Among women ages 70 to 89, a history of cardiac disease may be strongly associated with an increased risk of developing nonamnestic mild cognitive impairment (MCI), according to a study published online in the January 28 JAMA Neurology. This association was not found among elderly men, said Rosebud O. Roberts, MB, CHB, a health sciences researcher at Mayo Clinic in Rochester, Minnesota.
Dr. Roberts and her colleagues analyzed data from the Mayo Clinic Study of Aging, which assessed risk factors for MCI in people who were ages 70 to 89 at baseline. Subjects underwent physical examinations and extensive cognitive testing every 15 months. At each follow-up visit, participants were diagnosed as having normal cognition, MCI, or dementia by a team of clinicians that included a physician, a nurse, and a neuropsychologist. For this study, Dr. Roberts and her associates assessed a random sample of 2,719 participants who were followed for a median of four years.
A total of 1,450 participants had at least one follow-up assessment, 348 of them developed incident MCI, and 18 developed incident dementia. About 66% of patients with MCI had amnestic MCI, 27% had nonamnestic MCI, and the remaining 7% had MCI of unknown subtype.
The incidence of MCI was higher among subjects with cardiac disease (73.2 per 1,000 person-years) than in those without it (62.1 per 1,000 person-years). When the data were analyzed by type of MCI, cardiac disease had no correlation with amnestic MCI but was linked to a doubling of the rate of nonamnestic MCI. Subjects with cardiac disease had a rate of nonamnestic MCI of 23.4 per 1,000 person-years, compared with 12.2 per 1,000 person-years for subjects without cardiac disease.
Cardiac disease had no correlation with nonamnestic MCI among men. The incidence of this condition was similar between men with cardiac disease (22.3 per 1,000 person-years) and men without cardiac disease (18.9 per 1,000 person-years). However, the rate of nonamnestic MCI was significantly higher among women with cardiac disease (24.3 per 1,000 person-years) than in those without (7.4 per 1,000 person-years). This association in women remained robust in analyses that adjusted for a history of stroke, age, education, and APOE genotype status.
Roberts RO, Geda YE, Knopman DS, et al. Cardiac disease associated with increased risk of nonamnestic cognitive impairment: stronger effect on women. JAMA Neurol. 2013 Jan 28:1-9 [Epub ahead of print].