Patients with type 1 diabetes face nearly double the risk for dementia as they age
The first study of dementia risk, including Alzheimer's disease, in older adults with type 1 diabetes (T1D) was reported at the Alzheimer's Association International Conference® 2015 (AAIC® 2015) in Washington, D.C. People in the study with T1D were 93% more likely to get dementia (73% after adjustment for cardiovascular risk factors) compared with people without diabetes.
Studies have shown that type 2 diabetes (T2D) is associated with a greater risk of dementia, including Alzheimer's disease; however, little is known about how T1D affects cognitive aging and dementia risk. At AAIC 2015, Rachel Whitmer, PhD, Kaiser Permanente Division of Research, Oakland CA, and colleagues reported results from first study of dementia in elderly adults with T1D.
"Elderly people with type 1 diabetes are a population that is unique from elderly people with type 2 diabetes," Whitmer said. "They have a much younger age of diabetes onset, continuous insulin treatment, more frequent severe hypoglycemic episodes, but less vascular risk factors."
The researchers followed the health histories of 490,344 people over 60 years old with no prior dementia who are in the Kaiser Permanente Northern California health system, tracking them over 12 years for new dementia diagnoses. 334 individuals had T1D. Analyses compared the T1D group with two control groups: one with T2D and one without diabetes, taking into account differences in gender, race, stroke, peripheral arterial disease and hypertension.
Results presented at AAIC 2015 show that 16% of those with T1D in the study were diagnosed with dementia during the follow-up period while 12% of those without T1D developed dementia. In other words, people in the study with T1D were 83% more likely to get dementia compared with people who did not have T1D; 61% more likely after adjustment for stroke, peripheral arterial disease and hypertension. The magnitude of T1D on dementia risk was larger when people with T2D were excluded for the comparison group (93% more likely; 73% after adjustment).
"Both type 1 and type 2 diabetes are rapidly increasing worldwide, and people with type 1 are living longer than ever before," Whitmer said. "Since management of type 1 diabetes requires vigilance and constant self-care, cognitive impairment poses a particular threat to this vulnerable population. More research is needed to identify risk and protective factors for Alzheimer's and other dementias in this group that is newly entering the aging population." |