Acute renal failure in diabetics

Renoprotective effects of asialoerythropoietin in diabetic mice against ischaemia-reperfusion-induced acute kidney injury

AIM

Diabetic patients are at higher risk of failure to recover after acute kidney injury, however, the mechanism and therapeutic strategies remain unclear. Erythropoietin is cytoprotective in a variety of non-haematopoietic cells. The aim of the present study was to clarify the mechanism of diabetes-related acceleration of renal damage after ischaemia-reperfusion injury and to examine the therapeutic potential of asialoerythropoietin, a non-haematopoietic erythropoietin derivative, against ischaemia-reperfusion-induced acute kidney injury in diabetic mice.

METHODS

C57BL/6J mice with and without streptozotocin-induced diabetes were subjected to 30 min unilateral renal ischaemia-reperfusion injury at 1 week after induction of diabetes. They were divided into four group: (i) non-diabetic plus ischaemia-reperfusion injury; (ii) non-diabetic plus ischaemia-reperfusion injury plus asialoerythropoietin (3000 IU/kg bodyweight); (iii) diabetic plus ischaemia-reperfusion injury; and (iv) diabetic plus ischemia-reperfusion injury plus asialoerythropoietin. Experiments were conducted at the indicated time periods after ischaemia-reperfusion injury.

RESULTS

Ischaemia-reperfusion injury of diabetic kidney resulted in significantly low protein expression levels of bcl-2, an anti-apoptotic molecule, and bone morphogenetic protein-7 (BMP-7), an anti-fibrotic and pro-regenerative factor, compared with non-diabetic kidneys. Diabetic kidney subsequently showed severe damage including increased tubular cell apoptosis, tubulointerstitial fibrosis and decreased tubular proliferation, compared with non-diabetic kidney. Treatment with asialoerythropoietin induced bcl-2 and BMP-7 expression in diabetic kidney and decreased tubular cell apoptosis, tubulointerstitial fibrosis and accelerated tubular proliferation.

CONCLUSION

Reduced induction bcl-2 and BMP-7 may play a role in the acceleration of renal damage after ischaemia-reperfusion injury in diabetic kidney. The renoprotective effects of asialoerythropoietin on acute kidney injury may be mediated through the induction of bcl-2 and BMP-7.

Hematuria in children and adolescents with insulin-dependent diabetes mellitus

Hematuria is not described as a common finding in diabetic nephropathy, and may suggest nondiabetic renal disease. We reviewed the records of 59 children and adolescents with insulin-dependent diabetes mellitus referred to the Children's Kidney Center from 1983 to 1992. Fifty-two patients had clinical and/or biopsy evidence of diabetic nephropathy; 18/52 (35%) had microscopic hematuria at the time of referral. Patients with hematuria on presentation were referred for: hypertension (61%), proteinuria (61%), and decreased glomerular filtration rate (GFR) (11%). For patients without hematuria on presentation, reasons for referral included hypertension (79%), proteinuria (56%), and decreased GFR (3%). When comparing patients with and without hematuria, those with hematuria had a significantly longer duration of diabetes (12.8 +/- 3.1 versus 10.8 +/- 3.7 years, p < 0.05). The groups did not differ significantly with regard to age (18.3 +/- 1.8 versus 17.1 +/- 2.9 years), height (162.2 +/- 10.4 versus 159.3 +/- 11.3 cm), weight (63.9 +/- 10.9 versus 59.4 +/- 14.8 kg), systolic blood pressure (137.2 +/- 11.9 versus 133.2 +/- 13.2 mm Hg), diastolic blood pressure (85.6 +/- 7.6 versus 83.9 +/- 13.4 mm Hg), serum creatinine (1.0 +/- 0.18 versus 1.0 +/- 0.43 mg/dL), blood urea nitrogen (15 +/- 5 versus 13 +/- 4 mg/dL), glomerular filtration rate (117 +/- 34 versus 117 +/- 46 mL/min/1.73 m2), 24-h urine protein (2311 +/- 3862 versus 570 +/- 476 mg/day), or microalbuminuria (75 +/- 41 versus 34 +/- 35 micrograms/min). We detected a significant association between retinopathy and microscopic hematuria (sensitivity 47%, specificity 82%, p < 0.05), but no association between labstix proteinuria or sex and hematuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonketotic hypertonicity in diabetes mellitus

Nonketotic hypertonicity (NKH) is one of the most common endocrine emergencies. It is more common in the elderly patient with noninsulin-dependent diabetes mellitus but may occur in insulin-dependent diabetes as well. Although there are many possible precipitating causes, the final common pathway is usually decreased access to water. Treatment consists of vigorous hydration, electrolyte replacement, and small amounts of insulin. Most deaths from NKH occur in the first 2 days of hospitalization; therefore, a significant decrease in morbidity and mortality can be expected by education of patients and their caregivers in the prevention of NKH.