Efficacy of self-monitoring of blood glucose versus retrospective continuous glucose monitoring in improving glycaemic control in diabetic kidney disease patients.

Aims: Patients with diabetic kidney disease (DKD) on anti-diabetic agents, are at greater risk of glycemic variations, both hypoglycemia and hyperglycemia. We aimed to compare glycemic control (using HbA1c) and hypoglycemia incidence in patients with Stage 3 DKD (eGFR 30-60 mL/min per 1.73 m ), receiving retrospective CGM-guided anti-diabetic therapy versus self-monitoring of blood glucose (SMBG) over 3 months.

Methods: Thirty patients with HbA1c >8% were randomized to 6-day retrospective CGM or SMBG. In the CGM group, CGM was worn at the beginning and 6 weeks. HbA1c, assessment of hypoglycaemia events (self-reported and BG < 4 mmol/L from CGM/SMBG data) and medication adjustment were performed at baseline and 3 months. All patients received education on hypoglycaemia avoidance.

Results: Fourteen patients were allocated to CGM and 16 to SMBG. Mean (±SD) eGFR was 42.9 ± 10.3 mL/min. Majority (86.7%) of patients had diabetes duration >10 years and on insulin therapy (90%). HbA1c improved significantly from baseline 9.9 ± 1.2 to 9.0 ± 1.5% (P < 0.001) at 3 months, with no difference between CGM (9.8 ± 1.2 to 8.8 ± 1.8%, P = 0.009) or SMBG (9.9 ± 1.3 to 9.1 ± 1.1%, P = 0.007) groups (P = 0.869 between groups). In the CGM group, percentage duration in hyperglycaemia (BG > 10 mmol/L) reduced from baseline 65.4 ± 22.4% to 54.6 ± 23.6% (P = 0.033) at 6 weeks, with a non-significant rise in percentage duration in hypoglycaemia from 1.2 ± 2.2% to 4.0 ± 7.0% (P = 0.176). There was no difference in self-reported and documented hypoglycaemia events.

Conclusion: In a pilot study of DKD patients, short-term episodic use of CGM reduced time spent in hyperglycaemia range without significantly increasing time-exposure to hypoglycaemia. However, both CGM and SMBG were equally effective in improving glycaemic control.