Men More Likely to Develop Cognitive Impairment

Men and individuals who have only a high school education are more likely to develop mild cognitive impairment (MCI) than women and individuals who have completed some higher education, researchers at the Mayo Clinic report in a study published online on Jan. 25 in Neurology.

The researchers conducted a population-based prospective study including 1,450 subjects aged 70 to 89 in Olmsted County, Minn. Starting in October 2004, they evaluated the participants every 15 months, with each evaluation including the Clinical Dementia Rating scale (a neurologic evaluation) and neuropsychological testing. (A panel of experts with no knowledge of the participants’ prior diagnoses reviewed their data at each evaluation.)

Of the 1,450 participants, 296 (6%) went on to develop MCI, Overall, the condition was more common in men (72.4 cases per 1,000 people) than women (57.3 cases per 1,000 people). The researchers also measured the incidence of amnestic MCI (aMCI) and nonamnestic MCI (naMCI) and found that the incidence of aMCI was higher for men (43.9 per 1,000) than women (33.3 per 1,000). The incidence of naMCI was higher as well for individuals with less than 12 years of education, (42.6 per 1,000) compared with those who had completed some higher education (32.5 per 1,000).

“The risk of naMCI was also higher for men (20.0) than women (10.9) and for subjects with ≤12 years of education (20.3) than higher education (10.2),” the authors wrote in the study’s abstract.

“The incidence rates for MCI are substantial,” they continued. “Differences in incidence rates by clinical subtype and by sex suggest that risk factors for MCI should be investigated separately for aMCI and naMCI, and in men and women.”

"Understanding the distribution of incident MCI by age, sex, and other demographic variables is critical to helping us understand the cause of the condition, as well as how to prevent MCI and its progression to full-blown, irreversible dementia," said lead author Rosebud O. Roberts, MB, ChB, of the Mayo Clinic division of epidemiology, in a Mayo Clinic press release. "This study advances our understanding of MCI and will help clinicians provide even better care for their patients, especially during initial evaluations."