The C-1021T polymorphism of dopamine β-hydroxylase is not associated with orthostatic hypotension in a Chinese population.

To explore the association between the dopamine β-hydroxylase (DBH) gene C-1021T polymorphism and the occurrence of orthostatic hypotension (OH) in Chinese patients, the DBH C-1021T polymorphism was genotyped in 317 patients with OH and 664 age- and sex-matched controls with orthostatic normotension. All subjects underwent an upright posture study for the measurement of orthostatic blood pressure. OH was defined as a drop in blood pressure of 20/10 mm Hg or more within 3 min of assuming the upright posture. The allele frequency of the DBH C-1021T polymorphism in the orthostatic hypotensive group was similar to the orthostatic normotensive group (17.4 versus 14.9%, P>0.05). No statistical significant association was found between the distribution of the C-1021T genotypes and the risk of OH in both the orthostatic hypotensive and orthostatic normotensive groups even after adjustment for demographic parameters. Among the three different genotypes, blood pressure levels did not significantly differ in the general population in this study. The changes in orthostatic systolic or diastolic blood pressures among the different genotype groups were not detected (all P>0.05). The C-1021T polymorphism of the DBH was not associated with orthostatic hypotensive risk in a Chinese population.