Assessment of Glycemic Control in Patients With Type 2 Diabetes Mellitus and Late Stage Chronic Kidney Disease

Diabetes control is often assessed by tests of glucose levels over time, such as the glycosylated hemoglobin A1c (HbA1c) and fructosamine. In the later stages of chronic kidney disease (CKD) there is limited data available on the utility of these tests. There are reasons to believe that the tests may be less accurate in this population. Continuous glucose monitoring (CGM) offers an effective method for understanding the totality of glucose exposure and incidence of both hyperglycemic and hypoglycemic excursions.

In the proposed study Investigator plan to utilize CGM in patients with late stage CKD stages 3b-5 to 1) determine accuracy of HbA1c and serum fructosamine testing as measures of glucose control in patients with Type 2 Diabetes Mellitus (T2DM), 2) Better understand test characteristics in the late stage CKD population (correlation, linear equation, slope, Y intercept, average glucose at different HbA1c levels), 3) Develop a preliminary understanding of how test characteristics differ in late stage CKD compared to other patients with diabetes, 4) quantify time burden and number of episodes of hypoglycemia, 4) study hyperglycemic burden and 5) analyze glucose variability. The research staff will explain the study to patients that meet all inclusion criteria. Patients will get time to understand the study, review the consent document, ask questions to the PI, and then provide their consent to participate in the study. On Day 1 of the study, a CGM (Freestyle Libre) device will be placed on patients with CKD 3b-5 which will be worn for 14 consecutive days. Patients will return on Day 14 to remove the CGM device. HbA1c and fructosamine values will be drawn on Day 14 and these results will be compared with average glucose monitoring values as recorded on the CGM device. Incidence, duration, and severity of both hypoglycemic and hyperglycemic events will be analyzed. Investigators hypothesis that there will be significant variability in the serum HbA1c values when compared with calculated HbA1c from CGM readings. Investigators also hypothesize that the results will reflect a greater incidence of hypoglycemia in this population by CGM analysis.