Hypoglycemia in Patients with Type 2 Diabetes Mellitus and Chronic Kidney Disease: A Prospective Observational Study

Background: Glycemic management in patients with type 2 diabetes mellitus (T2DM) and CKD can become complicated. One factor that may affect treatment is hypoglycemia. Hypoglycemia risk may be increased by several biologic processes in CKD. The objective of this study was to determine the frequency, severity, and risk factors for hypoglycemia in patients with T2DM and CKD.

Methods: The design was a prospective observational study. A continuous glucose monitor (CGM) was worn by 80 patients for up to 14 days; glucose was measured every 15 minutes. Patients with T2DM and eGFR <45 ml/min were enrolled. Patients on dialysis were excluded. The primary outcome was to assess the frequency of hypoglycemic episodes during the study period. Hypoglycemic episodes were defined as a reduced glucose concentration (<70 mg/dl) lasting ≥15 minutes. Secondary outcomes included assessment of severity of hypoglycemia and risk factors for its development.

Results: A total of 80 patients wore the CGM for a mean of 12.7±2.9 days. Hypoglycemic events occurred in 61 of 80 patients (76%) with glucose <70 mg/dl, and 49 of 80 (61%) with glucose <60 mg/dl. Prolonged hypoglycemic events (CGM glucose <54 mg/dl for ≥120 consecutive minutes) occurred in 31 patients (39%) with 118 total events. Most hypoglycemic episodes occurred overnight, from 1:00 am to 9:00 am. By multivariate analysis, lower hemoglobin A1c and treatment with insulin were two modifiable risk factors for hypoglycemic events.

Conclusions: Patients with T2DM and CKD have frequent periods of hypoglycemia that can be severe and prolonged. Hemoglobin A1c does not portray the full scope of hypoglycemia risk. This study illustrates the need for careful monitoring of glucose levels in patients with T2DM and CKD.