Adherence to a Mediterranean diet is associated with a lower risk of diabetic kidney disease among individuals with hyperglycemia: a prospective cohort study.

BACKGROUND: Type 2 diabetes is associated with a variety of complications, including micro- and macrovascular complications, neurological manifestations and poor wound healing. Adhering to a Mediterranean Diet (MED) is generally considered an effective intervention in individuals at risk for type 2 diabetes mellitus (T2DM). However, little is known about its effect with respect to the different specific manifestations of T2DM. This prompted us to explore the effect of MED on the three most significant microvascular complications of T2DM: diabetic retinopathy (DR), diabetic kidney disease (DKD), and vascular diabetic neuropathies (DN). METHODS: We examined the association between the MED and the incidence of these microvascular complications in a prospective cohort of 33,441 participants with hyperglycemia free of microvascular complications at baseline, identified in the UK Biobank. For each individual, we calculated the Alternate Mediterranean Diet (AMED) score, which yields a semi-continuous measure of the extent to which an individual's diet can be considered as MED. We used Cox proportional hazard models to analyze hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics, lifestyle factors, medical histories and cardiovascular risk factors. RESULTS: Over a median of 12.3 years of follow-up, 3,392 cases of microvascular complications occurred, including 1,084 cases of diabetic retinopathy (DR), 2,184 cases of diabetic kidney disease (DKD), and 632 cases of diabetic neuropathies (DN), with some patients having 2 or 3 microvascular complications simultaneously. After adjusting for confounders, we observed that higher AMED scores offer protection against DKD among participants with hyperglycemia (comparing the highest AMED scores to the lowest yielded an HR of 0.79 [95% CIs: 0.67, 0.94]). Additionally, the protective effect of AMED against DKD was more evident in the hyperglycemic participants with T2DM (HR, 0.64; 95% CI: 0.50, 0.83). No such effect, however, was seen for DR or DN. CONCLUSIONS: In this prospective cohort study, we have demonstrated that higher adherence to a MED is associated with a reduced risk of DKD among individuals with hyperglycemia. Our study emphasizes the necessity for continued research focusing on the benefits of the MED. Such efforts including the ongoing clinical trial will offer further insights into the role of MED in the clinical management of DKD.

Vitamin B for treating diabetic peripheral neuropathy - A systematic review.

This systematic review assesses the effectiveness and safety of vitamin B supplements for the management of neuropathy in people with diabetes. METHODS: Several databases including, the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL Plus were searched from their inception until May 2020. RESULTS: Five studies were eligible to be included in this review with a total of 348 participants. Overall, the evidence is too uncertain to draw conclusions on the effects of B vitamins in people with DPN. CONCLUSION: It is uncertain whether vitamin B supplements change pain intensity or impairment in the short or long term in people with DPN.

Role of dietary modifications in the management of type 2 diabetic complications.

Diabetes is a chronic metabolic disorder with a high rate of morbidity and mortality. Insufficient insulin secretion and insulin action are two major causes for the development of diabetes, which is characterized by a persistent increase in blood glucose level. Diet and sedentary life style play pivotal role in development of vascular complications in type 2 diabetes. Dietary modification is associated with a reprogramming of nutrient intake, which are proven to be effective for the management of diabetes and associated complications. Dietary modifications modulate various molecular key players linked with the functions of nutrient signalling, regulation of autophagy, and energy metabolism. It activates silent mating type information regulation 2 homolog1 (SIRT1) and AMP-activated protein kinase (AMPK). AMPK mainly acts as an energy sensor and inhibits autophagy repressor Mammalian target of rapamycin (mTOR) under nutritional deprivation. Under calorie restriction (CR), SIRT1 gets activated directly or indirectly and plays a central role in autophagy via the regulation of protein acetylation. Dietary modification is also effective in controlling inflammation and apoptosis by decreasing the level of pro-inflammatory cytokines like nuclear factor kappa- beta (NF-kß), tissue growth factor-beta (TGF-ß), tissue necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). It also improves glucose homeostasis and insulin secretion through beta cell regeneration. This indicates calorie intake plays a crucial role in the pathogenesis of type 2 diabetes-associated complications. The present review, emphasizes the role of dietary modifications in diabetes and associated complications.

High-Dose Vitamin D Supplementation Improves Microcirculation and Reduces Inflammation in Diabetic Neuropathy Patients.

We assessed the effect of different doses of vitamin D supplementation on microcirculation, signs and symptoms of peripheral neuropathy and inflammatory markers in patients with type 2 diabetes (T2DM). Sixty-seven patients with T2DM and peripheral neuropathy (34 females) were randomized into two treatment groups: Cholecalciferol 5000 IU and 40,000 IU once/week orally for 24 weeks. Severity of neuropathy (NSS, NDS scores, visual analogue scale), cutaneous microcirculation (MC) parameters and inflammatory markers (ILs, CRP, TNFα) were assessed before and after treatment. Vitamin D deficiency/insufficiency was detected in 78% of the 62 completed subjects. Following treatment with cholecalciferol 40,000 IU/week, a significant decrease in neuropathy severity (NSS, p = 0.001; NDS, p = 0.001; VAS, p = 0.001) and improvement of cutaneous MC were observed (p < 0.05). Also, we found a decrease in IL-6 level (2.5 pg/mL vs. 0.6 pg/mL, p < 0.001) and an increase in IL-10 level (2.5 pg/mL vs. 4.5 pg/mL, p < 0.001) after 24 weeks of vitamin D supplementation in this group. No changes were detected in the cholecalciferol 5000 IU/week group. High-dose cholecalciferol supplementation of 40,000 IU/week for 24 weeks was associated with improvement in clinical manifestation, cutaneous microcirculation and inflammatory markers in patients with T2DM and peripheral neuropathy.

Will the plant-based movement redefine physicians' understanding of chronic disease?

The world is experiencing a cataclysmically increasing burden from chronic illnesses. Chronic diseases are on the advance worldwide and treatment strategies to counter this development are dominated by symptom control and polypharmacy. Thus, chronic conditions are often considered irreversible, implying a slow progression of disease that can only be hampered but not stopped. The current plant-based movement is attempting to alter this way of thinking. Applying a nutrition-first approach, the ultimate goal is either disease remission or reversal. Hereby, ethical questions arise as to whether physicians' current understanding of chronic illness is outdated and morally reprehensible. In this case, physicians may need to recommend plant-based diets to every patient suffering from chronic conditions, while determining what other socioecological factors and environmental aspects play a role in the chronic disease process. This article provides insights to aspects of diet and chronic illness and discusses how the plant-based movement could redefine current understanding of chronic disease. The ethical justifications for recommending of a plant-based diet are analyzed. The article concludes that not advocating for plant-based nutrition is unethical and harms the planet and patients alike.

[Lipoic acid: physiological role and prospects for clinical application].

α-Lipoic acid (also known as thioctic acid) is a natural vitamin-like compound. Lipoic acid contains asymmetrical carbon, which causes the presence of two possible optical isomers (enantiomers): R-lipoic acid (levogyrate isomer) and S-lipoic acid (rightspinning isomer). Lipoic acid functions as a cofactor for several important mitochondrial multienzyme complexes, enhances the uptake of glucose by the cells, and modulates the activity of various signaling molecules and transcription factors. It was shown that α-lipoic acid and its derivative, dihydrolipoic acid, have a direct antioxidant effect due to the neutralization of reactive oxygen species that are destructive to DNA, proteins and lipids of cells. Dihydrolipoic acid enhances the antioxidant properties of ascorbic acid, glutathione and ubiquinone. Available evidence suggests that supplementation with lipoic acid reduces the symptoms of peripheral diabetic neuropathy. Results from randomized controlled trials show that high doses of lipoic acid can improve the glycemic profile of subjects with metabolic disorders. Lipoic acid can be used to control body weight in people with obesity. R-Lipoic acid is synthesized in the human body and is contained in foods in a form covalently associated with lysine (lipoyllysine). Its dose in dietary supplements significantly exceeds the amount in the diet. Most dietary supplements contain a racemic mixture of R- and S-lipoic acid.

Effect of Early and Late Interventions with Dietary Oils on Vascular and Neural Complications in a Type 2 Diabetic Rat Model.

AIMS: Determine the effect of dietary oils enriched in different mono- or polyunsaturated fatty acids, i.e., olive oil (18 : 1, oleic acid), safflower oil (18 : 2 n-6, linoleic acid), flaxseed oil (18 : 3 n-3, alpha linolenic acid), evening primrose oil (18 : 3 n-6, gamma linolenic acid), or menhaden oil (20:5/22 : 6 n-3 eicosapentaenoic/docosahexaenoic acids), on vascular and neural complications in high-fat-fed low-dose streptozotocin-treated Sprague-Dawley rats, an animal model for late-stage type 2 diabetes. MATERIALS AND METHODS: Rats were fed a high-fat diet (45% kcal as fat primarily derived from lard) for 8 weeks and then treated with a low dose of streptozotocin (30 mg/kg) in order to induce hyperglycemia. After an additional 8 (early intervention) or 20 (late intervention) weeks, the different groups of rats were fed diets with 1/2 of the kcal of fat derived from lard replaced by the different dietary oils. In addition, a control group fed a standard diet (4.25% kcal as fat) and a diabetic group maintained on the high-fat diet were maintained. The treatment period was approximately 16 weeks. The endpoints evaluated included vascular reactivity of epineurial arterioles, motor and sensory nerve conduction velocity, thermal and corneal sensitivity, and innervation of sensory nerves in the cornea and skin. RESULTS: Our findings show that menhaden and flaxseed oil provided the greatest benefit for correcting peripheral nerve damage caused by diabetes, whereas enriching the high-fat diet with menhaden oil provided the most benefit to acetylcholine-mediated vascular relaxation of epineurial arterioles of the sciatic nerve. Enriching the diets with fatty acids derived from the other oils provided none to partial improvements. CONCLUSIONS: These studies imply that long-chain n-6 and n-3 polyunsaturated fatty acids could be an effective treatment for diabetic peripheral neuropathy with n-3 polyunsaturated fatty acids derived from fish oil being the most effective.

Asymptomatic Pontine Lesion and Diabetic Amyotrophy after Rapid Improvement of Poor Glycemic Control in a Patient with Type 1 Diabetes.

We herein report a 28-year-old woman with type 1 diabetes with an asymptomatic pontine lesion and diabetic amyotrophy. She had suffered from diabetes from 10 years old. Treatment in a hospital reduced the hemoglobin A1c level from 14.2% to 7.2% for approximately 2 months. She suffered from acute-onset pain and weakness of the lower limb muscles without central nervous system manifestations. Magnetic resonance imaging showed high-intensity lesions at the brainstem and lower limb muscles on T2-weighted images. These findings and symptoms gradually resolved. Rapid treatment of poor glycemic control might increase the risk of asymptomatic pontine lesions and diabetic amyotrophy.

[Recommendations of the GARIN group for dietary managing of patient with chronic kidney disease]. / Recomendaciones del grupo GARIN para el tratamiento dietético de los pacientes con enfermedad renal crónica.

INTRODUCTION: Background and objectives: by means of this update, the GARIN working group aims to define its position regarding the dietary treatment of patients with chronic kidney disease (CKD). In this area there are many aspects of uncertainty. Material and methods: bibliographical review and specific questions in advance were discussed and answered at a meeting in the form of conclusions. Results: the therapeutic action must be individualized and taking into account the degree of renal failure that the patient presents and their comorbidities. Regarding nutritional medical therapy, our group proposes three different levels of action, in which the recommendations of protein intake, fiber, fatty acids or potassium are different. In addition, we suggest using the phosphorus/protein ratio concept in adjusting the diet of the patient with CKD. We give recommendations regarding treatment in diabetes and artificial supplementation. Conclusions: these recommendations about dietary issues in patients with CKD can add value to clinical work.

INTRODUCCIÓN: Introducción y objetivos: en el tratamiento dietético de los pacientes con enfermedad renal crónica (ERC) existen muchas áreas de incertidumbre. El grupo de trabajo GARIN tiene como objetivo definir su posición en este campo. Material y métodos: revisión bibliográfica previa y reunión presencial en la que se discutieron y contestaron preguntas específicas sobre el tema. Resultados: la actuación terapéutica debe ser individualizada y atendiendo al grado de enfermedad renal que presente el paciente y a sus comorbilidades. En cuanto a la terapia médica nutricional, nuestro grupo propone tres niveles diferentes de actuación, en los que las recomendaciones de ingesta proteica, fibra, ácidos grasos o potasio son distintas. Además, sugerimos utilizar el concepto ratio fósforo/proteína en el ajuste de la dieta del paciente con ERC. Damos recomendaciones en cuanto al tratamiento en diabetes y en suplementación artificial. Conclusiones: estas recomendaciones aportan respuestas concretas sobre cuestiones comunes en la asistencia a pacientes con ERC.

Effect of folic acid supplementation on nerve conduction velocity in diabetic polyneuropathy patients.

OBJECTIVES: In diabetic polyneuropathy (DPN) patients, the effect of folic acid and homocysteine has been related to components of nerve conduction velocity (NCV). The objective of this study was to determine the effect of folic acid supplementation on NCV in DPN patients. METHODS: Patients were randomized to receive either 1 mg of folic acid (n = 40) or placebo (n = 40) for 16 weeks. Blood samples were collected to assess serum folic acid and homocysteine concentrations, and NCV was performed for assessment of diabetic neuropathy. RESULTS: At 16 weeks, in the supplemented group, serum levels of folic acid (p < 0.001) increased, homocysteine concentrations decreased (p < 0.001), with no change in serum vitamin B12 levels. There was a significant increase in sensory sural amplitude (p < 0.001), and components of motor nerves, including amplitude (p = 0.001) and velocity (p < 0.001), but decreased onset latency of peroneal (p = 0.019) and tibial (p = 0.011) motor nerves. CONCLUSION: Our data suggest that supplementation with 1 mg of folic acid for 16 weeks may be useful for enhancing NCV in DPN patients.

The role of dietary non-heme iron load and peripheral nerve inflammation in the development of peripheral neuropathy (PN) in obese non-diabetic leptin-deficient ob/ob mice.

INTRODUCTION: Here, we investigated inflammatory signs of peripheral nerves in leptin-deficient obese ob/ob mice and the modulating effects of the exogenous iron load. METHODS: Ob/ob and ob/+ control mice were fed with high, standard, or low iron diet for four months. RESULTS: We found intraepidermal nerve fiber degeneration in foot skin and low-grade neuropathic abnormalities including mildly slowed motor and compound sensory nerve conduction velocities and low-grade macrophage and T-cell infiltration without overt neuropathology in sciatic nerves of all ob/ob mice. Low dietary iron load caused more pronounced abnormalities than high iron load in ob/ob mice. DISCUSSION: Our data suggest that dietary non-heme iron deficiency may be a modulating factor in the pathogenesis of peripheral neuropathy in obese ob/ob mice with metabolic syndrome. Once the mechanisms can be further elucidated, how low dietary iron augments peripheral nerve degeneration and dysfunction via pro-inflammatory pathways and new therapeutic strategies could be developed. ABBREVIATIONS: CMAP: compound muscle action potential; cSNCV: compound sensory nerve conduction velocity; IENFD: intraepidermal nerve fiber density; LDL: low-density lipoprotein; MetS: metabolic syndrome; MNCV: motor conduction velocity; NCV: nerve conduction velocity; PN: peripheral neuropathy; PNS: peripheral nervous system; STZ: streptozotocin; T2D: type 2 diabetes mellitus; TNF alpha: tumor necrosis factor alpha; WHO: World Health Organization.

Observational clinical and nerve conduction study on effects of a nutraceutical combination on painful diabetic distal symmetric sensory-motor neuropathy in patients with diabetes type 1 and type 2.

BACKGROUND: Painful distal symmetric polyneuropathy (pDSPN) is one of the most common and invalidating complications of diabetes mellitus, both of type 1 and type 2. Mechanisms responsible for the occurrence of the pDSPN are multifactorial and involve metabolic pathways regulating inflammation, microvessel circulation, axonal degeneration and so on. Several therapeutic approaches have been proposed to treat pain and each of them showed positive effects associated to drug-related side effects. METHODS: Twenty-five consecutive patients with diagnosis of diabetes mellitus and pDSPN and tried to manage pain with a dietary supplement composed of a mixture of natural extracts (ß-caryophyllene, myrrh, carnosic acid) and PEA. This is a nutraceutical with potential multiple effects on metabolic, pain and vascular compartments, a profile considered useful in pDSPN. Patients were enrolled and polyneuropathy evaluated by means of nerve conduction study. Pain was assessed using VAS score scale and MNSI. Each patient was evaluated at T0 (time of enrollment) and at T1 (after 16 weeks of treatment). RESULTS: Supplement administration was well tolerated and induced unexpectedly significant amelioration of polyneuropathy with increase amplitude and reduction of pain. No side effects were reported. CONCLUSIONS: This fixed combination could well be considered as a potential nutraceutical option to manage pDSPN in diabetic patients.

Ankle-brachial index and diabetic neuropathy: study of 225 patients.

OBJECTIVE: To evaluate neuropathic pain and peripheral vascular disease in diabetics and compare this with the length of time since diagnosis in type 1, and type 2 diabetes. METHODS: A cross-sectional study with 225 diabetics chosen from their responses on the DN4 questionnaire, who were then evaluated with the ankle-brachial index (ABI), separating type 1 diabetes from type 2 diabetes. RESULTS: A higher incidence of neuropathic pain in those over 60 years of age showed an ABI > 1.3. Neuropathic pain was related to an abnormal ABI in 144 patients (64.2%). A statistically significant value was obtained in type 2 diabetes patients with more than 10 years from disease onset, 69 with altered ABI and 25 with normal ABI. There was an altered ABI (< 0.9) observed in 33% of type 1 diabetes patients and in 67% of type 2 diabetes patients. CONCLUSION: The ABI test in type 1 diabetes and type 2 diabetes patients is important even in those who are asymptomatic. A diagnosis of more than 10 years prior, regardless of the presence of neuropathic pain or ischemic signs, altered the ABI.

Ankle-brachial index and diabetic neuropathy: study of 225 patients / Index tornozelo-braquial e neuropatia diabética: estudo de 225 pacientes

ABSTRACT Objective To evaluate neuropathic pain and peripheral vascular disease in diabetics and compare this with the length of time since diagnosis in type 1, and type 2 diabetes. Methods A cross-sectional study with 225 diabetics chosen from their responses on the DN4 questionnaire, who were then evaluated with the ankle-brachial index (ABI), separating type 1 diabetes from type 2 diabetes. Results A higher incidence of neuropathic pain in those over 60 years of age showed an ABI > 1.3. Neuropathic pain was related to an abnormal ABI in 144 patients (64.2%). A statistically significant value was obtained in type 2 diabetes patients with more than 10 years from disease onset, 69 with altered ABI and 25 with normal ABI. There was an altered ABI (< 0.9) observed in 33% of type 1 diabetes patients and in 67% of type 2 diabetes patients. Conclusion The ABI test in type 1 diabetes and type 2 diabetes patients is important even in those who are asymptomatic. A diagnosis of more than 10 years prior, regardless of the presence of neuropathic pain or ischemic signs, altered the ABI.

RESUMO Objetivo Avaliar dor neuropática e doença vascular periférica em diabéticos e comparar com, tempo de diagnóstico de diabetes tipo 1(DM 1) e diabetes tipo 2(DM2). Métodos Estudo de corte transversal onde, 225 diabéticos responderam ao questionário (DN4) sendo submetidos ao índice tornozelo-braquial (ITB). Resultados predomínio de dor neuropática foi em pacientes acima de 60 anos com (DM2), com um ITB > 1,3 nesta população; assim a dor neuropática foi relacionada com o ITB anormal em 144 pacientes, total de 64,2%. Um valor estatisticamente significativo foi com (DM2).Um ITB alterado (< 0,9) em 33% no (DM 1) e em 67% (DM 2). Totalizando 132 indivíduos com alterações no ITB. Conclusão O teste ITB é útil em pacientes com DM 1 e DM 2 quando a dor neuropática é suspeita, mesmo em assintomáticos. E o tempo prolongado de diabetes (> 10 anos), independentemente da presença de dor ou sinais isquêmicos, alterou o ITB.

Isoliquiritigenin reduces oxidative damage and alleviates mitochondrial impairment by SIRT1 activation in experimental diabetic neuropathy.

Sirtuin (SIRT1) inactivation underlies the pathogenesis of insulin resistance and hyperglycaemia-associated vascular complications, but its role in diabetic neuropathy (DN) has not been yet explored. We have evaluated hyperglycaemia-induced alteration of SIRT1 signalling and the effect of isoliquiritigenin (ILQ) on SIRT1-directed AMP kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) signalling in peripheral nerves of streptozotocin (STZ) (55 mg/kg, ip)-induced diabetic rats and in high glucose (30 mM)-exposed neuro2a (N2A) cells. Diabetic rats and high glucose-exposed N2A cells showed reduction in SIRT1 expression with consequent decline in mitochondrial biogenesis and autophagy. ILQ (10 & 20 mg/kg, po) administration to diabetic rats for 2 weeks and exposure to glucose-insulted N2A cells resulted in significant SIRT1 activation with concurrent increase in mitochondrial biogenesis and autophagy. ILQ administration also enhanced NAD+/NADH ratio in peripheral sciatic nerves which explains its possible SIRT1 modulatory effect. Functional and behavioural studies show beneficial effect of ILQ as it alleviated nerve conduction and nerve blood flow deficits in diabetic rats along with improvement in behavioural parameters (hyperalgesia and allodynia). ILQ treatment to N2A cells reduced high glucose-driven ROS production and mitochondrial membrane depolarization. Further, ILQ-mediated SIRT1 activation facilitated the Nrf2-directed antioxidant signalling. Overall, results from this study suggest that SIRT1 activation by ILQ mimic effects of calorie restriction, that is, PGC-1α-mediated mitochondrial biogenesis, FOXO3a mediated stress resistance and AMPK mediated autophagy effects to counteract the multiple manifestations in experimental DN.

Effect of omega-3 supplementation on neuropathy in type 1 diabetes: A 12-month pilot trial.

OBJECTIVE: To test the hypothesis that 12 months of seal oil omega-3 polyunsaturated fatty acids (ω-3 PUFA) supplementation will stop the known progression of diabetic sensorimotor polyneuropathy (DSP) in type 1 diabetes mellitus (T1DM). METHODS: Individuals with T1DM and evidence of DSP as determined by a Toronto Clinical Neuropathy Score ≥1 were recruited to participate in a single-arm, open-label trial of seal oil ω-3 PUFA supplementation (10 mL·d-1; 750 mg eicosapentaenoic acid, 560 mg docosapentaenoic acid, and 1,020 mg docosahexaenoic acid) for 1 year. The primary outcome was the 1-year change in corneal nerve fiber length (CNFL) measured by in vivo corneal confocal microscopy, with sensory and nerve conduction measures as secondary outcomes. RESULTS: Forty participants (53% female), aged 48 ± 14 years, body mass index 28.1 ± 5.8 with diabetes duration of 27 ± 18 years, were enrolled. At baseline, 23 participants had clinical DSP and 17 did not. Baseline CNFL was 8.3 ± 2.9 mm/mm2 and increased 29% to 10.1 ± 3.7 mm/mm2 (p = 0.002) after 12 months of supplementation. There was no change in nerve conduction or sensory function. CONCLUSIONS: Twelve months of ω-3 supplementation was associated with increase in CNFL in T1DM. CLINICALTRIALSGOVIDENTIFIER: NCT02034266. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with T1DM and evidence of DSP, 12 months of seal oil omega-3 supplementation increases CNFL.

Dietary reversal of neuropathy in a murine model of prediabetes and metabolic syndrome.

Patients with metabolic syndrome, which is defined as obesity, dyslipidemia, hypertension and impaired glucose tolerance (IGT), can develop the same macro- and microvascular complications as patients with type 2 diabetes, including peripheral neuropathy. In type 2 diabetes, glycemic control has little effect on the development and progression of peripheral neuropathy, suggesting that other metabolic syndrome components may contribute to the presence of neuropathy. A parallel phenomenon is observed in patients with prediabetes and metabolic syndrome, where improvement in weight and dyslipidemia more closely correlates with restoration of nerve function than improvement in glycemic status. The goal of the current study was to develop a murine model that resembles the human condition. We examined longitudinal parameters of metabolic syndrome and neuropathy development in six mouse strains/genotypes (BKS-wt, BKS-Leprdb/+ , B6-wt, B6-Leprdb/+ , BTBR-wt, and BTBR-Lepob/+ ) fed a 54% high-fat diet (HFD; from lard). All mice fed a HFD developed large-fiber neuropathy and IGT. Changes appeared early and consistently in B6-wt mice, and paralleled the onset of neuropathy. At 36 weeks, B6-wt mice displayed all components of the metabolic syndrome, including obesity, IGT, hyperinsulinemia, dyslipidemia and oxidized low density lipoproteins (oxLDLs). Dietary reversal, whereby B6-wt mice fed a HFD from 4-20 weeks of age were switched to standard chow for 4 weeks, completely normalized neuropathy, promoted weight loss, improved insulin sensitivity, and restored LDL cholesterol and oxLDL by 50% compared with levels in HFD control mice. This dietary reversal model provides the basis for mechanistic studies investigating peripheral nerve damage in the setting of metabolic syndrome, and ultimately the development of mechanism-based therapies for neuropathy.

Effect of enriching the diet with menhaden oil or daily treatment with resolvin D1 on neuropathy in a mouse model of type 2 diabetes.

The purpose of this study was to determine the effect of supplementing the diet of a mouse model of type 2 diabetes with menhaden (fish) oil or daily treatment with resolvin D1 on diabetic neuropathy. The end points evaluated included motor and sensory nerve conduction velocity, thermal sensitivity, innervation of sensory nerves in the cornea and skin, and the retinal ganglion cell complex thickness. Menhaden oil is a natural source for n-3 polyunsaturated fatty acids, which have been shown to have beneficial effects in other diseases. Resolvin D1 is a metabolite of docosahexaenoic acid and is known to have anti-inflammatory and neuroprotective properties. To model type 2 diabetes, mice were fed a high-fat diet for 8 wk followed by a low dosage of streptozotocin. After 8 wk of hyperglycemia, mice in experimental groups were treated for 6 wk with menhaden oil in the diet or daily injections of 1 ng/g body wt resolvin D1. Our findings show that menhaden oil or resolvin D1 did not improve elevated blood glucose, HbA1C, or glucose utilization. Untreated diabetic mice were thermal hypoalgesic, had reduced motor and sensory nerve conduction velocities, had decreased innervation of the cornea and skin, and had thinner retinal ganglion cell complex. These end points were significantly improved with menhaden oil or resolvin D1 treatment. Exogenously, resolvin D1 stimulated neurite outgrowth from primary cultures of dorsal root ganglion neurons from normal mice. These studies suggest that n-3 polyunsaturated fatty acids derived from fish oil could be an effective treatment for diabetic neuropathy.

Effects of sodium restriction and hydrochlorothiazide on RAAS blockade efficacy in diabetic nephropathy: a randomised clinical trial.

BACKGROUND: Reduction of dietary sodium intake or diuretic treatment increases renin-angiotensin-aldosterone system (RAAS) blockade efficacy in non-diabetic nephropathy. We aimed to investigate the effect of sodium restriction and the diuretic hydrochlorothiazide, separately and in combination, added to RAAS blockade on residual albuminuria in patients with type 2 diabetic nephropathy. METHODS: In this multicentre, double-blind, placebo-controlled, crossover randomised trial, we included patients with type 2 diabetic nephropathy. Main entry criteria were microalbuminaria or macroalbuminuria, and creatinine clearance of 30 mL/min or higher with less than 6 mL/min decline in the previous year. We tested the separate and combined effects of sodium restriction (dietary counselling in the outpatient setting) and hydrochlorothiazide (50 mg daily), added to standardised maximal angiotensin-converting enzyme (ACE) inhibition (lisinopril 40 mg daily), on albuminuria (primary endpoint). Patients were given hydrochlorothiazide (50 mg per day) or placebo during four treatment periods of 6 weeks. Both treatments were combined with regular sodium diet or sodium restriction (target sodium intake 50 mmol Na(+) per day). The 6-week treatment periods were done consecutively in a random order. Patients were randomised in blocks of two patients. The trial was analysed by intention to treat. The trial is registered with TrialRegister.nl, number 2366. FINDINGS: Of 89 eligible patients, 45 were included in the study. Both sodium restriction and hydrochlorothiazide significantly reduced albuminuria, irrespective of treatment sequence. Residual geometric mean albuminuria with baseline treatment was 711 mg per day (95% CI 485-1043); it was significantly reduced by sodium restriction (393 mg per day [258-599], p=0·0002), by hydrochlorothiazide (434 mg per day [306-618], p=0·0003), and to the greatest extent by their combination (306 mg per day [203-461], p<0·0001). Orthostatic complaints were present in two patients (4%) during baseline treatment, five (11%) during addition of sodium restriction, five (11%) during hydrochlorothiazide treatment, and 12 (27%) during combination treatment. No serious adverse events occurred. INTERPRETATION: We conclude that sodium restriction is an effective non-pharmacological intervention to increase RAAS blockade efficacy in type 2 diabetic nephropathy. FUNDING: None.