N Engl J Med. 2016 Feb 11;374(6):523-32. doi: 10.1056/NEJMoa1504327.
Incidence of Dementia over Three Decades in the Framingham Heart Study.
Satizabal CL1, Beiser AS, Chouraki V, Chêne G, Dufouil C, Seshadri S.
循環器分野の大きな研究であるFramingham Heart Studyのサブ解析によって、この30年で認知症の有病率が低下したことがわかりました。
Riotenberg et al (Feb. 11 issue)1 suggest that the age-specific incidence of dementia may have decreased from 1977 to 2008. It is notable that the age-specific incidence of vascular dementia significantly decreased, while that of Alzheimer’s disease did not.
It has been previously estimated that a decreased prevalence of hypertension could reduce the incidence of both vascular dementia and Alzheimer’s disease.2 However, the effect of antihypertensive therapy on dementia may differ between drug classes. Meta-analyses indicate larger benefits of Angiotensin II receptor blockers (ARBs), which may improve cognitive function due to blocking AT1 receptors, or potassium-sparing diuretics, which may reduce the risk of dementia due to increased potassium concentrations,3, 4 though randomized trials have yielded mixed results. Some of this discrepancy can be explained by the length of follow-up in these trials, up to 4.5 years on average.5
The present study could be extraordinarily useful in assessing associations between antihypertensive therapy and dementia because of its extensive follow-up. We would be grateful if the authors provide comments on this issue.
1. Satizabal CL, Beiser AS, Chouraki V, Chene G, Dufouil C, Seshadri S. Incidence of Dementia over Three Decades in the Framingham Heart Study. N Engl J Med 2016;374:523-32.
2. Barnes DE, Yaffe K. The projected effect of risk factor reduction on Alzheimer’s disease prevalence. Lancet Neurol 2011;10:819-28.
3. Levi Marpillat N, Macquin-Mavier I, Tropeano AI, Bachoud-Levi AC, Maison P. Antihypertensive classes, cognitive decline and incidence of dementia: a network meta-analysis. J Hypertens 2013;31:1073-82.
4. Khachaturian AS, Zandi PP, Lyketsos CG, et al. Antihypertensive medication use and incident Alzheimer disease: the Cache County Study. Archives of neurology 2006;63:686-92.
5. Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension. Final results of the Systolic Hypertension in the Elderly Program (SHEP). SHEP Cooperative Research Group. JAMA : the journal of the American Medical Association 1991;265:3255-64.