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

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.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  11 mmol/mol for 3.8 h per day, and  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.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.