Date: 12 Feb 2013
The impact of metabolic control and QTc prolongation on all-cause mortality in patients with type 2 diabetes and foot ulcers
The increased all-cause mortality in patients with chronic diabetic foot ulcers cannot fully be explained by traditional cardiovascular risk factors. The significance of heart-rate-corrected QT (QTc) prolongation, a finding often seen in these patients, is unknown. Recently, the importance of metabolic control and hypoglycaemia has been discussed. The aim of this study was to evaluate the impact of different HbA1c levels and QTc prolongation on all-cause mortality in the high-risk population of patients with type 2 diabetes mellitus and foot ulcers.
All patients with type 2 diabetes, younger than 80 years, visiting our diabetes foot unit, with a foot ulcer duration >4 weeks, were screened for participation. Patients on dialysis were excluded. Patients were grouped according to HbA1c level and QTc time ≤ or > 440 ms.
Patients (n = 214, median age 69.1 years) were grouped according to HbA1c level (HbA1c < 7.5% [<58 mmol/mol] n = 81, 7.5–8.9% [58–74 mmol/mol] n = 70, >8.9% [>74 mmol/mol] n = 63). Baseline characteristics, including use of potential hypoglycaemic drugs, were similar between groups. During the 8 years of follow-up 151 patients died (70.6%) and HbA1c < 7.5% (<58 mmol/mol) was strongly associated with increased mortality. The highest mortality was seen in patients with a combination of HbA1c < 7.5% (<58 mmol/mol) and QTc prolongation, with an 8 year mortality of 92.1% as compared with 48.8% in those with HbA1c < 7.5% (<58 mmol/mol) but without QTc prolongation.
HbA1c < 7.5% (<58 mmol/mol) in a high-risk population of patients with type 2 diabetes and foot ulcers is associated with a significantly higher mortality, particularly in patients with QTc prolongation.
Boulton AJ (2008) The diabetic foot: grand overview, epidemiology and pathogenesis. Diabetes Metabol Res Rev 24(Suppl 1):S3–S6CrossRef
UK Prospective Diabetes Study (UKPDS) Group (1998) Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). Lancet 352:854–865CrossRef
UK Prospective Diabetes Study (UKPDS) Group (1998) Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet 352:837–853CrossRef
American Diabetes Association (2012) Standards of medical care in diabetes–2012. Diabetes Care 35(Suppl 1):S11–S63
Wright RJ, Frier BM (2008) Vascular disease and diabetes: is hypoglycaemia an aggravating factor? Diabetes Metabol Res Rev 24:353–363CrossRef
Levey AS, Coresh J, Greene T et al (2006) Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 145:247–254PubMed
Macfarlane PW, Devine B, Latif S, McLaughlin S, Shoat DB, Watts MP (1990) Methodology of ECG interpretation in the Glasgow program. Meth Inform Med 29:354–361PubMed
Bazett H (1920) An analysis of time relations of the electrocardiogram. Heart 7:353–370
Britton KA, Aggarwal V, Chen AY et al (2011) No association between hemoglobin A1c and in-hospital mortality in patients with diabetes and acute myocardial infarction. Am Heart J 161(657–663):e651
Goldman D (1940) The electrocardiogram in insulin shock. Arch Intern Med 66:93–108CrossRef
Chelliah YR (2000) Ventricular arrhythmias associated with hypoglycaemia. Anaesth Intensive Care 28:698–700PubMed
Veglio M, Chinaglia A, Cavallo-Perin P (2004) QT interval, cardiovascular risk factors and risk of death in diabetes. J Endocrinol Investig 27:175–181
Cryer PE (2001) Hypoglycemia-associated autonomic failure in diabetes. Am J Physiol Endocrinol Metab 281:E1115–E1121PubMed
- The impact of metabolic control and QTc prolongation on all-cause mortality in patients with type 2 diabetes and foot ulcers
Volume 56, Issue 5 , pp 1140-1147
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Foot ulcers
- Metabolic control
- QTc prolongation
- Industry Sectors
- Author Affiliations
- 1. Institution of Clinical Sciences in Lund, Lund University, Lund, Sweden
- 2. MAVA, Department of Emergency Medicine, Skåne University Hospital, 221 85, Lund, Sweden
- 3. Department of Endocrinology, Skåne University Hospital, Lund, Sweden