AMBULATORY BLOOD-PRESSURE MONITORING FOR DETECTING THE RELATION BETWEEN ANGIOTENSINOGEN GENE POLYMORPHISM AND HYPERTENSION

Compared to office measurements, ambulatory monitoring is a more accur ate method of blood pressure (BP) characterization and may therefore b e useful in a genetics study of hypertension. We studied the relation between the M235T polymorphism of the angiotensinogen gene and hyperte nsion using office and ambulatory (BP) measurements. We enrolled untre ated subjects (33 men and 17 women) who were referred for evaluation o f office BP >140/90 mm Hg on at least two separate occasions. The M235 T genotypes of the angiotensinogen gene were determined by polymerase chain reaction (PCR) amplification of DNA extracted from peripheral bl ood leukocytes and digested with BSTU1. The distribution of the genoty pes were MM = 0.22, MT = 0.44, TT = 0.34. Based on office measurements , a significant difference in diastolic blood pressure (BP) was detect ed only between the TT and the MT genotype subjects (office BP: MM = 1 50 +/- 25/97 +/- 13 mm Hg, MT = 147 +/- 23/ 95 +/- 13 mm Hg, TT = 161 +/- 25/104 +/- 15 mm Hg). By contrast, with ambulatory BP monitoring, both systolic and diastolic blood pressures were significant higher in TT versus MM and MT (ambulatory BP, MM = 138 +/- 10/88 +/- 9 mm Hg, M T = 141 +/- 15/89 +/- 11 mm Hg, TT = 152 +/- 18/97 +/- 12 mm Hg). Cova riate analysis revealed an independent relationship between the M235T genotype and systolic, diastolic, and mean ambulatory BP. Ambulatory m onitoring improved the analytic power of our study and allowed detecti on of a clear and consistent relationship between angiotensinogen poly morphism and hypertension with a relatively small sample size. (C) 199 7 American Journal of Hypertension, Ltd.