Strategies implemented in high-income countries to improve blood glucose control in people with type 1 diabetes and so reduce complications, such as heart attacks, strokes, and early death, are working, but there is much need for further improvement, according to a study from Scotland published in this week's PLOS Medicine.
Using information from national databases representing over 20 000 patients from 2005 to 2008, Scottish researchers led by Helen Colhoun from the University of Dundee, found that people with type 1 diabetes have 2 to 3 times the risk of heart attacks, strokes, or premature death than the general population and that this increased risk is higher in women than in men. The authors found that in those with type 1 diabetes, the risk (chance) of having a cardiovascular event (heart attack or stroke) for the first time was 2.5 higher in men and 3.2 higher in women, than in the general Scottish population. Furthermore, in those with type 1 diabetes, death ratesfrom any cause were 2.6 higher in men and 2.7 higher in women than in the general Scottish population.
The authors also found a high number of deaths from coma in younger people with diabetes (caused by either an extremely high or an extremely low blood sugar level) and two to three extra deaths per 100 people a year inthose aged 60 to 69 years with type 1 diabetes.
Worryingly, the authors also found that the majority of patients in this Scottish dataset had poorly controlled blood glucose levels, with only 13% having HbA1c levels (a test that measures the blood sugar control over the previous 3 months) in the target range. People with type 1 diabetes also had similar levels of smoking and of being overweight--risk factors of cardiovascular disease--as the general population.
The importance of tight blood sugar control for minimizing complications from diabetes has been understood for almost two decades. Therefore, there is an urgent need to understand why so few people with type 1 diabetes in settings such as that studied here have good control of their blood sugar, and what can be done to improve this situation.
The authors say: "Although the relative risks for cardiovascular disease and total mortality associated with type 1 diabetes in this population have declined relative to earlier studies, type 1 diabetes continues to be associated with higher cardiovascular disease and death rates than the non-diabetic population."
They continue: "A striking feature of the data is the very low rate of achievement of glycaemic control targets."
The authors add: "Risk factor management should be improved to further reduce risk but better treatment approaches for achieving good glycaemic control are badly needed."
Funding: This work was supported by the Wellcome Trust through the Scottish Health Informatics Programme (SHIP) Grant (Ref WT086113), the Chief Scientist Office Scotland and NHS Research Scotland (NRS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared the following competing interests: Sarah H. Wild has received two honoraria from Novo Nordisk, paid to her research funds in December 2010 and March 2011, for speaking at an advisory board and symposium on the topic of diabetes and cancer. Norman R. Peden has received travel grants from Pfizer Inc., Novo Nordisk, and Eli Lilly, and he holds shares in GlaxoSmithKline. John R. Petrie is the recipient of lecture honoraria, travel support and consultancy fees from pharmaceutical companies manufacturing thiazolodinediones (Takeda & GlaxoSmithKline), as well as from companies manufacturing other diabetes products (Novo Nordisk, Sanofi-Aventis). Recipient of support in kind from Merck-Serono for a charity-funded investigator-led study (REMOVAL NCT01483560). Helen M. Colhoun has served on clinical trial advisory panels for Sanofi-Aventis, Pfizer Inc., Novartis Pharmaceuticals, and Eli Lilly. She has also received research support from Roche Pharmaceuticals, Pfizer Inc., Eli Lilly, Boehringer Ingelheim, and Astra Zeneca as part of an EU Innovative Medicines Initiative research grant. None of these activities directly relate to this manuscript. Shona J. Livingstone, Helen C. Looker, Eleanor J. Hothersall, Robert S. Lindsay, John Chalmers, Stephen Cleland, Graham P. Leese, John McKnight, Andrew D. Morris, Donald W. M. Pearson, Sam Philip, Naveed Sattar, and Frank Sullivan have no conflicts of interest to declare.
Citation: Livingstone SJ, Looker HC, Hothersall EJ, Wild SH, Lindsay RS, et al. (2012) Risk of Cardiovascular Disease and Total Mortality in Adults with Type 1 Diabetes: Scottish Registry Linkage Study. PLoS Med 9(10): e1001321. doi:10.1371/journal.pmed.1001321
Helen M. Colhoun
University of Dundee
Dundee, United Kingdom