Background: A relation between apolipoprotein E (APOE) genotypes and high sensitive C-reactive protein (hsCRP) has been observed in some studies with elderly subjects and different patient groups. We studied whether serum hsCRP levels are linked with common APOE (epsilon 2, epsilon 3, epsilon 4) polymorphism already in children and young adults.
Methods: The study cohort included 1221 subjects participating in the Cardiovascular Risk in Young Finns Study at age 3-18 years at baseline in 1980. These subjects were reexamined at the 21-year follow-up at age 24-39 years in 2001. APOE phenotypes were examined in 1986, serum hsCRP was measured from fresh samples in 2001 and baseline hsCRP (in 1980) was measured from frozen samples in 2005.
Results: Serum hsCRP was significantly associated with APOE phenotypes in children and young adults using multivariate analysis adjusted for age, body mass index, smoking, total cholesterol and low-density lipoprotein cholesterol. Male epsilon 4 carriers had significantly lower hsCRP levels both in childhood (p=0.003) and in adulthood (p=0.013). hsCRP increased in both phenotype classes (epsilon 4+ and epsilon 4-) during the 21-year follow-up. Female epsilon 4 carriers had lower hsCRP levels in childhood (p=0.032) but not in adulthood (p=0.995). An interaction effect between time and APOE phenotype (p=0.045) in relation to hsCRP was observed in females during the 21-year follow-up.
Conclusions: Common APOE polymorphism affects the level of circulating hsCRP already in children and young adults. Male APOE epsilon 4 carriers have consistently lower hsCRP levels. In females, APOE epsilon 4 carriers had lower hsCRP levels in childhood but not in adulthood.