Effect of a COL1A1 Sp1 binding site polymorphism on arterial pulse wave velocity - An index of compliance

Reduced arterial compliance precedes changes in blood pressure, which may b e mediated through alterations in vessel wall matrix composition. We invest igated the effect of the colla gen type I-alpha1 gene (COL1A1) +2046G>T pol ymorphism on arterial compliance in healthy individuals. We recruited 489 s ubjects (251 men and 238 women; mean age, 22.6 +/-1.6 years). COL1A1 genoty pes were determined using polymerase chain reaction and digestion by restri ction enzyme Ball. Arterial pulse wave velocities were measured in 3 segmen ts, aortoiliac (PWVA), aortoradial (PWVB), and aorto-dorsalis-pedis (PWVF), as an index of compliance using a noninvasive optical method. Data were av ailable for 455 subjects. The sample was in Hardy-Weinberg equilibrium with genotype distributions and allele frequencies that were not significantly different from those reported previously. The T allele frequency was 0.22 ( 95% confidence interval, 0.19 to 0.24). Two hundred eighty-three (62.2%) su bjects were genotype GG, 148 (35.5%) subjects were genotype GT, and 24 (5.3 %) subjects were genotype TT. A comparison of GG homozygotes with GT and TT individuals demonstrated a statistically significant association with arte rial compliance: PWVF 4.92 +/-0.03 versus 5.06 +/-0.05 m/s (ANOVA, P=0.009) , PWVB 4.20 +/-0.03 versus 4.32 +/-0.04 m/s (ANOVA, P=0.036), and PWVA 3.07 +/-0.03 versus 3.15 +/-0.03 m/s (ANOVA, P=0.045). The effects of genotype were independent of age, gender, smoking, mean arterial pressure, body mass index, family history of hypertension, and activity scores. We report an a ssociation between the COL1A1 gene polymorphism and arterial compliance. Al terations in arterial collagen type 1A deposition may play a role in the re gulation of arterial compliance.