Assessing glycemic control in maintenance hemodialysis patients with type 2 diabetes

Abstract

Objective: Optimizing glycemic control in diabetic patients undergoing maintenance hemodialysis requires accurate assessment. We hypothesize that 1) 48-h continuous glucose monitoring (CGM) provides additional, clinically relevant, information to that provided by the A1C measurement and 2) glycemic profiles differ significantly between day on and day off dialysis.

Research design and methods: With the use of GlucoDay S, 48-h CGM was performed in 19 type 2 diabetic subjects undergoing hemodialysis to capture consecutive 24-h periods on and off dialysis. Energy intake was calculated using food diaries. A1C was assayed by a high-performance liquid chromatography method.

Results: CGM data were available for 17 subjects (13 male) with a mean (range) age of 61.5 years (42-79 years) and diabetes duration of 18.8 years (4-30 years). The 24-h CGM area under the glucose curve and 24-h mean glucose values were significantly higher during the day off dialysis than on dialysis (5,932.1 +/- 2,673.6 vs. 4,694 +/- 1,988.0 mmol x 3 min(-1) x l(-1), P = 0.022, and 12.6 +/- 5.6 vs. 9.8 +/- 3.8 mmol/l, P = 0.013, respectively), independent of energy intake. Asymptomatic hypoglycemia occurred in 4 subjects, 3 within 24 h of dialysis, and the glucose nadir in 14 subjects occurred within 24 h of dialysis.

Conclusions: Glucose values are significantly lower on dialysis days than on nondialysis days despite similar energy intake. The risk of asymptomatic hypoglycemia was highest within 24 h of dialysis. Physicians caring for patients undergoing hemodialysis need to be aware of this phenomenon and consider enhanced glycemic monitoring after a hemodialysis session. CGM provides glycemic information in addition to A1C, which is potentially relevant to clinical management.

Figures

Figure 1

CGM data for day on (day 1) and day off (day 2) dialysis, expressed as AUC glucose (A) and mean glucose (B) for each 24-h period. ▲—▲, data for individual subjects; ■, mean ± SD for each 24-h period. A: Mean ± SD area under the 3-min glucose curve for the whole study group was 5,932.1 ± 2,673.6 mmol · 3 min−1 · l−1 on the day off dialysis vs. 4,694 ± 1,988 mmol · 3 min−1 · l−1 on the day on dialysis (P = 0.022). B: Mean ± SD CGM glucose values for the whole group were 12.6 ± 5.6 mmol/l on the day off dialysis vs. 9.8 ± 3.8 mmol/l on the day on dialysis (P = 0.013).

Figure 2

Nocturnal CGM data for the 6-h period from midnight to 6:00 a.m. for day on (night 1) and day off (night 2) dialysis, expressed as AUC glucose (A) and mean glucose (B). ▲—▲, data for individual subjects; ■, mean ± SD for each 24-h period. A: Mean ± SD area under the 3-min glucose curve for the whole study group was 1,541 ± 834 mmol · 3 min−1 · l−1 for the night of the day off dialysis (night 2) vs. 1,137 ± 529 mmol · 3 min−1 · l−1 for the night of the day on dialysis (night 1) (P < 0.05). B: Mean ± SD CGM glucose values for the whole group were 12.9 ± 7.0 mmol/l on night 2 vs. 9.5 ± 4.4 mmol/l on night 1.