Type 1 diabetes patients with on-target glycemic control still have twice the risk for dying from any cause or from cardiovascular (CV) causes than the general population, data from a Swedish study suggest.
Type 1 diabetes has been linked to premature death and excess mortality, with CVD being a common cause of death later in life, according to the study, which was published in the New England Journal of Medicine. It is also well established that better glycemic control decreases the risk for microvascular complications and CVD in these patients.
However, the excess risks of death from any cause and from CV causes in patients with varying degrees of glycemic control in patients with type 1 diabetes vs. the general population have not been studied, the researchers wrote.
To find out more, the researchers conducted a registry-based observational study including 33,915 patients with type 1 diabetes using data from the Swedish National Diabetes Register and 169,249 controls. Mean age at baseline was 35.8 and 35.7 years, respectively, and mean follow-up was 8.0 and 8.3 years, respectively. The researchers followed patients and controls via the Swedish Register for Cause-Specific Mortality.
A total of 2,701 patients (8.0%) of patients with type 1 diabetes died during the study, translating to a death rate of 9.97 per 1,000 observation-years. In contrast, among controls, 4,835 (2.9%) patients died, translating to a death rate of 3.45 per 1,000 observation-years, according to the data. Adjusted hazard ratio (HR) for death was 3.52 (95% CI, 3.06-4.04).
Results indicated that the rates of death from CV causes were 2.7% for those with type 1 diabetes vs. 0.9% for controls, with an adjusted HR of 4.60 (95% CI, 3.47-6.10).
The researchers also assessed HRs for death according to glycated hemoglobin level. For death from any cause, multivariable-adjusted HRs for patients with diabetes vs. controls were 2.36 (95% CI, 1.97-2.83) for a glycated hemoglobin level of 6.9% or lower; 2.38 (95% CI, 2.02-2.80) for a level of 7.0% to 7.8%; 3.11 (95% CI, 2.66-3.62) for a level of 7.9% to 8.7%; 3.65 (95% CI, 3.11-4.30) for a level of 8.8% to 9.6%; and 8.51 (95% CI, 7.24-10.01) for a level of 9.7% or higher.
Similarly, HRs for death from CV causes were 2.92 (95% CI, 2.07-4.13) for a glycated hemoglobin level of 6.9% or lower; 3.39 (95% CI, 2.49-4.61) for a level of 7.0% to 7.8%; 4.44 (95% CI, 3.32-5.96) for a level of 7.9% to 8.7%; 5.35 (95% CI, 3.94-7.26) for a level of 8.8% to 9.6%; and 10.46 (95% CI, 7.62-14.37) for a level 9.7% or greater.
“In conclusion, our data show that among patients with type 1 diabetes who have a glycated hemoglobin level of 6.9% or lower, the risks of death from any cause and from cardiovascular causes are twice as high as those in the general population and that the risks are several times as high among patients with poor glycemic control,” the researchers wrote.