Nephropathy, Diabetic

Most common cause of end-stage renal disease in United States

Prior evidence of diabetes mellitus, typically more than 10 years duration

Incidence is about 30% in both types 1 and 2 diabetes mellitus

Males, African Americans, and Native Americans are at higher risk

Diabetic retinopathy is common

Microalbuminuria develops within 10–15 years after onset of diabetes and progresses over the next 3–7 years to overt proteinuria

Kidney size usually enlarged

First stage of diabetic nephropathy is hyperfiltration, with an increase in glomerular filtration rate (GFR), followed by the development of microalbuminuria (30–300 mg/day)

With progression, albuminuria increases to > 300 mg/day and can be detected on a urine dipstick as overt proteinuria; GFR subsequently declines over time

Renal biopsy is not required in most patients unless atypical findings are present

• Sudden onset of proteinuria

• Nephritic spectrum features

• Massive proteinuria (> 10 g/day)

• Urinary cellular casts

• Rapid decline in GFR

Patients with diabetes who require contrast imaging study

• Those with normal kidney function do not appear to be at increased risk for contrast nephropathy

• Patients at highest risk for radiographic contrast nephropathy are those with GFR < 30 mL/min/1.73 m²

• Adequate hydration can help prevent AKI: intravenous 0.9% (normal) saline, 1–3 mL/kg for 1–12 hours (usually 6 hours) administered both before and after the contrast

Microalbuminuria requires aggressive treatment

Strict glycemic control

Blood pressure goals should be tailored:

• 140/90 mm Hg in patients with microalbuminuria (30–300 mg/day) and preserved GFR and in patients with significant cardiovascular disease

• < 130/80 mm Hg in patients with overt proteinuria (especially when > 1 g/day)

ACE inhibitors and ARBs

• Recommended in those with microalbuminuria to

  • Lower the rate of progression to overt proteinuria

  • Slow progression to ESRD by reducing intraglomerular pressure and by antifibrotic effects

• Not absolutely indicated in diabetic patients with normal blood pressure and no microalbuminuria

• May provide benefit in patients with markedly diminished GFR

• With initiation or uptitration of therapy, close monitoring to exclude resultant hyperkalemia or decline in GFR of > 30%

• Combination ARB and ACE inhibitor therapy is not recommended due to lack of efficacy and increased adverse events (hyperkalemia and acute kidney injury)

Newer antidiabetic agents show early promise in slowing the progression of diabetic nephropathy, including

• Canagliflozin and empagliflozin (SGLT-inhibitors)

• Linagliptin (DPP-4 inhibitor)

• Liraglutide (GLP-1 receptor antagonist)

SGLT inhibitors should not be used in advanced chronic kidney disease

Treatment of other cardiovascular risk factors and obesity is crucial

Patients who are relatively healthy benefit from kidney transplantation