Clinical Edge

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Is Prevalence of Dementia Declining in US?

JAMA Intern Med; ePub 2016 Nov 21; Langa, et al

Publish date:

Between 2000 and 2012, the prevalence of dementia in the US declined significantly, partly due to an increase in educational attainment, according to a recent study. Data was analyzed from the Health and Retirement study (HRS), a nationally representative, population-based longitudinal survey of individuals in the US aged ≥65 years from the 2000 (n=10,546) and 2012 (n=10,511) waves of the HRS. Researchers found:

  • Average age of participants was 75.0 years in 2000 and 74.8 years in 2012.
  • Dementia prevalence among those aged ≥65 years decreased from 11.6% in 2000 to 8.8% in 2012.
  • More years of education was associated with a lower risk for dementia, and average years of education increased significantly between 2000 and 2012.
  • There was a significant age- and sex-adjusted increase between years in the CV risk profile among older adults despite a decline in dementia prevalence.

Citation:

Langa KM, Larson EB, Crimmins EM, et al. A comparison of the prevalence of dementia in the United States in 2000 and 2012. [Published online ahead of print November 21, 2016]. JAMA Intern Med. doi:10.1001/jamainternmed.2016.6807.

Commentary:

Dementia is a devastating disease and, with the greying of America, there has been concern for years about the expected increase in the number of people with dementia. Beginning about 10 years ago, studies started showing a surprising decrease in the prevalence of dementia.1 They also showed an inverse relationship between level of education and the development of dementia, though the real explanation for the decrease in dementia remains uncertain. Important with regard to what we might be able to do to help prevent dementia in our patients, and emphasizing the importance of another article reviewed this week from the AHA on the importance of cardiorespiratory fitness, there is emerging data that in addition to decreasing the development of heart disease and cancer, exercise may decrease the development of dementia.2 While we certainly can be happy that the prevalence of dementia is decreasing, research into therapies for this devastating disease remains critical. —Neil Skolnik, MD

  1. Manton KC, Gu XL, Ukraintseva SV. Declining prevalence of dementia in the US elderly population. Adv Gerontol. 2005;16:30-37
  2. Larsen EB, et al. Exercise is associated with reduced risk for incident dementia among persons 65 years of age and Older. Ann Intern Med. 2006;144(2):73-81.

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