Glucose variability and glycated hemoglobin HbA1c in type 1 and type 2 diabetes
Abstract
Introduction. The ultimate goal of diabetes therapy is to prevent chronic complications of the disease. HbA1c level is closely related to the risk of development of micro- and macrovascular complications, however blood glucose variability (BGV) has emerged recently as yet another possible risk factor for vascular, particularly endothelial damage in diabetes. Continuous glucose monitoring systems (CGMS) are currently used for the BGV assessment, however due to their costs they are rarely utilised in daily clinical practice. The aim of the study was to assess BGV and its relationship with HbA1c in patients with well (HbA1c ∼7%) and poorly (HbA1c ∼10%) controlled type 1 and type 2 diabetes.
Material and methods. 131 patients subdivided in 4 groups according to diabetes type and level of metabolic control were enrolled into the study. All patients underwent continuous glucose monitoring with the use of iPRO2 system (Medtronic).
Results. BGV was lower in type 2 than in type 1 diabetes patients. There was no statistically significant relationship between BGV and HbA1c in well or poorly controlled patients with type 1 or type 2 diabetes. However, well controlled type 1 diabetes patients presented with greater degree of BGV than poorly controlled type 1 diabetes subjects.
Conclusions. HbA1c does not reflect blood glucose variability as assessed with CGMS in type 1 or type 2 diabetes subjects. BGV is significantly greater in type 1 diabetes than in type 2 diabetes, therefore the use CGMS might be of particular benefit for the former group of patients, especially those with good glycemic control.
Keywords: glycaemic variabilitycontinuous glucose monitoring systemglycated haemoglobin HbA1c
References
- Monnier L, Mas E, Ginet C, et al. Activation of oxidative stress by acute glucose fluctuations compared with sustained chronic hyperglycemia in patients with type 2 diabetes. JAMA. 2006; 295(14): 1681–1687.
- Kilpatrick ES, Rigby AS, Atkin SL. The effect of glucose variability on the risk of microvascular complications in type 1 diabetes. Diabetes Care. 2006; 29(7): 1486–1490.
- Jung HS. Clinical Implications of Glucose Variability: Chronic Complications of Diabetes. Endocrinol Metab (Seoul). 2015; 30(2): 167–174.
- Suh S, Kim JH. Glycemic Variability: How Do We Measure It and Why Is It Important? Diabetes Metab J. 2015; 39(4): 273–282.
- Maiorino MI, Della Volpe E, Olita L, et al. Glucose variability inversely associates with endothelial progenitor cells in type 1 diabetes. Endocrine. 2015; 48(1): 342–345.
- Škrha J, Šoupal J, Škrha J, et al. Glucose variability, HbA1c and microvascular complications. Rev Endocr Metab Disord. 2016; 17(1): 103–110.
- Glucose Variability in a 26-Week Randomized Comparison of Mealtime Treatment With Rapid-Acting Insulin Versus GLP-1 Agonist in Participants With Type 2 Diabetes at High Cardiovascular Risk. Diabetes Care. 2016; 39(6): 973–981.
- Polskie Towarzystwo Diabetologiczne. Zalecenia kliniczne dotyczące postępowania u chorych na cukrzycę 2016. Diabetologia Kliniczna. 2016; 5(supl. A): A3–A5.
- L. Czupryniak, K. Strojek. Diabetologia 2016. ViaMedica, Gdańsk. ; 2016.
- L. Czupryniak. Zapobieganie i leczenie cukrzycy typu 2. W: Diabetologia. Kompendium. (red. L. Czupryniak) Termedia, Poznań, 2014, str. : 126–128.
- Frayn KN. Metabolic Regulation. A Human Perspective. Wiley-Blackwell, Oxford 2010.
- Brownlee M. The pathobiology of diabetic complications: a unifying mechanism. Diabetes. 2005; 54(6): 1615–1625.
- Monnier L, Colette C, Owens DR. Glycemic variability: the third component of the dysglycemia in diabetes. Is it important? How to measure it? J Diabetes Sci Technol. 2008; 2(6): 1094–1100.
- Okada K, Hibi K, Gohbara M, et al. Association between blood glucose variability and coronary plaque instability in patients with acute coronary syndromes. Cardiovasc Diabetol. 2015; 14: 111.
- U. Thurm, B. Gehr. Osobiste pompy insulinowe i ciągłe monitorowanie glikemii. Termedia, Poznań 2014.
- A. Szymborska-Kajanek, J. Górska, G. Kuleszyńska, W. Grzeszczak, K. Strojek Zastosowanie systemu ciągłego pomiaru glikemii Minimed CGMS do oceny wyrównania metabolicznego u chorych na cukrzycę typu 2. Diabetologia Doświadczalna i Kliniczna. 2003; 3: 439–444.
- Ryan EA, Germsheid J. Use of continuous glucose monitoring system In the management of severe hypoglycemia. Diabetes. 2010; 59(supl. 1): A583.
- Guillod D, Comte-Perret S, Monbaron D, et al. Nocturnal hypoglycamias in type 1 diabetic patients: what can we learn with continuous glucose monitoring? Diabetes. 2010; 59(supl. 1): A821.
- Kohnert KD, Vogt L, Augstein P, et al. Chronic hyperglycemia but not glucose variability determines HbA1c levels in well-controlled patients with type 2 diabetes. Diabetes Res Clin Pract. 2007; 77(3): 420–426.
- Guder WG, Narayanan S, Wisser H, Zawta B. Próbki: od pacjenta do laboratorium, Wpływ zmienności przedanalitycznej na jakość wyników badań laboratoryjnych. Medpharm, Wrocław 2009, wyd. 1 .
- Rahbar S. The discovery of glycated hemoglobin: a major event in the study of nonenzymatic chemistry in biological systems. Ann N Y Acad Sci. 2005; 1043: 9–19.