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Background: Chromium plays a role in insulin sensitivity., Objectives: To compare chromium measurements in HIV-positive patients with or without (N) antiretroviral therapy (ART) to that of healthy controls (HC) and, to determine if there is any association between chromium levels and abnormalities in body composition, glucose and lipid metabolism., Design: A cross-sectional study in 91 HIV patients (75 HIV-ART, 16 HIV-N) and 13 HC. Chromium was assessed in the diet, plasma, toenails, and urine. Fasting blood glycemia and lipids, lipodystrophy score and body fat were also determined., Results: Dietary intake of chromium was similar in the 3 groups. Plasma and toenail Cr were lower in HIV compared to HC, but urinary chromium was similar. However, when the HIV-positive patients on ART were compared to those who were naïve to therapies, urinary excretion of chromium was higher in HIV-ART. In addition, urinary excretion of chromium significantly and positively correlated with lipodystrophy score and negatively with various parameters of metabolic syndrome., Conclusion: Despite a similar dietary intake, chromium levels were lower in HIV-positive patients and urinary chromium excretion correlated with some metabolic parameters. Low chromium levels may be due to increased chromium losses. These results support further studies on chromium in HIV patients.

Background: Chromium (Cr) potentiates the action of insulin in the cell and improves glucose tolerance after long-term supplementation., Objective: We hypothesized that Cr may also have acute effects and might be beneficial in lowering the glycemic index of a meal., Methods: We studied the effects of short-term Cr supplementation using a randomized crossover design. Thirteen apparently healthy, non-smoking young men of normal body mass index performed three trials each separated by one week. Test meals, providing 75 g of available carbohydrates, consisted of white bread with added Cr (400 or 800 microg as Cr picolinate) or placebo., Results: After addition of 400 and 800 microg Cr incremental area under the curve (AUC) for capillary glucose was 23% (p = 0.053) and 20% (p = 0.054), respectively, lower than after the white bread meal. These differences reached significance if the subjects were divided into responders (n = 10) and non-responders (n = 3). For the responders AUC after 400 and 800 microg Cr was reduced by 36% and 30%, respectively (Placebo 175 +/- 22, Cr400 111 +/- 14 (p < 0.01), Cr800 122 +/- 15 mmol. min/L (p < 0.01)). Glycemia was unchanged after addition of Cr in the non-responders. Responders and non-responders differed significantly in their nutrient intake and eating pattern, and total serum iron concentration tended to be lower in the responder group (p = 0.07)., Conclusions: Acute chromium supplementation showed an effect on postprandial glucose metabolism in most but not all subjects. The response to Cr may be influenced by dietary patterns.

Objective: To investigate the effect of chromium picolinate (CP) supplementation on body composition, resting metabolic rate (RMR), selected biochemical parameters and iron and zinc status in moderately obese women participating in a 12-week exercise program., Methods: Forty-four women, 27 to 51 years of age, were randomly assigned to two groups based on their body mass index. Subjects received either 400 microg/day of chromium as a CP supplement or a placebo in double-blind fashion and participated in a supervised weight-training and walking program two days per week for 12 weeks. Body composition and RMR were measured at baseline, 6 and 12 weeks. Selected biochemical parameters and iron and zinc status were measured at baseline and 12 weeks., Results: Body composition and RMR were not significantly changed by CP supplementation. No significant differences in fasting plasma glucose, serum insulin, plasma glucagon, serum C-peptide and serum lipid concentrations or in iron and zinc indices were found between the two groups over time. Serum total cholesterol concentration significantly decreased (p = 0.0016) over time for all subjects combined, probably as a result of the exercise training. Exercise training significantly reduced total iron binding capacity (TIBC) by 3% for all subjects combined (p = 0.001 1)., Conclusions: Twelve weeks of 400 microg/day of chromium as a CP supplement did not significantly affect body composition, RMR, plasma glucose, serum insulin, plasma glucagon, serum C-peptide and serum lipid concentrations or iron and zinc indices in moderately obese women placed on an exercise program. The changes in serum total cholesterol levels and TIBC were a result of the exercise program.

Objective: To determine the effects of combined zinc (Zn) and chromium (Cr) supplementation on oxidative stress and glucose homeostasis of people with type 2 diabetes., Design: Tunisian adult subjects with HbA1C > 7.5% were supplemented for 6 months with 30 mg/d of Zn as Zn gluconate or 400 microg/d of Cr as Cr pidolate or combined Zn/Cr supplementation or placebo. The effects of supplementation on plasma zinc (Zn), copper (Cu), selenium (Se), urinary Zn, Cr, plasma thiobarbituric acid reactive substances (TBARS), Cu-Zn superoxide dismutase (SOD) and Se glutathione peroxidase (GPx) in red blood cells, blood lipids and lipoproteins, HbA1C and fasting glucose were measured at the beginning of the study and after six months., Results: At the beginning of the study, more than 30% of the subjects may have been Zn deficient with plasma Zn values less than 10.7 mircomol/L, whereas levels of plasma Cu, Se and antioxidant RBC enzyme activities were in the normal ranges. Following supplementation, there were significant decreases of plasma TBARS in the Cr (13.6%), Zn (13.6%) and Zn/Cr (18.2%) groups with no significant changes in the placebo group. The value for the TBARS of the control healthy Tunisian subjects was 2.08 +/- 0.04 micromol/L and that of the Tunisian subjects with diabetes was 3.32 +/- 0.05 micromol/L. This difference of 1.24 micromol/L between the control group and the subjects with diabetes was reduced from 36% to 50% in the three supplemented groups. Supplementation did not modify significantly HbAIC nor glucose homeostasis. No adverse effects of Zn supplementation were observed on Cu status. HDL cholesterol nor interactions in Zn or Cr., Conclusions: These data suggest the potential beneficial antioxidant effects of the individual and combined supplementation of Zn and Cr in people with type 2 DM. These results are particularly important in light of the deleterious consequences of oxidative stress in people with diabetes.

Within the last 5 years chromium (Cr) has been shown to play a role in glucose intolerance, Type 2 diabetes mellitus (Type 2 DM), and gestational diabetes. In addition, diabetes and the neuropathy of a patient on home parenteral nutrition were alleviated when supplemental Cr was added to total parenteral nutrition (TPN) solutions. In a study conducted in China that has been supported by studies in the United States, supplemental Cr as Cr picolinate improved the blood glucose, insulin, cholesterol, and hemoglobin A1C in people with Type 2 DM in a dose dependent manner. Follow-up studies of > 1 year have confirmed these studies. The requirement for Cr is related to the degree of glucose intolerance: 200 microg/day of supplemental Cr is adequate to improve glucose variables of those who are mildly glucose intolerant. However, people with more overt impairments in glucose tolerance and diabetes usually require more than 200 microg/day. Daily intake of 8 microg of Cr per kg body weight was also more effective than 4 microg/kg in women with gestational diabetes. The mechanism of action of Cr involves increased insulin binding, increased insulin receptor number, and increased insulin receptor phosphorylation. In summary, supplemental Cr has been shown to have beneficial effects without any documented side effects on people with varying degrees of glucose intolerance ranging from mild glucose intolerance to overt Type 2 DM.

Objective: To determine the association between current zinc intake and prevalence of coronary artery disease (CAD) and diabetes as well as factors associated with insulin resistance., Design, Subjects and Methods: In this cross sectional survey, 3575 subjects, aged 25 to 64 years, including 1769 rural (894 men. 875 women) and 1806 urban (904 men, 902 women) subjects were studied. The survey methods included questionnaires for 7-day food intake record, physical examination, and electrocardiography using World Health Organization criteria., Results: The prevalence of CAD, diabetes and glucose intolerance was significantly higher among subjects consuming lower intakes of dietary zinc. There was a higher prevalence of hypertension, hypertriglyceridemia and low high-density lipoprotein cholesterol levels which showed significant upward trend with lower zinc intakes. Serum lipoprotein (a) and 2-hour plasma insulin levels also were associated with low zinc intake. Multivariate logistic regression analysis after adjustment for age showed that zinc intake and CAD were inversely associated. Serum zinc (odds ratio:men 0.77, women 0.57), serum triglycerides (men 0.86, women 0.81), blood pressure (0.83 men, women 0.76), diabetes mellitus (men 0.90, women 0.85), central obesity (men 0.88, women 0.87), glucose intolerance (men 0.66, women 0.57) and low high-density lipoprotein cholesterol (men 0.72, women 0.70) were significant risk factors for CAD (explained by tertiles of zinc status) in urban subjects. These associations were not observed in rural subjects., Conclusion: Lower consumption of dietary zinc and low serum zinc levels were associated with an increased prevalence of CAD and diabetes and several of their associated risk factors including hypertension, hypertriglyceridemia and other factors suggestive of mild insulin resistance in urban subjects.

Chromium (Cr) improves the glucose/insulin system in subjects with hypoglycemia, hyperglycemia, diabetes and hyperlipemia with no detectable effects on control subjects. Chromium improves insulin binding, insulin receptor number, insulin internalization, beta cell sensitivity and insulin receptor enzymes with overall increases in insulin sensitivity. There have been several studies involving Cr supplementation of subjects with NIDDM and/or lipemia and most have reported beneficial effects of Cr on the glucose/insulin system. In a recent study, Chinese subjects with NIDDM were divided into three groups of 60 subjects and supplemented with placebo, 100 or 500 micrograms of Cr as chromium picolinate 2 times per day for 4 months. Improvements in the glucose/insulin system were highly significant in the subjects receiving 500 micrograms twice per day with less or no significant improvements in the subjects receiving 100 micrograms twice per day after 2 and 4 months. In summary, Cr is involved in the control of the glucose/insulin system and the amount, and likely form of chromium, are critical when evaluating the role of chromium in this system.