Insulin-treated diabetes patients with severe chronic kidney disease (CKD) often have reduced awareness of hypoglycaemia that can lead to severe consequences, including death. This study addressed whether capillary blood glucose measures correlate with flash interstitial glucose monitoring (iGM) levels in ambulatory patients with insulin-treated diabetes (on 2 or more injections/d) who have CKD stage 4 or 5, and assessed the frequency of asymptomatic hypoglycaemia in this cohort. The iGM was performed in 13 patients (8F/5M, aged 72 ±10 y) for two consecutive 14d periods, during which capillary BGL was measured as per the patients’ usual routine. Insulin therapy was adjusted between periods using iGM results.
Twelve patients had type 2 and one had type 1 diabetes, of 24 ± 7 y duration. Four patients were receiving haemodialysis while 9 had eGFR 21 ± 4 mL/min/1.73 m2. All had reduced hypoglycaemia awareness, per Clarke1. The HbA1c was 7.2 ± 1.4% (56 ± 15mmol/mol) and serum fructosamine was 351 ± 68 µM (ref: 200-290µM). There was a statistically significant correlation between iGM and capillary glucose (n=479 data points, r=0.86, p<0.0001). In Period 1, more asymptomatic hypoglycaemia events were detected by iGM than by capillary BGL (5.7 ± 6.4 vs. 0.3 ± 0.9, p <0.05). Percentage of time below target (<5.0 mM) was also high at 13.9 ± 13.0%. Patients were at 5.0-10.0 mM for only approximately half the time. Insulin dosage was decreased between the periods; however there was no statistically significant change in the number of hypoglycaemic events and time below /in target glycaemia.
This study indicates that flash interstitial glucose monitoring is valuable in detecting occult hypoglycaemia in insulin-treated patients with severe CKD. Adjustment of insulin treatment with iGM over a longer period than in this study would be expected to decrease occult hypoglycaemia and improve patient safety.