Abstract

High rate of asymptomatic hypoglycemia in insulin-treated diabetes with severe chronic kidney disease: Utility of flash interstitial glucose monitoring

Author(s): Connie Luo, Maria Ines Constantino, Margaret Joy McGill, Timothy Middleton, Ted Wu, Jencia Wong, Stephen Morris Twigg & P Jean Ho*

Objective: Insulin-treated diabetes patients with severe chronic kidney disease (CKD) commonly have reduced hypoglycemia awareness that can potentiate hypoglycemia risk. We assessed in such patients: whether flash interstitial glucose monitoring (iGM) measures correlate with capillary blood glucose (cBGL) levels, the prevalence of asymptomatic hypoglycemia, and if iGM usage may help decrease hypoglycemia occurrence.

Methods: Thirteen adult insulin-treated, CKD stage 4 or 5 diabetes patients with reduced hypoglycemia awareness, from a tertiary hospital diabetes renal clinic, participated in a familiarization program with Freestyle Libre Flash Glucose Monitoring for two 14-d periods (P), and insulin treatment was adjusted as indicated between periods.

Results: Initial HbA1c was 7.2 ± 1.4%. The iGM correlated with cBGL (n=480, r=0.86, p<0.0001). By Clarke error grid analysis: 93.3% of data points were in combined Zones A and B, and 4 data points in Zone E. All hypoglycemia (iGM or cBGL < 3.9 mM) was asymptomatic. More hypoglycemic events were detected by iGM than by cBGL (7.9 ± 7.8 events/14 d vs. 0.4 ± 0.8, iGM vs cBGL, p<0.01 in P1, 5.4 ± 3.6 events/14 d vs. 0.3 ± 0.6, iGM vs cBGL, p<0.001 in P2). Hypoglycemia time in P1, 6.2 ± 6.2% (0%-20.0%), and number of events, did not change in P2. Ten patients recorded hypoglycemia in P1: their time in hypoglycemia decreased from 8.0% ± 5.9% to 3.2% ± 2.8% (p=0.01) in P2.

Conclusions: In this patient group, iGM detected high rates of hypoglycemia; its use may help to decrease hypoglycemia and improve patient safety.