Abstract Body: Background: Hypertension (HTN) and depression have been speculated to have a bidirectional relationship, and linked to risk of dementia. Long-term systolic blood pressure (SBP) variability has been associated with HTN in adults. Evidence regarding long-term SBP variability and worse cognitive function in older adults is increasing. Whether depressive symptoms at midlife modifies the association between long-term SBP variability from childhood and midlife cognitive function is unclear.
Methods: We examined 1104 midlife participants of the Bogalusa Heart Study (age at enrollment: 9 ± 3 years, follow-up: 39 ± 3 years, age at last exam: 48 ± 5 years, 61% women, 35% Black participants) with ≥3 measurements of SBP across follow-up. Depressive symptoms were measured using the 10-item Center for Epidemiologic Studies Depression Scale (scores of ≥10 defined as having depressive symptoms). Long-term SBP variability from childhood was measured as the deviation from age predicted value (DEV). DEV is the mean of the difference between each observed SBP value and predicted SBP value for age, which were obtained by fitting repeated SBP measures across follow-up to random effects models. Midlife cognitive function was measured by 8 neuropsychological tests, which were standardized by age, race, and sex, then averaged into a global cognitive score (GCS). Associations between long-term variability of SBP and GCS were analyzed using multivariable linear regression models Stratified analyses by midlife depressive symptom and HTN status were performed. Results: DEV of the study population was 7 ± 3 mmHg. A total of 692 (63%) and 360 (33%) participants had HTN and depressive symptoms at midlife, respectively. Of the 692 participants with HTN, 250 (36%) had depressive symptoms. Higher long-term variability of SBP was linked to poorer midlife cognitive function. Stratified analysis by depressive symptom and HTN status showed higher effect sizes in participants with depressive symptoms and HTN at midlife, compared to those without (Table). Conclusions: Both depressive symptoms and HTN status at midlife may interact with SBP variability and influence midlife cognitive function. Screening for both depressive symptoms in addition to SBP variability in individuals with HTN may be beneficial to preserve midlife cognitive function.