Bakhshaei, Sina

Hyperuricemia is described as a serum uric acid level more than 6.0 mg/dL. It is demonstrated by basic research and clinical studies, which the elevation of uric acid level may change the renal histology and function by developing acute and chronic kidney diseases (CKDs), diabetic nephropathy and end-stage renal disease (ESRD). There is no doubt about a significant relationship between uric acid and renal impairment. However, the details of this correlation, especially; between uric acid and renal failure, are discussable. Renal vasoconstriction, antiangiogenic properties, endothelial dysfunction, proinflammatory properties, renal fibrosis, pro-oxidative properties, and alteration of renal autoregulation are the most common mechanisms, which approve the association between uric acid and renal impairment. Allopurinol administration for CKD treatment in patients with gout is one of the most discussable challenges. It should be investigated whether allopurinol can diminish the deterioration of the glomerular filtration rate (GFR) in CKD patients who are at risk of ESRD. Some previous studies reported that allopurinol decreases the CKD incident risk, but others could not confirm this association. The benefit or risks of allopurinol in different stages of CKD, dialysis, and renal transplant are discussed in this study.

High blood pressure is a potential adjustable risk factor for vascular complications of diabetes. Numerous categories of anti-hypertensive medications have proven to effectively reduce these complications. Additionally, metformin, besides lowering glucose and lipid levels, has advantages on vascular blood flow and improving endothelial function. In this review, we investigate the potential benefits of metformin in lowering blood pressure. Previous studies suggested that the administration of metformin to non-diabetic patients could efficiently reduce systolic blood pressure. The whole comparison of the evidence shows that metformin may have small effects on lowering blood pressure; however, this effect is not directly via a change in sympathetic activity. Mechanisms of blood pressure reduction by metformin may be due to its indirect effects on insulin resistance, nephroprotective, cardioprotective, improvement of the sympatric nerve system, and endothelial function.