Dr. Lopez's research involved 3,608 people aged 75 and older who participated in the Cardiovascular Health Study (CHS). He found that the majority of cognitive difficulties are the result of multiple problems, such as small "silent" ischemic lesions in the brain, depression, use of psychiatric medications, or other disease processes that can affect the brain (including chronic liver and kidney failure) rather than the onset of Alzheimer's.
MCI is a heterogenous condition that affects the areas of the brain that process memory and language and the areas that help keep attention and focus.
"We were surprised at how prevalent the condition was and how other medical conditions increased people's risk to have MCI," Dr. Lopez said. "This emphasizes the importance of good medical care in preventing the development of brain disease."
According to Dr. Lopez, MCI can be the result of many factors. Among them are the presence of the Apolipoprotein E4 alelle, which has been identified as a risk factor for Alzheimer's disease; race, MCI is more prevalent in African-Americans; and "silent" strokes.
"It is important to note that African Americans have more cardiovascular disease and cerebrovascular disease risk factors than whites, which may explain the increased prevalence of MCI in this group of subjects," Dr. Lopez said.
Dr. Lopez and his team examined 3,608 patients over age 75 who underwent detailed neurological, neuropsychological, neuroradiational (MRI scans) and psychiatric testing to identify dementia and MCI. The CHS was one of the largest single epidemiological