Continuous Glucose Monitoring and Use of Alternative Markers To Assess Glycemia in Chronic Kidney Disease

Abstract

In chronic kidney disease, glycated albumin and fructosamine have been postulated to be better biomarkers of glycemic control than HbA 1c . We evaluated the accuracy, variability, and covariate bias of three biomarkers (HbA 1c , glycated albumin, and fructosamine) compared with continuous glucose monitoring (CGM)-derived measurement of glycemia across estimated glomerular filtration rate (eGFR) in type 2 diabetes. RESEARCH DESIGN AND METHODSA prospective cohort study was conducted of 104 participants with type 2 diabetes, 80 with eGFR <60 mL/min/1.73 m 2 (not treated with dialysis) and 24 frequency-matched control subjects with eGFR ‡60 mL/min/1.73 m 2 . Participants wore a blinded CGM for two 6-day periods separated by 2 weeks, with blood and urine collected at the end of each CGM period. HbA 1c , glycated albumin, and fructosamine were measured by high-performance liquid chromatographic, enzymatic, and colorimetric nitroblue tetrazolium methods, respectively. RESULTSWithin-person biomarker values were strongly correlated between the two CGM periods (r 5 0.92-0.95), although no marker fully captured the within-person variability of mean CGM glucose. All markers were similarly correlated with mean CGM glucose (r 5 0.71-77). Compared with mean CGM glucose, glycated albumin and fructosamine were significantly biased by age, BMI, serum iron concentration, transferrin saturation, and albuminuria; HbA 1c was underestimated in those with albuminuria. CONCLUSIONSGlycated albumin and fructosamine were not less variable than HbA 1c at a given mean CGM glucose level, with several additional sources of bias. These results support measuring HbA 1c to monitor trends in glycemia among patients with eGFR <60 mL/min/1.73 m 2 . Direct measurements of glucose are necessary to capture short-term variability.Glycated hemoglobin (HbA 1c ) is commonly used in people with diabetes to monitor long-term (;3 months) glycemic control. However, HbA 1c may not appropriately measure glycemic burden in those who also have chronic kidney disease (CKD), with both bias (defined as a difference in mean values) and more variability around the

Executive summary of the 2020 KDIGO Diabetes Management in CKD Guideline: evidence-based advances in monitoring and treatment

“…Published studies suggest that the accuracy and precision of hemoglobin A1c, compared with direct measurements of blood glucose, do not vary by estimated glomerular filtration rate (eGFR) down to an eGFR of 30 ml/min per 1.73 m 2 . 11 Therefore, the Work Group recommended using hemoglobin A1c to monitor glycemic control in patients with diabetes and CKD, consistent with general diabetes care. At lower Figure 2 | Kidney-heart risk factor management.…”

“…CGM may be useful to index hemoglobin A1c values for patients in whom hemoglobin A1c is not concordant with directly measured blood glucose levels or clinical symptoms. 11,12 In addition, CGM and self-monitoring of blood glucose can be used for short-term titration of treatments, prevention of hypoglycemia, and improvement of overall glycemic control. 13 Monitoring of blood glucose is particularly relevant when the treatment includes antihyperglycemic therapies associated with risk of hypoglycemia, such as insulin or sulfonylureas.…”

Management of type 2 diabetes in chronic kidney disease

“…Both albumin-based assessments and fructosamine may be affected by hypoalbuminemia, a common finding among patients with advanced kidney disease. 17 For most patients with DKD, HbA1c monitoring every 3-6 months is adequate to guide therapy.…”

Use of continuous glucose monitoring system in patients with type 2 mellitus diabetic during hemodialysis treatment

“…Other markers of diabetes control such as fructosamine and glycated albumin can prevent problems related to the half-life of hemoglobin and provide alternatives to HbA1c [ 5 ]. The limitation of these markers is the impaired accuracy resulting from the influence of serum albumin, uric acid and bilirubin levels for their determination [ 2 ] and they still need more robust clinical evidence to elucidate their applicability in all the stages of CKD [ 6 ].…”