January 1, 1999Open Access
Angiotensinogen and Angiotensin-Converting Enzyme Genotypes, and Day and Night Blood Pressures in Elderly Japanese Hypertensives.
Key Result
In elderly Japanese hypertensive patients, the ATG T235 and ACE D alleles were associated with increased 24-hour and daytime blood pressure, while only the ACE D allele was associated with increased nighttime blood pressure.
Study Design
Type
Cross-Sectional (n=235)
Multicenter
No
Structured PICO
P
Population
235 elderly Japanese hypertensive outpatients aged 60 years or older, untreated or off medication, who underwent 24-hour ambulatory blood pressure monitoring.
O
Outcome
Association of the ATG T235 allele and ACE D allele with 24-hour blood pressure and diurnal blood pressure variationsurrogate
In elderly Japanese hypertensive patients, the ATG T235 and ACE D alleles are associated with elevated 24-hour and daytime blood pressure, with the ACE D allele also linked to higher nighttime blood pressure.
Main Result
Absolute Event Rate: 147% vs 138%
p-value: p=<0.05
Limitations
- The subjects were older, meaning the relationships between 24-hour blood pressure and these gene alleles may partly be due to advanced target organ damage with aging.
- The relatively small number of study subjects prevented the assessment of gender-specific differences.
Abstract
There are inconsistent reports that the angiotensinogen (ATG) variant Met235-->Thr (T235) allele and angiotensin-converting enzyme (ACE) insertion/deletion (I/D) variants are associated with hypertension and related target organ damage. Both high blood pressure (BP) and abnormal diurnal BP variation patterns are related to target organ damage, but it is not known whether the above genetic variants of the renin-angiotensin system are related to 24 h BP and the diurnal BP pattern in Japanese. We studied the association of the ATG T235 allele and ACE D allele with 24 h BP and diurnal BP variation in 235 of 262 consecutive untreated (or off medication) elderly Japanese hypertensives who underwent 24 h ambulatory BP monitoring. There was no significant association between the T235 or ACE D allele with office BP, but the T235 allele was significantly associated with 24 h BP and day BP, and the D allele was significantly associated with increased 24 h BP, day BP, and night BP. There were no effects of the T235 or D alleles on any BP parameters. Those with white-coat hypertension had a significantly lower T235 allele frequency (0.68) than those with sustained hypertension (0.79, p=0.010), but the difference in D allele frequency was marginal (0.30 vs. 0.38, p=0.057). In conclusion, in elderly Japanese hypertensive individuals, both the ATG T 235 and ACE D alleles are associated with increased 24 h BP and day BP, while only the ACE D allele is associated with increased night BP.