Wagner M, et al. - Researchers sought to model concurrently and assess the trajectories of cardiometabolic risk factors up to 14 years before a diagnosis in patients with dementia vs matched controls free of dementia. In this nested case-control study of 3,925 participants, body mass index (BMI) declined in prodromal dementia, possibly reflecting early preclinical changes. In the older age range, lower blood pressure (BP) before dementia could be both a result of and a contributing factor for the disease; higher blood glucose levels seem to be a risk factor for dementia in these patients. Researchers suggest that for primary and secondary prevention of dementia in the older age range, elevated glycemia, low BP, and weight loss may be primary targets for managing cardiometabolic health.

Methods

• Researchers performed a case-control study nested within the Three-City study, a French population-based cohort of older persons (≥65 years); the study included 6 home visits with neuropsychological testing between 1999 and 2014.
• In September 2017, they performed data analysis.
• They evaluated a total of 785 incident dementia cases and 3,140 controls matched by sex, age, educational level, and cohort center at the time of diagnosis.
• Between 1999 and 2014, they performed repeated measurements of BMI and systolic (SBP) and diastolic (DBP) blood pressure, high-density lipoprotein (HDL-C) and low-density lipoprotein cholesterol (LDL-C), triglycerides, and glycemia levels.
• Based on systematic detection and validated diagnosis, they determined dementia incidence.

Results

• For this study, researchers included a total of 785 cases and 3,140 controls (2,530 [65%] women; mean [SD] age, 76 [5] years).
• A faster decline in BMI, slower increase of SBP and constantly lower DBP were evident among cases.
• For the most common profile, following were the mean values (95% CI) 14 years before diagnosis (−14 years) and at diagnosis (year 0): BMI, 26.1 (25.6-26.5) and 24.8 (24.5-25.1) for a case, and 25.7 (25.4-26.1) and 25.3 (25.0-25.5) for a control; for SBP, 135.2 (131.8-138.7) and 142.1 (140.3-143.9) mm Hg for a case, and 135.8 (132.9-138.6) and 144.9 (143.7-146.1) mm Hg for a control; for DBP, 76.5 (74.7-78.5) and 74.0 (73.1-74.9) mm Hg for a case, and 76.7 (75.1-78.3) and 75.0 (74.2-75.7) mm Hg for a control.
• In contrast, cases displayed higher glycemia (mean fasting glucose values [95% CI] at −14 years and year 0: 89.4 [86.9-92.1] and 96.4 [93.7-99.3] mg/dL for a case, and 87.1 [85.1-89.2] and 95.3 [93.5-97.1] mg/dL for a control), with a significant case-control difference from −1.6 to −14 years prior to diagnosis.