Kidney Failure Risk in Diabetic Patients

Q: I have many diabetic patients who do not monitor their blood sugars or watch their diet. I try to encourage them to manage their diabetes better to decrease their risk for kidney disease, blindness, or amputation. But they want to know what are their chances of ending up on dialysis. What percentage of patients develop kidney failure? What can I say to encourage my patients to take better care of themselves?

Diabetes is an epidemic in the United States and worldwide. It is the leading cause of chronic kidney disease and kidney failure.¹ Diabetes is the primary diagnosis for about 44% of US patients who start dialysis, and hypertension for about 28%.²

Chronic kidney disease (CKD) can be viewed as a spectrum, ranging from mild (glomerular filtration rate [GFR] ≥ 60 mL/min/1.73 m²) to severe (GFR < 15 mL/min/1.73 m², also referred to as end-stage renal disease [ESRD]).

A diabetic patient’s likelihood of developing diabetic nephropathy (DN) varies by race and geographic location. For patients with type 2 diabetes (T2DM), the rate is 5% to 10% for white patients and 10% to 20% for African-Americans.³ Hispanic patients develop DN at 1.5 times the rate among non-Hispanic whites.¹ In the Pima Indians, who live primarily in Arizona, the incidence of DN approaches 60%. For patients with type 1 diabetes, the incidence of DN is 30% to 40%.¹

While not all patients progress to ESRD, they are at increased risk for renal and cardiovascular complications, compared with nondiabetic patients.¹ In general, about one in three patients with diabetes will develop significant nephropathy during the five to 10 years following diagnosis. For many years, microalbuminuria has been considered a predictor of renal disease progression.⁴

Previously, it was thought that patients with T2DM were more likely to die of cardiovascular complications than to progress to ESRD and require renal replacement therapy (RRT). However, researchers recently showed that patients with T2DM, DN, and proteinuria were more likely to progress to ESRD than to die of other complications.⁵

Given the alarming increase in the incidence of diabetes and diabetic kidney disease, a tool to predict the likelihood of an individual patient’s risk for kidney failure would be extremely helpful. As there are no widely accepted predictive instruments for CKD progression, providers must make ad hoc decisions about patients. This practice can result in treatment delays for patients whose disease does progress or unnecessary treatments for patients unlikely to experience kidney failure.⁶

In 2011, Tangri et al⁷ published a predictive model for patients with stages 3 to 5 CKD. The model relies on demographic data and clinical laboratory markers of CKD severity to accurately predict risk for future kidney failure. The study is available at http://jama.ama-assn.org/content/305/15/1553.long,⁷ and a smartphone app can be accessed at www.qxmd.com/Kidney-Failure-Risk-Equation.

To improve patient compliance, however, I would suggest the following steps:

• Ask yourself, “Does my patient perceive there is a problem?” Assess the patient’s readiness to modify behavior.⁸
• Target no more than one behavior change at each visit.
• Find at least one reason to praise the patient at each visit (eg, remembering to bring his/her glucose log, keeping the scheduled appointment, initiating an exercise program, cutting down on cigarettes).
• Use diabetes educators to reinforce teaching.
• Suggest that your patient join the ADA. The more interested and informed patients become about this chronic illness, the more likely they are to become active participants in their own long-term care.

Wanda Y. Willis, MSN, FNP-C, CNN, Renal nurse practitioner
Washington Nephrology Associates, LLC
Takoma Park, Maryland

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