Pub Date: Monday, Mar 15, 2021
Author: 1. Rebecca F. Gottesman, MD, PhD and 2. Thomas H. Mosley Jr., PhD
Affiliation: 1. Departments of Neurology and Epidemiology, Johns Hopkins University; 2. Departments of Medicine (Geriatrics) and Neurology, University of Mississippi Medical Center
Motivating individuals to improve their health in order to prevent as-of-yet undetected, asymptomatic disease is one of the greatest challenges of primary care. What makes it even more challenging is that those individuals who do not even have access to regular primary care are often those in greatest need of improvements in health behaviors. But preserving one’s cognitive abilities is a uniquely motivating factor, and the shared risk factors between cognitive decline and dementia and cardiovascular diseases including cardiac disease and stroke provide an opportunity to focus on prevention of all of these conditions with a similar set of lifestyle modifications.
The Scientific Statement from the American Heart Association titled, “A Primary Care Agenda for Brain Health” focuses on some of these modifiable health and lifestyle risk factors which might be screened by primary care physicians and which, if controlled and optimized, ultimately might lead to improved late-life brain health.1 In the statement, the authors emphasize the role of the primary care physician as the person who not only has an opportunity to help patients achieve more optimal cardiovascular health, using the Life’s Simple 7 measures, but also detect early changes in cognition. Many, but not all of the aspects of Life’s Simple 7, are already routinely screened in adults as part of recommended medical checkups. But, given evidence that vascular and lifestyle health, even in earlier adulthood and probably in adolescence, and certainly in middle age, are impactful for late-life brain health, it emphasizes that perhaps screening should start at an even earlier age, or should be done more routinely in young adults. Heavy smoking in early adulthood has been associated with worse midlife cognitive function in the CARDIA study,2 and elevated blood pressure, hypercholesterolemia, and smoking in childhood were all associated with worse midlife cognitive performance, in the Young Finns study.3 Since cognition may be impaired decades before a diagnosis of dementia,4, 5 this suggests that prevention starting in adolescence and young adulthood is likely to be impactful for better brain health over the entire life course.
Importantly, because these vascular and lifestyle risk factors are so common in the population, and because of the large and growing number of older adults, slowing cognitive decline and delaying dementia through risk factor modification for even a small percentage of older adults translates into substantial numbers at the population level. One challenge in making a series of recommendations for prevention, however, is the lack of data clearly demonstrating that interventions to improve the Life’s Simple 7 measures actually improve brain health. Although SPRINT-MIND failed to meet its primary outcome, reduction in probable dementia, in hypertensive individuals randomized to intensive (<120 mm Hg) vs standard (<140 mm Hg) blood pressure control, the trial did lead to a reduction in mild cognitive impairment (MCI) and in a composite outcome of MCI and dementia.6 As cited in the Statement, the FINGER trial showed a benefit in cognitive trajectories for individuals treated with a multimodal approach, focusing on vascular risk factor control, as well as lifestyle training, including diet and physical activity, and cognitive training.7 The Worldwide FINGERS consortium8 will continue to pursue these multimodal designs at international sites, including U.S. POINTER in the U.S.. Other than these trials, however, one of the primary reasons that there may never be definitive clinical trial data supporting management of these risk factors in order to improve brain health is the long-term relationships. Vascular risk factors, such as hypertension, appear most strongly related to brain health when evaluated in midlife, and therefore 3-5 year clinical trials of older adults are less likely to show a benefit of interventions.9 As emphasized in the Lancet Commission on dementia prevention,8 and the National Academies’ “Preventing Cognitive Decline and Dementia: A Way Forward” consensus report,9 however, the observational data are compelling enough that recommendations aimed at controlling these risk factors are justified.10
Another key consideration in an evaluation of the potential role of primary care physicians in optimizing late-life brain health is the fact that some of the individuals most in need of guidance and management of vascular and lifestyle risk factors are those least likely to regularly see a physician. A young or middle-aged adult who doesn’t regularly see a physician may still score poorly on Life’s Simple 7. This is especially relevant for individuals from racial/ethnic minority groups: in the National Health and Nutrition Examination (NHANES) Survey, among adults 25 and older, 40% of whites had optimal cardiovascular health (measured by the Life’s Simple 7), dropping to 25% in Mexican Americans and 15% in African-Americans, with reductions in cardiovascular health over time in all race/ ethnic groups.11 Furthermore, undiagnosed diabetes is more common in race/ ethnic minorities,12 and undiagnosed hypertension is estimated to be present in up to 8% of the population.13 Since key social determinants of health may not only be directly relevant to cognitive assessment and likelihood of evaluation by a primary care physician, but are also likely impact the individual vascular and lifestyle components of Life’s simple 7 and other relevant factors for brain health, there is an especially high risk for ongoing disparities in prevention of poor brain health. Thus, a focus on the key role of primary care physicians in screening for and optimizing vascular and lifestyle factors should consider ways to improve primary care access to underrepresented communities and should also emphasize the particular importance in prevention in these communities.
So, what does this statement add to what is already being done? Perhaps peoples’ unique motivation to prevent cognitive decline should be used more explicitly: “Mr. Smith, you’re due for a screen of your brain health risk factors. You currently have optimal health in 5 of the 7 measures. If we can get your diet and physical activity in the optimal health range, you have an even greater chance of a healthy brain as you age.” Primary care physicians can have a key role in prevention but doing so in partnership with well-informed patients as active participants is more likely to lead to success. Furthermore, assuring that opportunities for careful health monitoring and prevention strategies are available to all race/ ethnic groups is critical. Finally, the entire life course needs to be considered with a careful eye on preventive strategies. This is clearly not a trivial task: implementing major prevention efforts across the life span is likely to require aggressive and ambitious screening and treatment goals — goals that may be necessary in order to have the greatest impact on brain health.
Lazar RM, Howard VJ, Kernan WN, Aparicio HJ, Levine DA, Viera AJ, Jordan LC, Nyenhuis DL, Possin KL, Sorond FA, White CL; on behalf of the American Heart Association Stroke Council. A primary care agenda for brain health: a scientific statement from the American Heart Association [published online ahead of print March 15, 2021]. Stroke doi: 10.1161/STR.0000000000000367
- Lazar RM, Howard VJ, Kernan WN, Aparicio HJ, Levine DA, Viera AJ, Jordan LC, Nyenhuis DL, Possin KL, Sorond FA, White CL; on behalf of the American Heart Association Stroke Council. A primary care agenda for brain health: a scientific statement from the American Heart Association [published online ahead of print March 15, 2021]. Stroke. doi: 10.1161/STR.0000000000000367
- Bahorik AL, Sidney S, Kramer-Feldman J, et al. Early to midlife smoking trajectories and cognitive function in middle-aged US adults: the CARDIA study. Journal of General Internal Medicine 2021;epub ahead of print.
- Rovio SP, Pahkala K, Nevalainen J, et al. Cardiovascular risk factors from childhood and midlife cognitive performance: The Young Finns Study. Journal of the American College of Cardiology 2017;69:2279-2289.
- Rajan KB, Wilson RS, Weuve J, Barnes LL, Evans DA. Cognitive impairment 18 years before clinical diagnosis of Alzheimer disease dementia. Neurology 2015;85:898-904.
- Rawlings AM, Sharrett AR, Mosley TH, Wong DF, Knopman DS, Gottesman RF. Cognitive reserve in midlife is not associated with amyloid-beta deposition in late-life. Journal of Alzheimer's Disease 2019;epub ahead of print.
- Williamson JD, Pajewski NM, Auchus AP, et al. Effect of intensive vs standard blood pressure control on probable dementia: A randomized clinical trial. JAMA 2019;321:553-561.
- Kivipelto M, Helkala EL, Laakso MP, et al. Midlife vascular risk factors and Alzheimer's disease in later life: longitudinal, population based study. British Medical Journal 2001;322:1447-1451.
- Kivipelto M, Mangialasche F, Snyder HM, et al. World-wide FINGERS network: a global approach to risk reduction and prevention of dementia. Alzheimers and Dementia 2020;16:1078-1094.
- Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2020 report of the Lancet commission. Lancet 2020;392:413-446.
- National Academies of Sciences Engineering and Medicine. Preventing Cognitive Decline and Dementia: A Way Forward. www.nationalacademies.org, 2017.
- Brown AF, Liang L-J, Vassar SD, et al. Trends in racial/ ethnic and nativity disparities in cardiovascular health among adults without prevalent cardiovascular diseases in the United States, 1988 to 2014. Annals of Internal Medicine 2018;168:541-549.
- Selvin E, Wang D, Lee AK, Bergenstal RM, Coresh J. Identifying trends in undiagnosed diabetes in U.S. adults by using a confirmatory definition: A cross-sectional study. Annals of Internal Medicine 2017;167:769-776.
- Park S, Gillespie C, Baumgardner J, et al. Modeled state-level estimates of hypertension prevalence and undiagnosed hypertension among US adults during 2013-2015. Journal of Clinical Hypertension 2018;20:1395-1410.
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-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association --