Alzheimer Disease Research Center (ADRC)

Featured Q&A

Helena Chui, MD Answers Your Questions

Dr. Chui's research focuses on brain-behavior correlations in dementia. Her publications have examined clinical heterogeneity, natural history, clinical diagnosis, and clinical-pathologic correlations in Alzheimer Disease (AD) and ischemic vascular dementia.

To contact Dr. Chui with a question, please email gsc@usc.edu.

Dear Dr. Chui,

People are saying that women are more likely to get Alzheimer's disease than men.  Is this true?

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Dear Dr. Chui,

People are saying that women are more likely to get Alzheimer's than men.  Is this true?  What can you tell me about the research and science of women having a higher prevalence for Alzheimer’s disease than men (2 women for every 1 man)?

 

Dr. Chui's answer: 

Women and men have similar incidence rates of AD, but because women have longer life expectancies than men, there are significantly more women than men with AD. 

Here is a more information about what these words mean:

  • Prevalence refers to the percentage of persons who have Alzheimer disease during a given survey period.  
  • Incidence refers to the number of persons who are newly diagnosed with AD during a given survey period.
  • Duration reflects how long a person lives after diagnosis of Alzheimer disease.
    Prevalence =  incidence  X  number at risk X  duration.
  • Although women and men have similar incidence rates of AD (Kukull et al.,Arch Neurol 2002), there are more women at risk for AD and women with AD live longer than men with AD.  Therefore, the prevalence of AD is much higher in women than men.

In fact, Life time risk (LTR) is a more useful metric (than incidence or prevalence) when a person is interested in their individual risk for AD.  Again, because of greater life expectancy of women than men after age 65 years, women are at higher lifetime risk of AD (about 17%) compared to men (about 9%). 

                                             Women_vs_men_AD.jpg                                          

Dear Dr. Chui,

Someone who heard you speak at the Eisenhower Clinic in Palm Springs said you mentioned that Aricept probably works for 6-12 months and that’s it. Is that accurate?

LB

Dear LB

I am attaching the slide I showed at the opening of the Memory Assessment Center in 2007, when perhaps the person you mentioned might have heard me speak.  I am also including another slide which I didn't show.

First slide: In a 3-year study of persons with mild cognitive impairment (Peterson et al., NEJM 2005) found that persons taking donepezil (aricept) showed a statistically significant benefit compared to the placebo group for only 12 months.

chui-01-graph1.jpg

However, in a secondary analyses of the subgroup of persons with apolipoprotein E4 (a risk factor for Alzheimer), a beneficial effect from donepezil was evident for 36 weeks.   Unfortunately, we do not currently perform apolipoprotein E4 genotyping in clinical practice.

chui-01-graph2.jpg

Second slide:  In open label studies (no placebo control group) (Doody et al., 2001), noted a benefit from donepezil for 51 weeks).  But these studies need to be interpreted cautiously, since persons continuing to take donepezil may differ from the comparison group in other ways other than their medication status.  These "other factors" might explain the differences, rather than the donepezil.

chui-01-graph3.jpg

So once we start donepezil or other cholinesterase inhibitor, we generally keep patients on the medication indefinitely.  If plans are made to discontinue these medications, the dosage should be dropped gradually.  If the medication is stopped abruptly, persons may show a temporary increase in confusion.
 
I hope this is helpful to you in general.
 
If you or your associates would like individual advice, we would be happy to schedule an appointment at our Center. 

HC