The effect of chromium picolinate and biotin supplementation on glycemic control in poorly controlled patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized trial

A Mediterranean Diet May Be Protective in the Development of Diabetic Retinopathy

The Mediterranean diet is recognized as one of the healthiest available dietary patterns. This perception results from its beneficial effects on the cardiovascular system and, also, on hypertension, diabetes, and cancer compared with other diets. Its impact on the course of diabetes is assessed in the available scientific literature; however, little information is available about its impact on diabetic retinopathy. The MD is characterized mainly by the consumption of fish, seafood, foods of plant origin, and fresh fruit and vegetables. It is also recommended to consume legumes, which are a source of folic acid, magnesium, iron, and dietary fiber. High consumption of nuts and unrefined grains is also recommended in the MD. Marine fish provide polyunsaturated acids from the omega-3 group. Olive oil plays a very important role, especially olive oil obtained from mechanical pressing. Additionally, olive oil contains vitamins E, K, and polyphenols. Polyphenols, which are present in a diverse range of vegetables, fruits, and seeds, have the ability to decrease oxidative stress, inflammation, and insulin resistance. Resveratrol is naturally found in grape skins and seeds, as well as in peanuts and berries, and is a constituent of red wine. Resveratrol can inhibit increased vascular leakage and loss of pericytes and regulate the level of VEGF protein in the retina, thus inhibiting the development of DR. Consumption of fruits, vegetables, fish, and olive oil may be correlated with a lower risk of diabetic retinopathy. This paper presents the definition of the Mediterranean diet and its influence on the course of diabetes and diabetic retinopathy.

Impact of biotin supplemented diet on mouse pancreatic islet β-cell mass expansion and glucose induced electrical activity

Biotin supplemented diet (BSD) is known to enhance β-cell replication and insulin secretion in mice. Here, we first describe BSD impact on the islet β-cell membrane potential (Vm) and glucose-induced electrical activity. BALB/c female mice (n ≥ 20) were fed for nine weeks after weaning with a control diet (CD) or a BSD (100X). In both groups, islet area was compared in pancreatic sections incubated with anti-insulin and anti-glucagon antibodies; Vm was recorded in micro dissected islet β-cells during perfusion with saline solutions containing 2.8, 5.0, 7.5-, or 11.0 mM glucose. BSD increased the islet and β-cell area compared with CD. In islet β-cells of the BSD group, a larger ΔVm/Δ[glucose] was found at sub-stimulatory glucose concentrations and the threshold glucose concentration for generation of action potentials (APs) was increased by 1.23 mM. Moreover, at 11.0 mM glucose, a significant decrease was found in AP amplitude, frequency, ascending and descending slopes as well as in the calculated net charge influx and efflux of islet β-cells from BSD compared to the CD group, without changes in slow Vm oscillation parameters. A pharmacological dose of biotin in mice increases islet insulin cell mass, shifts islet β-cell intracellular electrical activity dose response curve toward higher glucose concentrations, very likely by increasing K_ATP conductance, and decreases voltage gated Ca²⁺ and K⁺ conductance at stimulatory glucose concentrations.

Impairment of gut microbial biotin metabolism and host biotin status in severe obesity: effect of biotin and prebiotic supplementation on improved metabolism

OBJECTIVES

Gut microbiota is a key component in obesity and type 2 diabetes, yet mechanisms and metabolites central to this interaction remain unclear. We examined the human gut microbiome's functional composition in healthy metabolic state and the most severe states of obesity and type 2 diabetes within the MetaCardis cohort. We focused on the role of B vitamins and B7/B8 biotin for regulation of host metabolic state, as these vitamins influence both microbial function and host metabolism and inflammation.

DESIGN

We performed metagenomic analyses in 1545 subjects from the MetaCardis cohorts and different murine experiments, including germ-free and antibiotic treated animals, faecal microbiota transfer, bariatric surgery and supplementation with biotin and prebiotics in mice.

RESULTS

Severe obesity is associated with an absolute deficiency in bacterial biotin producers and transporters, whose abundances correlate with host metabolic and inflammatory phenotypes. We found suboptimal circulating biotin levels in severe obesity and altered expression of biotin-associated genes in human adipose tissue. In mice, the absence or depletion of gut microbiota by antibiotics confirmed the microbial contribution to host biotin levels. Bariatric surgery, which improves metabolism and inflammation, associates with increased bacterial biotin producers and improved host systemic biotin in humans and mice. Finally, supplementing high-fat diet-fed mice with fructo-oligosaccharides and biotin improves not only the microbiome diversity, but also the potential of bacterial production of biotin and B vitamins, while limiting weight gain and glycaemic deterioration.

CONCLUSION

Strategies combining biotin and prebiotic supplementation could help prevent the deterioration of metabolic states in severe obesity.

TRIAL REGISTRATION NUMBER

NCT02059538.

Influence of biotin intervention on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Background

Biotin is a water-soluble vitamin acting as a covalently bound coenzyme in regulating energy production. Previous studies have reported that biotin supplementation may influence blood glucose and lipid level in patients with type 2 diabetes mellitus (T2DM).

Methods

We searched Pubmed, Embase, and Cochrane library databases up to 8th August 2022 for studies examining the effects of biotin supplementation in T2DM patients. Pooled effects were measured by weighted mean differences (WMDs) with 95% confidence intervals (CI) using random effects models. Inter-study heterogeneity was assessed and quantified.

Results

A total of five random controlled trials (RCT), involving 445 participants were included. It was suggested that biotin supplementation for 28 to 90 days significantly decreased the level of fasting blood glucose (FBG) (MD: -1.21 mmol/L, 95% CI: -2.73 to 0.31), total cholesterol (TC) (MD: -0.22 mmol/L, 95% CI: -0.25 to -0.19) and triglycerides (TG) (MD: -0.59 mmol/L, 95% CI: -1.21 to 0.03). No significant beneficial effects were observed on insulin (MD: 1.88 pmol/L 95% CI: -13.44 to 17.21). Evidence for the impact of biotin supplementation on the levels of glycated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and very low-density lipoprotein cholesterol (VLDL-C) was limited to draw conclusion.

Conclusions

Biotin supplementation may decrease FBG, TC and TG levels. However, its influence on insulin is not significant and further studies on the effects of biotin on HbA1c, LDL-C, HDL-C and VLDL-C are expected.

Fabrication of Biopolymer Based Nanoparticles for the Entrapment of Chromium and Iron Supplements

The objective of this study was to encapsulate iron and chromium into novel nanoparticles formulated using chitosan (CS), dextran sulfate (DS) and whey protein isolate (WPI) for oral drug delivery. Empty and loaded CS-DS nanoparticles were prepared via complex coacervation whilst whey protein nanocarriers were produced by a modified thermal processing method using chitosan. The physiochemical properties of the particles were characterized to determine the effects of formulation variables, including biopolymer ratio on particle size and zeta potential. Permeability studies were also undertaken on the most stable whey protein–iron nanoparticles by measuring Caco-2 ferritin formation. A particle size analysis revealed that the majority of samples were sub-micron sized, ranging from 420–2400 nm for CS-DS particles and 220–1000 nm for WPI-CS samples. As expected, a higher chitosan concentration conferred a 17% more positive zeta potential on chromium-entrapped WPI nanoparticles, whilst a higher dextran volume decreased the size of CS-DS nanoparticles by 32%. The addition of iron also caused a significant increase in size for all samples, as seen where the loaded WPI samples were 296 nm larger than the empty particles. Caco-2 iron absorption revealed that one formulation, which had the lowest particle size (226 ± 10 nm), caused a 64% greater iron absorption compared to the ferrous sulfate standard. This study describes, for the first time, the novel design of chromium- and iron-entrapped nanoparticles, which could act as novel systems for oral drug delivery.

Protective Effects of Chromium Picolinate Against Diabetic-Induced Renal Dysfunction and Renal Fibrosis in Streptozotocin-Induced Diabetic Rats

Diabetic nephropathy (DN) is one of the most important complications of diabetes, and the leading cause of end-stage renal disease (ESRD). While Chromium picolinate (CrPic) supplementation has been found to be effective in treating diabetes, its effects on diabetic-induced nephropathy have not been studied. Therefore, in this study, CrPic (1 mg kg⁻¹ d⁻¹) was administered to a DN rat model by oral gavage for eight weeks to investigate its effects. The results show that CrPic supplementation caused a decrease in levels of blood glucose, serum insulin, blood urea nitrogen (BUN), serum creatinine, and urinary albumin in DN rats. It also reversed renal pathological changes, including renal glomerular sclerosis and interstitial fibrosis. In addition, the oxidative defense system in the kidneys of DN rats was found to be improved; the biological activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) increased; and the content of malondialdehyde (MDA) lowered. Immunohistochemical results reveal that the expression levels of renal transforming growth factor-β1 (TGF-β1), Smad 2, and Smad 3 decreased significantly in the kidneys of rats in the CrPic-treated group. CrPic administration was thus found to ameliorate diabetic nephropathy in SD rats via an antioxidative stress mechanism, as well the ability to inhibit TGF-β1/Smad2/3 expression. This study suggests that CrPic could be a potential renal-protective nutrient against diabetic nephropathy.

Obese Individuals with and without Type 2 Diabetes Show Different Gut Microbial Functional Capacity and Composition

Obesity and type 2 diabetes (T2D) are metabolic disorders that are linked to microbiome alterations. However, their co-occurrence poses challenges in disentangling microbial features unique to each condition. We analyzed gut microbiomes of lean non-diabetic (n = 633), obese non-diabetic (n = 494), and obese individuals with T2D (n = 153) from German population and metabolic disease cohorts. Microbial taxonomic and functional profiles were analyzed along with medical histories, serum metabolomics, biometrics, and dietary data. Obesity was associated with alterations in microbiome composition, individual taxa, and functions with notable changes in Akkermansia, Faecalibacterium, Oscillibacter, and Alistipes, as well as in serum metabolites that correlated with gut microbial patterns. However, microbiome associations were modest for T2D, with nominal increases in Escherichia/Shigella. Medications, including antihypertensives and antidiabetics, along with dietary supplements including iron, were significantly associated with microbiome variation. These results differentiate microbial components of these interrelated metabolic diseases and identify dietary and medication exposures to consider in future studies.

Mitigating effect of biotin against irradiation-induced cerebral cortical and hippocampal damage in the rat brain tissue

Radiation-induced brain injury is common and mainly occurs in patients receiving radiotherapy for malignant head and neck tumors. The brain is oversensitive to oxidant injury induced by radiation. Biotin is a member of the vitamin B complex family and its deficiency has been associated with neurogenesis impairment in animals and humans. The present study was undertaken to investigate the mitigating effect of biotin on the cerebral cortical and hippocampal damage induced by radiation exposure. Animals were exposed to radiation in the presence or absence of biotin and sacrificed on day 10. The results demonstrated that the administration of biotin 2 mg to irradiated rats had no significant effect on the radiation-induced damage of the cerebral cortex and the hippocampus, while the administration of biotin 6 mg has significantly attenuated oxidative stress in the hippocampus, manifested by a reduction of 4-hydroxynonenal (4HNE), total nitrate/nitrite (NOx), and xanthine oxidase (XO) levels associated with an elevation of glutathione (GSH) content as well as superoxide dismutase (SOD) and catalase (CAT) activities. In addition, biotin decreased the pro-inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrotic factor alpha (TNF-α)), caspase-3, poly(ADP-ribose) polymerase 1 (PARP1) level, and PARP1 gene expression. Moreover, biotin 6 mg treatment diminished serum S100 protein (S100B) and neuron-specific enolase (NSE) levels. In conclusion, biotin treatment at high dose post-irradiation has efficiently neutralized the effect of free radicals in the hippocampal region of rats. Thus, it could be applicable as a radio-mitigator for reducing or delayed radiation-induced brain injury in patients post-radiotherapy.

Biotin and chromium histidinate improve glucose metabolism and proteins expression levels of IRS-1, PPAR-γ, and NF-κB in exercise-trained rats

BACKGROUND

Chromium histidinate (CrHis) and biotin are micronutrients commonly used to improve health by athletes and control glycaemia by patients with diabetes. This study investigates the effects of 8-week regular exercise training in rats together with dietary CrHis and biotin supplementation on glucose, lipids and transaminases levels, as well as protein expression levels of peroxisome proliferator-activated receptor gamma (PPAR-γ), insulin receptor substrate-1 (IRS-1) and nuclear transcription factor kappa B (NF-κB).

METHODS

A total of 56 male Wistar rats were randomly divided into 8 groups of 7 animals each and treated as follows: Control, CrHis, Biotin, CrHis+Biotin, Exercise, CrHis+Exercise, Biotin+Exercise, and CrHis+Biotin+Exercise. The doses of CrHis and biotin were 400 μg/kg and 6 mg/kg of diet, respectively. The training program consisted of running at 30 m/min for 30 min/day at 0% grade level, 5 days per week, once a day for 6 weeks. Serum glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL), triglycerides (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured with an automatic biochemical analyzer. Muscle and liver PPAR-γ, IRS-1 and NF-κB expressions were detected with real-time polymerase chain reaction.

RESULTS

Regular exercise significantly (p < 0.001) decreased glucose, TC and TG levels, but increased HDL cholesterol. Dietary CrHis and biotin supplementation exhibited a significant (p < 0.001) decrease in glucose (effect size = large; ƞ2 = 0.773) and TG (effect size = large; ƞ2 = 0.802) levels, and increase in HDL cholesterol compared with the exercise group. No significant change in AST and ALT (effect size = none) levels was recorded in all groups (p > 0.05). CrHis/biotin improves the proteins expression levels of IRS-1, PPAR-γ, and NF-κB (effect size: large for all) in the liver and muscle of sedentary and regular exercise-trained rats (p < 0.001).

CONCLUSIONS

CrHis/biotin supplementation improved serum glucose and lipid levels as well as proteins expression levels of PPAR-γ, IRS-1 and NF-κB in the liver and muscle of exercise-trained rats, with the highest efficiency when administered together. CrHis/biotin may represent an effective nutritional therapy to improve health.

Perspective: Fundamental Limitations of the Randomized Controlled Trial Method in Nutritional Research: The Example of Probiotics

Studies on the relation between health and nutrition are often inconclusive. There are concerns about the validity of many research findings, and methods that can deliver high-quality evidence-such as the randomized controlled trial (RCT) method-have been embraced by nutritional researchers. Unfortunately, many nutritional RCTs also yield ambiguous results. It has been argued that RCTs are ill-suited for certain settings, including nutritional research. In this perspective, we investigate whether there are fundamental limitations of the RCT method in nutritional research. To this end, and to limit the scope, we use probiotic studies as an example. We use an epistemological approach and evaluate the presuppositions that underlie the RCT method. Three general presuppositions are identified and discussed. We evaluate whether these presuppositions can be considered true in probiotic RCTs, which appears not always to be the case. This perspective concludes by exploring several alternative study methods that may be considered for future probiotic or nutritional intervention trials.

Nutrition for diabetic retinopathy: plummeting the inevitable threat of diabetic vision loss

Diabetic retinopathy (DR) is among the leading causes of preventable blindness. Hyperglycemia, hypertension, hyperlipidemia and anemia majorly predispose its pathogenesis. The current treatment modalities of DR include laser photocoagulation therapy, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents and vitreo-retinal surgery which are costly, highly invasive, unproven for prolonged use and opted in advanced stages of DR. By then retina already encounters a vast damage. Nutrients by their natural physiological, biochemical and molecular action can preserve retinal structure and functions by interfering with the various pathological steps prompting DR incidence, thereby altering the risk of developing this ocular morbidity. Nutrients can also play a central role in DR patients resistant towards the conventional medical treatments. However due to the byzantine interplay existing between nutrients and DR, the worth of nutrition in curbing this vision-threatening ocular morbidity remains silent. This review highlights how nutrients can halt DR development. A nutritional therapy, if adopted in the initial stages, can provide superior-efficacy over the current treatment modalities and can be a complementary, inexpensive, readily available, anodyne option to the clinically unmet requirement for preventing DR. Assessment of nutritional status is presently considered relevant in various clinical conditions except DR. Body Mass Index (BMI) conferred inconclusive results in DR subjects. Subjective Global Assessment (SGA) of nutritional status has recently furnished relevant association with DR status. By integrating nutritional strategies, the risk of developing DR can be reduced substantially. This review summarizes the subsisting knowledge on nutrition, potentially beneficial for preventing DR and sustaining good vision among diabetic subjects.

Dietary Biotin Supplementation Modifies Hepatic Morphology without Changes in Liver Toxicity Markers

Pharmacological concentrations of biotin have pleiotropic effects. Several reports have documented that biotin supplementation decreases hyperglycemia. We have shown that a biotin-supplemented diet increased insulin secretion and the mRNA abundance of proteins regulating insulin transcription and secretion. We also found enlarged pancreatic islets and modified islet morphology. Other studies have shown that pharmacological concentrations of biotin modify tissue structure. Although biotin administration is considered safe, little attention has been given to its effect on tissue structure. In this study, we investigated the effect of biotin supplementation on hepatic morphology and liver toxicity markers. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet for 8 weeks. Versus the control mice, biotin-supplemented mice had an altered portal triad with dilated sinusoids, increased vascularity, and bile conducts. Furthermore, we observed an increased proportion of nucleomegaly and binucleated hepatocytes. In spite of the liver morphological changes, no differences were observed in the serum liver damage indicators, oxidative stress markers, or antioxidant enzymes. Our data demonstrate for the first time that biotin supplementation affects liver morphology in normal mice, and that these modifications are not paralleled with damage markers.

Chromium supplements for glycemic control in type 2 diabetes: limited evidence of effectiveness

Some adults with type 2 diabetes mellitus (T2DM) believe that chromium-containing supplements will help control their disease, but the evidence is mixed. This narrative review examines the efficacy of chromium supplements for improving glycemic control as measured by decreases in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c). Using systematic search criteria, 20 randomized controlled trials of chromium supplementation in T2DM patients were identified. Clinically meaningful treatment goals were defined as an FPG of ≤7.2 mmol/dL, a decline in HbA1c to ≤7%, or a decrease of ≥0.5% in HbA1c. In only a few randomized controlled trials did FPG (5 of 20), HbA1c (3 of 14), or both (1 of 14) reach the treatment goals with chromium supplementation. HbA1c declined by ≥0.5% in 5 of 14 studies. On the basis of the low strength of existing evidence, chromium supplements have limited effectiveness, and there is little rationale to recommend their use for glycemic control in patients with existing T2DM. Future meta-analyses should include only high-quality studies with similar forms of chromium and comparable inclusion/exclusion criteria to provide scientifically sound recommendations for clinicians.

B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review

The B-vitamins comprise a group of eight water soluble vitamins that perform essential, closely inter-related roles in cellular functioning, acting as co-enzymes in a vast array of catabolic and anabolic enzymatic reactions. Their collective effects are particularly prevalent to numerous aspects of brain function, including energy production, DNA/RNA synthesis/repair, genomic and non-genomic methylation, and the synthesis of numerous neurochemicals and signaling molecules. However, human epidemiological and controlled trial investigations, and the resultant scientific commentary, have focused almost exclusively on the small sub-set of vitamins (B9/B12/B6) that are the most prominent (but not the exclusive) B-vitamins involved in homocysteine metabolism. Scant regard has been paid to the other B vitamins. This review describes the closely inter-related functions of the eight B-vitamins and marshals evidence suggesting that adequate levels of all members of this group of micronutrients are essential for optimal physiological and neurological functioning. Furthermore, evidence from human research clearly shows both that a significant proportion of the populations of developed countries suffer from deficiencies or insufficiencies in one or more of this group of vitamins, and that, in the absence of an optimal diet, administration of the entire B-vitamin group, rather than a small sub-set, at doses greatly in excess of the current governmental recommendations, would be a rational approach for preserving brain health.

Beneficial effects of oral chromium picolinate supplementation on glycemic control in patients with type 2 diabetes: A randomized clinical study

BACKGROUND

Chromium is an essential mineral that contributes to normal glucose function and lipid metabolism. This study evaluated the effect of chromium picolinate (CrPic) supplementation in patients with type 2 diabetes mellitus (T2DM).

METHODS

A four month controlled, single blind, randomized trial was performed with 71 patients with poorly controlled (hemoglobin A1c [HbA1c]>7%) T2DM divided into 2 groups: Control (n=39, using placebo), and supplemented (n=32, using 600μg/day CrPic). All patients received nutritional guidance according to the American Diabetes Association (ADA), and kept using prescribed medications. Fasting and postprandial glucose, HbA1c, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and serum ferritin were evaluated.

RESULTS

CrPic supplementation significantly reduced the fasting glucose concentration (-31.0mg/dL supplemented group; -14.0mg/dL control group; p<0.05, post- vs. pre-treatment, in each group) and postprandial glucose concentration (-37.0mg/dL in the supplemented group; -11.5 mg/dL in the control group; p<0.05). HbA1c values were also significantly reduced in both groups (p<0.001, comparing post- vs. pre-treatment groups). Post-treatment HbA1c values in supplemented patients were significantly lower than those of control patients. HbA1c lowering in the supplemented group (-1.90), and in the control group (-1.00), was also significant, comparing pre- and post-treatment values, for each group (p<0.001 and p<0.05, respectively). CrPic increased serum chromium concentrations (p<0.001), when comparing the supplemented group before and after supplementation. No significant difference in lipid profile was observed in the supplemented group; however, total cholesterol, HDL-c and LDL-c were significantly lowered, comparing pre- and post-treatment period, in the control group (p<0.05).

CONCLUSIONS

CrPic supplementation had a beneficial effect on glycemic control in patients with poorly controlled T2DM, without affecting the lipid profile. Additional studies are necessary to investigate the effect of long-term CrPic supplementation.

Microarray analysis of pancreatic gene expression during biotin repletion in biotin-deficient rats

Biotin is a B vitamin involved in multiple metabolic pathways. In humans, biotin deficiency is relatively rare but can cause dermatitis, alopecia, and perosis. Low biotin levels occur in individuals with type-2 diabetes, and supplementation with biotin plus chromium may improve blood sugar control. The acute effect on pancreatic gene expression of biotin repletion following chronic deficiency is unclear, therefore we induced biotin deficiency in adult male rats by feeding them a 20% raw egg white diet for 6 weeks. Animals were then randomized into 2 groups: one group received a single biotin supplement and returned to normal chow lacking egg white, while the second group remained on the depletion diet. After 1 week, pancreata were removed from biotin-deficient (BD) and biotin-repleted (BR) animals and RNA was isolated for microarray analysis. Biotin depletion altered gene expression in a manner indicative of inflammation, fibrosis, and defective pancreatic function. Conversely, biotin repletion activated numerous repair and anti-inflammatory pathways, reduced fibrotic gene expression, and induced multiple genes involved in pancreatic endocrine and exocrine function. A subset of the results was confirmed by quantitative real-time PCR analysis, as well as by treatment of pancreatic AR42J cells with biotin. The results indicate that biotin repletion, even after lengthy deficiency, results in the rapid induction of repair processes in the pancreas.

Natural products for the management of type 2 diabetes mellitus and comorbid conditions

OBJECTIVE

To provide pharmacists with practical information to guide consumers in their choices of herbal products and dietary supplements for the management of type 2 diabetes mellitus (T2DM) and its comorbid disease states.

SUMMARY

The herbal and dietary supplement market has grown exponentially over the past decade as Americans increasingly use such agents for generalized health and the prevention and treatment of chronic disease states.1 Pharmacist advice is often requested on the use of these agents for the management of T2DM; however, this is an area that has insufficient evidence to support confident recommendations. Many published studies involving herbal agents and dietary supplements are small and poorly designed, with heterogeneous results. Pharmacists should be aware of the safety and efficacy data available for these agents, recognize potential drug interactions, and identify acceptable manufactured products.

CONCLUSION

The strongest scientific evidence for blood glucose lowering effect is associated with alpha-lipoic acid and fenugreek. There is also good evidence supporting the use of ivy gourd, gymnema, and vitamin E for management of hyperglycemia; however, caution should be used when recommending vitamin E. Pharmacists should advise consumers to disclose use of any of these products to all of their health care providers.

Dietary chromium supplementation for targeted treatment of diabetes patients with comorbid depression and binge eating

Dietary chromium supplementation for the treatment of diabetes remains controversial. The prevailing view that chromium supplementation for glucose regulation is unjustified has been based upon prior studies showing mixed, modest-sized effects in patients with type 2 diabetes (T2DM). Based on chromium's potential to improve insulin, dopamine, and serotonin function, we hypothesize that chromium has a greater glucoregulatory effect in individuals who have concurrent disturbances in dopamine and serotonin function--that is, complex patients with comorbid diabetes, depression, and binge eating. We propose, as suggested by the collective data to date, the need to go beyond the "one size fits all" approach to chromium supplementation and put forth a series of experiments designed to link physiological and neurobehavioral processes in the chromium response phenotype.

Micronutrient status in type 2 diabetes: a review

Type 2 diabetes is characterized by significant losses of important micronutrients due to metabolic basis of the disease and its complications. Evidence of changes in trace mineral and vitamin metabolism as a consequence of type 2 diabetes is reviewed in this chapter. This review is not a meta-analysis but an overview of the micronutrient status, metabolic needs, and potential micronutrient requirements in type 2 diabetics. This chapter will not concentrate on vitamin D and type 2 diabetes as this is a topic that has been extensively reviewed before. The less well-known micronutrients notably zinc, magnesium, chromium, copper, manganese, iron, selenium, vanadium, B-group vitamins, and certain antioxidants are assessed. While some evidence is available to demonstrate the positive influence of micronutrient supplementation on glycemic control, much remains to be investigated. Additional research is necessary to characterize better biomarkers of micronutrient status and requirements in type 2 diabetics. The optimal level of micronutrient supplementation to achieve glucose homeostasis in type 2 diabetics remains a challenge.

Systematic review and meta-analysis of the efficacy and safety of chromium supplementation in diabetes

WHAT IS KNOWN AND OBJECTIVE

Chromium is an essential mineral for carbohydrate and lipid metabolism. Results of previous systematic reviews and meta-analyses of chromium supplementation and metabolic profiles in diabetes have been inconsistent. Recently, several published trials have emerged. We conducted a systematic review and meta-analysis to assess the effects on metabolic profiles and safety of chromium supplementation in diabetes mellitus.

METHODS

Clinical trials were identified through MEDLINE, the Cochrane library, CINAHL, Web of Science, Scopus and www.clinicaltrial.gov up to May 2013. Historical search of reference lists of related articles was also conducted. Studies were included if they (i) were randomized controlled trials comparing chromium mono- or combined supplementation against placebo, (ii) reported HbA1c or fasting plasma glucose and (iii) were of at least 3 weeks when reporting fasting plasma glucose, or of at least 8 weeks if HbA1c was reported. No language restriction was imposed. Treatment effect and adverse events were estimated with mean difference and odds ratio, respectively.

RESULTS AND DISCUSSION

Twenty-five randomized controlled trials met the inclusion criteria. Of these, 22 studies evaluated chromium monosupplementation. One study evaluated chromium yeast combined with vitamins C and E, and two others evaluated chromium picolinate plus biotin (CPB). Overall, chromium mono- and combined supplementation significantly improved glycaemic control (mean difference for HbA1c -0·55%; 95% CI -0·88 to -0·22%; P = 0·001, mean difference for FPG -1·15 mm; 95% CI -1·84 to -0·47 mm; P = 0·001). In particular, chromium monotherapy significantly reduced triglycerides and increased HDL-C levels. The effects on glucose and triglycerides levels were shown especially with chromium picolinate. Glycaemic control may improve with chromium monosupplementation of more than 200 μg daily. HbA1c and FPG also improved in patients with inadequate glycaemic control at baseline. The risk of adverse events did not differ between chromium and placebo.

WHAT IS NEW AND CONCLUSIONS

The available evidence suggests favourable effects of chromium supplementation on glycaemic control in patients with diabetes. Chromium monosupplement may additionally improve triglycerides and HDL-C levels. Chromium supplementation at usual doses does not increase the risk of adverse events compared with placebo. Data on chromium combined supplementation are limited and inconclusive. Long-term benefit and safety of chromium supplementation remain to be further investigated.

Heavy metal in the intensive care unit: a review of current literature on trace element supplementation in critically ill patients

Trace elements are essential for many physiologic processes. In recent years, supplementation has been studied for a variety of indications, including glycemic control, wound healing, antioxidant effect, and anemia. Critical illness, especially states such as burns, traumas, and septic shock, is associated with inflammatory and oxidative stress, immune dysfunction, and malnutrition. In these patients, enteral and parenteral nutrition or pharmaceutical supplementation is used to provide essential macronutrients, including trace elements. The purpose of this review is to describe trace element supplementation, including iron, copper, chromium, manganese, selenium, and zinc, and highlight their mechanism, pharmacology, outcome data, and adverse effects.

Modulation of the rat hepatic cytochrome P4501A subfamily using biotin supplementation

Studies have found that biotin favors glucose and lipid metabolism, and medications containing biotin have been developed. Despite the use of biotin as a pharmacological agent, few studies have addressed toxicity aspects including the possible interaction with cytochrome P450 enzyme family. This study analyzed the effects of pharmacological doses of biotin on the expression and activity of the cytochrome P4501A subfamily involved in the metabolism of xenobiotics. Wistar rats were treated daily with biotin (2 mg/kg, i.p.), while the control groups were treated with saline. All of the rats were sacrificed by cervical dislocation after 1, 3, 5, or 7 days of treatment. CYP1A1 and CYP1A2 mRNAs were modified by biotin while enzyme activity and protein concentration were not affected. The lack of an effect of biotin on CYP1A activity was confirmed using other experimental strategies, including (i) cotreatment of the animals with biotin and a known CYP1A inducer; (ii) the addition of biotin to the reaction mixtures for the measurement of CYP1A1 and CYP1A2 activities; and (iii) the use of an S9 mixture that was prepared from control and biotin-treated rats to analyze the activation of benzo[a]pyrene (BaP) into mutagenic metabolites using the Ames test. The results suggest that biotin does not influence the CYP1A-mediated metabolism of xenobiotics.

Survey of the effect of biotin on glycemic control and plasma lipid concentrations in type 1 diabetic patients in kermanshah in iran (2008-2009)

OBJECTIVE

Diabetes mellitus is the most common chronic endocrine disease worldwide. Intensive glycemic control plays an important role in decreasing morbidity and mortality rate of the disease. Preclinical studies have shown that biotin has an essential role in regulating blood glucose and serum lipid metabolism. This study aims to evaluate the effect of biotin on glycemic control and plasma lipids concentrations in type 1diabetic patients.

METHODS

This randomized double-blind placebo-controlled clinical trial study was conducted 70 type 1 diabetic patients with an age range 5-25 years old with poorly controlled (glycosylated hemoglobin ≥8%). Subjects were randomly allocated into two groups. In the intervention group biotin (40 microgram/kg) was administered plus daily insulin, while the control group received placebo plus daily insulin regimen for three months. Laboratory tests including glycosylated hemoglobin (HbA1c), fasting blood sugar and plasma lipids were measured at the base and after 3 months.

RESULTS

In this study, seventy patients were evaluated, 35 were allocated to each group. There were no statistically significant differences between age, gender, duration of diabetes, BMI and BP between the two groups (p>0.05). HbA1c in the intervention (biotin) group was 9.84±1.80 at base and after 3 months treatment, it declined to 8.88±1.73 (p<0.001). In the control group HbA1c at base was 9.39±1.58, after 3 months it increased to10.11± 1.68. There were statistically significant differences in the mean of HbA1c in both the biotin and the control groups (p<0.001). FBS in the biotin group at base was 275±65.76 mg/dl and after 3 months it had reduced to 226± 41.31 (p<0.001). There were statistically significant differences in the mean of total cholesterol, low density lipoprotein cholesterol and triglyceride between the two groups at the end of 3 months (p<0.05).

CONCLUSION

Results of this study showed that biotin administration as an adjuvant in addition to insulin regimen can improve glycemic management and decrease plasma lipids concentrations in poorly controlled type 1 diabetic patients.

Anti-diabetic activity of chromium picolinate and biotin in rats with type 2 diabetes induced by high-fat diet and streptozotocin

The objective of the present study was to evaluate anti-diabetic effects of chromium picolinate (CrPic) and biotin supplementations in type 2 diabetic rats. The type 2 diabetic rat model was induced by high-fat diet (HFD) and low-dose streptozotocin. The rats were divided into five groups as follows: (1) non-diabetic rats fed a regular diet; (2) diabetic rats fed a HFD; (3) diabetic rats fed a HFD and supplemented with CrPic (80 μg/kg body weight (BW) per d); (4) diabetic rats fed a HFD and supplemented with biotin (300 μg/kg BW per d); (5) diabetic rats fed a HFD and supplemented with both CrPic and biotin. Circulating glucose, cortisol, total cholesterol, TAG, NEFA and malondialdehyde concentrations decreased (P< 0·05), but serum insulin concentrations increased (P< 0·05) in diabetic rats treated with biotin and CrPic, particularly with a combination of the supplements. Feeding a HFD to diabetic rats decreased PPAR-γ expression in adipose tissue and phosphorylated insulin receptor substrate 1 (p-IRS-1) expression of liver, kidney and muscle tissues, while the supplements increased (P< 0·001) PPAR-γ and p-IRS-1 expressions in relevant tissues. Expression of NF-κB in the liver and kidney was greater in diabetic rats fed a HFD, as compared with rats fed a regular diet (P< 0·01). The supplements decreased the expression of NF-κB in diabetic rats (P< 0·05). Results of the present study revealed that supplementing CrPic and biotin alone or in a combination exerts anti-diabetic activities, probably through modulation of PPAR-γ, IRS-1 and NF-κB proteins.

Effects of biotin supplementation in the diet on insulin secretion, islet gene expression, glucose homeostasis and beta-cell proportion

Besides its role as a carboxylase cofactor, biotin has a wide repertoire of effects on gene expression, development and metabolism. Pharmacological concentrations of biotin enhance insulin secretion and the expression of genes and signaling pathways that favor islet function in vitro. However, the in vivo effects of biotin supplementation on pancreatic islet function are largely unknown. In the present study, we investigated whether in vivo biotin supplementation in the diet has positive effects in rodent pancreatic islets. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet over 8 weeks postweaning and tested for glucose homeostasis, insulin secretion, islet gene expression and pancreatic morphometry. Insulin secretion increased from the islets of biotin-supplemented mice, together with the messenger RNA (mRNA) expression of several transcription factors regulating insulin expression and secretion, including forkhead box A2, pancreatic and duodenal homeobox 1 and hepatocyte nuclear factor 4α. The mRNA abundance of glucokinase, Cacna1d, acetyl-CoA carboxylase, and insulin also increased. Consistent with these effects, glucose tolerance improved, and glucose-stimulated serum insulin levels increased in biotin-supplemented mice, without changes in fasting glucose levels or insulin tolerance. Biotin supplementation augmented the proportion of beta cells by enlarging islet size and, unexpectedly, also increased the percentage of islets with alpha cells at the islet core. mRNA expression of neural cell adhesion molecule 1, an adhesion protein participating in the maintenance of islet architecture, decreased in biotin-supplemented islets. These findings provide, for the first time, insight into how biotin supplementation exerts its effects on function and proportion of beta cells, suggesting a role for biotin in the prevention and treatment of diabetes.

Favorable effects on metabolic risk factors with daily brewer's yeast in type 2 diabetic patients with hypercholesterolemia: a semi-experimental study

BACKGROUND

The aim of the present study was to investigate the effect of brewer's yeast on plasma glucose and lipid profiles in patients with type 2 diabetes (T2D).

METHODS

The present semi-experimental study was performed on 55 T2D patients with hypercholesterolemia. All patients received 12 tablets of 300 mg yeast per day for 8 weeks. Each tablet contained 1.2 μg chromium. Fasting plasma glucose, total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and triglyceride levels were measured at baseline and then again at Weeks 4 and 8.

RESULTS

Although there was a tendency for plasma glucose levels to decrease at Week 4, the difference failed to reach statistical significance (P = 0.065). However, after 8 weeks, the decrease in plasma glucose was significant (P = 0.043). Again, although there was a tendency for decreased plasma cholesterol at Week 8 compared with baseline, the difference failed to reach statistical significance (215 ± 29 vs 226 ± 37 mg/dL, respectively; P = 0.056). Brewer's yeast significantly decreased plasma triglyceride and LDL-C levels at Weeks 4 and 8. In contrast, plasma HDL-C levels were significantly increased at both 4 and 8 weeks compared with baseline (41.3 ± 8.8 and 43.3 ± 7.5 vs 36 ± 5 mg/dL, respectively; P < 0.01 and P < 0.01, respectively).

CONCLUSION

In conclusion, the consumption of brewer's yeast over a period of 8 weeks may improve cardiometabolic risk factors in T2D patients. However, these findings need to be confirmed in a large double-blind clinical trial.

Adjunctive naturopathic care for type 2 diabetes: patient-reported and clinical outcomes after one year

Background

Several small, uncontrolled studies have found improvements in self-care behaviors and reductions in clinical risk in persons with type 2 diabetes who received care from licensed naturopathic physicians. To extend these findings and determine the feasibility and promise of a randomized clinical trial, we conducted a prospective study to measure the effects of adjunctive naturopathic care (ANC) in primary care patients with inadequately controlled type 2 diabetes.

Methods

Forty patients with type 2 diabetes were invited from a large integrated health care system to receive up to eight ANC visits for up to one year. Participants were required to have hemoglobin A1c (HbA1c) values between 7.5-9.5 % and at least one additional cardiovascular risk factor (i.e., hypertension, hyperlipidemia or overweight). Standardized instruments were administered by telephone to collect outcome data on self-care, self-efficacy, diabetes problem areas, perceived stress, motivation, and mood. Changes from baseline scores were calculated at 6- and 12-months after entry into the study. Six and 12-month changes in clinical risk factors (i.e., HbA1c, lipid and blood pressure) were calculated for the ANC cohort, and compared to changes in a cohort of 329 eligible, non-participating patients constructed using electronic medical records data. Between-cohort comparisons were adjusted for age, gender, baseline HbA1c, and diabetes medications. Six months was pre-specified as the primary endpoint for outcome assessment.

Results

Participants made 3.9 ANC visits on average during the year, 78 % of which occurred within six months of entry into the study. At 6-months, significant improvements were found in most patient-reported measures, including glucose testing (P = 0.001), diet (P = 0.001), physical activity (P = 0.02), mood (P = 0.001), self-efficacy (P = 0.0001) and motivation to change lifestyle (P = 0.003). Improvements in glucose testing, mood, self-efficacy and motivation to change lifestyle persisted at 12-months (all P < 0.005). For clinical outcomes, mean HbA1c decreased by −0.90 % (P = 0.02) in the ANC cohort at 6-months, a −0.51 % mean difference compared to usual care (P = 0.07). Reductions at 12-months were not statistically significant (−0.34 % in the ANC cohort, P = 0.14; -0.37 % difference compared to the usual care cohort, P = 0.12).

Conclusions

Improvements were noted in self-monitoring of glucose, diet, self-efficacy, motivation and mood following initiation of ANC for patients with inadequately controlled type 2 diabetes. Study participants also experienced reductions in blood glucose that exceeded those for similar patients who did not receive ANC. Randomized clinical trials will be necessary to determine if ANC was responsible for these benefits.

The malnutrition of obesity: micronutrient deficiencies that promote diabetes

Obesity and diabetes are increasing in prevalence worldwide. Despite excessive dietary consumption, obese individuals have high rates of micronutrient deficiencies. Deficiencies of specific vitamins and minerals that play important roles in glucose metabolism and insulin signaling pathways may contribute to the development of diabetes in the obese population. This paper reviews the current evidence supporting this hypothesis.

Administration of biotin prevents the development of insulin resistance in the skeletal muscles of Otsuka Long-Evans Tokushima Fatty rats

Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for type 2 diabetes mellitus. In the present study, we investigated whether pharmacologic doses of biotin have the potential to abate insulin resistance in the skeletal muscles of OLETF rats. OLETF rats (34 weeks of age) were divided into 2 groups and given distilled water (OLETF-control group) or distilled water containing 3.3 mg L(-1) of biotin (OLETF-biotin group) for 8 weeks. At the end of experimental period, the OLETF-control rats developed severe hyperglycemia and hyperinsulinemia, whereas the OLETF-biotin rats showed significantly smaller responses to oral glucose tolerance test than the OLETF-control rats. The glucose uptake in the hind limbs of the rats was significantly higher in the OLETF-biotin group than in the OLETF-control group. Biotin administration increased the glucose transporter type 4 (GLUT4) protein content in the total membrane fraction but had little effect on the GLUT4 content in the plasma membrane fraction. These results indicate that administration of a pharmacological dose of biotin prevents the development of insulin resistance in the skeletal muscles of OLETF rats presumably via an increase in GLUT4 protein expression but not via GLUT4 translocation.

Trace elements in glucometabolic disorders: an update

Many trace elements, among which metals, are indispensable for proper functioning of a myriad of biochemical reactions, more particularly as enzyme cofactors. This is particularly true for the vast set of processes involved in regulation of glucose homeostasis, being it in glucose metabolism itself or in hormonal control, especially insulin. The role and importance of trace elements such as chromium, zinc, selenium, lithium and vanadium are much less evident and subjected to chronic debate. This review updates our actual knowledge concerning these five trace elements. A careful survey of the literature shows that while theoretical postulates from some key roles of these elements had led to real hopes for therapy of insulin resistance and diabetes, the limited experience based on available data indicates that beneficial effects and use of most of them are subjected to caution, given the narrow window between safe and unsafe doses. Clear therapeutic benefit in these pathologies is presently doubtful but some data indicate that these metals may have a clinical interest in patients presenting deficiencies in individual metal levels. The same holds true for an association of some trace elements such as chromium or zinc with oral antidiabetics. However, this area is essentially unexplored in adequate clinical trials, which are worth being performed.

The role of complementary and alternative therapies in pediatric diabetes

Complementary and alternative medicine (CAM), also referred to as holistic, or integrative, medicine, are terms that describe a heterogeneous collection of nontraditional therapies, from chemical substances, to biofeedback, to prayer. This review focuses on CAM in pediatric patients with type 1 and type 2 diabetes. CAM prevalence in this population and the specific modalities that have been studied in children are described. Randomized, placebo-controlled, prospective studies in young adults are evaluated for their applicability to pediatric patients. CAM's "complementary" role is emphasized, as there is evidence of significant morbidity when CAM replaces standard-of-care therapy.

Chromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetes

BACKGROUND

Chromium and biotin play essential roles in regulating carbohydrate metabolism. This randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of the combination of chromium picolinate and biotin on glycaemic control.

METHODS

Four hundred and forty-seven subjects with poorly controlled type 2 diabetes (HbA(1c) > or = 7.0%) were enrolled and received either chromium picolinate (600 microg Cr(+3)) with biotin (2 mg), or matching placebo, for 90 days in combination with stable oral anti-diabetic agents (OADs). Major endpoints were reductions in HbA(1c), fasting glucose, and lipids. Safety and tolerability were assessed.

RESULTS

Change in HbA(1c) was significantly different between treatment groups (p = 0.03). HbA(1c) in the chromium picolinate/biotin group decreased 0.54%. The decrease in HbA(1c) was most pronounced in chromium picolinate/biotin subjects whose baseline HbA(1c) > or = 10%, and highly significant when compared with placebo (-1.76% vs - 0.68%; p = 0.005). Fasting glucose levels were reduced in the entire chromium picolinate/biotin group versus placebo (-9.8 mg/dL vs 0.7 mg/dL; p = 0.02). Reductions in fasting glucose were also most marked in those subjects whose baseline HbA(1c) > or = 10.0%, and significant when compared to placebo (-35.8 mg/dL vs. 16.2 mg/dL; p = 0.01). Treatment was well tolerated with no adverse effects dissimilar from placebo.

CONCLUSIONS

These results suggest that the chromium picolinate/biotin combination, administered as an adjuvant to current prescription anti-diabetic medication, can improve glycaemic control in overweight to obese individuals with type 2 diabetes; especially those patients with poor glycaemic control on oral therapy.

Combination of chromium and biotin improves coronary risk factors in hypercholesterolemic type 2 diabetes mellitus: a placebo-controlled, double-blind randomized clinical trial

Dyslipidemia, often found in type 2 diabetes mellitus (T2DM) patients, plays an important role in the progression of cardiometabolic syndrome. Two essential nutrients, chromium and biotin, may maintain optimal glycemic control. The authors report here a randomized, double-blind placebo-controlled trial (N=348; chromium picolinate and biotin combination [CPB]: 226, placebo: 122; T2DM participants with hemoglobin A1c [HbA1c] >or=7%) evaluating the effects of CPB on lipid and lipoprotein levels. Participants were randomly assigned (2:1 ratio) to receive either CPB (600 microg chromium as chromium picolinate and 2 mg biotin) or a matching placebo once daily for 90 days. Statistical analyses were conducted in all eligible participants. Subsequent supplemental analyses were performed in T2DM participants with hypercholesterolemia (HC) and in those using stable doses of statins. In the primary analysis, CPB lowered HbA1c (P<.05) and glucose (P<.02) significantly compared with the placebo group. No significant changes were observed in other lipid levels. In participants with HC and T2DM, significant changes in total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels and atherogenic index were observed in the CPB group (P<.05). Significant decreases in LDL-C, total cholesterol, HbA1c , and very low-density cholesterol levels (P<.05) were observed in the CPB group taking statins. CPB treatment was well tolerated with no adverse effects, dissimilar from those associated with placebo. These data suggest that intervention with CPB improves cardiometabolic risk factors.