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.