Microvascular Complications? A Case-Control Study

Background Type 2 diabetes mellitus (T2DM) is a chronic disease with macrovascular and microvascular complications. Nesfatin-1 is a neuropeptide that develops from a more substantial intermediate compound known as nucleobindin 2 (NUCB2). Nesfatin-1 is known to play a role in regulating various physiological processes related to appetite, energy balance, and body weight. The purpose of the current study was to investigate the serum levels of nesfatin-1 in Egyptian patients with type 2 diabetes mellitus (T2DM) in comparison to healthy subjects and to assess the association of serum nesfatin-1 levels with the occurrence of diabetic microvascular complications in those patients. Methods This matched case-control study was conducted on 90 subjects 40-80 years old, with normal hepatic, cardiac, and respiratory functions, and 60 of them had T2DM. The included participants were divided into two groups: group 1, which was the control group and included 30 healthy subjects, and group 2, which included 60 subjects with T2DM. Group 2 was subdivided according to the presence or absence of microvascular complications into group 2a, which included 30 patients having T2DM with no microvascular complications, and group 2b, which included 30 patients having T2DM with one or more microvascular complications. Results T2DM patients had significantly lower serum nesfatin-1 levels (5.07±1.78 versus 9.05±2.1 mmol/L, <0.001) compared to healthy controls. Also, T2DM patients with microvascular complications had lower serum nesfatin-1 levels (4.32±1.72 versus 5.83±1.51 mmol/L, <0.001) compared to T2DM patients without microvascular complications. Serum nesfatin-1 level at a cutoff value of <8.09 mmol/L can be a marker for the detection of diabetes mellitus (DM) with the area under the curve (AUC) of 94.3%, 95% sensitivity, 74.3% specificity, 77.9% positive predictive value (PPV), and 65.7% negative predictive value (NPV), and at a cutoff value of <5.87 mmol/L can be a marker for the detection of microvascular complications of diabetes mellitus at AUC of 75.5%, 76.7% sensitivity, 67.3% specificity, 77.1% PPV, and 62.9% NPV. Conclusions Serum Nesfatin-1 may play a potential protective role in diabetes mellitus (DM) and its microvascular complications, as it decreases in individuals with diabetes and those with diabetic microvascular complications compared to controls. Additionally, serum Nesfatin-1 levels may have predictive value for the early detection of Type 2 diabetes mellitus (T2DM) patients, diabetic microvascular complications, and diabetic kidney disease (DKD) at cut-off values of < 8.09 (mmol/L), < 5.87 (mmol/L), and < 5.46 (mmol/L), respectively. Therefore, targeted Nesfatin-1 drug therapy may be tried to reduce morbidity and mortality caused by microvascular complications of diabetes.

Assessment of Neuropathy by Temperature Threshold Testing in Type 2 Diabetes Mellitus

Introduction

Diagnosing diabetic neuropathy is a challenge at times as it is asymptomatic. Diagnosing diabetic neuropathy involves the use of quantitative sensory testing, nerve conduction study, and autonomic testing. Tempearture threshold testing (TTT) can aid in diagnosing small fiber neuropathy at early stages. This study aimed to assess the small fiber neuropathy using TTT in diabetes mellitus (DM) and correlate with age, duration of diabetes, and lipid profile.

Materials and Methods

The study was commenced after obtaining ethics approval from the institute ethics committee. The study participants included 100 patients with type 2 DM of both genders between the ages of 40 and 65 years. The glycemic status and lipid profile were noted along with physical examination. Neuropathy assessment was done using Michigan Neuropathy Screening Instrument (MNSI) and TTT.

Results

The prevalence of small fiber neuropathy based on TTT was 63%. The lipid profile was similar in both the groups. The MNSI B scale had significantly higher scores in the neuropathy group. In the neuropathy group, the thresholds for hot were significantly greater in all four limbs and cold were significantly lower. Age and years of DM were positively correlated with the neuropathy. Hot threshold in the lower limb had shown a strong positive correlation.

Conclusion

The age and duration of diabetes are independent risk factors for diabetic peripheral neuropathy. Small fiber neuropathy is a prequel to the motor neuropathy. Hot threshold testing in the lower limb is more sensitive than cold threshold testing for diagnosing small fiber neuropathy.

The metabolic and functional roles of sensory nerves in adipose tissues

Homeostatic regulation of adipose tissue is critical for the maintenance of energy balance and whole-body metabolism. The peripheral nervous system provides bidirectional neural communication between the brain and adipose tissue, thereby providing homeostatic control. Most research on adipose innervation and nerve functions has been limited to the sympathetic nerves and their neurotransmitter norepinephrine. In recent years, more work has focused on adipose sensory nerves, but the contributions of subsets of sensory nerves to metabolism and the specific roles contributed by sensory neuropeptides are still understudied. Advances in imaging of adipose innervation and newer tissue denervation techniques have confirmed that sensory nerves contribute to the regulation of adipose functions, including lipolysis and browning. Here, we summarize the historical and latest findings on the regulation, function and plasticity of adipose tissue sensory nerves that contribute to metabolically important processes such as lipolysis, vascular control and sympathetic axis cross-talk.

Syringic Acid Ameliorates Cardiac, Hepatic, Renal and Neuronal Damage Induced by Chronic Hyperglycaemia in Wistar Rats: A Behavioural, Biochemical and Histological Analysis

This study investigated the effects of syringic acid (SA) on renal, cardiac, hepatic, and neuronal diabetic complications in streptozotocin-induced neonatal (nSTZ) diabetic rats. STZ (110 mg/kg i.p) was injected into Wistar rat neonates as a split dose (second and third postnatal day). Diabetes mellitus was diagnosed in adults by measuring fasting blood glucose levels, urine volume, and food and water intake. The treatment of SA (25 mg/kg, 50 mg/kg p.o) was given from the 8th to 18th postnatal week. To assess the development of diabetic complications and the effect of therapy, biochemical indicators in serum and behavioural parameters were recorded at specific intervals during the study period. SA (25 mg/kg, 50 mg/kg p.o) treatment reduced hyperglycaemia, polydipsia, polyphagia, polyuria, relative organ weight, cardiac hypertrophic indices, inflammatory markers, cell injury markers, glycated haemoglobin, histopathological score, and oxidative stress, and increased Na/K ATPase activity. These findings suggest that SA might significantly alleviate diabetic complications and/or renal, neuronal, cardiac, and hepatic damage in nSTZ diabetic rats.

In Vitro and In Vivo Antiglycation Effects of Connarus ruber Extract

Accumulation of advanced glycation end products (AGEs) of the Maillard reaction has been implicated in the pathogenesis of diabetes and its complications. Connarus ruber has been used as a folk remedy for several diseases, including diabetes; however, its underlying mechanism has not yet been investigated. This study investigated the effects of C. ruber extract against glycation on collagen-linked AGEs in vitro and streptozotocin-induced diabetic rats (STZ-DM rats) in vivo. The antiglycation activities of C. ruber extract and aminoguanidine (AG) were examined using a collagen glycation assay kit. Nonfluorescent AGE, N^ε-carboxymethyl lysine (CML), N^ω-carboxymethyl arginine, and N^ε-carboxyethyl lysine levels were measured via electrospray ionization-liquid chromatography-tandem mass spectrometry. The effect of the extract on the cytotoxicity of methylglyoxal (MG), a precursor of AGEs, was examined in HL60 cells. STZ-DM rats were treated with the extract for 4 wk, and the effect was assessed using biochemical markers in the serum and CML-positive cells in renal tissues. C. ruber extract dose-dependently inhibited the glycation of collagen and formation of nonfluorescent AGEs, which was comparable to AG, and it significantly attenuated MG-induced cytotoxicity in HL60 cells. Furthermore, the glycated albumin levels in STZ-DM rats decreased, the increase in serum lipid levels was reversed, and immunohistochemistry demonstrated that CML deposition in the glomerulus of STZ-DM rats significantly decreased. Although further studies are needed, C. ruber could be a potential therapeutic for preventing and progressing many pathological conditions, including diabetes.

An experimental study of rosuvastatin's analgesic effect and its interaction with etoricoxib, tramadol, amlodipine, and amitriptytline in albino mice

Background

Statins are the mainstay for the treatment of dyslipidemia. Recently, rosuvastatin has also been demonstrated to possess analgesic properties in animal studies. The present study has been planned to further confirm the analgesic activity of rosuvastatin, etoricoxib, tramadol, amlodipine, and amitriptyline and study the interaction of rosuvastatin with the above-mentioned analgesics. The objective of the study was to confirm the analgesic activity of rosuvastatin and determine the minimum analgesic dose of rosuvastatin, etoricoxib, tramadol, amlodipine and amitriptyline and to study the analgesic effect of combination of subanalgesic doses of rosuvastatin with sub-analgesic doses of etoricoxib, tramadol, amlodipine, and amitriptyline.

Method

After IAEC approval, the study was carried out in albino mice in two phases. In phase I, the analgesic effect of rosuvastatin, etoricoxib, tramadol, amlodipine, and amitriptyline was confirmed by using tail-flick and writhing methods. In phase II, analgesic effect of combinations of subanalgesic dose of rosuvastatin with subanalgesic dose of etoricoxib, tramadol, amlodipine, and amitriptyline was studied.

Results

Minimal analgesic dose of rosuvastatin, etoricoxib, tramadol, amlodipine, and amitriptyline was observed as 5, 20, 10, 5, and 10 mg/kg, respectively. In phase II, combination of subanalgesic dose of rosuvastatin 2.5 mg/kg with subanalgesic doses of etoricoxib (10 mg/kg), tramadol (5 mg/kg), amlodipine (2.5 mg/kg), and amitriptyline (5 mg/kg), demonstrated synergistic analgesic activity.

Conclusion

Rosuvastatin exerts dose-dependent analgesic activity that is synergistic to that of etoricoxib, tramadol, amlodipine, and amitriptyline. If established in clinical studies as well, this finding can lead to the reduction of analgesic dosing in patients already on statins.

Lipid variability and risk of microvascular complications in Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial: A post hoc analysis

BACKGROUND

Greater lipid variability may cause adverse health events among diabetic patients. We aimed to examine the effect of lipid variability on the risk of diabetic microvascular outcomes among type 2 diabetes mellitus patients.

METHODS

We assessed the association between visit-to-visit variability (measured by variability independent of mean) in high-density lipoprotein (HDL) cholesterol, low-density lipoprotein-cholesterol (LDL), triglyceride, and remnant cholesterol (RC) measurements among participants involved in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study and the risk of incident microvascular outcomes, including nephropathy, neuropathy, and retinopathy. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for potential confounders.

RESULTS

There were 2400, 2470, and 2468 cases of nephropathy, neuropathy, and retinopathy during a follow-up period of 22 600, 21 542, and 26 701 person-years, respectively. Higher levels of HDL, triglyceride, and RC variability were associated with an increased risk of incident nephropathy and neuropathy. Compared with the lowest quartile, the fully adjusted HRs (95% CI) for the highest quartile of HDL, triglyceride, and RC variability for nephropathy risk were 1.57 (1.22, 2.01), 1.50 (1.18, 1.92), and 1.40 (1.09, 1.80), respectively; and for neuropathy, the corresponding risks were 1.36 (1.05, 1.75), 1.47 (1.14, 1.91), and 1.35 (1.04, 1.74), respectively. Null association was observed between LDL variability and all microvascular complications. Additionally, all associations of variability in the other lipids with retinopathy risk were null.

CONCLUSION

Among individuals with type 2 diabetes mellitus, HDL, triglyceride, and RC variability were associated with increased risks of nephropathy and neuropathy but not retinopathy.

TRIAL REGISTRATION

ClinicalTrials.gov., no. NCT00000620.

Human Sensory Neuron-like Cells and Glycated Collagen Matrix as a Model for the Screening of Analgesic Compounds

Increased collagen-derived advanced glycation end-products (AGEs) are consistently related to painful diseases, including osteoarthritis, diabetic neuropathy, and neurodegenerative disorders. We have recently developed a model combining a two-dimensional glycated extracellular matrix (ECM-GC) and primary dorsal root ganglion (DRG) that mimicked a pro-nociceptive microenvironment. However, culturing primary cells is still a challenge for large-scale screening studies. Here, we characterized a new model using ECM-GC as a stimulus for human sensory-like neurons differentiated from SH-SY5Y cell lines to screen for analgesic compounds. First, we confirmed that the differentiation process induces the expression of neuron markers (MAP2, RBFOX3 (NeuN), and TUBB3 (β-III tubulin), as well as sensory neuron markers critical for pain sensation (TRPV1, SCN9A (Nav1.7), SCN10A (Nav1.8), and SCN11A (Nav1.9). Next, we showed that ECM-GC increased c-Fos expression in human sensory-like neurons, which is suggestive of neuronal activation. In addition, ECM-GC upregulated the expression of critical genes involved in pain, including SCN9A and TACR1. Of interest, ECM-GC induced substance P release, a neuropeptide widely involved in neuroinflammation and pain. Finally, morphine, the prototype opiate, decreased ECM-GC-induced substance P release. Together, our results suggest that we established a functional model that can be useful as a platform for screening candidates for the management of painful conditions.

Non-glucose risk factors in the pathogenesis of diabetic peripheral neuropathy

In this review, we consider the diverse risk factors in diabetes patients beyond hyperglycemia that are being recognized as contributors to diabetic peripheral neuropathy (DPN). Interest in such alternative mechanisms has been encouraged by the recognition that neuropathy occurs in subjects with metabolic syndrome and pre-diabetes and by the reporting of several large clinical studies that failed to show reduced prevalence of neuropathy after intensive glucose control in patients with type 2 diabetes. Animal models of obesity, dyslipidemia, hypertension, and other disorders common to both pre-diabetes and diabetes have been used to highlight a number of plausible pathogenic mechanisms that may either damage the nerve independent of hyperglycemia or augment the toxic potential of hyperglycemia. While pathogenic mechanisms stemming from hyperglycemia are likely to be significant contributors to DPN, future therapeutic strategies will require a more nuanced approach that considers a range of concurrent insults derived from the complex pathophysiology of diabetes beyond direct hyperglycemia.

Early disruption of nerve mitochondrial and myelin lipid homeostasis in obesity-induced diabetes

Diabetic neuropathy is a major complication of diabetes. Current treatment options alleviate pain but do not stop the progression of the disease. At present, there are no approved disease-modifying therapies. Thus, developing more effective therapies remains a major unmet medical need. Seeking to better understand the molecular mechanisms driving peripheral neuropathy, as well as other neurological complications associated with diabetes, we performed spatiotemporal lipidomics, biochemical, ultrastructural, and physiological studies on PNS and CNS tissue from multiple diabetic preclinical models. We unraveled potentially novel molecular fingerprints underlying nerve damage in obesity-induced diabetes, including an early loss of nerve mitochondrial (cardiolipin) and myelin signature (galactosylceramide, sulfatide, and plasmalogen phosphatidylethanolamine) lipids that preceded mitochondrial, myelin, and axonal structural/functional defects; started in the PNS; and progressed to the CNS at advanced diabetic stages. Mechanistically, we provided substantial evidence indicating that these nerve mitochondrial/myelin lipid abnormalities are (surprisingly) not driven by hyperglycemia, dysinsulinemia, or insulin resistance, but rather associate with obesity/hyperlipidemia. Importantly, our findings have major clinical implications as they open the door to novel lipid-based biomarkers to diagnose and distinguish different subtypes of diabetic neuropathy (obese vs. nonobese diabetics), as well as to lipid-lowering therapeutic strategies for treatment of obesity/diabetes-associated neurological complications and for glycemic control.

Instrumental Acoustic Voice Characteristics in Adults with Type 2 Diabetes

OBJECTIVE

The objective of this study was to investigate if there are differences in acoustic parameters between diabetic patients and normal controls.

METHODS

A prospective cross-sectional study was performed in 83 diabetic patients and 70 healthy controls. Voice parameters including fundamental frequency (F0), jitter, shimmer, amplitude perturbation quotient, noise-to-harmonic ratio, smoothed amplitude perturbation quotient, and relative average perturbation were analyzed using Computerized Speech Lab with the Multi-Dimensional Voice Program.

RESULTS

F0 in female diabetic patients was significantly lower than controls (222.23 ± 27.89 Hz versus 241.08 ± 28.21 Hz, P< 0.01). In female diabetic subgroups with disease duration more than 10 years, poor glycemic control, or neuropathy, the F0 was still significantly lower. Multivariate analysis showed that F0 was significantly associated with diabetes after controlled for age, body mass index, presence of hypertension, and dyslipidemia. (P= 0.022). However, F0 was not able to predict the presence of diabetes as shown by logistic regression analysis (P= 0.243).

CONCLUSIONS

Voice fundamental frequency is lower in females with diabetes. However, voice fundamental frequency cannot adequately predict the presence of diabetes.

Serum Lipid Profile and Its Association with Diabetes and Prediabetes in a Rural Bangladeshi Population

Dyslipidemia is commonly associated with diabetes (T2DM). This has been demonstrated for the Caucasian population, but few data are available for Asian Indians. The paper aims to investigate serum lipids (separately or in combination) and their association with glucose intolerance status (T2DM and prediabetes) in a rural Bangladeshi population. A sample of 2293 adults (≥20 years) were included in a community based cross-sectional survey in 2009. Anthropometric measures, blood pressure, blood glucose (fasting and 2-h oral glucose tolerance test) and fasting serum lipids (total cholesterol, T-Chol; triglycerides, Tg; low density lipoprotein cholesterol, LDL-C and high density lipoprotein cholesterol, HDL-C) were registered. Analysis of covariance (ANCOVA) and regression analysis were performed. High Tg levels were seen in 26% to 64% of the participants, depending on glucose tolerance status. Low HDL-C levels were seen in all groups (>90%). Significant linear trends were observed for high T-Chol, high Tg and low HDL-C with increasing glucose intolerance (p for trend <0.001). T2DM was significantly associated with high T-Chol (Odds ratio (OR): 2.43, p < 0.001), high Tg (OR: 3.91, p < 0.001) and low HDL-C (OR: 2.17, p = 0.044). Prediabetes showed a significant association with high Tg (OR: 1.96, p < 0.001) and low HDL-C (OR: 2.93, p = 0.011). Participants with combined high Tg and low HDL-C levels had a 12.75-fold higher OR for T2DM and 4.89 OR for prediabetes. In Asian Indian populations an assessment of serum lipids is warranted not only for T2DM patients, but also for those with prediabetes.

Metabolic parameters in diabetic neuropathic patients after treatment with pregabalin

OBJECTIVE

To assess metabolic parameters in patients with diabetic peripheral neuropathy (DPN) before and after 3 months treatment with a flexible dose pregabalin.

METHODS

This is a prospective clinical trial. The metabolic parameters observed and recorded after 3 months treatment with a flexible dose pregabalin (n=331).

RESULTS

The lipid profile parameters were significantly improved after treatment, total cholesterol, TC (P<0.01, 95% CI, 25.91-41.98), low-density lipoprotein, LDL (P<0.01, 95% CI, 21.11-34.80), triglycerides, TG (P<0.001, 95% CI, 56.43-79.26), all the three parameters significantly decreased while high-density lipoprotein, HDL, significantly increased (P<0.05, 95% CI, -8.61 to -5.51). Microalbumin mean was 16±1.39 before treatment versus 6.5±0.59 after treatment. Glycolated hemoglobin, HbA1c mean was 9.6±0.099 before pregabalin therapy and 7.6 ±0.06 after. BMI mean was 33.5±0.45 before versus 31.1±0.33 after (P<0.001). HbA1C was positively correlated with DPN severity before treatment (r=0.18, P<0.01). Same results were observed with weight and waist circumference (r=0.17, P<0.01, r=0.14, P<0.05 respectively). Oral anti diabetic medications (OAD) were also positively correlated to DPN severity before treatment (r=0.115, P<0.05).

CONCLUSIONS

Prompt treatment of DPN has a significant effect on the metabolic parameters.

Detrimental impact of hyperlipidemia on the peripheral nervous system: A novel target of medical epidemiological and fundamental research study

Recently, epidemiological studies on the etiology of peripheral neuropathies have revealed that hyperlipidemia is a novel risk factor. Plasma lipid levels were confirmed to be associated with the incidence of many peripheral neuropathies including axonal distal polyneuropathy, vision and hearing loss, motor nerve system lesions and sympathetic nerve system dysfunction. Moreover, different lipid components such as cholesterol, triacylglycerols and lipoprotein are involved in the pathogenesis of these neuropathies. This review aimed to discuss the effect of hyperlipidemia on the peripheral nervous system and its association with peripheral neuropathies. Furthermore, a detailed discussion focusing on the explicit mechanisms related to hyperlipidemia-induced peripheral neuropathies is presented here. These mechanisms, including intracellular oxidative stress, inflammatory lesions, ischemia and dysregulation of local lipid metabolism, share pathways and interact mutually. In addition, we examined current information on clinical trials to prevent and treat peripheral neuropathies caused by hyperlipidemia, with a predictive discussion regarding the orientation of future investigations.

High fatty acids modulate P2X(7) expression and IL-6 release via the p38 MAPK pathway in PC12 cells

Diabetic neuropathy (DNP) is the most common chronic complication of diabetes. Elevated free fatty acids (FFAs) have been recently recognized as a major cause of nervous system damage in diabetes. P2X receptors play a primary role in regulation of neuronal interleukin (IL)-6 release, which is of paramount relevance to the functional changes of nerve system. The present study aimed to investigate the effects of high FFAs on the P2X7 expression and IL-6 release in PC12 cells. High FFAs induced P2X7 expression and IL-6 release significantly in PC12 cells. Moreover, high FFAs enhanced ATP or BzATP-induced Ca(2+) signals in PC12 cells. Inhibition of P2X7 by transfection with P2X7-siRNA or co-culture with BBG (a specific P2X7 inhibitor) at high concentrations of FFAs decreased ATP or BzATP-promoted Ca(2+) signals and IL-6 release in PC12 cells. High FFAs induced the phosphorylation of p38 in PC12 cells. Blockade of p38 pathways by SB-203580 inhibited P2X7 up-expression, ATP or BzATP-evoked [Ca(2+)]i rises as well as IL-6 release in PC12 cells exposed to high FFAs. Therefore, high concentrations of FFAs increased the expression of P2X7 in PC12 cells via activation of p38 mitogen-activated protein kinase (MAPK) signaling pathway, which contributed to P2X7-mediated IL-6 release from PC12 cells.