A polymorphism in the DOCK7 gene (rs1167998) is associated with salt restriction behavior in hypertensive patients

Patients with hypertension are recommended to decrease their salt intake. However, some patients do not follow this recommendation. It is possible that some of these individuals cannot restrict their salt intake due to a genetic preference for salt. Thus, we attempted to identify genetic factors related to salt restriction behavior. The subjects were 817 patients with hypertension. Salt restriction status was determined by self-reported answers (yes/no) to the question "Do you restrict your salt intake in everyday meals?" We focused on 21 single-nucleotide polymorphisms related to genes involved in the regulation of blood pressure, salt metabolism, or neurotransmission, and analyzed the associations of the single-nucleotide polymorphisms with salt restriction behavior. Of the 817 subjects, 568 (69.5%) reported that they restricted their salt intake. Two single-nucleotide polymorphisms (rs1167998 and rs2970847) were found to be correlated with salt restriction behavior. Among the 21 single-nucleotide polymorphisms, rs1167998 in the intron region of the dedicator of cytokinesis 7 gene, which encodes a guanine nucleotide exchange factor that plays a role in axon formation and neuronal polarization, showed the strongest association (odds ratio per allele, 1.48; 95% confidence interval, 1.11 to 1.95). In conclusion, rs1167998, a single-nucleotide polymorphism in the dedicator of cytokinesis 7 gene that is associated with blood lipid levels and cardiovascular disease risk was associated with salt restriction behavior in a population of Japanese patients with hypertension. Further confirmatory studies are warranted.