Methods and Findings
The Scottish Care Information-Diabetes Collaboration database was used to identify all people registered with T1DM and aged =20 years in 2005- 2007 and to provide risk factor data. Major CVD events and deaths were obtained from the national hospital admissions database and death register. The age-adjusted incidence rate ratio (IRR) for CVD and mortality in T1DM (n=21,789) versus the non-diabetic population (3.96 million) was estimated using Poisson regression. The age-adjusted IRR for first CVD event associated with T1DM vs. the non-diabetic population was higher in women (3.0: 95% CI 2.4-3.8, p<0.001) than men (2.3: 2.0-2.7, p<0.001) while the IRR for all-cause mortality associated with T1DM was comparable at 2.6 (2.2-3.0, p<0.001) in men and 2.7 (2.2-3.4, p<0.001) in women.
Between 2005-2007, among individuals with T1DM, 34 of 123 deaths among 10,173 who were <40 years and 37 of 907 deaths among 12,739 who were = 40 years had an underlying cause of death of coma or diabetic ketoacidosis. Among individuals 60-69 years, approximately two extra deaths per 100 per year occurred among those with T1DM (for men, 19.14/1000 person years at risk; for women, 17.99/ 1000 person years at risk). 28% of those with T1DM were current smokers, 13% achieved target HbA1c of <7% and 37% had very
poor (=9%) glycaemic control. Among those aged =40, 37% had blood pressures above even conservative targets (=140/90 mmHg) and 39% of those =40 years were not on a statin. Although many of these risk factors were comparable to those in other developed countries, CVD and mortality rates may not be
generalizable to other countries. Limitations included lack of information on the specific insulin therapy used.
Although the relative risks for CVD and total mortality associated with T1DM in this population have declined relative to earlier studies, T1DM continues to be associated with higher CVD and death rates than the nondiabetic population. Risk factor management should be improved to further reduce risk but better treatment approaches for achieving good glycaemic control are badly needed.