The study, which focused on the health of 13,693 Swedish twins, found that people who are diagnosed with diabetes before age 65 have more than double the chance of developing Alzheimer's disease. The link was not as strong for people diagnosed with diabetes late in life.
Weili Xu, PhD of the Karolinska Institutet in Stockholm, Sweden, and colleagues write that their findings offer one more reason for people "to maintain a healthy lifestyle during adulthood in order to reduce the risk of dementia late in life."
Nearly 24 million Americans have diabetes, according to the American Diabetes Association.
Participants in the study were all part of the Swedish Twin Registry and were at least 65 when the study began in 1998. The study lasted until 2001. The study looked at the twins as a group and also made comparisons within twin sets.
Of all the participants, 467 were diagnosed with dementia, including 292 with Alzheimer's. There were 1,396 participants with diabetes.
By focusing on twins, researchers removed many genetic differences, as well as differences in poverty level, at least during childhood.
"Twins provide naturally matched pairs, in which confounding factors such as genetics and childhood environment may be removed when comparisons are made between twins," co-author Margaret Gatz, PhD, professor of psychology, gerontology, and preventive medicine at the University of Southern California and foreign adjunct professor of medical epidemiology and biostatistics at the Karolinska Institutet, says in a news release.
The study is published in the January issue of the journal Diabetes.
By Caroline Wilbert
Reviewed by Louise Chang
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