DNA damage and oxidative status in newly diagnosed, untreated, dipper and non-dipper hypertensive patients

Abstract

DNA damage occurs more often in hypertensive patients than in non-hypertensive individuals. We sought to investigate lymphocyte DNA damage and total antioxidant status (TAS) levels in patients with dipper hypertension (DH) and non-dipper hypertension (NDH). Thirty-three patients with NDH (NDH group), 31 patients with DH (DH group) and 20 healthy volunteers (control group) were included in the study. Measurements from ambulatory blood pressure monitoring were obtained for all subjects. DNA damage was assessed in peripheral lymphocytes by comet assay, and plasma TAS levels were determined using an automated measurement method. The mean DNA damage value of the NDH group was higher than that of both the DH and control groups (P=0.002 and P<0.001, respectively). The mean DNA damage value of the DH group was higher than that of the control group (P<0.001). The mean TAS level of the NDH group was lower than that of both the DH and control groups (P=0.001 and P<0.001, respectively), and the mean TAS level of the DH group was lower than that of the control group (P<0.001). DNA damage was negatively associated with TAS level (r=-0.692, P<0.001) and positively associated with high sensitive c-reactive protein level (r=0.315, P<0.012). DNA damage increased in the NDH group compared with both the DH group and control group. This condition may be related to increased oxidative stress in the NDH group compared with the DH and control groups. Hypertension Research (2013) 36, 166-171; doi: 10.1038/hr.2012.156; published online 25 October 2012