Department of Family and Community Medicine, The Ohio State University, Columbus (Dr. Ahmad); Department of Family Medicine, Cleveland Clinic, OH (Dr. Goldman) faraz.ahmad@osumc.edu
The authors reported no potential conflict of interest relevant to this article.
Annual screening of urinary parameters, ongoing clinical vigilance, and proper medical therapy can help to keep declining renal function at bay.
Chronic kidney disease (CKD) is a significant comorbidity of diabetes mellitus. The Kidney Disease Outcomes Quality Initiative (KDOQI) of the National Kidney Foundation defines CKD as the presence of kidney damage or decreased kidney function for ≥ 3 months. CKD caused by diabetes is called diabetic kidney disease (DKD), which is 1 of 3 principal microvascular complications of diabetes. DKD can progress to end-stage renal disease (ESRD), requiring kidney replacement therapy, and is the leading cause of CKD and ESRD in the United States.1-3Studies have also shown that, particularly in patients with diabetes, CKD considerably increases the risk of cardiovascular events, which often occur prior to ESRD.1,4
This article provides the latest recommendations for evaluating and managing DKD to help you prevent or slow its progression.
Defining and categorizing diabetic kidney disease
CKD is defined as persistently elevated excretion of urinary albumin (albuminuria) and decreased estimated glomerular filtration rate (eGFR), or as the presence of signs of progressive kidney damage.5,6 DKD, also known as diabetic nephropathy, is CKD attributed to long-term diabetes. A patient’s eGFR is the established basis for assignment to a stage (1, 2, 3a, 3b, 4, or 5) of CKD (TABLE 17) and, along with the category of albuminuria (A1, A2, or A3), can indicate prognosis.
Taking its toll in diabetes
As many as 40% of patients with diabetes develop DKD.8-10 Most studies of DKD have been conducted in patients with type 1 diabetes (T1D), because the time of clinical onset is typically known.
Type 1 diabetes.DKD usually occurs 10 to 15 years, or later, after the onset of diabetes.6 As many as 30% of people with T1D have albuminuria approximately 15 years after onset of diabetes; almost one-half of those develop DKD.5,11 After approximately 22.5 years without albuminuria, patients with T1D have approximately a 1% annual risk of DKD.12
Type 2 diabetes (T2D). DKD is often present at diagnosis, likely due to a delay in diagnosis and briefer clinical exposure, compared to T1D. Albuminuria has been reported in as many as 40% of patients with T2D approximately 10 years after onset of diabetes.12,13
Multiple risk factors with no standout “predictor”
Genetic susceptibility, ethnicity, glycemic control, smoking, blood pressure (BP), and the eGFR have been identified as risk factors for renal involvement in diabetes; obesity, oral contraceptives, and age can also contribute. Although each risk factor increases the risk of DKD, no single factor is adequately predictive. Moderately increased albuminuria, the earliest sign of DKD, is associated with progressive nephropathy.12