Elevated Urinary Cr Loss Induces a Reduction in Renal Cr Concentration and the Negative Cr Balance in Streptozotocin-Induced Diabetic Mice

Essential and Non-essential Elements in Scalp Hair of Diabetics: Correlations with Glycated Hemoglobin (HbA1c)

Essential elements (Ca, Mg, Zn, Cu, Fe, Cr, Mn and V) and non-essential elements (As, Cd, Hg and Pb) were measured in scalp hair samples of 45 diabetic subjects and 59 control subjects in Japan using inductively coupled plasma mass spectrometry. All diabetic subjects took insulin and/or antidiabetic agents, with glycated hemoglobin (HbA1c) ranging between 6.2 and 14.4%. The levels of Zn, Cu and Cr in the diabetic subjects (HbA1c>7) were significantly lower than those in the control subjects (p<0.05), and these concentrations decreased significantly with increases in HbA1c (p<0.01). The levels of Fe and Mg in the diabetic subjects were insignificantly lower, and the concentration of Fe decreased significantly with increases in HbA1c (p<0.05) and the concentration of Mn tended to decrease (p<0.10). In contrast, the concentration of As tended to increase with increases in HbA1c (p<0.10). The concentrations of other elements, such as Ca, Mn, V, Pb, Cd and Hg, in the diabetic subjects were similar to those of control subjects, and did not correlate with HbA1c. The average of estimated glomerular filtration rate (eGFR) in the diabetic subjects was 77.7±29.7 mL/min/1.73 m² with large variation (12.7-148 mL/min/1.73 m²), and previous study reported the increase of urinary excretion of Zn, Cr, Mn and Mg in diabetic subjects. The decreases of Zn, Cu, Cr, Fe and Mg concentrations in hair may reflect increased urinary excretion of these elements due to diabetic nephropathy.

Chromium(III) propionate complex supplementation improves carbohydrate metabolism in insulin-resistance rat model

The purpose of this study was to evaluate the antidiabetic potential and safety of the chromium(III) propionate complex (CrProp) in insulin resistance induced by a high-fructose diet in rats. The experiment was carried out on 32 nine-week old male Wistar rats divided into 4 groups of 8 rats each. Animals were fed at libitum: the control diet (AIN-93M), and high-fructose diets (HF) containing various levels of Cr(III) given as CrProp (1 mg Cr kg(-1) diet (HF) and supplemented with 10 mg Cr kg(-1) diet (HFCr10), or 50 mg Cr kg(-1) diet (HFCr50), equal to approx. 0.1, 1 and 5 mg kg(-1) body mass per day) for 8 weeks. It was found that supplemental CrProp improved carbohydrate metabolism indices (decreasing serum insulin levels and insulin resistance indices HOMA-IR and HOMA-B, while increasing insulin sensitivity index QUICKI). Supplemental CrProp did not affect overall nutritional indices, blood morphology, most of the toxicity indices, blood glucose and lipids levels, while it increased kidney Cr level (HFCr50), normalized decreased liver Cu concentrations, and decreased kidney Fe and Cu levels (HFCr50). Supplemental CrProp administered at 10- and 50-fold doses of the basal dietary Cr level has a significant antidiabetic effect in insulin resistant rats. However, a prolonged treatment with this compound can affect Fe status.