For the preDIVA study 3526 Dutch men and women aged 70-78 years were randomized to either intensive vascular care or standard care. The intervention comprised of four-monthly visits to a practice nurse in the GP practice, over a period of six years (18 visits). During these visits, cardiovascular risk factors were scrutinized: smoking habits, diet, physical activity, weight, and blood pressure. Blood glucose and lipids were assessed every two years and when indicated otherwise. Based on these assessments, individually tailored lifestyle advice was given according to a detailed protocol conform prevailing Dutch GP-guidelines on cardiovascular risk management and supported by motivational interviewing techniques. If indicated, drug treatment of hypertension, dyslipidemia, and type 2 diabetes mellitus (T2DM) was initiated or optimised.
During a follow-up of 6-8 years, dementia developed in 233 participants. The incidence of dementia was 8% lower in the intervention group than in the control group, though this difference was not significant. The protective effect of the intensive vascular care was bigger in those compliant to the treatment, and in the group with hypertension and not using antihypertensive medication at baseline.
The modest result may be due to primary care settings already providing high standards of cardiovascular risk management (CVRM) in the Netherlands, making it difficult to improve overall efficacy, especially for secondary cardiovascular prevention. Multi-domain interventions to prevent dementia might have a larger impact in low and middle income countries because of the lower standards of care and given the projected increase in hypertension, incident cardiovascular disease and dementia in these settings. Especially if vascular care is started at a younger age, in people with a high dementia risk and with extra attention to compliance.
Principal investigator Van Gool concludes: “Knowledge on dementia prevention goes with baby-steps. This study shows that there is no magical bullet. But it also gave us concrete clues which people to target to prevent dementia.”
The results of the preDIVA study were published in the LANCET. As part of the HATICE project, the preDIVA data are pooled with 2 other large dementia prevention trials.