Use of complementary markers in assessing glycaemic control in people with diabetic kidney disease undergoing iron or erythropoietin treatment

• Published in: Diabetic medicine Vol. 30; no. 10; pp. 1250 - 1254
• Main Authors: Konya, J., Ng, J. M., Cox, H., Cooke, M., Lewis, N., Bhandari, S., Atkin, S. L., Kilpatrick, E. S.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.10.2013; Blackwell; Wiley Subscription Services, Inc
• Subjects: Administration, Intravenous; Aged; Biological and medical sciences; Biomarkers - blood; Blood Glucose - metabolism; Delivery of Health Care; Diabetes; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - drug therapy; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; Diabetic Nephropathies - blood; Diabetic Nephropathies - drug therapy; Diabetic Nephropathies - physiopathology; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Epoetin Alfa; Erythropoietin - therapeutic use; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Feeding. Feeding behavior; Female; Follow-Up Studies; Fructosamine - blood; Fundamental and applied biological sciences. Psychology; Glycated Hemoglobin A - drug effects; Glycated Hemoglobin A - metabolism; Hematinics - therapeutic use; Humans; Iron - therapeutic use; Male; Medical sciences; Monitoring, Physiologic; Prospective Studies; Recombinant Proteins - therapeutic use; Renal Insufficiency, Chronic - blood; Renal Insufficiency, Chronic - drug therapy; Renal Insufficiency, Chronic - physiopathology; Serum Albumin - metabolism; Severity of Illness Index; Time Factors; Treatment Outcome; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Endocrinopathy; Kidney disease; Evaluation; Obesity; Urinary system disease; Erythropoietin; Nutrition; Diabetes mellitus; Use; Nutrition disorder; Biological marker; Metabolic diseases; Iron; Inorganic element; Treatment; Surveillance; Polypeptide; Endocrinology; Nutritional status; Glycemia
• ISSN: 0742-3071; 1464-5491
• DOI: 10.1111/dme.12249

Aims HbA1c values are unreliable in patients with diabetes who have chronic kidney disease who receive iron and/or erythropoiesis stimulating agents. The study aimed to evaluate the utility of the complementary glycaemic markers glycated albumin, fructosamine and 1,5 anhydroglucitol in this group of patients. Methods A prospective study of patients with Type 2 diabetes and chronic kidney disease stage IIIB/IV undergoing intravenous iron or erythropoiesis‐stimulating agent therapy. Glycaemic control was monitored using HbA1c, seven‐point daily glucose thrice weekly, continuous glucose monitoring, glycated albumin, fructosamine and 1,5 anhydroglucitol. Results Fifteen patients [9 men; median age 72 years (interquartile range 68–74), follow‐up period (16.4 ± 3.7 weeks)] received parenteral iron; 15 patients [11 men; 70 years (interquartile range 62–75), (17.3 ± 3.3 weeks)] received erythropoiesis‐stimulating agent. HbA1c fell following treatment with both iron [57 mmol/mol (7.4%) to 53 mmol/mol (7.0%), P < 0.001] and erythropoiesis‐stimulating agent [56 mmol/mol (7.3%) to 49 mmol/mol (6.6%), P = 0.01] despite mean blood glucose remaining unchanged (iron: 9.55 to 9.71 mmol/l, P = 0.07; erythropoiesis‐stimulating agent: 8.72 to 8.78 mmol/l, P = 0.89). Unlike HbA1c, the glycated albumin, fructosamine and 1,5 anhydroglucitol levels did not change following iron [glycated albumin (16.8 to 16.3%, P = 0.10); fructosamine (259.5 to 256 μmol/l, P = 0.89); 1,5 anhydroglucitol (54.2 to 50.9 μmol/l, P = 0.89)] or erythropoiesis‐stimulating agent [glycated albumin (17.9 to 17.5%, P = 0.29), fructosamine (324.3 to 306.0 μmol/l, P = 0.52), 1,5 anhydroglucitol (58.2 to 46.7 μmol/l, P = 0.35)]. Despite this, HbA1c was consistently the marker most closely related to mean blood glucose before and after each treatment (R range 0.7–0.88). Conclusions These data indicate that HbA1c was statistically most closely related to mean blood glucose, but clinical trends in glycaemia in patients undergoing iron or erythropoiesis‐stimulating agent therapy are likely best assessed by including one of these additional glycaemic markers. What's new? HbA1c values are unreliable in patients with diabetes who receive iron and/or erythropoiesis‐stimulating agents for their severe chronic kidney disease. This study shows that while HbA1c fell following both iron and erythropoiesis‐stimulating agent treatment, mean blood glucose as well as other glycaemic markers (glycated albumin, fructosamine and 1,5 anhydroglucitol) remained unchanged. HbA1c still correlated most closely with mean blood glucose overall. This suggests that combined use of HbA1c (to assess mean blood glucose) with another marker (to assess true changes in glycaemia following iron/erythropoiesis‐stimulating agent treatment) may complement one another in this group of patients.