b'CHAPTER 2 | THE AGING BRAINThose who say they did well in school,illness requiring hospitalization. Information on regardless of the level completed, have ahospitalization for severe sepsis was obtained from linked Medicare data (Iwashyna et al. 2010) much lower risk of being diagnosed withand used to identify HRS participants who had an Alzheimers disease later in life. episode of severe sepsis. Severe sepsis is associat-ed with substantial and persistent new cognitive researchers to assign treated versus untreatedimpairment and functional disability among status to each of the four medical conditionssurvivors. Figure 2-6 shows that among those investigated. Both treated and untreated strokewho survive severe sepsis, 6.1% had moderate to and APOEe 4 allele significantly elevate dementiasevere cognitive impairment at the last survey risk. Treated hypertension decreases dementiaprior to the episode of sepsis. This percentage risk. Interestingly, heart disease and diabetes areincreased to 16.7% by the first survey after the not associated with dementia. The interaction ofepisode and persisted even two years later. Severe Another study uses ADAMS to investigateAPOEe 4 allele with stroke confers very high risksepsis episode has no impact on changes in MCI.educational quality as an independent risk forfor dementia. D. Levine et al. (2015) find that race dementia later in life (Mehta et al. 2009). Below-differences in cognition and cognitive decline are average self-assessed school performance is asso- not explained by differences in the higher strokeFIGURE 2-6Percent of patients withciated with a four-fold risk of AD independent ofrisk for African Americans compared to Whites. cognitive impairment before and aftereducational level, literacy score, and other relevantBuilding on clinical research findings thatsevere sepsis: 1998-2006risk factors. Educational level attained is an im- visual problems are associated with cognitiveSource: Iwashyna et al. (2010).portant asset, but educational quality may do evenimpairment, Rogers and Langa (2010) investigateBefore sepsis After sepsismore to build cognitive capacity. Those who saythe role of visual impairment in the development16%they did well in school, regardless of the level com- of dementia. They follow ADAMS participants for pleted, have a much lower risk of being diagnosed8.5 years to see if changes in vision are associated14%with AD later in life. These findings suggest thatwith changes in cognitive functioning. HRS data12%merely staying in school may not result in the fullare also linked with Medicare treatment records benefits of education for dementia risk. to estimate the effects of vision procedures like10%corneal transplant or cataract removal/lens8%Medical Risks implantation. Those diagnosed with dementia, Medical risks are a promising area of investiga- especially AD, have poorer vision at baseline and6%tion, especially given that their identificationhave received fewer eye services prior to their di- 4%has great potential for intervention to reduce theagnosis than those who do not experience serious 2%burden of the medical risk itself as well as poten- cognitive decline. Uncorrected poor vision is a tially associated dementia. Llewellyn et al. (2010)very significant risk factor for dementia. 0%examine hypertension, heart disease, diabetes,HRS findings show that acute health events-4 yrs -2 yrs 2 yrs 4 yrsstroke, APOEe 4, and dementia risk. Supplemen- may also lead to cognitive decline. Severe sepsis,Time to and since sepsis episodetal information, such as medication use, allowsor blood infection, is a major cause of criticalMild cognitive impairmentModerate to severe cognitive impairment43'