Benefits of short-term professional continuous glucose monitoring in clinical practice.

BACKGROUND

The clinical utility of short-term professional continuous glucose monitoring (CGM) is uncertain.

SUBJECTS AND METHODS

This is a retrospective review of 121 consecutive insulin-treated patients seen in a university-based subspecialty clinic who completed a 72-120-h professional CGM study. Based on the indications for the study, patients were divided into three groups: hyperglycemia (Hyper) (n=51), widely fluctuating glycemia (Fluctuating) (n=50), or hypoglycemia (Hypo) (n=20). Hemoglobin A1c (A1c) was compared before and 3-6 months after CGM. Hypoglycemia frequency was recorded by patients' self-report.

RESULTS

Among the entire cohort, the A1c level dropped a small amount (0.18%; P=0.04). In the Hyper group, the A1c level fell from 9.0±1.1% to 8.6±1.2% (P<0.02). In the Fluctuating group, there was no change (from 8.0±1.0% to 8.0±0.9%). The A1c level of the Hypo group patients did not change (7.6±1.1% before and after), but 14 of 20 (70%; P<0.01) had a drop in self-reported frequency of hypoglycemia. For the whole cohort, the drop in A1c level was correlated with the initial A1c value (r=0.54, P<0.01). Patients with an initial A1c level of >9.0% saw a drop of 0.7% (from 10.2±1.1% to 9.4±1.1%; P<0.01), and those with an A1c level of >7.5% saw a drop of 0.4% (from 8.9±1.2% to 8.5±1.1%; P=0.01). Subgroup analysis showed that patients with type 1 diabetes had a drop in A1c level that was not statistically significant. However, type 1 diabetes patients in the Hypo group did have a decrease in self-reported hypoglycemia (11 of 16 [68%]; P=0.03).

CONCLUSIONS

Professional CGM can lead to a lowering of elevated A1c levels in insulin-treated patients, especially those with type 2 diabetes. There also appears to be benefit in decreasing self-reported hypoglycemia.