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

• Published in: Diabetes care Vol. 43; no. 10; pp. 2379 - 2387
• Main Authors: Zelnick, Leila R., Batacchi, Zona O., Ahmad, Iram, Dighe, Ashveena, Little, Randie R., Trence, Dace L., Hirsch, Irl B., de Boer, Ian H.
• Format: Journal Article
• Language: English
• Published: United States American Diabetes Association 01.10.2020
• Subjects: Albumin; Albumins; Bias; Biomarkers; Blood glucose; Clinical Care/Education/Nutrition/Psychosocial Research; Colorimetry; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Dialysis; Epidermal growth factor receptors; Glomerular filtration rate; Glucose; Glucose monitoring; Kidney diseases; Kidneys; Monitoring; Research design; Telemedicine; Transferrin; Transferrins; Variability
• ISSN: 0149-5992; 1935-5548; 1935-5548
• DOI: 10.2337/dc20-0915

In chronic kidney disease, glycated albumin and fructosamine have been postulated to be better biomarkers of glycemic control than HbA . We evaluated the accuracy, variability, and covariate bias of three biomarkers (HbA , glycated albumin, and fructosamine) compared with continuous glucose monitoring (CGM)-derived measurement of glycemia across estimated glomerular filtration rate (eGFR) in type 2 diabetes. A prospective cohort study was conducted of 104 participants with type 2 diabetes, 80 with eGFR <60 mL/min/1.73 m (not treated with dialysis) and 24 frequency-matched control subjects with eGFR ≥60 mL/min/1.73 m . 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 , glycated albumin, and fructosamine were measured by high-performance liquid chromatographic, enzymatic, and colorimetric nitroblue tetrazolium methods, respectively. Within-person biomarker values were strongly correlated between the two CGM periods ( = 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 ( = 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 was underestimated in those with albuminuria. Glycated albumin and fructosamine were not less variable than HbA at a given mean CGM glucose level, with several additional sources of bias. These results support measuring HbA to monitor trends in glycemia among patients with eGFR <60 mL/min/1.73 m . Direct measurements of glucose are necessary to capture short-term variability.