The impact of protein oxidation on sustained and white coat hypertension

OBJECTIVE The present study compared the unfavorable effects of protein oxidation and deoxyribonucleic acid damage on patients with white coat hypertension (WCH), sustained hypertension (HT), and normotensives. METHODS Participants were allocated into 3 groups: 40 healthy controls, 36 patients with WCH, and 40 patients with sustained HT. Patients with risk factors for atherosclerosis, endocrine diseases, alcoholism, or masked hypertension were excluded. Plasma level of protein carbonyl (PCO), ischemia modified albumin (IMA), total thiol (T-SH), prooxidant-antioxidant balance (PAB), advanced protein oxidation products (AOPPs), and urinary level of 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured and relationship between these oxidative stress parameters and WCH and sustained HT was analyzed. RESULTS Ambulatory 24-hour, daytime and night-time systolic and diastolic blood pressure readings of sustained HT group were significantly higher than those of WCH and control groups (p<0.001, all). AOPPs, PCO, IMA, 8-OHdG, and PAB levels were significantly higher in HT group than WCH and control groups (p<0.001, all). Additionally, T-SH level was significantly lower in HT group than WCH and control groups (p<0.001). A similar statistically significant relationship was detected between WCH and control groups. CONCLUSION Results indicate that increased level of AOPPs, PCO, IMA, 8-OHdG, PAB, and decreased level of T-SH are likely to be indicators of oxidative stress, which may play a key role both in WCH and sustained HT.