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

Abstract

ObjectiveTo 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 resultsRisk 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.ConclusionIgM-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.

Low levels of IgM antibodies to phosphorylcholine predict cardiovascular disease in 60-year old men: Effects on uptake of oxidized LDL in macrophages as a potential mechanism

“…So far data obtained indicate that this antibody could be a risk marker in men only, but larger series of incident cases of women are needed to establish or refute its role in women. The data from the present cohort showed higher values in women as compared to men, also demonstrated in clinical materials from our group [12,17,18]. It is tempting to speculate on the potential impact of these gender differences.…”

Patients with polycystic ovary syndrome have lower levels of IgM anti-phosphorylcholine antibodies than healthy women

“…The relatively high levels of IgM anti-PC in our cohort are presumably attributed to the female study population, the relatively low age of our subjects and the fact that cardiovascular events are rare in premenopausal women [22]. Levels of IgM anti-PC decrease with increasing age [21] and are higher in women compared to men [16,19]. Also, the IgM anti-PC antibodies are suggested to have an atheroprotective function, by reducing development of atherosclerosis in mice and humans [14][15][16].…”

“…However, levels of IgM anti-PC did not differ in the overall comparison between patients with PCOS and control subjects. As levels of IgM anti-PC tend to decrease with increasing age [21], the findings of low levels of IgM anti-PC predominantly in older women with PCOS may indicate a more rapid age-related decrease of IgM anti-PC in women with PCOS, or possibly, decreased levels of IgM anti-PC does not become evident until women with PCOS reach premenopausal ages. Hence, the overall difference between women with PCOS and healthy controls may have been more pronounced if primarily older women had been included in the study.…”

Low Levels of Antibodies Against Phosphorylcholine Predict Development of Stroke in a Population-Based Study From Northern Sweden

“…We hypothesized that differences in diet factors and in exposure to microorganisms including nematodes and parasites may contribute. 30 Women have significantly higher anti-PC levels than men in all our cohorts for which this comparison has been made, 18,19,30 suggesting that higher anti-PC levels may be one factor that could contribute to the later onset of atherosclerosis and CVD in women compared with men.…”