Patients with type 1 diabetes can expect to live between 11 and 13 years less than other people, depending on their gender, according to findings from a large Scottish study.
The average estimated loss of life expectancy was about 11 years for male diabetes patients aged 20, compared with the general Scottish population. For women with the condition, the average loss of life expectancy was around 13 years.
“The suggested increase in life expectancy is likely due to the improvements we have seen in diabetes care over the last 20 to 30 years”
Researchers from the University of Dundee used a large national registry of patients with type 1 diabetes living in Scotland to provide contemporary comparisons of life expectancy with the general population without type 1 diabetes.
Their analysis, published in the Journal of the American Medical Association, included 24,691 type 1 patients who were 20 years of age or older from 2008-10.
Men aged 20 with type 1 diabetes were expected to live an additional 46.2 years compared with 57.3 years for men without it.
Life expectancy from age 20 years was an additional 48 years among women with type 1 diabetes and 61.0 years among women without it.
In the general population without type 1 diabetes, 76% of men and 83% of women survived to age 70 years, compared with 47% of men and 55% of women with type 1.
Even among patients with type 1 diabetes and preserved kidney function, life expectancy was reduced, with an estimated loss from age 20 years of 8.3 years for men and 7.9 years for women.
Overall, the study authors said the largest percentage of the estimated loss in life expectancy was related to ischemic heart disease, but death from diabetic coma or the condition ketoacidosis was associated with the largest percentage of the estimated loss occurring before age 50 years.
The authors cautioned that they could not “directly assess” whether life expectancy had improved over time for people with type 1 diabetes, because of a lack of historical life expectancy data for the study population.
However, they noted a US study that ran from 1951 to 1971, which found type 1 patients lived 27 years less than other people, and a New Zealand study from 1984-93 that calculated the remaining life expectancy for diabetes patients aged 20 was about 40 years.
“Data from 2008 through 2010 indicated an estimated loss of life expectancy at age 20 years of approximately 11 years for men and 13 years for women”
They also noted that the difference they found was also much lower than that currently generally cited, for example, by Diabetes UK website, which has until now cited a loss of about 20 years associated with type 1 diabetes.
However, the researchers questioned whether the previous study populations were “sufficiently similar” to theirs to make comparison of life expectancy appropriate.
But Diabetes UK described the results as “encouraging”. Simon O’Neill, the charity’s director of health intelligence, said: “This large study adds to our understanding of the serious impact of type 1 diabetes on length of life.
“The suggested increase in life expectancy is likely due to the improvements we have seen in diabetes care over the last 20 to 30 years, such as home blood glucose testing, earlier detection of diabetes and management of complications of the condition.
“Further long-term studies of the UK population are needed to confirm that this is the case,” he said. “While this report is encouraging, much more work remains to ensure better routine care for people with type 1 diabetes to enable them to manage their condition and live longer, healthier lives.”