Affiliations: [a] Deparment of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden | [b] Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden | [c] Department of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden | [d] Department of Cardiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden | [e] Department of Psychology, University of Southern California, Los Angeles, CA, USA
Correspondence:
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Correspondence to: Johan Frostegård, Department of Medicine, Karolinska University Hospital Huddinge, KFC, 14186 Stockholm, Sweden. Tel.: +46 858589787; Fax: +46 858589787; E-mail: johan.frostegard@ki.se; Nancy L. Pedersen, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 17177 Stockholm, Sweden. Tel.: +468 5248 7418; Fax: +468 31 49 75; E-mail: nancy.pedersen@ki.se.
Abstract: Phosphorylcholine (PC) may play an important role in the atherogenic and pro-inflammatory effects of oxidized low density lipoproteins. We recently demonstrated that low levels of IgM antibodies against PC (anti-PC) are associated with development of myocardial infarction and stroke. We here evaluate the association between anti-PC and dementia and Alzheimer's disease (AD). We conducted a nested case-control study of 182 incident dementia cases (serum collected before onset of dementia) matched to 366 controls and a case-control study of 97 prevalent dementia cases (serum collected after dementia onset) matched to 205 controls. Controls were matched on gender and age at blood draw (± 1 year). Participants were from the Swedish Twin Registry. Anti-PC levels were measured by ELISA. The odds ratio (OR) of dementia was modeled using conditional logistic regression. Patients with dementia had significantly lower mean anti-PC levels than controls (39.1 versus 49.5 U/ml). The likelihood of having dementia or AD was doubled for individuals with the lowest 25% anti-PC levels (OR=2.04 and 2.70, respectively). The results were similar after adjustments for potential confounders. There was no association between anti-PC levels and incident dementia. Low levels of atheroprotective anti-PC could play a role in AD and dementia. Potential mechanisms include decreased anti-inflammatory potential and effects on the vasculature. Further attention is merited to elucidate the role of anti-PC in AD development and the usefulness of anti-PC as a part of risk prediction, prognosis, diagnosis, or treatment.
