A common polymorphism rs1800247 in osteocalcin gene is associated with hypertension and diastolic blood pressure levels: the Shanghai Changfeng study.

Osteocalcin may have a role in hypertension due to its close relationship with energy metabolism and insulin sensitivity. The aim of this study was to evaluate the association of a common polymorphism rs1800247 in osteocalcin gene with hypertension and related traits. This was a population-based cross-sectional study including 5647 individuals. Baseline information was collected. Body mass index (BMI), waist circumference, blood pressure, glucose and lipids were determined. Homeostasis model assessment for insulin resistance (HOMA-IR) was used to estimate insulin sensitivity. Genotyping was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The carriers of C allele of rs1800247 were associated with a decreased odds of hypertension compared with the carriers of T allele adjusted for age, sex and BMI (odds ratio (OR)=0.89, 95% confidence interval (CI) 0.81-0.97, P=0.01). The carriers of C allele were also associated with a lower diastolic blood pressure (DBP) level adjusted for age, sex and BMI in normotensive individuals (β=-0.55, 95% CI -0.99 to -0.10, P=0.02), but its association with systolic blood pressure levels was not significant. The interaction between rs1800247 and HOMA-IR on hypertension was significant (P<0.001). In the stratified analysis by the median of HOMA-IR (1.93), rs1800247 was significantly associated with hypertension in the subgroup with HOMA-IR⩽1.93 (OR=0.82, 95% CI 0.71-0.94, P=0.005), but this association was not significant in the subgroup with HOMA-IR >1.93. We demonstrated that a common polymorphism rs1800247 in osteocalcin gene was associated with hypertension and DBP levels. The association of rs1800247 with hypertension was affected by its interaction with HOMA-IR.