A Better Marker of Glycemic Control
PHILADELPHIA—Serum fructosamine (SF) may be a better marker of glycemic control than glycosylated hemoglobin (HbA1c) in diabetic patients on hemodialysis, new data suggest.
SF reflects the previous 21 days of glycemic control compared with 60-90 days with HbA1c. Researchers at Long Island College Hospital in Brooklyn, N.Y., believe that HbA1c levels significantly underestimate glycemic control in diabetic hemodialysis patients because of shortened red blood cell (RBC) survival and high RBC turnover due to repeated erythropoietin (EPO) dosing. The researchers previously have reported that SF, when corrected for serum proteins levels, appears to be a reliable index of glycemic control.
The new study examined the relationship of cumulative EPO dosing with HbA1c and SF in 94 diabetic and 100 non-diabetic hemodialysis patients. Demographic and clinical data were recorded, including total EPO dose administration during the four weeks preceding enrollment. SF values were corrected serum albumin concentration. The study population had a mean age of 60 years (range 20-93 years), was 53% were female and 77% were African American. The mean dialysis vintage was 51 months at enrollment.
As the investigators expected, HbA1c correlated positively with SF and with albumin-corrected SF. The total monthly EPO dose, however, was inversely related to HbA1c levels but not to SF or albumin-corrected SF. “This is the first time this has been shown, so there needs to be further study before there could be a change in guidelines,” said study investigator Hiteshkumar Kapupara, MD, a 3rd year resident.
By changing the glycemic indices that are used, it may be possible to lower overall health care costs and improve quality of life in diabetic hemodialysis patients, said lead investigator Neal Mittman, MD, associate professor of clinical medicine.
“Better indices are unquestionably needed, and our work suggests that SF may be one potential answer,” Dr. Mittman said. “There was a recent report that glycated albumin may be better than A1c in this population, but this test is not routinely available in this country. SF, on the other hand, has been widely available through the large laboratory providers, and would certainly be cost-effective if our results are confirmed.”