Albuminuria and Cardiovascular Events Biggest Threats to Patients in End-Stage Renal Disease

Denise Link, MPAS, PA-C, of the University of Texas Southwestern Medical Center in Dallas, and an expert in end-stage renal disease (ESRD), gave an informative educational track to physician assistants at AAPA 2017 on managing their patients with diabetes and chronic kidney disease (CKD).

According to data she presented from the US Renal Data System, more than 600,000 US adults have ESRD, and their treatment costs $75,000 per person, per year. This cost takes up 6% of the Medicare budget despite this patient population making up only 1% of Medicare’s population.

As an example, she illustrated a case presented as an abstract at last year’s Kidney Week on a commercial insurance plan comparing the standard of care for an individual with no CKD, one in Stage 3a CKD, and one in Stage 4 or Stage 5 CKD.

The individual with no CKD costs a private insurer, on average, $7500; the individual in Stage 3a CKD costs $27,200, and for the individual in Stage 4 or 5 CKD, the cost jumps to $77,000.

She told the attendees that most patients with Stage 3a and Stage 3b kidney disease do not die from kidney failure. In fact, the number of deaths between these 2 stages due to kidney failure drops significantly as the number of deaths from cardiovascular events, such as stroke, myocardial infarction, or heart failure, begin to increase. Patients with type 2 diabetes (T2D) and severe albuminuria are more likely to die from one of these cardiovascular events than they are to develop ESRD.

Therefore, treatment approaches need to take the risk factors for both organ systems into account, with the ultimate goals being to lower patients’ cardiovascular risk and simultaneously slow or halt their diabetic progression.

The greatest culprit leading up to ESRD, Link explained, is albuminuria. Albumin is a protein found in the blood, where it belongs. Once it is detected in the urine, however, the patient is on a pathway to kidney damage. When a patient has reached the level of severe albuminuria, she emphasized, the kidney is already damaged.

“Albumin in the urine is toxic to the kidney,” she warned the audience.

Severe albuminuria is defined as >300 mg/g, and moderate albuminuria as 30 mg/g to 299 mg/g in the presence of diabetic retinopathy and type 1 diabetes of at least 10 years’ duration. In most patients with diabetes, CKD should be attributable to that condition if one of these 2 definitions are met.

“Patients with diabetic kidney disease develop structural and functional changes,” Link explained. “Unfortunately, we can’t see the structural changes—those are based on a kidney biopsy. Please be aware, the structural changes happen before the function changes that you will see in clinical practice. By the time you see a diabetic kidney disease patient in clinical practice, there has already been damage done,” she emphasized.

“So though we have terms called ‘micro,’ please know that it’s not a small thing,” Link said. “Microalbuminuria is still a significant thing.”