Objective: To investigate carotid atherosclerosis in individuals with masked hypertension (MHT) and white-coat hypertension (WCHT) in a general population.
Methods: Self-measurement of blood pressure at home (HBP) and casual blood pressure (CBP) measurements were recorded in 812 individuals aged at least 55 years (mean 66.4 years) from the general Japanese population. The intima–media thickness (IMT) of the near and far wall of both common carotid arteries was measured and averaged. The relationships between carotid atherosclerosis (IMT and plaque) and the four blood pressure groups (sustained normal blood pressure: HBP < 135/85 mmHg, CBP < 140/90 mmHg; WCHT: HBP < 135/85 mmHg, CBP ≥ 140/90 mmHg; MHT: HBP ≥ 135/85 mmHg, CBP < 140/90 mmHg; sustained hypertension: HBP ≥ 135/85 mmHg, CBP ≥ 140/90 mmHg) were examined using multivariate analysis adjusted for possible confounding factors.
Results: Adjusted IMT in individuals with sustained hypertension [0.77 mm; 95% confidence interval (CI) 0.75 to 0.79 mm] and MHT (0.77 mm; 95% CI 0.73 to 0.80 mm) was significantly greater than in those with sustained normal blood pressure (0.71 mm; 95% CI 0.69 to 0.72 mm) and WCHT (0.72 mm; 95% CI 0.71 to 0.74 mm) (P < 0.0001). The odds ratios for the presence of plaques in all four groups were similar to the trends in IMT.
Conclusions: Our findings imply that CBP measurements alone are insufficient to distinguish individuals at high risk of carotid atherosclerosis from those at low risk. However, these individuals do have distinct HBP measurements, suggesting that HBP measurement could become a valuable tool for predicting carotid atherosclerosis.
aDepartment of Clinical Pharmacology and Therapeutics
bDepartment of Planning for Drug Development and Clinical Evaluation
cDepartment of Environmental Health Sciences, Tohoku University Graduate School of Pharmaceutical Sciences and Medicine, Sendai
dTohoku University 21st Century COE Program ‘Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation’, Sendai
eOhasama Hospital, Iwate, Japan
Received 19 April, 2006
Revised 21 September, 2006
Accepted 28 September, 2006
Correspondence and requests for reprints to Takayoshi Ohkubo, MD, PhD, Department of Clinical Pharmacology and Therapeutics, Tohoku University Hospital, 1-1 Seiryo-cho, Aoba-ku, Sendai, 980-8574, Japan Tel: +81 22 717 8590; fax: +81 22 717 8591; e-mail: firstname.lastname@example.org
Sponsorship: This work was supported by Grants for Scientific Research (14657600, 14370217, 15790293, 1654041) from the Ministry of Education, Culture, Sports, Science and Technology, by Health Science Research Grants and Medical Technology Evaluation Research Grants from the Ministry of Health, Labor and Welfare, Japan, by Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) fellows (16.54041, 18.54042), and by the Japan Atherosclerosis Prevention Fund, Uehara Memorial Foundation, and the Takeda Medical Research Foundation.
Conflicts of interest: none.