Midlife Obesity May Be Associated With Risk Of Dementia And Alzheimer's Disease

Obesity is onthe rise all over the world and is related to vascular diseases, whichmay be linked to dementia and Alzheimer's disease (AD), according tobackground information in the article. However, the link betweenobesity and dementia risk has not been extensively studied andlong-term follow-up studies performed thus far have yielded somewhatconflicting results.

Miia Kivipelto, M.D., Ph.D., from theKarolinska Institutet, Stockholm, Sweden, and colleagues re-examinedparticipants in the Cardiovascular Risk Factors, Aging, and Dementia(CAIDE) study to investigate the relationship between midlife body massindex (BMI; weight in kilograms divided by square of height in meters)and a group of vascular risk factors, and subsequent dementia and AD.Participants in the CAIDE study were derived from random, population-based samples previously studied in a survey carried out in 1972, 1977,1982, or 1987. After an average follow-up of 21 years, 1,449individuals aged 65 to 79 years participated in the 1998 reexamination.

Theresearchers discovered dementia and AD to be prevalent significantlymore among those with a higher midlife BMI. One-third of theparticipants had a BMI lower than 25 (normal weight), half had a BMIfrom 25 to 30 (overweight), and the remaining 16 percent had a BMIhigher than 30 (obese) at midlife. A history of heart attack anddiabetes mellitus were more prevalent in those with the highest midlifeBMI . Midlife obesity, high systolic blood pressure, and high totalcholesterol level were all significant risk factors for late-lifedementia. Being overweight in midlife was not significantly associatedwith dementia later in life.

"This study shows that obesity atmidlife may increase the risk of dementia and AD later in life," theauthors write. "… midlife obesity, high SBP, and high total cholesterollevel were all significant risk factors for dementia, each of themincreasing the risk around two times. Clustering of these vascular riskfactors increased the risk of dementia and AD in an additive manner sothat persons with all three risk factors had around a six times higherrisk for dementia than persons having no risk factors."

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(Arch Neurol. 2005; 62: 1556 – 1560. Available pre-embargo to the media at www.jamamedia.org.)

Editor'sNote: This study was supported by the Aging Program of the Academy ofFinland, Helsinki; EVO grants from the Kuopio University Hospital,Kupio, Finland; Academy of Finland grants (Dr. Kivipelto); and theGamla Tjänarinnor Foundation (Dr. Kivipelto), grant from the SwedishCoucil for Working Life and Scoial Research, and the SADF(Insamligsstiftelsen för Alzheimeroch Demensforskning) (co-author, Ms.Ngandu), Stockholm.