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

The effect of chromium supplementation on cardio-metabolic risk factors in overweight and obese patients. A systematic review and meta-analysis of randomized controlled trial

OBJECTIVE

This study was conducted with the aim of evaluating the effect of chromium supplementation on cardiovascular-metabolic risk factors including lipid profile, glycemic index, anthropometric factors, blood pressure and liver function.

METHODS

Relevant studies were identified through electronic database searches (PubMed, Scopus, Web of Science) up to March 2024. The overall effect size was calculated using the mean changes and standard deviations for the intervention and control groups. The I2 statistic and Cochran's Q-test were used to determine the existence of heterogeneity. A non-linear modeling explored heterogeneity, dose-response relationships, and the overall impact of Chromium supplementation.

RESULTS

Twenty trials, with interventions ranging from 1 to 137 participant were included. Chromium supplementation significantly reduced Fasting blood glucose (FBG) ([WMD]: -1.60 mg/dl; 95 % [CI]: -3.28, 0.07; p = 0.06) and A1C ([WMD]: -0.05 %; 95 % [CI]: -0.19, 0.07; p = 0.38) HOMO-IR ([WMD]: -0.26; 95 % [CI]: 0.48, -0.03; p = 0.02) and insulin ([WMD]: -12.55 pmol/l; 95 % [CI]: -23.62, -1.47; p = 0.02) and a slight decrease in lipid profiles and anthropometric measures. However, there were some factors that Chromium was slightly increased compared to other groups, including: HDL, ALT, Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP). Chromium has no significant effect on AST.

CONCLUSION

The results of this experiment show that chromium supplementation had a positive effect on blood sugar control and various factors including weight, BMI, SBP, DBP, triglycerides, and waist circumference, and had an effective role in improving the level of liver enzymes.

Molecular Mechanisms of Biotin in Modulating Inflammatory Diseases

Biotin, also known as vitamin B7 or vitamin H, is a water-soluble B-complex vitamin and serves as an essential co-enzyme for five specific carboxylases. Holocarboxylase synthase (HCS) activates biotin and facilitates its covalent attachment to these enzymes, while biotinidase releases free biotin in the biotin cycle. The transport of biotin, primarily from the intestine, is mediated by the sodium-dependent multi-vitamin transporter (SMVT). Severe biotin deficiency leads to multiple carboxylase deficiency. Moreover, biotin is crucial to glucose and lipid utilization in cellular energy production because it modulates the expression of metabolic enzymes via various signaling pathways and transcription factors. Biotin also modulates the production of proinflammatory cytokines in the immune system through similar molecular mechanisms. These regulatory roles in metabolic and immune homeostasis connect biotin to conditions such as diabetes, dermatologic manifestations, and multiple sclerosis. Furthermore, deficiencies in biotin and SMVT are implicated in inflammatory bowel disease, affecting intestinal inflammation, permeability, and flora. Notably, HCS and probably biotin directly influence gene expression through histone modification. In this review, we summarize the current knowledge on the molecular aspects of biotin and associated molecules in diseases related to both acute inflammatory responses and chronic inflammation, and discuss the potential therapeutic applications of biotin.

Anti-Obesity Effect of Combining White Kidney Bean Extract, Propolis Ethanolic Extract and CrPi3 on Sprague-Dawley Rats Fed a High-Fat Diet

Obesity has been associated with the occurrence and prevalence of various chronic metabolic diseases. The management of obesity has evolved to focus not only on reducing weight, but also on preventing obesity-related complications. Studies have shown that bioactive components in natural products like white kidney bean extract (WKBE), propolis ethanolic extract (PEE), and chromium picolinate (CrPi3) showed anti-obesity properties. However, no studies have examined the outcomes of combining any of these nutraceutical supplements. We compared the effects of HFD supplemented with WKBE, WKBE+PEE, or WKBE+PEE+CrPi3 against control and obese groups using Sprague-Dawley rats fed a 45% high-fat diet as an in vivo model. Nutritional parameters, biochemical parameters, and biomarkers of cardiovascular disease, liver function, kidney function, and gut health were among the comparable effects. Our findings showed that combining the three nutraceutical supplements had a synergetic effect on reducing weight gain, food utilization rate, abdominal fat, serum lipids, arterial and hepatic lipids, risk of cardiovascular disease, and blood glucose level, in addition to improving renal function and gut microbiota. We attributed these effects to the α-amylase inhibitor action of WKBE, flavonoids, and polyphenol content of PEE, which were potentiated with CrPi3 resulting in a further reduction or normalization of certain parameters.

Individual, sociodemographic, and lifestyle influence on blood chromium, cobalt, and nickel levels in healthy population living in Belgrade, Serbia

The rapid trend of industrialization and urbanization can lead to greater exposure of the general population to chromium, cobalt, and nickel. Their total body burden from all routes of recent exposure, as well as interindividual variability in exposure levels, metabolism, and excretion rates, are reflected in the blood metal concentrations. The main goals in this study were as follows: observing the reference levels of chromium, cobalt, and nickel in the blood of the population living in Belgrade, identification of individual and sociodemographic factors that most affect their blood levels, and comprehension of recent exposure to chromium, cobalt, and nickel. Blood was sampled from 984 participants, voluntary blood donors, who agreed to participate in this study. Individual and sociodemographic data were collected using questionnaire adapted for different subpopulations. Blood metal analyses were measured using ICP-MS method (7700×, Agilent, USA). Our study provided reference values of chromium, cobalt, and nickel in blood for adult population (18-65 years) and confirmed that blood cobalt and nickel levels were mostly influenced by age and gender, and age, respectively. Furthermore, weight status affected blood chromium and cobalt levels, while national origin affected blood chromium levels. The present study highlighted the importance of human biomonitoring studies to monitor exposure status and identify subpopulations with increased exposure to chromium, cobalt, and nickel.

The role of chromium supplementation in cardiovascular risk factors: A comprehensive reviews of putative molecular mechanisms

In the recent years, micronutrients play an important role in improving body health with preventing and treating of chronic diseases. Chromium is one of the vital minerals involved in the regulation of insulin action. According to abundant evidences this mineral seems to be an essential factor involved in the reduction of insulin resistance and decreasing the risk of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVDs). Moreover, it has been proposed that Chromium supplementation affects mechanisms involved in blood pressure, lipid metabolism, inflammation, and oxidative stress. For instance, it may affect blood pressure through alteration of the renin-angiotensin system, as well as reducing the angiotensin-converting enzyme activity. Furthermore, Chromium supplementation might help reduce the coronary heart disease rates. This study aims to provide a comprehensive review regarding to the effects of Chromium supplementation on CVDs risk factors with an emphasis on possible molecular mechanisms.

Joint Effect of Multiple Metals on Hyperuricemia and Their Interaction with Obesity: A Community-Based Cross-Sectional Study in China

Metal exposures have been inconsistently related to the risk of hyperuricemia, and limited research has investigated the interaction between obesity and metals in hyperuricemia. To explore their associations and interaction effects, 3300 participants were enrolled from 11 districts within 1 province in China, and the blood concentrations of 13 metals were measured to assess internal exposure. Multivariable logistic regression, restricted cubic spline (RCS), Bayesian kernel machine regression (BKMR), and interaction analysis were applied in the single- and multi-metal models. In single-metal models, five metals (V, Cr, Mn, Co, and Zn) were positively associated with hyperuricemia in males, but V was negatively associated with hyperuricemia in females. Following the multi-metal logistic regression, the multivariate-adjusted odds ratios (95% confidence intervals) of hyperuricemia were 1.7 (1.18, 2.45) for Cr and 1.76 (1.26, 2.46) for Co in males, and 0.68 (0.47, 0.99) for V in females. For V and Co, RCS models revealed wavy and inverted V-shaped negative associations with female hyperuricemia risk. The BKMR models showed a significant joint effect of multiple metals on hyperuricemia when the concentrations of five metals were at or above their 55th percentile compared to their median values, and V, Cr, Mn, and Co were major contributors to the combined effect. A potential interaction between Cr and obesity and Zn and obesity in increasing the risk of hyperuricemia was observed. Our results suggest that higher levels of Cr and Co may increase male hyperuricemia risk, while higher levels of V may decrease female hyperuricemia risk. Therefore, the management of metal exposure in the environment and diet should be improved to prevent hyperuricemia.

Analysis of correlations between gut microbiota, stool short chain fatty acids, calprotectin and cardiometabolic risk factors in postmenopausal women with obesity: a cross-sectional study

BACKGROUND

Microbiota and its metabolites are known to regulate host metabolism. In cross-sectional study conducted in postmenopausal women we aimed to assess whether the microbiota, its metabolites and gut barrier integrity marker are correlated with cardiometabolic risk factors and if microbiota is different between obese and non-obese subjects.

METHODS

We analysed the faecal microbiota of 56 obese, postmenopausal women by means of 16S rRNA analysis. Stool short chain fatty acids, calprotectin and anthropometric, physiological and biochemical parameters were correlates to microbiome analyses.

RESULTS

Alpha-diversity was inversely correlated with lipopolysaccharide (Rho = - 0.43, FDR P (Q) = 0.004). Bray-Curtis distance based RDA revealed that visceral fat and waist circumference had a significant impact on metabolic potential (P = 0.003). Plasma glucose was positively correlated with the Coriobacteriaceae (Rho = 0.48, Q = 0.004) and its higher taxonomic ranks, up to phylum (Actinobacteria, Rho = 0.46, Q = 0.004). At the metabolic level, the strongest correlation was observed for the visceral fat (Q < 0.15), especially with the DENOVOPURINE2-PWY, PWY-841 and PWY0-162 pathways. Bacterial abundance was correlated with SCFAs, thus some microbiota-glucose relationships may be mediated by propionate, as indicated by the significant average causal mediation effect (ACME): Lachnospiraceae (ACME 1.25, 95%CI (0.10, 2.97), Firmicutes (ACME 1.28, 95%CI (0.23, 3.83)) and Tenericutes (ACME - 0.39, 95%CI (- 0.87, - 0.03)). There were significant differences in the distribution of phyla between this study and Qiita database (P < 0.0001).

CONCLUSIONS

Microbiota composition and metabolic potential are associated with some CMRF and fecal SCFAs concentration in obese postmenopausal women. There is no unequivocal relationship between fecal SCFAs and the marker of intestinal barrier integrity and CMRF. Further studies with appropriately matched control groups are warranted to look for causality between SCFAs and CMRF.

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.

Biotin alleviates hepatic and intestinal inflammation and apoptosis induced by high dietary carbohydrate in juvenile turbot (Scophthalmus maximus L.)

Excessive dietary carbohydrate commonly impairs the functions of liver and intestine in carnivorous fish. In the present study, a 10-week feeding trial was carried out to explore the regulation of biotin on the hepatic and intestinal inflammation and apoptosis in turbot (Scophthalmus maximus L.) fed with high carbohydrate diets. Three isonitrogenous and isolipidic experimental diets were designed as follows: the CC diet with 18.6% of carbohydrate and 0.04 mg/kg of biotin, the HC diet with 26.9% of carbohydrate and 0.05 mg/kg of biotin, and the HCB diet with 26.9% of carbohydrate and 1.62 mg/kg of biotin. Results showed that high dietary carbohydrate (HC diet) impaired the morphology of liver and intestine, however, inclusion of dietary biotin (HCB diet) normalized their morphology. Inflammation-related gene expression of nuclear factor κB p65 (nf-κb p65), tumor necrosis factor α (tnf-α), interleukin-1β (il-1β), il-6 and il-8, and the protein expression of NF-κB p65 in the liver and intestine were significantly up-regulated in the HC group compared to those in the CC group (P < 0.05), the HCB diet decreased their expression compared to the HC group (P < 0.05). The gene expression of il-10 and transforming growth factor-β (tgf-β) in the liver and intestine were significantly decreased in the HC group compared to the CC group (P < 0.05), and inclusion of dietary biotin increased the il-10 and tgf-β expression in the liver and intestine (P < 0.05). Moreover, compared to the CC group, the HC group had a stronger degree of DNA fragmentation and more TUNEL-positive cells in the liver and intestine, and the HCB group had a slighter degree of DNA fragmentation and fewer TUNEL-positive cells compared to the HC group. Meanwhile, the gene expression of B-cell lymphoma protein-2-associated X protein (bax) and executor apoptosis-related cysteine peptidase 3 (caspase-3) were significantly up-regulated and the gene expression of B-cell lymphoma-2 (bcl-2) was significantly down-regulated both in the liver and intestine in the HC group compared with those in the CC group (P < 0.05). Inclusion of dietary biotin significantly decreased the bax and caspase-3 mRNA levels and increased bcl-2 mRNA level in the liver and intestine (P < 0.05). In conclusion, high dietary carbohydrate (26.9% vs 18.6%) induced inflammation and apoptosis in liver and intestine. Supplementation of biotin (1.62 mg/kg vs 0.05 mg/kg) in diet can alleviate the high-dietary-carbohydrate-induced hepatic and intestinal inflammation as well as inhibit apoptosis in turbot. The present study provides basic data for the application of biotin into feed, especially the high-carbohydrate feed for turbot.

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.

Potential of Natural Honey in Controlling Obesity and its Related Complications

Honey has a long history of therapeutic properties for multiple diseases, including inflammation and oxidative stress. This review aimed to provide a better understanding and renewed interest in the potential role of honey in obesity control, obesity-related diseases treatment and weight management, with specific reference to its components and the effect of honey overall. There is compelling evidence that honey possesses the desired properties for this purpose, as seen in the in vitro, in silico, in vivo and clinical analyses discussed in this review. This review also highlights the components potentially responsible for the health benefits of honey. Honey and its components reduce blood sugar levels, improve insulin sensitivity and lipid metabolism by reducing triglycerides, and reduce total cholesterol and LDL levels while increasing HDL levels that prevent excessive weight gain and reduce the risk of obesity and its complications. Further controlled studies are necessary to validate the role of honey in the management of obesity, both as a preventive and as a therapeutic agent.

Negatively interactive effect of chromium and cadmium on obesity: Evidence from adults living near ferrochromium factory

BACKGROUND

Researchers have reported that chromium (Cr) exposure may be associated with metabolism of glucose and lipids in residents living in a long-term Cr polluted area. Previous statistical analysis is mainly focused on individual chromium exposure. Furtherly, we aim to investigated the independent, combined, and interaction effects of the co-exposure of urine Cr (UCr) with cadmium (UCd), lead (UPb) and manganese (UMn) on body mass index (BMI), waist circumference, and the risk of overweight and abdominal obesity.

METHOD

We enrolled 1187 participants from annual surveys between 2017 and 2019. Heavy metal concentrations in urine were standardized using covariate-adjusted urine creatinine levels. Multiple linear/logistic regression models were applied to measure the single effect of urine heavy metal concentration on the outcomes. The quantile-based g-computation (g-comp) model was used to evaluate the combined effect of metal mixture on the outcomes and to compare the contribution of each metal. Both additive and multiplicative interactions were measured for UCr with UCd, UPb, UMn on the outcomes. Analysis was performed on the overall population and stratified by smoking habit.

RESULTS

For the overall study population, UCr was positively associated with BMI (p trend = 0.023) and waist circumference (p trend = 0.018). For smoking participants, the g-comp model demonstrated that the metal mixture was negatively associated with BMI, with UCr and UCd contributing the most in the positive and negative direction. A negative additive interaction was observed between UCr and UCd on BMI and abdominal obesity. We did not observe a significant interaction effect of UCr with UPb or UMn.

CONCLUSION

Our study indicated that Cr and Cd exposure may be associated with BMI and waist circumference, with combined and interaction effects of the heavy metals noted. Further epidemiological and experimental researches could simultaneously consider single and complex mixed exposure to verify the findings and biological mechanisms.

Revised D-A-CH reference values for the intake of biotin

Purpose

The reference values for biotin intake for Germany, Austria and Switzerland lead back to a report in 2000. Following a timely update process, they were revised in 2020.

Methods

For infants aged 0 to < 4 months, adequate biotin supply via human milk was assumed and in consequence the reference value reflects the amount of biotin delivered by human milk. For infants aged 4 to < 12 months, biotin intake was extrapolated from the reference value for younger infants. Due to missing data on average requirement, the reference values for biotin intake for children, adolescents and adults were derived based on observed intake levels. The reference value for lactating women considered in addition biotin losses via human milk.

Results

The reference value for biotin intake for infants aged 0 to < 4 months was set at 4 µg/day and for infants aged 4 to < 12 months at 6 µg/day. In children and adolescents, the reference values for biotin intake ranged from 20 µg/day in children 1 to < 4 years to 40 µg/day in youths 15 to < 19 years. For adults including pregnant women, 40 µg/day was derived as reference value for biotin intake. For lactating women, this value was set at 45 µg/day.

Conclusions

As deficiency symptoms of biotin do not occur with a usual mixed diet and the average requirement cannot be determined, reference values for an adequate biotin intake for populations from Germany, Austria and Switzerland were derived from biotin intake levels assessed in population-based nutrition surveys.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02756-0.

Discovering Potential Taxonomic Biomarkers of Type 2 Diabetes From Human Gut Microbiota via Different Feature Selection Methods

Human gut microbiota is a complex community of organisms including trillions of bacteria. While these microorganisms are considered as essential regulators of our immune system, some of them can cause several diseases. In recent years, next-generation sequencing technologies accelerated the discovery of human gut microbiota. In this respect, the use of machine learning techniques became popular to analyze disease-associated metagenomics datasets. Type 2 diabetes (T2D) is a chronic disease and affects millions of people around the world. Since the early diagnosis in T2D is important for effective treatment, there is an utmost need to develop a classification technique that can accelerate T2D diagnosis. In this study, using T2D-associated metagenomics data, we aim to develop a classification model to facilitate T2D diagnosis and to discover T2D-associated biomarkers. The sequencing data of T2D patients and healthy individuals were taken from a metagenome-wide association study and categorized into disease states. The sequencing reads were assigned to taxa, and the identified species are used to train and test our model. To deal with the high dimensionality of features, we applied robust feature selection algorithms such as Conditional Mutual Information Maximization, Maximum Relevance and Minimum Redundancy, Correlation Based Feature Selection, and select K best approach. To test the performance of the classification based on the features that are selected by different methods, we used random forest classifier with 100-fold Monte Carlo cross-validation. In our experiments, we observed that 15 commonly selected features have a considerable effect in terms of minimizing the microbiota used for the diagnosis of T2D and thus reducing the time and cost. When we perform biological validation of these identified species, we found that some of them are known as related to T2D development mechanisms and we identified additional species as potential biomarkers. Additionally, we attempted to find the subgroups of T2D patients using k-means clustering. In summary, this study utilizes several supervised and unsupervised machine learning algorithms to increase the diagnostic accuracy of T2D, investigates potential biomarkers of T2D, and finds out which subset of microbiota is more informative than other taxa by applying state-of-the art feature selection methods.

The Association between Excess Body Mass and Disturbances in Somatic Mineral Levels

BACKGROUND

Obesity and excess body weight are significant epidemiological issues, not only because they are costly to treat, but also because they are among the leading causes of death worldwide. In 2016, an estimated 40% of the global population was overweight, reflecting the importance of the issue. Obesity is linked to metabolism malfunction and concomitantly with altered mineral levels in the body. In this paper, we review alterations in somatic levels of iron, calcium, magnesium, copper, iodine, chromium, selenium, and zinc in relation to excess body mass.

METHODOLOGY

An electronic literature search was performed using PubMed. Our search covered original English research articles published over the past five years, culminating in 63 papers included for study.

RESULTS

The reviewed papers presented correlation between obesity and hypomagnesemia and hypozincemia. They also indicated that patients with excess body mass present increased body copper levels. Studies have similarly indicated that obesity appears to be associated with lower selenium levels in both blood and urine, which may be correlated with the decline and weakening of defenses against oxidative stress. It has been found that decreased level of chromium is connected with metabolic syndrome. Chromium supplementation influences body mass, but the effect of the supplementation depends on the chemical form of the chromium. It is hypothesized that obesity poses a risk of iodine deficiency and iodine absorption may be disrupted by increased fat intake in obese women. A range of studies have suggested that obesity is correlated with iron deficiency. On the other hand, some reports have indicated that excess body mass may coexist with iron excess. The relation between obesity and body iron level requires further investigation. Calcium signaling seems to be disturbed in obesity, due to the increased production of reactive oxygen species and low level of fast troponin isoform responsible for mediating calcium sensitivity of muscle relaxation. Correlation between excess body mass and calcium levels needs further research.

CONCLUSIONS

Excess body mass is associated with alterations in mineral levels in the body, in particular hypomagnesemia and decreased selenium (Se) and zinc (Zn) levels. Chromium (Cr) deficiency is associated with metabolic syndrome. Obese patients are at risk of iodine deficiency. Excess body mass is associated with elevated levels of copper (Cu). Data on the association between obesity and iron (Fe) levels are contradictory. Obesity coexists with disturbed calcium (Ca) signaling pathways. The association between obesity and body Ca levels has not been investigated in detail.

The Gut Microbiota in Prediabetes and Diabetes: A Population-Based Cross-Sectional Study

The link between the gut microbiota and type 2 diabetes (T2D) warrants further investigation because of known confounding effects from antidiabetic treatment. Here, we profiled the gut microbiota in a discovery (n = 1,011) and validation (n = 484) cohort comprising Swedish subjects naive for diabetes treatment and grouped by glycemic status. We observed that overall gut microbiota composition was altered in groups with impaired glucose tolerance, combined glucose intolerance and T2D, but not in those with impaired fasting glucose. In addition, the abundance of several butyrate producers and functional potential for butyrate production were decreased both in prediabetes and T2D groups. Multivariate analyses and machine learning microbiome models indicated that insulin resistance was strongly associated with microbial variations. Therefore, our study indicates that the gut microbiota represents an important modifiable factor to consider when developing precision medicine approaches for the prevention and/or delay of T2D.

Metals and trace elements in relation to body mass index in a prospective study of US women

BACKGROUND

Epidemiologic studies on the association between metals and body mass index (BMI) have been cross-sectional and have demonstrated inconsistent associations. Our study prospectively examined whether metals measured at baseline were associated with later BMI. We considered metals individually and as joint exposure to pre-defined metal groupings.

METHODS

We measured concentrations of 16 metals in toenails collected at baseline (2003-2009) in a subset of 1221 women from the Sister Study. We calculated BMI from height and weight reported on a follow-up questionnaire an average of 5.2 years (range = 3.5-8.3) after baseline. Multivariable linear regression was used to estimate β coefficients and 95% confidence intervals (CIs) for associations between BMI and individual metals (with estimates given per interquartile range (IQR) increase or in quartiles). Quantile g-computation was used to examine joint associations between groups of metals and BMI. Groups considered were (1) all metals combined, and metals classified as (2) non-essential or (3) essential.

RESULTS

In individual metal models we found that, with the exception of cobalt, no single metal was strongly related to BMI. In our mixture analyses, a quartile increase in all non-essential metals was associated with higher BMI (β = 0.32; 95%CI: 0.00, 0.63 kg/m²), whereas essential metals were suggestively associated with lower BMI (β = -0.25; 95%CI: 0.58, 0.07 kg/m²).

CONCLUSIONS

In this population of women who were, on average, overweight, essential metals were jointly associated with slightly healthier, lower BMI whereas non-essential metals were jointly associated with slightly higher, unhealthier BMI, after controlling for other health indicators and predictors of metals exposures.

Vitamin B and vitamin D as modulators of gut microbiota in overweight individuals

Growing evidence indicates that vitamin B (VB) and vitamin D (VD) are associated with the development of obesity. The effects of supplemental dietary VB and VD on the gut microbiota of obese individuals are still largely unknown. In the present study, 997 normoweight (NW) and 773 overweight (OW) samples were screened from the American Gut Project. The microbial α-diversity was not affected by VB, VD or VB combined with VD (VBD) supplementation in the normoweight population or the overweigh population. VD significantly modulated 20 gut microbial metabolic pathways in NW. Moreover, VBD supplementation significantly affected 3 phyla and 3 families and 22 pathways in the OW gut microbiota. In summary, our results highlight that VD and VBD might be necessary for reshaping the gut microbiota in NW and OW, respectively.

Nutraceutical Improves Glycemic Control, Insulin Sensitivity, and Oxidative Stress in Hyperglycemic Subjects: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

The aim of this research was to investigate the effects of nutraceuticals including bitter melon, fenugreek, cinnamon, alpha-lipoic acid, zinc, biotin, chromium, and cholecalciferol on glycemic control, insulin sensitivity, lipid profiles, oxidative stress, and inflammatory markers in hyperglycemia. The study design was a randomized, double-blind, placebo-controlled trial. Subjects with hyperglycemia were randomly divided into 2 groups. The treatment group ( n = 52) was given a nutraceutical and the control group ( n = 50) was provided with a placebo for 12 weeks. Fasting blood glucose (FBG), hemoglobin A1c (HbA1C), homeostatic model assessment of insulin resistance (HOMA-IR), lipid profiles, biomarkers of oxidative stress, and inflammation were assessed before and after the intervention at 6 weeks and 12 weeks. Nutraceutical supplementation demonstrated a statistically significant decrease in FBG (13.4% and 18.9%), HbA1C (6.5% and 11.3%), and HOMA-IR (28.9% and 35.2%) compared with the placebo. Moreover, low-density lipoprotein-cholesterol (LDL-C) level was significantly reduced in the nutraceutical group (7.1% and 9.3%). Furthermore, the nutraceutical significantly decreased oxidative stress markers, oxidized LDL-C (14.8% and 18.9%) and malondialdehyde (16.6% and 26.2%) compared with the placebo. In conclusion, this nutraceutical can improve glycemic control, insulin resistance, lipid profiles, and oxidative stress markers in hyperglycemic subjects. Therefore, it has the potential to decrease cardiovascular disease risk factors. Clinical trial registration: TCTR20180907001, www.clinicaltrials.in.th.

Nuts

Nuts are fruits composed of two parts: an inedible hard shell and an edible seed. Nuts are known as an energy-dense and nutrient-rich food source. In general, nuts are recognized as a good source of fat, fiber, and protein. Nuts are extremely beneficial parts of any diet since their consumption may lower risk for some diseases, such as cardiovascular diseases and cancer. They are acknowledged for their low glycemic index owning to high unsaturated fat and protein content and relatively low carbohydrate content. They have been shown to increase cognitive function as well.

Serum Chromium Level is Increased in Jordanian Smokers, Decreased in Jordanians with Prediabetes and type 2 Diabetes, But not Altered in Jordanians with Hypertension, With Obesity, or With Family History of Diabetes

Background

Chromium was found to be crucial for several biochemical processes in the human body, including, in particular, carbohydrate and lipid metabolism whereas the exact mechanisms of its actions have yet to be explored. Here, we asked whether low serum chromium levels are present in Jordanian smokers and Jordanians with prediabetes and type 2 diabetes (T2D), with hypertension, with overweight and obesity, and with a family history of diabetes.

Methods

A total of 360 patients (120 with T2D, 120 with prediabetes, and 120 healthy controls) were recruited randomly based on the American Diabetes Association criteria. Smokers (n = 26), and patients with hypertension (n = 46), with overweight (n = 47) and obesity (n = 57), and with family history of diabetes (n = 63) were included in the tested population. Serum chromium concentration was measured using the graphite furnace atomic absorption spectrometry.

Results

The results from this study revealed significant increase (P = 0.001 univariate, P = 0.038 multivariate) and significant decrease (P = 0.046 univariate,P = 0.038 multivariate) in serum chromium concentrations in smokers and people with T2D and prediabetes, respectively. In addition, serum chromium insignificantly altered (P > 0.05) in people with hypertension, with a family history of diabetes, and with overweight or obesity.

Conclusions

Higher levels of serum chromium were observed in smokers, whereas lower levels were found to be present in patients with T2D and patients with prediabetes. In addition, serum chromium level may not be affected by hypertension, overweight and obesity, and family history of diabetes.

Potential roles of chromium on inflammatory biomarkers in diabetes: A Systematic

Diabetes, as a low-grade chronic inflammatory disease, causes disruption in proper function of immune and metabolic system. Chromium is an important element required for normal lipid and glucose metabolism. Chromium deficiency is correlated with elevation in cardiometabolic risk, which results from increased inflammation. This systematic review was conducted to discover the potential roles of chromium on inflammatory biomarkers. Eligible studies were all in vitro, animal and human studies published in English-language journals from inception until October 2018. PubMed, Scopus, Embase, ProQuest and Google Scholar databases were searched to fined interventional studies from the effects of chromium on inflammatory biomarkers such as tumour necrosis factor a (TNF-a), C-reactive protein (CRP), interleukins, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1) and adipocytokines in hyperglycaemia and diabetes. Out of 647 articles found in the search, only 14 articles were eligible for analysis, three in vitro studies, eight animal studies and three human studies. Twelve of the 14 studies included in this review, chromium significantly decreased inflammatory factors. The findings of this review indicate, based on in vitro and in vivo studies, that chromium might have potential anti-inflammatory properties, but some of the studies did not show anti-inflammatory effects for chromium (two studies). There are only three studies in humans with controversial results. Therefore, more consistent randomized double-blind controlled trials are needed to reach relevant clinical recommendations, as well as to determine the precise mechanism, of chromium on inflammation in diabetes.

A meta-analysis of the effect of chromium supplementation on anthropometric indices of subjects with overweight or obesity

The role of chromium as a weight loss agent remains questionable, and although previous meta-analyses findings have reported small reductions in body weight in individuals with overweight/obesity following chromium supplementation, there have been significant limitations with these findings. The objective of this meta-analysis was to evaluate the current evidence for the efficacy of oral chromium supplementation in individuals with overweight/obesity from randomized controlled trials. Studies were identified by a search of electronic databases from inception to November 2018 and combined and stratified analyses were used. Twenty-one trials from 19 studies were identified which met all inclusion criteria which were suitable for statistical pooling, and data from 1316 participants were included. Pooled analysis showed significant reductions in anthropometric indices associated with body composition; for weight loss (weighted mean difference [WMD]: -0.75 kg, 95% confidence interval [CI], -1.04, -0.45, P < 0.001), body mass index (WMD: -0.40, 95% CI, -0.66, -0.13, P = 0.003 and body fat percentage (WMD: -0.68%, 95% CI, -1.32, -0.03, P = 0.04) in individuals with overweight/obesity. No changes were detected in controls. Subgroup analysis showed significant improvements in weight loss and body fat percentage, particularly for study durations ≤12 weeks and doses ≤400 μg/d. Chromium supplementation was associated with some improvements in body composition in subjects with obesity/overweight. The effect size was medium and the clinical relevance of chromium as a weight loss aid remains uncertain. Further investigation from larger and well-designed randomized controlled studies, especially in patients with diabetes, is warranted.

Efficacy of combination therapy of inositols, antioxidants and vitamins in obese and non-obese women with polycystic ovary syndrome: an observational study

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine disorders in women of both developed and developing countries. It is associated with insulin resistance, hyperinsulinemia, hyperandrogenism, oxidative stress and various long-term complications. The present study was undertaken to evaluate the efficacy and safety of the supplementation (Trazer F Forte^TM-CORONA Remedies Pvt. Ltd.) providing combination of insulin sensitising agents (myo-inositol, D-chiro-inositol and chromium picolinate), antioxidants (N-acetylcysteine and lycopene) and vitamins (vitamin D, biotin and folic acid) in women with PCOS. After 12 weeks of supplementation, a significant improvement was observed in menstrual cyclicity, acne and hirsutism in both obese and lean PCOS patients. A significant reduction was observed in body weight and BMI of obese subjects. However, both parameters remain unchanged in lean subjects. We suggest that combination therapy of insulin sensitising agents, antioxidants and vitamins may be a fruitful approach for the management of PCOS.Impact statementWhat is already known on this subject? Monotherapy of insulin sensitising agents, antioxidants and vitamins is beneficial in the treatment of PCOS.What do the results of this study add? Combined use of insulin sensitising agents (myo-inositol, D-chiro-inositol and chromium picolinate), antioxidants (N-acetylcysteine and lycopene), and vitamins (vitamin D, biotin and folic acid) is safe and effective in obese and non-obese women with PCOS.What are the implications of these findings for clinical practice and/or further research? Since PCOS is a multifactorial and a complex endocrine disorder, combination therapy can be used for the comprehensive management of PCOS.

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.

The effects of plasma chromium on lipid profile, glucose metabolism and cardiovascular risk in type 2 diabetes mellitus. A case - control study

BACKGROUND

The study was aimed at determining the effect of plasma chromium concentration on the metabolism of glucose, and lipids and their subsequent cardiovascular risk in patients with type 2 diabetes in the Bolgatanga district of Ghana.

MATERIAL AND METHODS

Fasting blood glucose and lipids profile were determined by enzymatic assay using the BT 5000® Random Access Chemistry Analyzer. Fasting serum insulin and High sensitive C-reactive protein were determined by ELISA, a solid phase direct sandwich immunoassay method. HOMA-IR, which is based on fasting blood sample for insulin and glucose concentrations measured in a single blood sample, was used to calculate insulin resistance. Plasma chromium was measured using an atomic Absorption Spectrometer.

RESULTS

Patientswith diabeteshad significantly (p<0.0001) increased LDL, TC, TG, VLDL, insulin, CRP and HOMAIR and a significantly reduced plasma chromium (p<0.0001) (0.53± 0.02μg/l and 0.11±0.01μg/l control and case respectively). Low Cr (p ≤0.001) was associated with high blood pressure, obesity and lipid dysregulation. Plasma Cr significantly correlated negatively with blood pressure and LDL.

CONCLUSION

Lower plasma Cr level was associated with hyperglycaemia, hyperinsulinemia, hypertension, insulin resistance and high inflammation marker HsCRP.

Purslane Extract and Glucose Homeostasis in Adults with Type 2 Diabetes: A Double-Blind, Placebo-Controlled Clinical Trial of Efficacy and Safety

Purslane extract (PE) is derived from Portulaca oleracea L., a medicinal plant used in traditional medicine for its antidiabetic properties. This randomized, placebo-controlled clinical trial was designed to evaluate the efficacy and safety of PE in improving glucose control, blood pressure, and lipid profile in adults with type 2 diabetes mellitus (T2DM) treated with a single oral hypoglycemic agent at baseline. Subjects were randomized to treatment with three capsules of PE/day or a matched placebo. Change from baseline to the week 12 end-of-follow-up visit measures of glucose homeostasis, hemodynamics, and lipid profile was compared by treatment assignment. In addition, these measures were evaluated in a subgroup of "responders," defined as patients whose week 12 HbA1c was lower than baseline values, regardless of treatment assignment. This group was further assessed in subgroups of baseline oral hypoglycemic treatment. A total of 63 participants were treated with either PE (n = 31, 11 females, mean age 52.4 ± 7.9 years) or matched placebo (n = 32, 11 females, mean age 58.3 ± 10.8 years). In the total cohort, systolic blood pressure declined significantly more in the PE group than the placebo group: -7.5 ± 5.0 versus -0.01 ± 0.3 mmHg, P < .0001. In the responders' subgroup, HbA1c declined significantly more in the PE group than the placebo group: -0.8% ± 0.4% versus -0.6% ± 0.5%, P = .03. Few adverse events were reported. These were mild and did not differ by treatment assignment. PE appears to be a safe, adjunct treatment for T2DM, significantly reducing systolic blood pressure in the total cohort and HbA1c in the subgroup of responders.

A Double-Blind, Randomized Pilot Trial of Chromium Picolinate for Overweight Individuals with Binge-Eating Disorder: Effects on Glucose Regulation

PURPOSE

Chromium treatment has been shown to improve glucose regulation in some populations. The purpose of this study was to evaluate whether chromium picolinate (CrPic) supplementation improves glucose regulation in overweight individuals with binge-eating disorder (BED).

METHODS

In this double-blinded randomized pilot trial, participants (N = 24) were randomized to high (HIGH, 1000 mcg/day, n = 8) or moderate (MOD, 600 mcg/day, n = 9) dose of CrPic or placebo (PL, n = 7) for 6 months. Participants completed an oral glucose tolerance test (OGTT) at baseline, 3 months, and 6 months. Fixed effects models were used to estimate mean change in glucose area under the curve (AUC), insulin_AUC, and insulin sensitivity index (ISI).

RESULTS

Results revealed a significant group and time interaction (p < 0.04) for glucose_AUC, with glucose_AUC increasing significantly in the PL group (p < 0.02) but decreasing significantly in the MOD group (p < 0.03) at 6 months. Insulin_AUC increased significantly over time (main effect, p < 0.02), whereas ISI decreased significantly over time (main effect, p < 0.03).

CONCLUSION

As anticipated, a moderate dose of CrPic was associated with improved glycemic control, whereas PL was associated with decreased glycemic control. It was unexpected that the improved glycemic control seen in the MOD dose group was not seen in the HIGH dose group. However, although participants randomized to the HIGH dose group did not have improved glycemic control, they had better glycemic control than participants randomized to the PL group. These findings support the need for larger trials.

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.

Evaluation Series on Safety and Efficacy of Nutritional Supplements in Newly Diagnosed Hyperglycemia: A Placebo-Controlled, Randomized Study

BACKGROUND

Diabetes is endemic with developing economies contributing to the bulk of this pandemic. Despite the evidence of incremental benefit of glycemic control starting early in life, acceptance of and adherence to modern medications remain suboptimal.

AIMS

To determine the hemoglobin A1c (HbA1c)-lowering efficacy and safety of nutritional supplement, PreCrea(®), in adult Indians with newly diagnosed hyperglycemia.

MATERIALS AND METHODS

Double-blind, randomized study conducted in six diabetes centers in India. A total of 193 treatment-naïve subjects with newly diagnosed hyperglycemia and fasting plasma glucose (FPG) >100 mg/dL were randomized into either PreCrea(®) 600 mg (n = 90) or matched placebo (n = 89) capsules twice daily, along with lifestyle modification, for 12 weeks. The main outcomes were changes in HbA1c and FPG levels, attainment of the American Diabetes Association (ADA)-defined goals for HbA1c, and clinical and biochemical measures of safety.

RESULTS

At 12 weeks, mean HbA1c in PreCrea(®) group reduced by 0.91% compared with 0.08% increase in the placebo group (P < .001). The reductions in the mean FPG at week 4 (P < .001) and week 12 (P = 0.04) were significant compared to the baseline. ADA goal of HbA1c <7% increased from 15.5% at the baseline to 35.6% at week 12 in PreCrea(®) subjects. Clinical safety and biochemical safety did not change. Hypoglycemia and weight gain were not observed with PreCrea(®).

CONCLUSIONS

Nearly 1% point reduction in HbA1c at week 12 with PreCrea(®) is comparable with most first-line glucose-lowering drugs. The safety and tolerability of PreCrea(®) highlights its potential as a first-line therapy in newly detected hyperglycemia.

The Effect of Tianmai Xiaoke Pian on Insulin Resistance through PI3-K/AKT Signal Pathway

In the clinical setting, given the potential adverse effects of thiazolidinediones and biguanides, we often have difficulty in treatment that no other insulin sensitizers are available for use in type 2 diabetic mellitus (T2DM) patients. Tianmai Xiaoke Pian (TMXKP) is a traditional Chinese medicine tablet, which is comprised of chromium picolinate, Tianhuafen, Maidong, and Wuweizi. To understand its mechanism of action on insulin resistance, TMXKP (50 mg/kg orally) was tested in T2DM rats (induced by a high-fat diet and streptozotocin). Eight weeks later, fasting blood glucose (FBG) and oral glucose tolerance tests (OGTT) were performed. Area under the curve (AUC) and homeostatic model assessment of insulin resistance (HOMA-IR) were calculated, and PI3-K/AKT signal pathway-related genes and proteins were tested by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis in muscle, adipose, and liver tissues, respectively. TMXKP significantly reduced FBG, OGTT, AUC, and HOMA-IR in diabetic rats (P < 0.05). Furthermore, we also observed that TMXKP could significantly decrease IRS-1, IRS-2, PI3-K p85α, and AKT2 gene expression and also IRS-1, IRS-2, PI3-K, AKT2, and p-AKT2 protein expression levels (P < 0.05) in diabetic rats. These findings confirm that TMXKP can alleviate insulin resistance in T2DM rats through the PI3K/AKT pathway. Thus TMXKP appears to be a promising insulin sensitizer.

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.

Trivalent chromium inhibits TSP-1 expression, proliferation, and O-GlcNAc signaling in vascular smooth muscle cells in response to high glucose in vitro

Trivalent chromium (Cr(3+)) is a mineral nutrient reported to have beneficial effects in glycemic and cardiovascular health. In vitro and in vivo studies suggest that Cr(3+) supplementation reduces the atherogenic potential and lowers the risk of vascular inflammation in diabetes. However, effects of Cr(3+) in vascular cells under conditions of hyperglycemia, characteristic of diabetes, remain unknown. In the present study we show that a therapeutically relevant concentration of Cr(3+) (100 nM) significantly downregulates a potent proatherogenic matricellular protein, thrombospondin-1 (TSP-1), in human aortic smooth muscle cells (HASMC) stimulated with high glucose in vitro. Promoter-reporter assays reveal that this downregulation of TSP-1 expression by Cr(3+) occurs at the level of transcription. The inhibitory effects of Cr(3+) on TSP-1 were accompanied by significant reductions in O-glycosylation of cytoplasmic and nuclear proteins. Using Western blotting and immunofluorescence studies, we demonstrate that reduced protein O-glycosylation by Cr(3+) is mediated via inhibition of glutamine: fructose 6-phosphate amidotransferase, a rate-limiting enzyme of the hexosamine pathway, and O-linked N-acetylglucosamine (O-GlcNAc) transferase, a distal enzyme in the pathway that controls intracellular protein O-glycosylation. Additionally, we found that Cr(3+) attenuates reactive oxygen species formation in glucose-stimulated HASMC, suggesting an antioxidant effect. Finally, we report an antiproliferative effect of Cr(3+) that is specific for high glucose and conditions triggering elevated protein O-glycosylation. Taken together, these findings provide the first cellular evidence for a novel role of Cr(3+) to modulate aberrant vascular smooth muscle cell function associated with hyperglycemia-induced vascular complications.

Chromium-containing traditional Chinese medicine, Tianmai Xiaoke Tablet improves blood glucose through activating insulin-signaling pathway and inhibiting PTP1B and PCK2 in diabetic rats

OBJECTIVE

Chromium is an essential mineral that is thought to be necessary for normal glucose homeostasis. Numerous studies give evidence that chromium picolinate can modulate blood glucose and insulin resistance. The main ingredient of Tianmai Xiaoke (TMXK) Tablet is chromium picolinate. In China, TMXK Tablet is used to treat type 2 diabetes. This study investigated the effect of TMXK on glucose metabolism in diabetic rats to explore possible underlying molecular mechanisms for its action.

METHODS

Diabetes was induced in rats by feeding a high-fat diet and subcutaneously injection with a single dose of streptozotocin (50 mg/kg, tail vein). One week after streptozotocin-injection, model rats were divided into diabetic group, low dose of TMXK group and high dose of TMXK group. Eight normal rats were used as normal control. After 8 weeks of treatment, skeletal muscle was obtained and was analyzed using Roche NimbleGen mRNA array and quantitative polymerase chain reaction (qPCR). Fasting blood glucose, oral glucose tolerance test and homeostasis model assessment of insulin resistance (HOMA-IR) index were also measured.

RESULTS

The authors found that the administration of TMXK Tablet can reduce the fasting blood glucose and fasting insulin level and HOMA-IR index. The authors also found that 2 223 genes from skeletal muscle of the high-dose TMXK group had significant changes in expression (1 752 increased, 471 decreased). Based on Kyoto encyclopedia of genes and genomes pathway analysis, the most three significant pathways were "insulin signaling pathway", "glycolysis/gluconeogenesis" and "citrate cycle (TCA)". qPCR showed that relative levels of forkhead box O3 (FoxO3), phosphoenolpyruvate carboxykinase 2 (Pck2), and protein tyrosine phosphatase 1B (Ptp1b) were significantly decreased in the high-dose TMXK group, while v-akt murine thymoma viral oncogene homolog 1 (Akt1) and insulin receptor substrate 2 (Irs2) were increased.

CONCLUSION

Our data show that TMXK Tablet reduces fasting glucose level and improves insulin resistance in diabetic rats. The mechanism may be linked to the inactivation of PTP1B and PCK enzymes, or through intracellular pathways, such as the insulin signaling pathway.

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.

The role of antioxidants and other agents in alleviating hyperglycemia mediated oxidative stress and injury in liver

Several antioxidants and agents having similar antioxidant effects are known to exert beneficial effects in ameliorating the injurious effects of hyperglycemia on liver in different diabetic in vitro and in vivo models. The review deals with some of the agents which have been shown to exert protective effects on liver against hyperglycemic insult and the various mechanisms involved. The different classes of agents which protect the diabetic liver or decrease the severity of hyperglycemia mediated injury include flavonoids, catechins, and other polyphenolic compounds, curcumin and its derivatives, certain vitamins, hormones and drugs, trace elements, prototypical antioxidants and amino acids. Some of the pronounced changes mediated by the antioxidants in liver exposed to hyperglycemia include decreased oxidative stress, and alterations in carbohydrate and lipid metabolism. Other mechanisms through which the agents ameliorate hyperglycemia mediated liver injury include decrease in oxidative DNA and protein damage, restoration of mitochondrial structural and functional integrity, decrease in inflammation and improved insulin signaling. Thus, antioxidants may prove to be an important mode of defense in maintaining normal hepatic functions in diabetes.

miR-375 and miR-30d in the effect of chromium-containing Chinese medicine moderating glucose metabolism

In China, TianMai Xiaoke tablet (TM) is used to treat type 2 diabetes. However, the exact mechanism of TM is not clear. This study is to investigate the effect of TM on glucose metabolism in diabetic rats and to identify whether TM takes a direct action through microRNAs on islet. Rats were divided into control group, diabetic group, low dose of TM group (TML), and high dose of TM group (TMH). Pancreas samples were analyzed using microRNA array and Q-PCR. Eight-week treatment with TM significantly decreased fasting blood glucose. The blood glucose was significantly reduced in TM-treated groups before and after oral glucose administration. Fasting insulin and HOMA-IR were suppressed in TM-treated groups. miR-448, let-7b, miR-540, miR-296, miR-880, miR-200a, miR-500, miR-10b, miR-336, miR-30d, miR-208, let-7e, miR-142-5p, miR-874, miR-375, miR-879, miR-501, and miR-188 were upregulated, while miR-301b, miR-134, and miR-652 were downregulated in TMH group. Through target gene analysis and real-time PCR verification, we found that these miRNAs, especially miR-375 and miR-30d, can stimulate insulin secretion in islet. Our data suggest that TM can improve blood glucose in diabetic rats which involved increasing the expression of miR-375 and miR-30d to activate insulin synthesis in islet.

Chromium picolinate supplementation for overweight or obese adults

BACKGROUND

Obesity is a global public health threat. Chromium picolinate (CrP) is advocated in the medical literature for the reduction of bodyweight, and preparations are sold as slimming aids in the USA and Europe, and on the Internet.

OBJECTIVES

To assess the effects of CrP supplementation in overweight or obese people.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, ISI Web of Knowledge, the Chinese Biomedical Literature Database, the China Journal Full text Database and the Chinese Scientific Journals Full text Database (all databases to December 2012), as well as other sources (including databases of ongoing trials, clinical trials registers and reference lists).

SELECTION CRITERIA

We included trials if they were randomised controlled trials (RCT) of CrP supplementation in people who were overweight or obese.We excluded studies including children, pregnant women or individuals with serious medical conditions.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles and abstracts for relevance. Screening for inclusion, data extraction and 'Risk of bias'assessment were carried out by one author and checked by a second. We assessed the risk of bias by evaluating the domains selection,performance, attrition, detection and reporting bias. We performed a meta-analysis of included trials using Review Manager 5.

MAIN RESULTS

We evaluated nine RCTs involving a total of 622 participants. The RCTs were conducted in the community setting, with interventions mainly delivered by health professionals, and had a short- to medium-term follow up (up to 24 weeks). Three RCTs compared CrPplus resistance or weight training with placebo plus resistance or weight training, the other RCTs compared CrP alone versus placebo.We focused this review on investigating which dose of CrP would prove most effective versus placebo and therefore assessed the results according to CrP dose. However, in order to find out if CrP works in general, we also analysed the effect of all pooled CrP doses versus placebo on body weight only.Across all CrP doses investigated (200 μg, 400 μg, 500 μg, 1000 μg) we noted an effect on body weight in favour of CrP of debatable clinical relevance after 12 to 16 weeks of treatment: mean difference (MD) -1.1 kg (95% CI -1.7 to -0.4); P = 0.001; 392 participants;6 trials; low-quality evidence (GRADE)). No firm evidence and no dose gradient could be established when comparing different doses of CrP with placebo for various weight loss measures (body weight, body mass index, percentage body fat composition, change in waist circumference).Only three studies provided information on adverse events (low-quality evidence (GRADE)). There were two serious adverse events and study dropouts in participants taking 1000 μg CrP, and one serious adverse event in an individual taking 400 μg CrP. Two participants receiving placebo discontinued due to adverse events; one event was reported as serious. No study reported on all-cause mortality,morbidity, health-related quality of life or socioeconomic effects.

AUTHORS' CONCLUSIONS

We found no current, reliable evidence to inform firm decisions about the efficacy and safety of CrP supplements in overweight or obese adults.

Water-soluble vitamins in people with low glomerular filtration rate or on dialysis: a review

People with low glomerular filtration rate and people on dialysis are spontaneously at risk for vitamin deficiency because of the potential for problems with decreased appetite and decreased sense of smell and taste, leading to decreased intake, and because decreased energy or decreased cognitive ability results in difficulties in shopping and cooking. Imposed dietary restrictions because of their renal dysfunction and because of comorbidities such as hypertension and diabetes exacerbate this problem. Finally, particularly for water-soluble vitamins, loss may occur into the dialysate. We did not identify any randomized trials of administering daily doses close to the recommended daily allowances of these vitamins. In people who are eating at all, deficiencies of B5 and B7 seem unlikely. It is unclear whether supplements of B2 and B3 are necessary. Because of dialyzability and documented evidence of insufficiency in dialysis patients, B1 supplementation is likely to be helpful. B6, B9, and B12 are implicated in the hyperhomocysteinemia observed in patients on dialysis. These vitamins have been studied in combinations, in high doses, with the hope of reducing cardiovascular outcomes. No reductions in patient-important outcomes were seen in adequately powered randomized trials. Because of their involvement in the homocysteine pathway, however, supplementation with lower doses, close to the recommended daily allowances, may be helpful. Vitamin C deficiency is common in patients on dialysis who are not taking supplements: low-dose supplements are warranted. Vitamins for dialysis patients contain most or all of the B vitamins and low-dose vitamin C. We are not aware of any medical reasons to choose one over another.

Nutritional supplements for diabetes sold on the internet: business or health promotion?

Background

Diabetes is one of the most widespread chronic disease. Although many medications are available for the treatment and prevention of diabetes, many people turn to nutritional supplements (NSs). In these years, the online sales have contributed to the growth of use of nutritional supplement. The aim of the research was to investigate the type of information provided by sales websites on NSs, and analyse the existence of scientific evidence about some of the most common ingredients found in available NSs for diabetes.

Methods

A web search was conducted in April 2012 to identify web sites selling NSs in the treatment of diabetes using Google, Yahoo and Bing! and the key word used was “diabetes nutritional supplements”. Website content was evaluated for the quality of information available to consumers and for the presence of a complete list of ingredients in the first NS suggested by the site. Subsequently, in order to analyze the scientific evidence on the efficacy of these supplements a PubMed search was carried out on the ingredients that were shared in at least 3 nutritional supplements.

Results

A total of 10 websites selling NSs were selected. Only half of the websites had a Food and Drug Administration disclaimer and 40% declared clearly that the NS offered was not a substitute for proper medication. A total of 10 NS ingredients were searched for on PubMed. Systematic reviews, meta-analyses or randomized control trials were present for all the ingredients except one. Most of the studies, however, were of poor quality and/or the results were conflicting.

Conclusions

Easy internet access to NSs lacking in adequate medical information and strong scientific evidence is a matter of public health concern, mainly considering that a misleading information could lead to an improper prevention both in healthy people and people suffering from diabetes. There is a clear need for more trials to assess the efficacy and safety of these NSs, better quality control of websites, more informed physicians and greater public awareness of these widely used products.