Research

Atheroprotective natural anti-phosphorylcholine antibodies of IgM subclass are decreased in Swedish controls as compared to non-westernized individuals from New Guinea

Johan Frostegård¹ , WenJing Tao¹ , Anastasia Georgiades² , Lennart Råstam³ , Ulf Lindblad³ and Staffan Lindeberg³

¹Department of Medicine, Karolinska University Hospital, Huddinge, Stockholm, Sweden

²Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA

³Department of Clinical Sciences, Lund University, Sweden

author email corresponding author email

Nutrition & Metabolism 2007, 4:7doi:10.1186/1743-7075-4-7

Published:	20 March 2007

Abstract

Objective

To determine the importance of IgM antibodies against phosphorylcholine (aPC), a novel protective factor for cardiovascular disease (CVD), in a population with a non-western life style as compared with a Swedish control group.

Methods and results

Risk factors for cardiovascular disease were determined in a group of 108 individuals aged 40–86 years from New Guinea and 108 age-and sex-matched individuals from a population based study in Sweden. Antibodies were tested by ELISA. aPC IgM levels were significantly higher among New Guineans than among Swedish controls (p < 0.0001). This difference remained significant among both men and women when controlled for LDL and blood pressure which were lower and smoking which was more prevalent in New Guineans as compared to Swedish controls (p < 0.0001). aPC IgM was significantly and negatively associated with age and systolic blood pressure among Swedish controls and with waist circumference among New Guineans. aPC IgM levels were significantly higher among women than men in both groups. The proportion of the saturated fatty acid (FA) myristic acid in serum cholesterol esters was negatively but polyunsaturated eicosapentaenoic acid and also lipoprotein (a) were positively associated with aPC IgM levels.

Conclusion

IgM-antibodies against PC, which have atheroprotective properties, are higher in a population from Kitava, New Guinea with a traditional lifestyle, than in Swedish Controls, and higher among women than men in both populations tested. Such antibodies could contribute to the low incidence of cardiovascular disease reported from Kitava and could also provide an explanation as to why women have a later onset of CVD than men.