Feb. 25 (HealthDay News) -- The current standard test for measuring blood sugar control in people with diabetes gives inaccurate results for people on kidney hemodialysis, a U.S. study finds.

Hemodialysis, used to treat patients with kidney failure, involves cleansing blood by circulating it through an artificial kidney machine.

This Wake Forest University Baptist Medical Center study of 307 diabetes patients -- 258 with end-stage kidney disease and 49 who didn't have kidney failure -- found that the HbA1c test underestimated true glucose control in hemodialysis patients. The report is published in the journal Kidney International.

These results suggest that the almost 200,000 diabetic hemodialysis patients in the United States who use this test may not be receiving optimal care for their blood sugar, study senior author Dr. Barry J. Freedman, a professor of internal medicine and nephrology, said in a prepared statement.

Diabetic patients on hemodialysis who believe their blood sugar levels are in the ideal range may actually have unacceptably high blood sugar levels, he noted.

"This was a surprise to the nephrology community. The test we've all come to accept as the gold standard has proven to be inaccurate in this patient population," Freedman said.

He said doctors and patients need to be aware that the HbA1c test underestimates glucose control.

This study was funded by Asahi Kasei Pharma Corp. of Japan, which makes a newer test that measures the amount of blood sugar that's reacted with albumin, a protein in the plasma. The GA (glycated albumin) test is not available in the United States.

SOURCE: Wake Forest University Baptist Medical Center, news release, February 2008