Oral Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2016

Glycaemic variability in Type 1 diabetes patients is better with continuous subcutaneous insulin infusion (CSII) therapy than with multiple daily injection (MDI) treatment. (#87)

Emma Scott 1 2 , Daniel Calandro 2 3 , Andrzej Januszewski 2 , David O'Neal 4 , Greg Fulcher 1 5 , Alicia Jenkins 2 4
  1. Department of Diabetes, Endocrinology and Metabolism, Royal North Shore Hospital, Sydney, NSW, Australia
  2. NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
  3. University of Melbourne, Melbourne, VIC, Australia
  4. St Vincent's Hospital, Melbourne, VIC, Australia
  5. Northern Clinical School, University of Sydney, Sydney, NSW, Australia

Introduction: Greater glycaemic variability (GV) is associated with higher risk of severe hypoglycaemia and chronic complications in T1D (1-7). CSII may improve short-term GV (measured by continuous glucose monitoring (CGM) and self-monitoring of blood glucose (SMBG)) (8-10). CSII can decrease long-term GV (HbA1c variability) in children, but has not been evaluated in adults (11).

Objectives: Compare HbA1c variability in T1D patients using CSII or MDI.

Methods: Cross-sectional and longitudinal studies were conducted by audit of electronic records (2010-2016) of T1D patients (Royal North Shore, Sydney and St Vincent’s Hospital, Melbourne). GV was determined by HbA1c standard deviation (SD) and coefficient of variation (CV) of 7+/-4 (MDI) and 7+/-5 (CSII) HbA1c values overall, and in a subset of patients, GV was compared pre vs. post CSII use, (excluding HbA1c for 12 months post-CSII initiation during HbA1c improvement). Analyses were by Mann-Whitney, Wilcoxon Signed Rank and Chi Squared tests and significance taken at p<0.05.

Results: T1D patients (n=180; MDI, n=86; CSII, n=94) were assessed cross-sectionally over mean +/-SD 3+/-2 years, with similar age (42+/-14.2; 42+/-14.2y), T1D duration (20+/-14.7; 18+/-13.5y), HbA1c (8.0+/-1.5%; 7.7±1.2%), chronic complications (44%; 34%) and severe hypoglycaemia frequency on MDI/CSII respectively. More CSII users were female (82% vs. 48% respectively, P=0.001). There was less HbA1c variability amongst CSII (HbA1c SD 0.57±0.45% CSII vs. 0.84±0.81% MDI; P=0.02). HbA1c CV was lower in CSII vs. MDI (CV: 7.1+/-5.0 vs. 10.3+/-9.3 respectively, P=0.007). In 22 patients changing from MDI to CSII, HbA1c improved (7.8+/-0.8% MDI; 7.3+/-0.8% CSII, P=0.002). SD and CV of HbA1c also significantly decreased (mean SD 0.82+/-0.50% vs. 0.39 +/-0.26% respectively; P=0.001, mean CV: 10.5+/-6.5 vs. 5.4+/-3.9 respectively; P=0.002).

Conclusions: In T1D CSII therapy reduces GV vs. MDI as assessed by HbA1c SD and CV.

  1. Bragd J, Adamson U, Bäcklund LB, Lins PE, Moberg E, Oskarsson P. Can glycaemic variability, as calculated from blood glucose self-monitoring, predict the development of complications in type 1 diabetes over a decade? Diabetes and Metabolism. 2008;34(6):612-6.
  2. Kilpatrick ES, Rigby AS, Atkin SL. A1c variability and the risk of microvascular complications in type 1 diabetes. Data from the Diabetes Control and Complications Trial. Diabetes Care. 2008;31(11):2198-202.
  3. Snell-Bergeon J, Roman R, Rodbard D, Garg S, Maahs D, Schauert I, et al. Glycaemic variability is associated with coronary artery calcium in men with Type 1 diabetes: the Coronary Artery Calcification in Type 1 Diabetes study. Diabetic Medicine. 2010;27:1436-42.
  4. Wadén J, Forsblom C, Thorn LM, Gordin D, Saraheimo M, Groop P-H, et al. A1C Variability Predicts Incident Cardiovascular Events, Microalbuminuria, and Overt Diabetic Nephropathy in Patients With Type 1 Diabetes. Diabetes. 2009;58(11):2649-55.
  5. Marcovecchio M, Dalton R, Chiarelli F, Dunger D. A1C variability as an independent risk factor for microalbuminuria in young people with type 1 diabetes. Diabetes Care. 2011;34(4):1011-3.
  6. Cox D, Kovatchev B, Julian D, Gonder-Frederick L, Polonsky W, Schlundt D, et al. Frequency of severe hypoglycemia in insulin-dependent diabetes mellitus can be predicted from self-monitoring blood glucose data. Journal of Clinical Endocrinology and Metabolism. 1994;79:1659-62.
  7. Kilpatrick ES, Rigby AS, Goode K, Atkin SL. Relating mean blood glucose and glucose variability to the risk of multiple episodes of hypoglycaemia in type 1 diabetes. Diabetologia. 2007;50:2553-61.
  8. Bruttomesso D, Crazzolara D, Maran A, Costa S, Dal Pos M, Girelli A, et al. In Type 1 diabetic patients with good glycaemic control, blood glucose variability is lower during continuous subcutaneous insulin infusion than during multiple daily injections with insulin glargine. Diabetic Medicine. 2008;25(3):326-32.
  9. Chimenti EM, de la Morena LH, Vaquero PM, Sáez-de-ibarra L, Domínguez MG, Sánchez LFP. Assessing glycaemic variability with continuous glucose monitoring system before and after continuous subcutaneous insulin infusion in people with Type 1 diabetes. Diabetes Research and Clinical Practice. 2010;90(3):e57-e9.
  10. Maiorino MI, Casciano O, Volpe ED, Bellastella G, Giugliano D, Esposito K. Reducing glucose variability with continuous subcutaneous insulin infusion increases endothelial progenitor cells in type 1 diabetes: an observational study. Endocrine 2016;52(2):244.
  11. Fendler W, Baranowska AI, Mianowska B, Szadkowska A, Mlynarski W. Three-year comparison of subcutaneous insulin pump treatment with multi-daily injections on HbA1c, its variability and hospital burden of children with type 1 diabetes. Acta Diabetologica. 2012;49(5):363-70.