Effects of chronic chromium picolinate treatment on glycemic control and kidney function of db/db mice

Previous studies suggest a clastogenic effect of chromium picolinate (Cr(Pic)3). We tested the hypothesis that Cr(Pic)3 improves glycemic status accompanied by decreased renal accumulation and excretion of 8‐hydroxy deoxyguanosine (8‐OHdG). Male db/db mice were fed diets lacking or containing 5 or 100 mg/kg chromium (as Cr(Pic)3) from 6‐24 weeks of age; lean nondiabetic db/m mice served as controls. The untreated db/db mice displayed marked elevation in hemoglobin A1c than db/m controls. The db/db mice fed the 100 (but not 5) mg/kg diet displayed lower hemoglobin A1c (p<0.05). As expected, total proteinuria and albumin excretion were significantly greater in db/db than db/m mice; Cr(Pic)3 reduced total protein and albumin excretions in db/db mice. Urinary excretion of 8‐OHdG was also significantly higher in the untreated db/db than db/m mice and dietary Cr(pic)3 treatment reduced urinary 8‐OHdG excretion. Renal tubular cells of the db/db kidney showed moderate‐intense immunoreactivity for 8‐OHdG in the form of cytoplasmic microgranules. Interestingly, renal tissue of the Cr(Pic)3‐treated db/db mice showed a decrease in the intensity of staining for 8‐OHdG than those of untreated db/db mice. Taken together, the data suggest that while Cr(Pic)3 does not increase the propensity for oxidative DNA damage, it exerts dose‐dependent effects on glycemic control and kidney function in db/db mice. Supported by NIH.