"We wanted to see if mid-life risk factors translated into increased risk of dementia later in life, and the answer was 'yes,'" said Kristine Yaffe, MD, UCSF associate professor of psychiatry, neurology and epidemiology, and chief of geriatric psychiatry at the San Francisco VA Medical Center. Yaffe was senior researcher of the study.
Most previous studies showing the relation between cardiovascular risk factors and dementia have focused only on elderly patients. Mid-life risk factors for heart disease were identified as total cholesterol, diabetes, hypertension and smoking.
The study involved 11,341 men and women aged 40 to 44 who were members of a large HMO, and remained members from 1994 through 2003. From 1964 to 1973, the first years of the study, the subjects underwent detailed health evaluations. From January 1994 to April 2003, the final years, researchers studied electronic medical records for diagnoses of dementia.
Presence of each risk factor in one's 40s added 20 to 40 percent greater risk for developing dementia later in life, research showed. Using all four risk factors, researchers created a composite cardiovascular risk score. They found that a participant with all four of the risk factors had nearly three times (or 300 percent) greater chance of developing dementia than a participant with none of the risk factors.