Problem behavior of dementia patients predicts low-grade hypercoagulability in spousal caregivers.

BACKGROUND: Low-grade hypercoagulability might be one pathway to explain how the chronic stress of dementia caregiving increases cardiovascular disease risk, but the specific aspects of caregiver stress that elicit hypercoagulability are elusive. We hypothesized that dementia patients' problem behaviors and negative reactions of caregivers to these behaviors would relate to hypercoagulability in caregivers.
METHODS: One hundred and eight participants (mean age 74 +/- 8 years, 70% women) providing in-home care for their spouse with Alzheimer's disease were examined. Caregivers were interviewed about the number of 24 predefined patient problem behaviors in the previous week (range 0-24) and how upset or bothered they felt in response to these behaviors (total score 0-96). Von Willebrand factor, plasminogen activator inhibitor-1, and D-dimer were determined in plasma and standardized z-scores of their concentrations summed into a procoagulant index.
RESULTS: Greater number of problem behaviors (Delta R(2) = 0.046, p = .014) and negative reactions of caregivers to these behaviors (Delta R(2) = 0.044, p = .017) were associated with greater procoagulant index after controlling for sociodemographic factors, major cardiovascular risk factors, health habits, and health problems. However, the number of and reaction to problem behaviors did not significantly predict procoagulant activity independent from each other. Post hoc analysis revealed a positive association between the number of problem behaviors and D-dimer (p = .010, Delta R(2) = 0.053), even when controlling for negative reactions (p = .033, Delta R(2) = 0.036). Caregiver reaction to problem behaviors was not significantly associated with any procoagulant factor individually.
CONCLUSION: Alzheimer patients' problem behavior and their negative appraisal by the caregiver may contribute to the chronic low-grade hypercoagulable state in dementia caregivers.