C-reactive protein predicts functional decline in older adults newly diagnosed with dementia: A 5-year follow-up study

Background and objectives: With the increasing prevalence of dementia, identifying markers that predict prognosis in people newly diagnosed with the disease is crucial for developing targeted interventions and initiating early actions to improve their outcomes. On the other hand, C-reactive protein (CRP) is an easily accessible marker of inflammation. This study aims to evaluate whether CRP is a marker of weight loss, cognitive decline, functional decline, and mortality in older adults newly diagnosed with dementia. Methods: We utilized data from DemVest, a longitudinal cohort study, including participants diagnosed with mild dementia due to Alzheimer's Disease (AD) or Lewy Body Dementia (LBD). CRP levels were measured at diagnosis. Main outcome measures were functional decline, weight, body mass index (BMI), cognitive decline and mortality assessed during a 5-year follow-up period after diagnosis. Demographic and clinical factors were considered as potential confounders, and we performed linear regression models for baseline and linear mixed models for longitudinal analysis. Results: A total of 158 participants were included, with an average age of 75.2 years (SD 7.65). 60.8% (n = 96) of patients had AD, and 39.2% (n = 62) had LBD. Elevated CRP was associated with functional decline during follow-up (Est 0.0118, p-value < 0.001). For BMI or weight, we did not find any statistically significant associations, as well as for MMSE, and mortality. Conclusion: Higher CRP levels were associated with greater functional decline in individuals newly diagnosed with dementia.