Prognostic Tool Identifies Diabetes Patients At Risk of Kidney Failure

Although urinary albumin to creatinine ration (ACR) and estimated glomerular filtration rate are good biomarkers for detecting patients with diabetes who are at risk of kidney failure, they still miss many high-risk patients.

Scientists have created a new prognostic tool that accurately predicts the risk of end stage renal disease (ESRD) in patients withtype 1 and type 2 diabetes. The findings were published inKidney International.

The 2 biomarkers were often used by physicians to identify patients at a higher risk and to select patients for clinical trials. But scientists have said that the criteria miss many patients who are at high risk and fail to accurately predict time of onset of ESRD.

“Overall efficiency and cost effectiveness of clinical trials depends on the diagnostic tools used to enroll study patients,” said senior author Andrzej S. Krolewski, MD, PhD. “If you recruit people who are not at risk of progressing to ESRD during the clinical trial period, statistical power declines and you can’t prove anything.”

In 2012, Dr Krolewski found a link between tumor necrosis factor receptor 1 (TNFR1) and declining renal function in type 1 and 2 diabetes. Based on this finding, the investigators sought to translate the discovery into a practical prognostic test that physicians could use to assess care and enroll patients into clinical trials.

The investigators used data from patients with both diabetes types and stages III and IV chronic kidney disease. The participants had been enrolled in follow-up studies conducted by Dr Krolewski and were followed for 4 to 15 years.

They used classification and regression trees (CARTs) to identify specific values of biomarkers—the circulating level of TNFR1 and ACR combined. The findings were validated in a cohort of patients with type 2 diabetes.

The results of the study showed that the prognostic test for type 2 diabetes was similar to type 1 diabetes.

Overall, the composite prognostic criterion had a sensitivity value of 72% and a positive prognostic value of 81%, according to the study.

“Remarkably, when we used the TNF receptor to analyze risk of ESRD, the risk was almost identical for both type 1 and type 2 diabetes,” Dr Krolewski said. “This implies that the etiologies are similar. This is a very important observation because in the medical community, the impression is that the progression of ESRD in type 1 is somehow different from type 2. As a result, many clinical trials do not include patients with type 1.”

The investigators also applied the enrollment criterion to a hypothetical 3-year clinical trial to evaluate the impact of reducing sample size while increasing statistical power.

“Currently, about 80% of patients in these clinical trials provide no useful information,” Dr Krolewski said. “If our criterion is used in the recruitment of patients, you will not need 2 or 3 thousand patients for a clinical trial, you will only need 400 patients.”