Reversing Kidney Disease in Diabetes
For the thousands of Americans living with type 1 diabetes, new research helps shatter a commonly held notion that elevated protein levels in the urine signal the first step in the inexorable decline in kidney function, ultimately leading to kidney failure.
In a study of 386 patients with type 1 diabetes, individuals with microalbuminuria–leakage of small amounts of proteins from the blood into the urine–who obtained early diagnosis through frequent screening and maintained very good levels of blood sugar, blood pressure, and cholesterol actually promoted the healing process and in some cases reversed kidney complications. The six-year study, recently published in the New England Journal of Medicine, once again underscores the critical importance of early detection and aggressive intervention in preventing complications of the disease. Emerging studies continue to shed light on important risk factors that may slow and, in some cases, reverse the process by repairing initial damage to the kidneys due to diabetes.
To learn more about the study and lifestyle measures that individuals with diabetes can take to reduce the risk of kidney disease, the Post spoke with one of the paper’s lead authors, Bruce Perkins, M.D., M.P.H., F.R.C.P.C., assistant professor of medicine at University of Toronto.
Post: Could you discuss the toll that diabetes can exact on kidney function?
Perkins: The effect that diabetes has on the kidneys is a major public health issue. One in three patients with type 1 diabetes develops end-stage kidney failure, which eventually requires either a kidney transplant or hemodialysis treatment for life. These treatments have a dramatic impact on the quality of life of patients and on the economics of care delivery.
The key to intervention is prevention. In a major finding over 15 years ago, researchers noted that when microalbuminuria develops, it is the most important predictor for the risk of progressing to kidney disease in patients with diabetes. It has become a very crucial measure in the care of patients; as a result of that research, it is recommended that all patients with diabetes be screened on a yearly basis for microalbuminuria by providing at least one urine sample to their diabetes care doctor. Until now, when microalbuminuria was diagnosed, it was believed that one could only hope to postpone–but not prevent–kidney disease by intensified efforts to control blood sugar and treatment with certain blood pressure drugs.
To determine if these initial studies overestimated the risk, we investigated the finding at the Joslin Diabetes Center. The principal investigator of this study, Andrzej Krolewski, M.D., Ph.D., head of the section on genetics and epidemiology at Joslin, designed a very large clinical study to look at patients with type 1 diabetes who develop microalbuminuria to learn how their disease progresses and to determine the important risk factors for developing kidney disease. His research group has been following these patients since 1991.
Under the hypothesis that there are unique mechanisms that the body possesses to repair an injury to the kidneys caused by diabetes, we studied whether it is possible, under certain conditions, to reverse microalbuminuria. Recognizing these “salutary” factors that lead to kidney repair would greatly aid in developing better clinical strategies for preventing diabetes complications.
Post: Could you tell us about the major findings of the study, which was published in the NEJM?
Perkins: First, in the earliest stages of kidney disease caused by type 1 diabetes, we found that kidney injury is still a dynamic process that can either get worse or get better–even revert back to normal. In fact, the leakage of protein subsided in 58 percent of the patients we studied, even among those who were not taking ACE inhibitors, a type of drug known to be helpful in people with microalbuminuria.