Intensive glycemic control improved prognosis in patients on hemodialysis

Poor HbA1c predicted decreased cumulative survival rate.

Issue: August 2006

The use of tight glycemic control can improve the prognosis of patients with diabetes and chronic kidney disease who are undergoing regular hemodialysis, increasing evidence of the beneficial effects of strict glycemic control.

However, the chance of survival is still significantly lower for the patients receiving hemodialysis who initiated therapy with a poor HbA1c, according to the findings of the Osaka Diabetes and Dialysis Study 2 (ODDS-2).

“Even if a patient with diabetes is introduced to hemodialysis therapy due to the end-stage of diabetic nephropathy, proper glycemic control has an important impact on the prognosis of life,” said Masanori Emoto, MD, lecturer in metabolism, endocrinology and molecular medicine at the Osaka City University Graduate School of Medicine, Japan.

Emoto and colleagues published previous research from ODDS-1 that found that those patients with diabetes and chronic renal failure who had good glycemic control prior to initiation of hemodialysis had a higher survival rate after hemodialysis induction.

“Physicians need to keep on achieving good glycemic control in order to improve prognosis after hemodialysis induction as well as to prevent progression of diabetic nephropathy before hemodialysis induction,” Emoto said.

Regular hemodialysis

Masanori Emoto, MD [photo]
Masanori Emoto

Researchers enrolled 114 patients with diabetes and chronic kidney disease into the observational study. Participants had been undergoing regular hemodialysis for at least three months and had no acute illnesses. Eighty-six were men and 28 were women; 10 had type 1 diabetes. The mean age of participants was 60.8.

Participants were observed from May 1995 to December 2002. Regular hemodialysis was performed at 4-hour sessions three times a week.

Mean HbA1c prior to the observational period was used to evaluate glycemic control. Participants were divided into three groups according to their mean HbA1c level: good HbA1c <6.5%, fair HbA1c >6.5% to 8% and poor HbA1c >8%.

Seventy-two participants died during the study period. Those in the poor HbA1c group had a significantly lower cumulative survival, three-year survival and five-year survival than those in the fair and good groups.

chart

Unadjusted hazard ratios showed that age at entry and blood pressure were significant predictors of survival. The hazard ratio of the poor HbA1c group was 1.773 (95% CI, 1-3.145). However, when the data were adjusted for age at entry, sex, duration of hemodialysis and existence of cardiac diseases, the hazard ratio for this group increased to 2.889 (95% CI, 1.538-5.429).

“It was surprising that the hazard ratio per 1% HbA1c [1.26; 95% CI, 1.081-1.468], was statistically significant in a multivariate Cox hazard analysis, which indicates that a 1% increase of HbA1c increased the risk of death 26%,” Emoto told Endocrine Today.

The poor HbA1c group also had a higher incidence of cardiovascular or infectious diseases as the cause of death compared with the fair and good groups.

Emoto said patients on hemodialysis have many difficult problems to overcome, which may make focusing on tight glycemic control difficult. “Patients need to control body weight, volume intake, electrolytes and blood pressure while on hemodialysis,” Emoto said. “Furthermore, there are difficulties in achieving tight glycemic control due to increased risk of hypoglycemia, a high frequency of asymptomatic hypoglycemia due to severe diabetic autonomic neuropathy, loss of vision, and refusal by patients due to various psychological reasons.

“The final reason may be due to a decreased attention by medical staff, which is probably due to a lack of evidence about the clinical implications of tight glycemic control on quality of life, diabetic complications and life prognosis in patients with diabetes on hemodialysis,” he said. – by Leah Smith

For more information:

Oomichi T, Emoto M, Tabata T, et al. Impact of glycemic control on survival of diabetic patients on chronic regular hemodialysis. Diabetes Care. 2006;29:1496-1500.