I am often asked by diabetics, “Does diabetes affect life expectancy?” I used to say reassuringly, “As long as you control your blood sugar well, there are many elderly people with diabetes who live a long life. Some of those type 1 diabetics overseas have been on insulin for 50-60 years or more.” Now, I won’t say that anymore. Because according to a recent article published in the prestigious Journal of the American Medical Association (JAMA), life expectancy for type 1 diabetics over the age of 20 was reduced by 11.1 years for men and 12.9 years for women.
This came from a Scottish national registry study of type 1 diabetic patients from 2008 to 2010. During this period, a total of 24,691 type 1 diabetics over the age of 20 were registered, with 67,712 patient-years and 1043 deaths during this period.
The statistical results of the study showed that for type 1 diabetic patients over 20 years of age, the life expectancy of male patients increased by 46.2 years (i.e., they could live to 66.2 years on average), while the life expectancy of non-diabetic normal people increased by 57.3 years (i.e., they could live to 77.3 years). Compared to the two, type 1 diabetic men have 11.1 years less life expectancy (95% confidence interval is 10.1-12.1 years). So, I launch to conclude that the life expectancy of type 1 diabetics is reduced by at least ten years.
Turning to women with type 1 diabetes, their life expectancy is increased by 48.1 years (i.e., they can live to 68.1 years on average), while non-diabetic normal people have an increased life expectancy of 61.0 years (i.e., they can live to 81 years). Compared to the two, women with type 1 diabetes have a 12.9 year reduction in life expectancy (95% confidence interval is 11,7-14.1 years). It seems that women with type 1 diabetes also live only two years longer than men.
The study also showed that the cause of death in about one third of type 1 diabetic patients was attributed to ischemic cardiovascular disease (36% of male patients and 31% of female patients). Thus, the main cause of death in type 1 diabetics is still cardiovascular death, which is consistent with previous research findings. Here again, diabetic patients are reminded not to smoke, to drink less alcohol and to pay attention to regular visits to the hospital to check their heart. However, at a younger age (before less than 50 years), the greatest cause of death is still shock and ketoacidosis caused by diabetes (29.4% of male patients and 21.7% of female patients).