Chromium Supplementation Reduces Resting Heart Rate in Patients with Metabolic Syndrome and Impaired Glucose Tolerance

Effect of Chromium Supplementation on Serum Levels of Inflammatory Mediators: An Updated Systematic Review and Meta-analysis on Randomized Clinical Trials

Chromium has been recognized for its beneficial effects on inflammation reduction; therefore, we conducted a systematic review and meta-analysis to find the effect of chromium supplementation on serum levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) in subjects aged 18 years and older. Related articles were identified by searching databases such as the Cochrane Library, ClinicalTrials.gov, ISI Web of Science, Scopus, and PubMed up until Agust 2024. We computed the mean differences (MD) along with their standard deviations (SDs) to carry out the meta-analysis. Statistical heterogeneity of the intervention effects was assessed using I-squared statistics and Cochran's Q test. In total, twelve and eleven studies were included in the present systematic review and meta-analysis, respectively. The pooled results indicated that the differences in serum levels of CRP and TNF-α between chromium group and the comparison group were statistically significant (CRP: weighted mean difference (WMD) = -0.58 mg/L; 95% confidence interval (CI) = -0.95, -0.22 mg/L; P = 0.002; TNF-α: WMD = -1.22 pg/ml; 95% CI = -1.91, -0.53 pg/ml; p = 0.001). In contrast, chromium supplementation resulted in a non-significant decrease in serum levels of IL-6 (WMD = -0.63 pg/ml; 95% CI: -1.67, 0.4 pg/ml; P < 0.001). Our study supports the beneficial effect of chromium supplementation on serum concentration of CRP and TNF-α, but our results showed that chromium supplementation non-significantly reduced the serum levels of IL-6. However, it seems that chromium formulation, participants' BMI, sample size, and geographical region are strong variables that predict the effect of chromium supplementation on inflammatory mediators.

Association of heavy metals and bio-elements blood level with metabolic syndrome: a systematic review and meta-analysis of observational studies

Background and objectives

The literature has reported heavy metals might alter the physiological and biochemical functions of body organs and cause several health problems. So, the present systematic review and meta-analysis aimed to investigate the association of blood levels of essential or non-essential metals with metabolic syndrome (MetS).

Methods

In this systematic review, some international databases including PubMed, Embase, Scopus, and Web of Science were searched up to February 2024. All observational studies which assessed the association of three heavy metals (cadmium, mercury, lead) and bio-elements (chromium, iron, manganese, and magnesium, copper) with the risk of MetS were included. There was no limitation in the time of publication and language. A random-effects meta-analysis was performed to estimate the pooled effect sizes. Possible sources of heterogeneity were explored by meta-regression analysis.

Results

Totally, 29 studies were eligible for meta-analysis. Our results showed that increased level of cadmium (pooled OR: 1.24, 95% CI: 1.05, 1.46) and mercury (pooled OR: 1.22, 95% CI: 1.08, 1.38) significantly increased the risk of MetS. In contrast, increased level of chromium significantly reduced the risk of developing MetS (pooled OR: 0.68, 95% CI: 0.56, 0.83). Moreover, association between lead, iron, copper, magnesium, and manganese with MetS was not statistically significant (P > 0.05). However, elevated lead levels in men increased the odds of MetS.

Conclusion

Our results show a significant association between blood levels of some heavy metals, including cadmium, mercury, and lead, with increased odds of MetS. On the other hand, chromium as a biometal decreased the odds of MetS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01500-9.

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.

The protective effect of zinc, selenium, and chromium on myocardial fibrosis in the offspring of rats with gestational diabetes mellitus

The offspring of gestational diabetes mellitus (GDM) mothers are considered to be at the risk of cardiovascular diseases due to intrauterine hyperglycemia exposure. Our previous study showed that zinc, selenium, and chromium dramatically alleviated glucose intolerance in GDM rats and their offspring (P < 0.05). However, the effects of these elements on the damage of the cardiac myocytes of GDM offspring and the underlying mechanisms have not been demonstrated. Here, we investigated the beneficial effects of zinc (10 mg per kg bw), selenium (20 μg per kg bw), and chromium (20 μg per kg bw) supplementation on myocardial fibrosis in the offspring of GDM rats induced by a high-fat and sucrose (HFS) diet. The results showed that maternal GDM induced glucose intolerance, oxidative stress, cardiac inflammation and myocardial fibrosis in offspring rats during different ages (3 days, 3 weeks, and adulthood), which were ameliorated by zinc, selenium and chromium supplementation (P < 0.05). The activity of cardiac damage markers such as creatine kinase-myocardial band isoenzyme (CK-MB), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) decreased by 40-60% in element-supplemented offspring compared to that in non-supplemented offspring of GDM dams (P < 0.05). Moreover, maternal GDM-induced expression of fibrosis-related proteins and the transforming growth factor-beta 1 (TGF-β1)/small mothers against decapentaplegic homolog 3 (Smad3) signaling pathway in the heart tissue of offspring was down-regulated by zinc, selenium, and chromium supplementation (P < 0.05). In conclusion, zinc, selenium, and chromium may play a protective role in maternal GDM-induced myocardial fibrosis in offspring from birth to adulthood by inactivating the TGF-β1/Smad3 pathway.

The effects of chromium supplementation on blood pressure: a systematic review and meta-analysis of randomized clinical trials

Results of studies on the effect of chromium supplementation on blood pressure (BP) are contradictory. The purpose of the current study was to carry out a meta-analysis on the effects of chromium supplementation on systolic blood pressure (SBP) and diastolic blood pressure (DBP). We conducted a systematic literature search of PubMed, SCOPUS, Cochrane Library, Web of Science, and Embase databases from inception up to July 2020 for randomized controlled trials (RCTs) that evaluate the impacts of chromium on SBP and DBP. A random-effects model was used to compute weighted mean differences (WMDs) with 95% confidence intervals (CIs). Heterogeneity was determined by I² statistics and the Cochrane Q test. Sensitivity analysis was performed by eliminating each study one by one and recalculating the pooled effect. Ten studies comprising a total of 624 subjects were included in our meta-analysis. Chromium supplementation did not significantly change SBP (WMD: -0.642: 95% CI: (-2.15, 1.30) mmHg; p = 0.312; I² = 12.7%) and DBP (WMD: -0.10; 95% CI: (-1.39, 1.18) mmHg; p = 0.070; I² = 37.6%). Subgroup analysis based on dose and duration of chromium supplementation also did not significantly change the mean of SBP and DBP. The present meta-analysis of RCTs did not show the beneficial effects of chromium supplementation on BP in adults.

Biotic and Abiotic Biostimulation for the Reduction of Hexavalent Chromium in Contaminated Aquifers

Hexavalent chromium is a carcinogenic heavy metal that needs to be removed effectively from polluted aquifers in order to protect public health and the environment. This work aims to evaluate the reduction of Cr(VI) to Cr(III) in a contaminated aquifer through the stimulation of indigenous microbial communities with the addition of reductive agents. Soil-column experiments were conducted in the absence of oxygen and at hexavalent chromium (Cr(VI)) groundwater concentrations in the 1000–2000 μg/L range. Two carbon sources (molasses and EVO) and one iron electron donor (FeSO4·7H2O) were used as ways to stimulate the metabolism and proliferation of Cr(VI) reducing bacteria in-situ. The obtained results indicate that microbial anaerobic respiration and electron transfer can be fundamental to alleviate polluted groundwater from hazardous Cr(VI). The addition of organic electron donors increased significantly Cr(VI) reduction rates in comparison to natural soil attenuation rates. Furthermore, a combination of organic carbon and iron electron donors led to a longer life span of the remediation process and thus increased total Cr(VI) removal. This is the first study to investigate biotic and abiotic Cr(VI) removal by conducting experiments with natural soil and by applying biostimulation to modify the natural existing microbial communities.

The effect of chromium intake on oxidative stress parameters: A systematic review and meta-analysis

BACKGROUND

Trivalent chromium is a trace element thought to have a beneficial effect on oxidative stress (OS) parameters and inflammation. This review aimed to investigate the dose-response of chromium and summarize the effects of chromium supplementation on OS parameters in the literature.

METHODS

MEDLINE, Scopus, Web of Science and Cochrane CENTRAL databases were searched for RCTs published from inception to January 2021 evaluating the effect of chromium supplementation on OS parameters, namely MDA, TBARS, SOD, TAS, CAT, GPx, and GSH. A random-effects model was used to pool data and calculated standard mean difference and 95 % confidence intervals. Quantified heterogeneity among studies was assessed through Cochrane's I² values.

RESULTS

Nine studies enrolling 550 participants met the inclusion criteria. The obtained results indicate that chromium supplementation significantly increases TAC (SMD: 0.46; 95 % CI: 0.08, 0.84; I² = 00.0 % n = 2) and significantly decreases MDA levels (SMD: -0.46; 95 % CI: -0.86, -0.07; I² = 52.4 % n = 5). Supplementation did not significantly change CAT, GPx, GSH, SOD, TAS, and TBARS.

CONCLUSION

Chromium supplementation may improve OS parameters, however, due to high heterogeneity observed in the included studies, these findings should be interpreted with caution. Large RCTs on various patient groups evaluating the impact of chromium supplementation are needed to allow an adequate generalization of the benefits of chromium on human health.

Effects of chromium supplementation on blood pressure, body mass index, liver function enzymes and malondialdehyde in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Several studies reported beneficial effects of chromium supplementation for management of type 2 diabetes mellitus (T2DM). The present study aimed to provide a systematic review and meta-analysis of randomized controlled trials (RCTs) examining the effects of chromium supplementation on blood pressure, body mass index (BMI), liver function enzymes and malondialdehyde (MDA) in patients with T2DM.

METHODS

PubMed, Scopus, and Embase were searched up to 15 November 2020 with no language and time restriction. RCTs that reported the effects of chromium supplementation on blood pressure, BMI, liver function enzymes and MDA in patients with T2DM were included. A random-effects model was used to compute weighted mean differences (WMDs) with 95 % confidence intervals (CIs). Between-study heterogeneity was assessed by Cochran's Q test and quantified by I² statistic.

RESULTS

Of 3586 publications, 15 RCTs were included for the meta-analysis. Pooled effect sizes indicated that chromium significantly reduced diastolic blood pressure (DBP) (WMD): -2.36 mmHg, 95 % CI: -4.14, -0.60; P = 0.008), and MDA (WMD: -0.55 umol/l, 95 % CI: -0.96, -0.14; P = 0.008). However, chromium supplementation did not significantly affect BMI, systolic blood pressure (SBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST). Meta-regression analysis did not show significant linear relationship between dose of chromium and change in BMI (p = 0.412), SBP (p = 0. 319), DBP (p = 0.102), ALT (p = 0.923), AST (p = 0.986) and MDA (p = 0.055).

CONCLUSION

The present systematic review and meta-analysis shows that supplementation with chromium at dose of 200-1000 μg/day may reduce DBP and MDA in T2DM patients.

The Impact of Chromium Supplementation on Blood Pressure: A Systematic Review and Dose-Response Meta‑Analysis of Randomized‑Controlled Trials

INTRODUCTION

Potential effects of chromium supplementation on blood pressure (BP) have been examined in several interventional studies. Nevertheless, findings in this context are controversial.

AIM

Therefore, the current systematic review and meta-analysis aimed to comprehensively assess the impact of chromium supplementation on BP.

METHODS

Five online databases including Web of Science, Scopus, Embase, Google Scholar, and PubMed were systematically searched from inception to March 2020. We included all randomized clinical trials (RCTs) evaluating the effects of chromium supplementation on systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) in humans.

RESULTS

The random-effects meta-analysis of 11 eligible RCTs with 637 participants demonstrated the significant decline in both SBP (WMD - 2.51 mmHg; 95% CI - 4.97 to - 0.05, p = 0.04) and DBP (WMD - 1.04 mmHg; 95% CI - 1.96 to - 0.12, p = 0.026) following supplementation with chromium. In subgroup analysis, studies that were administered chromium yeast and brewer's yeast, showed greater decrease in SBP. Also, in stratification based on participants' health status, significant reduction in SBP only was seen in diabetic patients with chronic heart disease (CHD). Nonlinear dose-response analysis revealed a significant influence of chromium dosage on SBP changes.

CONCLUSION

The current meta-analysis, indicated that supplementation with chromium significantly decrease SBP and DBP. In subgroup analysis, administration of chromium yeast and brewer's yeast resulted in greater reduction in SBP. Further large-scale RCTs with better design are needed to confirm these findings.

Effects of chromium supplementation on oxidative Stress biomarkers

Aim: This systematic review and meta-analysis aimed to evaluate the effects of chromium supplementation on oxidative stress biomarkers such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPX), malondialdehyde (MDA), total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), catalase (CAT), nitric oxide (NO), total antioxidant capacity (TAC) and protein carbonyl. Methods: Relevant studies, published from inception until July 2019, were searched through PubMed/Medline, Scopus, ISI Web of Science, Embase, and Google Scholar. All randomized clinical trials investigating the effect of chromium supplementation on oxidative stress were included. Results: Out of 252 citations, 10 trials that enrolled 595 subjects were included. Chromium supplementation resulted in a significant increase in GSH (WMD: 64.79 mg/dl, 95% CI: 22.43 to 107.15; P=0.003) but no significant change in MDA, TAS, TBARS levels, SOD, CAT levels and GPX. Chromium picolinate supplementation resulted in a significant increase in TAC while failing to have a significant effect on NO. Moreover, both chromium picolinate and chromium dinicocysteinate supplementation reduced protein carbonyl levels. Conclusion: Overall, this meta-analysis demonstrated that chromium supplementation increased GSH without any significant changes in the mean of GPX, MDA, TAS, TBARS, CAT and SOD.

FT-IR and GC-MS analyses of potential bioactive compounds of cow urine and its antibacterial activity

The main emphasis of this study was to identify the bioactive compounds responsible for antibacterial activity of Badri cow urine isolated by thin layer chromatography. The most effective bioactive fraction was analysed by FT-IR and GC-MS analyses. Among the four major fractions (EW1, EW2, CA1 and CA2) obtained by TLC profiling, EW1 was found most active against bacterial strains viz., Listeria monocytogenes (MTCC657), Staphylococcus aureus (MTCC7443), Pseudomonas aeruginosa (MTCC424), Klebsiella pneumoniae (MTCC432) and Salmonella typhi (MTCC733). However, Escherichia coli (MTCC118), was found resistant to all the fractions. In FT-IR spectroscopy, functional groups like alcohol, amide, alkene, alkyl halide, polysulfide and phosphate ions were identified. The GC-MS analysis of EW1 fraction exhibited the presence of 12 compounds, of which 1-heneicosanol was found as the major compound. These compounds might be responsible synergistically or individually for antibacterial activity of cow urine. Nine elements namely sodium (Na), calcium (Ca), chromium (Cr), iron (Fe), magnesium (Mg), aluminium (Al), potassium (K) and zinc (Zn), Gold (Au) were measured by ICP-MS analysis.

A Comprehensive insight into the effect of chromium supplementation on oxidative stress indices in diabetes mellitus: A systematic review

Diabetes mellitus is a metabolic disorder defined as an increase in blood glucose levels (hyperglycaemia) and insufficient production or action of insulin produced by the pancreas. Chronic hyperglycaemia leads to increased reactive oxygen species (ROS) production and oxidative stress, which consequently results in insulin resistance, beta cell degeneration, dyslipidaemia, and glucose intolerance in diabetic patients. Chromium has an essential role in the metabolism of proteins, lipids, and carbohydrates through increasing insulin efficiency. This systematic review aimed to evaluate chromium supplementation's potential roles in oxidative stress indices in diabetes mellitus. A systematic search was performed in PubMed, Scopus, Google Scholar, Cochrane, and Science Direct databases until November 2020. All clinical trials and animal studies that assessed chromium's effect on oxidative stress indices in diabetes mellitus and were published in English-language journals were included. Finally, only 33 out of 633 articles met the required criteria for further analysis. Among 33 papers, 25 studies were performed on animals, and eight investigations were conducted on humans. Twenty-eight studies of chromium supplementation lead to reducing oxidative stress indices. Also, 23 studies showed that chromium supplementation markedly increased antioxidant enzymes' activity and improved levels of antioxidant indices. In conclusion, chromium supplementation decreased oxidative stress in diabetes mellitus. However, further clinical trials are suggested in a bid to determine the exact mechanisms.

Effect of chromium supplementation on hs-CRP, TNF-α and IL-6 as risk factor for cardiovascular diseases: A meta-analysis of randomized-controlled trials

BACKGROUND

The objective of this systematic review is to assess the relationship between chromium supplementation and inflammatory biomarkers levels (hs-CRP, TNF-α, IL-6) as risk factor for cardiovascular diseases. Recent studies raise questions regarding the potential of chromium supplementation to decrease the blood-levels of inflammatory markers, lowering cellular oxidative stress as markers of myocardial infarction; however, the results of the researches are inconclusive.

METHODS

The following databases including PubMed, Scopus, Cochran Library and Embase databases were systematically searched until April 2020. Analysis was performed using random-effect model.

RESULTS

The pooled findings for biomarkers of inflammation showed that chromium supplementation significantly reduced serum high-sensitivity C-reactive protein (hs-CRP) (WMD: -0.87 mg/dL, 95% CI: -1.49, -0.26), and tumor necrosis factor-alpha (TNF-α) (WMD: -0.97 pg/ml; 95% CI: -1.92, -0.01) and chromium insignificantly reduced interleukin -6 (IL-6) (WMD: -0.45 pg/ml, 95% CI: -1.18, 0.29).

CONCLUSION

Overall, the results of this systematic review and meta-analysis imply that chromium supplementation may help to improve biomarkers of inflammation as markers of myocardial infarction.

The effects of chromium supplementation on lipidprofile in humans: A systematic review and meta-analysis ofrandomized controlled trials

BACKGROUND AND AIM

This systematic review and meta-analysis aimed to evaluate the effects of chromium supplementation on lipid profile consisting of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) in humans.

METHODS

The PubMed/Medline, Scopus, Web of sciences, Google Scholar and Cochrane library were systematically searched for randomised control trails (RCTs) available which published before August 2020. The meta-analysis was conducted using Random or fixed-effects models, and between-study heterogeneity was assessed by I².

RESULTS

Thirty-eight studies comprising 41 treatment arms and 7605 participants included to the present meta-analysis. Our results of overall analysis show only a significant reduction in serum TC level in response to chromium supplementation (WMD: -0.17 mmol/l, 95 % CI: -0.27, -0.07, P = 0.001). In accordance with the results of the subgroup analyses, the lowering-effect of chromium supplementation may be synergist during short-term (less than 12 weeks), low dose (less than 200), diabetics patient, younger adults (less than 54 years) and picolinate and elemental form for TC, older and non-obese subjects (>54 years and ≤ 29 kg/m2, respectively), women, Asian and Australian and picolinate form for TG, short-term, low dose, non-obese subjects, women, and Asian for VLDL, and nicotinate form for HDL-C, but had no effect on LDL-C.

CONCLUSION

Our meta-analysis reveals that there was only an overall significant association between chromium supplementation with decreases in the concentration of TC. Additionally, we found considerable evidence of subgroup analysis that support a significant lowering effect of chromium supplementation on TC, TG and VLDL. Further RCTs with short-term and low dose chromium supplementation in subjects with diabetes are necessitated for a firm conclusion of the lipid-modulating properties.

The effect of chromium supplementation on apolipoproteins: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Apos play a role in lipoprotein metabolism. Several studies have been carried out on the effect of chromium supplement in improving CVD risk factors.

OBJECTIVE

This study is a systematic review and meta-analysis that aimed to investigate the effect of chromium supplementation on Apos levels of human studies.

MATERIALS AND METHODS

We searched PubMed, Scopus up to May 2020 up to September 2019. We retrieved studies from identified articles. The studies' quality was evaluated using Cochrane Risk of Bias Tool. We estimated the effect of chromium supplementation on Apo A, Apo A1, and Apo B by pooling mean and standard deviation (SD) values.

RESULTS

We obtained six trials involving 231 participants. Chromium consumption resulted significantly decreased Apo B while the subjects were ingesting chromium picolinate. Chromium supplementation did not significantly decrease Apo A (WMD: -3.89 mg/dl; 95% CI, -11.96 to 4.18) with no significant heterogeneity (I² = 0.00%, p = 0.37). The serum level of Apo A1 did not statistically change following chromium intervention (WMD: 6.11 mg/dl; 95% CI, -7.01 to 19.23) with no significant heterogeneity (I² = 0.00%, p = 0.68). Chromium supplementation did not significantly decrease Apo B (WMD: 3.81 mg/dl; 95% CI, -5.32 to 12.94). With no significant heterogeneity (I² = 42.3%, p = 0.12).

CONCLUSIONS

The chromium supplement did not have a significant effect on the Apolipoproteins (Apo A, ApoA1 and Apo B).

Association of plasma chromium with metabolic syndrome among Chinese adults: a case-control study

Backgroud

Chromium has been suggested playing a role in alleviating diabetes, insulin resistance and lipid anomalies, but the effect on metabolic syndrome (MetS) in humans remains controversial.

Methods

We conducted a matched case-control study in a Chinese population, involving 2141 MetS cases and 2141 healthy controls, which were 1:1 matched by age (±2 years) and sex. Plasma chromium was measured by inductively coupled plasma mass spectrometry.

Results

Plasma chromium levels were lower in MetS group than in control group (mean: 4.36 μg/L and 4.66 μg/L, respectively, P < 0.001), and progressively decreased with the number of MetS components (P for trend < 0.001). After adjustment for potential confounding factors, the odds ratios (95% confidence intervals) for MetS across increasing quartiles of plasma chromium levels were 1 (reference), 0.84 (0.67–1.05), 0.76 (0.61–0.95), and 0.62 (0.49–0.78), respectively (P for trend < 0.001). For the components of MetS (high waist circumference, high triglycerides and high blood glucose), the odds ratios (95% confidence intervals) of the highest quartiles were 0.77 (0.61–0.95), 0.67 (0.55–0.80), and 0.53 (0.44–0.64), respectively (P for trend < 0.05).

Conclusions

Our results indicated that plasma chromium levels were inversely associated with MetS in Chinese adults. The association may be explained by the relations between plasma chromium levels and high waist circumference, and the triglycerides and blood glucose levels.

Evaluation of Chromium and Manganese levels in sports supplements using graphite furnace atomic absorption spectrometry

ABSTRACT Objective In this paper, we studied three different types of ordinary sports supplements containing whey protein: whey protein-based ones, hypercaloric ones, and protein bars. Methods A sample preparation procedure was studied employing microwave-assisted wet digestion in order to determine the Chromium and Manganese levels by graphite furnace atomic absorption spectrometry. Results The developed methods have presented good accuracy (recoveries in the range of 90% to 109%) and precision (Relative standard deviation <8%). Although an adequate detectability was obtained (50ng g-1 for Manganese and 65ng g-1 for Chromium), the sample preparation method was also adequate to inductively coupled plasma mass spectrometry analysis. The method was applied to 26 commercial samples, in which the Chromium concentrations were in the range between 0.22 and 1.0μg g-1 and the Manganese concentrations varied from 2.0 to 37μg g-1. Conclusion The results obtained by atomic absorption for both analytes were in agreement with those obtained by mass spectrometry. In addition, some samples presented concentrations of Chromium above the recommended daily intake and, as a result, we used the X-ray powder diffraction technique as an analytical tool to evaluate the oxidation state of Chromium in such samples.

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.