CGM is commonly used in the management of Type 1 diabetes. Experience in T2DM is limited.
To determine the utility of CGM in T2DM.
6-day data from the Medtronic iPRO-Carelink CGM was audited from 37 consecutive subjects with poorly-controlled T2DM attending Blacktown Hospital between September 2015-April 2016. Subjects simultaneously self-monitored blood-glucose(SMBG) 4 times/day. Clinical and biochemical information was obtained from hospital records.
57% of subjects were male, mean age 64.7yrs. 80% had T2DM>10yrs. All but one were using insulin, average total daily dose 89U/day±59U. Insulin treatment: 69% basal-bolus, 22% pre-mixed. Additional oral agents: sulphonylureas 6%, metformin 61%, SGLT2-i 17%, DPPIV-i 6%.
There was no difference between mean(±SEM) glucose on CGM vs SMBG (10.1±0.42 vs 10.2±0.46 mmol/L, p=0.6). However mean lowest CGM-glucose level was significantly lower than SMBG(4.3±0.25 vs 5.1±0.29 mmol/L, p<0.01) and mean highest CGM-glucose was higher than SMBG(18.8±0.67 vs 17.3±0.73 mmol/L, p<0.01). In total, CGM detected 62 episodes of glucose<4.0mmol/L compared to 22 episodes from SMBG. Of the 40 excess episodes detected by CGM, 34 occurred in 4 patients. At least 1 episode of hypoglycaemia was detected in 40% of subjects using CGM compared to 31% using SMBG. No severe hypoglycaemia(glucose<2.5mmol/L) was detected by SMBG, but CGM revealed 5 episodes, all occurring in 3 subjects. 438 episodes of hyperglycaemia(glucose>10.0mmol/L) were recorded on CGM vs 407 by SMBG.
To date, 27 subjects have post-CGM management information recorded. CGM prompted a decrease in insulin dose in 9 subjects and an increase in 12. 1 further subject had redistribution of daily insulin dose and another switched from pre-mixed to basal-bolus. Changes to diet and activity were recommended in 11 subjects, based on CGM.
CGM detects unrecognised glycaemic excursions and has clinical utility in influencing both pharmacological and lifestyle management in T2DM.