Lifestyle and pharmacological interventions in South America: Potential barriers for recruitment, implementation, and effectiveness

Abstract

AbstractBackgroundThe study of vascular cognitive impairment and dementia (VCID) risk factors must be reproduced in every community so that disparities may be addressed. In South America, diverse levels of education, mixed ethnicity, genetic and cultural heterogeneity, and the burden of cerebrovascular risk are important features to be investigated for proper interventions.MethodsObservational and interventional VCID studies from South America will be discussed so that issues concerning potential barriers for participant recruitment and research effectiveness may be addressed.ResultsFew South American institutions have studied risk factors for VCID. Older people suffer the effects of restrictions to female education that occurred a century ago. Cross‐sectional studies demonstrated that APOE‐ε4 carrier status predisposes to physical inactivity and has smaller effects over dementia onset than in studies from the Northern Hemisphere, possibly due to ethnical disparities, while the burden of combined cerebrovascular risk factors (and smoking in particular) in this regard is high. Foreigners living in Brazil had later dementia onset, unexplained by common genetic variants. While prevalent in almost half of the older population, and associated with earlier dementia onset particularly in women, depression could be a risk factor or a prodromal symptom. Late life prospective studies verified that cerebrovascular risk factors such as arterial hypertension, hypercholesterolemia and a higher coronary heart disease risk, or increased creatinine clearance for women only, may be neuroprotective against cognitive and functional decline, probably due to enhanced cerebral perfusion. Lifetime sanitary conditions and increasing late life body mass index may protect against frailty, while education is neuroprotective for women and APOE‐ε4 carriers (though associated with faster cognitive decline in some cohorts). Longitudinal pharmacogenetic studies demonstrated that potential benefits of cerebrovascular metabolism modulators such as angiotensin‐converting enzyme inhibitors and lipophilic statins depend upon epistatic interactions among specific genetic variants. Caregiver awareness of the need to control cerebrovascular risk is beneficial for patients.ConclusionsGenomic effects of cognitive reserve, cerebral perfusion, and hormonal changes interact on mechanisms of neurodegeneration. Adherence to lifestyle and pharmacological interventions in South America is highly dependent upon proper funding, public support, harmonization efforts, institutional expertise and leadership, and caregiver education. (Supported by FAPESP grant #2015/10109‐5)