Serum surfactant protein D is correlated to development of dementia and augmented mortality

Development of dementia, including Alzheimer's disease (AD), is associated with lipid dysregulation and inflammation. As the host defense lectin surfactant protein D (SP-D) has multiple effects in lipid homeostasis and inflammation, the correlation between SP-D concentrations and development of dementia was investigated. A total of 418 non-demented persons were included in the study and cognitively re-examined after 3 years, while survival was followed for 11 years. Serum SP-D concentrations were measured at baseline. Logistic regression analysis controlling for age, gender, smoking status, and CRP showed that Odds Ratio for developing dementia was 2.62 (1.12-6.15) with an SP-D concentration in the highest quartile compared to the other quartiles. The risk of AD was 2.55 (0.95-6.90). Cox regression controlling for the same variables showed that hazard ratio of death was 1.43 (1.06-1.92) in the highest quartile. SP-D concentration thus correlates to development of dementia as well as to augmented mortality.