Abstract Body: Introduction: Renin-AII abnormalities in EH were documented by infusing saralasin, the AII analogue:patients with a abnormal fall in mean BP(<=-8mmHg) indicating a “angiotensinogenic” component to their hypertension and those with a abnormal rise in mean BP(>=8mmHg) indicating, as previously reported, an increased AII vascular sensitivity.

Methods: Patients tested for secondary HBP in a 1-day BP study with recumbent BP by Arteriosonde, infusion of Lasix, recumbent for 1 hr, stand for 2 hours, measure renin(ng/ml/hr), recumbent for 1/2 hr, infusion of saralasin for 1/2 hr, infusion of 2 l of 0.9%NS over 4 hr and measurement of plasma aldosterone and cortisol. Patients with secondary causes of hypertension, those age<18, those with renal insufficiency, vascular abnormalities (eg diabetes, ASHD) were excluded. Data is now stored using excel 365. Linear regression was calculated using GraphPad Prism version 10.0.0 for Windows, www.graphpad.com.

Results: 3691 adults(mean age = 43.4±0.2, 46.3% female) with EH of whom 3322 received saralasin: “Angiotensinogenic” HBP occurred in 12.9% of EH and they were younger[p=.0012,t=3.2]than the EH group, and had a high renin(nl:1.7-6.6). The saralasin-induced fall in BP was -15.6±.6/-13.0±.3. Saralasin increased the % of SBP that was <=130 from 28.1% to 54.7%. Saralasin induced an abnormal BP rise in 19.6% of patients who were older with low renin. There was a significant linear correlation with log¹⁰ of renin for 3322 patients with EH for Δ Mean BP with saralasin[ΔMBP = -9.3*(log renin) + 4.3] (p<.0001,f=1056, r=-.50). Results were similar in 1463 patients on no BP meds. [ΔMBP=-9.5*(log renin) +4.46](p<0.0001,f=470,r=-.50). 12.5% were "angiotensinogenic", 16.7% pressor responders.

Conclusions: EH has a significant “angiotensingenic” component (12.9%) and increased AII vascular sensitivity(19.6%), both of which may contribute to their HBP.

table: three saralasin groups(BP fall, rise,no Δ) as in abstract(data are mean+se)

Change in
mean BP to------------#(%)-------- initial BP -------post lasix BP----saralasin BP --Age(yr)-renin
infusion of
saralasin

(1)<= -8 mmHg----430(12.9%)--160+2*/99+1*---147+1*/96+1*----132+1*/83+1*---41.1+.7*---8.1+.4*
(2)>=+8 mmHg----651(19.6%)--170+1^&/103+1^&-142+1^&/90+1^ns1 160+1^&/101+1^&-50.2+.5^&---1.5+.1^&
(3)>8,<-8 mmHg-2241(67.5%)-155+1^@/98+1^! ---137+1^@/90+1^@-138+1^@/90+1^@-41.3+.9^ns2-3.4+.1^@
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*p<.00001(1v2),^&p<.0001(2v3),^@p<.0001(1v3),^!p=ns(1v3),^ns1(2v3),^ns2(1v3)