Use of continuous glucose monitoring in patients with diabetes on peritoneal dialysis: poor correlation with HbA1c and high incidence of hypoglycaemia.

BACKGROUND

Achieving adequate glycaemic control in patients with diabetes on peritoneal dialysis is challenging. Traditional assessment of glycaemia using HbA1c is difficult in such patients because of renal anaemia or carbamylation of haemoglobin, and significant glucose excursions may be masked. We describe three patients with diabetes on peritoneal dialysis with similar HbA1c levels, but with very different glucose profiles shown on continuous glucose monitoring.

CASE REPORTS

Patient 1 was treated with gliclazide, and had a number of solutions with high glucose concentration in his dialysis prescription. Continuous glucose monitoring showed glucose levels > 11 mmol/l for > 17 h per day, and < 4 mmol/l for 72 min per day with no symptoms. His HbA1c level was 61 mmol/mol (7.7%). Patient 2 was treated with insulin. Continuous glucose monitoring showed glucose levels > 11 mmol/mol for 3.8 h per day, and < 4 mmol/mol for 3.8 h per day. His HbA1c level was 59 mmol/mol (7.6%). Patient 3 was treated with pioglitazone and gliclazide, and glucose levels were > 11 mmol/l for 8 h per day and < 4 mmol/l for 1.6 h per day. His HbA1c was 62 mmol/mol (7.8%). None of the patients was aware of hypoglycaemia during the periods of low glucose recorded on continuous glucose monitoring.

CONCLUSION

Despite similar HbA1c levels, our three patients had very different glucose profiles. These cases highlight the fact that HbA1c is frequently inadequate in reflecting glucose control in patients with diabetes on peritoneal dialysis, and we suggest that intermittent continuous glucose monitoring may allow safer management of glycaemia in such patients.