For patients with type 1 diabetes in Scotland, at age 20 years, the average man has an estimated life expectancy loss of about 11 years; for women, it is 13 years, compared with the general Scottish population without type 1 diabetes, according to a study in the January 6 issue of JAMA.1
Major advances in treatment of type 1 diabetes have occurred in the past three decades. Accurate contemporary estimates of life expectancy would be useful as a measure of the current effect of diabetes and as a benchmark for assessing changes in diabetes care through time. Although there are many reports of the standardized mortality ratios for type 1 diabetes, few studies have provided life expectancy data, according to background information in the article.
Shona J. Livingstone, M.Sc., of the University of Dundee, Dundee, Scotland, and colleagues 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. The analysis included individuals who were 20 years of age or older from 2008 through 2010 (n = 24,691) with type 1diabetes.
Life expectancy at an attained age of 20 years was an additional 46.2 years among men with type 1 diabetes and 57.3 years among men without it, an estimated loss in life expectancy with diabetes of 11.1 years. Life expectancy from age 20 years was an additional 48.l years among women with type 1 diabetes and 61.0 years among women without it, an estimated loss with diabetes of 12.9 years. In the general population without type 1 diabetes, 76 percent of men and 83 percent of women survived to age 70 years compared with 47 percent of men and 55 percent of women with type 1 diabetes.
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 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 note that whether their findings are generalizable internationally cannot be directly assessed because there are no large contemporary or historical nationally representative studies from other countries. “Therefore, it would be of interest to see contemporary larger scale data from the United States and other countries too.”
In an editorial commenting on the two studies in this issue of JAMA that examine diabetes and mortality, Michelle Katz, M.D., M.P.H., and Lori Laffel, M.D., M.P.H., of the Joslin Diabetes Center, Boston, write that more is needed to improve the life-expectancy in type 1 diabetes.2
“The search for genetic factors and biomarkers related to risk of diabetes complications generally and risk of diabetic nephropathy specifically needs to accelerate. There continues to be inadequate access to advanced diabetes technologies, education and support from health care professionals, and, at times, even family encouragement, which all need to improve. Patients, families, and the health care community await more steps forward. There is some reassurance for the present; efforts to improve glycemic control and therapies that provide renal protection and cardiovascular risk reduction can prevent or postpone complications and preserve the futures of persons with type 1 diabetes.”