Frequency of Hypoglycemia Assessed by Continuous Glucose Monitoring in Advanced CKD

Abstract

Background Hypoglycemia represents a risk for serious morbidity. We evaluated the prevalence and risk factors of hypoglycemia by continuous glucose monitoring (CGM) in patients with CKD with or without diabetes. Methods In this cross-sectional study, outpatients with CKD stages G3–G5 (including hemodialysis) and type 2 diabetes without CKD were enrolled and underwent intermittently scanned CGM measurements for 7 days. The burden of CGM-measured hypoglycemia was assessed using the 7-day sum of area over the curve with glucose levels <70 mg/dl and the sum of time spent <54  mg/dl. Results A total of 366 participants (148 participants with CKD and diabetes, 115 with CKD and without diabetes, and 103 without CKD and with diabetes) were included. Glucose levels of <54  mg/dl were observed in 41% of participants with CKD and diabetes, 48% of participants with CKD and without diabetes, and 14% of participants with diabetes and without CKD. However, only two participants reported hypoglycemic symptoms during CGM measurements, which were confirmed and documented by capillary blood glucose measurements. Between-group differences of 7-day area over the curve (<70 mg/dl) were as follows: hemodialysis group versus CKD stage G4 and G5 groups, −0.25 min·mg/dl per hour (95% confidence interval [CI], −6.40 to −0.59) P<0.001; CKD stage G4 and G5 groups versus CKD stage G3 group, −0.08 min·mg/dl per hour (95% CI, −0.0 to −0.50) P=0.15; and CKD stage G3 group versus diabetes without CKD group, −0.14 min·mg/dl per hour (95% CI, −0.0 to −0.20) P=0.01. In addition, the subgroup analysis of the diabetic or nondiabetic and at daytime or nighttime showed that the 7-day area over the curve (<70 mg/dl) and time spent (<54 mg/dl) was larger with worse kidney function. Conclusions The lowering level of kidney function was strongly associated with the burden of hypoglycemia in patients with CKD.