Clinical and genetic correlates of soluble P-selectin in the community

Abstract

Background: P-selectin is a cell adhesion molecule that is involved in atherogenesis, and soluble concentrations of this biomarker reflect cardiovascular risk. However, the clinical correlates and genetic characterization of soluble P-selectin have not been clearly elucidated.

Objective: To describe clinical and genetic correlates of circulating P-selectin in the community.

Methods: In Framingham Heart Study Offspring (European descent) and Omni (ethnic/racial minority) participants, we examined the association of cardiovascular risk factors with soluble P-selectin concentrations. In Offspring participants, we evaluated heritability, linkage and association of 29 SELP single-nucleotide polymorphisms (SNPs) with adjusted P-selectin concentrations.

Results: In multivariable analysis of 3,690 participants (54% women, mean age 60 +/- 10 years), higher log-transformed P-selectin concentrations were inversely associated with female sex and hormone replacement therapy, and positively associated with age, ethnic/racial minority status, cigarette smoking, waist circumference, systolic blood pressure, fasting glucose, and total/high-density lipoprotein cholesterol and triglyceride concentrations. Clinical factors explained 10.4% of the interindividual variability in P-selectin concentrations. In 571 extended pedigrees (n = 1,841) with >or= 2 phenotyped members per family, multivariable-adjusted heritability was 45.4 +/- 5.8%. Among the SELP SNPs examined, a non-synonymous SNP (rs6136) encoding a threonine-to-proline substitution at position 715 was highly significantly associated with decreased P-selectin concentrations (P = 5.2 x 10(-39)), explaining 9.7% of variation after adjustment for clinical factors.

Conclusions: Multiple clinical factors and an SNP in the SELP gene were significantly associated with circulating P-selectin concentrations. One SNP in SELP explained significant variation in circulating P-selectin concentrations, even after accounting for known clinical correlates.