An international team of researchers reports that the benefits of insulin therapy for people over the age of 50 may not always outweigh the negatives….
Study co-author John S. Yudkin, emeritus professor of medicine at UCL says, "In many cases, insulin treatment may not do anything to add to the person’s quality life expectancy." "If people feel that insulin therapy reduces their quality of life by anything more than around 3-4%, this will outweigh any potential benefits gained by treatment in almost anyone with type 2 diabetes over around 50 years old."
For their study, led by Sandeep Vijan, professor of internal medicine at the University of Michigan Medical School, the team assessed 5,102 patients in the UK with type 2 diabetes who managed their condition through the use of pills or insulin.
Over a 20-year follow-up, the researchers looked at how the treatments affected patients’ overall quality of life and whether they were effective in reducing their risk of diabetes complications.
They then compared the reduced risk of such complications with the burden of using diabetes medications and the side effects associated with them.
According to the researchers, the benefits of insulin therapy for patients with type 2 diabetes are dependent on their age at treatment initiation and the potential side effects, rather than their blood sugar levels.
For example, they estimate that a person with type 2 diabetes who begins insulin therapy at age 45 and lowers their hemoglobin A1c levels by 1% may experience an extra 10 months of healthy life.
But for a patient who starts treatment for type 2 diabetes at age 75, they estimate the therapy may only gain them an additional 3 weeks of healthy life. The researchers say this prompts the question – is 10-15 years of pills or injections with possible side effects worth it?
Prof. Yudkin commented, "Ultimately, the aim of a treatment is not to lower blood sugar for its own sake but to prevent debilitating or deadly complications. If the risk of these complications is suitably low and the burden of treatment correspondingly high, treatment will do more harm than good. The balance between the two can never be defined by a simple figure like blood sugar level."
The team says their findings apply to type 2 diabetes patients with hemoglobin A1c levels below 8.5%. But they note that patients with levels above 8.5% may be likely to see greater benefits from insulin therapy, as they are at greater risk of diabetes complications.
However, the team concludes that using a patient’s hemoglobin A1c levels alone to judge whether they will benefit from insulin therapy is a "fundamentally flawed strategy."
"Instead," they add, "each glycemic treatment decision should be individualized, mostly on the basis of the patients’ views of the burdens of therapy, with age and initial level of glycemic control important secondary considerations."
"Currently, we are failing our patients by not recognizing that their preferences and views of treatment burden are the most important factors in helping them make glycemic treatment decisions that are best for them."
- The findings apply to older type 2 diabetes patients with hemoglobin A1c levels below 8.5%.
- Each treatment decision should be individualized, mostly on the basis of the patients’ views of the burdens of therapy
JAMA Internal Medicine, June 2014