Risk of Cognitive Decline Reduced for People 85 and Older With High Cholesterol, Mount Sinai Researchers Find
High Total Cholesterol in Late Old Age May be Marker Of Protective Factor
People aged 85 and older whose total cholesterol had increased from their levels at midlife had a reduced risk for marked cognitive decline, compared with those a decade younger whose choles-terol was similarly elevated, Mount Sinai researchers report in a new study.
The results of the study will be available online by Alzheimer's & Dementia: The Journal of the Alzheimer's Association as an article in press corrected proof on Monday, March 5, at 10 a.m.
The researchers found that people aged 85-94 with good cognitive function whose total choles-terol increased from midlife had a 32 percent reduced risk for marked cognitive decline over the next ten years, compared with people aged 75-84, who had a 50 percent increased risk.
The researchers said that the results did not suggest that those 85 and older should increase their cholesterol for better cognitive health, but rather that those in that age cohort with good cognition and high cholesterol probably also had some protective factor that someday could be identified and studied.
The research team evaluated the association of five total cholesterol values with a substantial de-cline in cognitive function from normal function, called marked cognitive decline. The five val-ues were midlife (average age 40) total cholesterol, late-life (average age 77) total cholesterol, mean total cholesterol since midlife, linear change since midlife (in other words, whether it was increasing or decreasing), and quadratic change since midlife (whether the linear change was ac-celerating or decelerating). Data were obtained from the original Framingham Heart Study, a long-term, ongoing cardiovascular cohort study on residents of Framingham, Massachusetts. That study began in 1948 with 5,209 adult subjects and is now on its third generation of partici-pants.
The team assessed whether marked cognitive decline was associated with the five cholesterol values, and whether the associations with those values changed depending on the age of cognitive assessment. They found several cholesterol values including high last cholesterol, increasing lev-els, and decreasing acceleration were predictors associated with increased risk of a marked cogni-tive decline, that were associated with increased risk of a marked cognitive decline. However, as the outcome age increased, some associations were reduced, or even reversed. Furthermore, in the subgroup of cognitively healthy 85-94 year olds, a high midlife cholesterol level was associ-ated with a reduced risk for marked cognitive decline. This contrasts with samples in other stud-ies that have focused on elderly subjects primarily below age 75, where midlife cholesterol was associated with increased risk of cognitive decline.
“Our results have important implications for researching genetic and other factors associated with successful cognitive aging,” said the study’s first author, Jeremy Silverman, PhD, Professor of Psychiatry, Icahn School of Medicine at Mount Sinai. “The data are consistent with our pro-tected survivor model – among individuals who survive to very old age with intact cognition, those with high risk factor levels are more likely to possess protective factors than those with lower risk factor levels. Long-lived individuals who are cognitively intact despite high risk should be targeted in research studies seeking protective factors, which could help identify future drugs and therapies to treat dementia and Alzheimer’s disease.”
Dr. Silverman notes that these results do not imply that those 85 and older should increase their cholesterol. His research team will next study other risk factors for cognitive decline, including body mass index and blood pressure.
“We don’t think high cholesterol is good for cognition at 85, but its presence might help us iden-tify those who are less affected by it. We hope to identify genes or other protective factors for cogitive decline by focusing on cognitively healthy very old people who are more likely to carry protective factors.”
About the Mount Sinai Health System
The Mount Sinai Health System is New York City's largest academic medical system, encompassing eight hospitals, a leading medical school, and a vast network of ambulatory practices throughout the greater New York region. Mount Sinai is a national and international source of unrivaled education, translational research and discovery, and collaborative clinical leadership ensuring that we deliver the highest quality care—from prevention to treatment of the most serious and complex human diseases. The Health System includes more than 7,200 physicians and features a robust and continually expanding network of multispecialty services, including more than 400 ambulatory practice locations throughout the five boroughs of New York City, Westchester, and Long Island. The Mount Sinai Hospital is ranked No. 14 on U.S. News & World Report's "Honor Roll" of the Top 20 Best Hospitals in the country and the Icahn School of Medicine as one of the Top 20 Best Medical Schools in country. Mount Sinai Health System hospitals are consistently ranked regionally by specialty and our physicians in the top 1% of all physicians nationally by U.S. News & World Report.