Angiotensinogen and blood pressure among blacks: findings from a community survey in Jamaica

OBJECTIVE: To examine the association between blood pressure, angiotensinogen levels, angiotensin converting enzyme activity and polymorphisms of the angiotensinogen and angiotensin converting enzyme genes in a population-based sample. METHOD: Five hundred participants were recruited in a house-to-house survey of three communities in metropolitan areas of Kingston and St. Andrew, in Jamaica. Demographic data, anthropometric and blood pressure measurements were obtained for each participant during a brief clinic visit. Circulating levels of angiotensinogen and angiotensin converting enzyme genes were determined. RESULTS: A weak association between angiotensinogen level, angiotensin converting enzyme activity and blood pressure was identified in this population, but substantial joint effect of angiotensin converting enzyme activity and agiotensinogen level on blood pressure was apparent. Variants of the angiotensinogen gene had inconsistent effects on blood pressure and on the risk of hypertension. Angiotensinogen level and angiotensin converting enzyme activity were significantly related to several measures of obesity, including body mass index, waist circumference and skin fold thickness. CONCLUSION: The angiotensinogen and angiotensin converting enzyme genetic variants which were studied appear to have only a modest relationship with blood pressure and associated anthropometric risk factors among blacks. (AU)

Effects of angiotensin

Angiotensin was found to induce an identical selective renal water and sodium retention in normal and adrenalectomised subjects. Hence the sodium retention was thought not to be due to increased aldosterone secretion. Low infusion dosage of Angiotensin, unlike those of aldosterone or noradrenaline, produced changes in creatine and P.A.H. clearance similar to those seen in orthostatic antidiuresis. The renal excretion of sodium in normal and hypertensive subjects infused with small increasing doses of Angiotensin was also investigated (AU)