Angiotensinogen and its relationship with blood pressure in young adults: the African-PREDICT study

The renin-angiotensin-aldosterone system (RAAS) plays a central role in blood pressure (BP) control through its downstream components including angiotensin II and aldosterone. However, recent data show that upstream RAAS components, such angiotensinogen, have a potential as targets for therapeutic interventions, yet remain underexplored. Our study compared BP and pulse pressure (PP) components across quartiles of circulating angiotensinogen in a healthy young population and further examined these associations after stratifying by ethnicity. The study population consisted of 1144 healthy Black and White men and women aged 20-30 years. We derived central systolic BP (SBP), central diastolic BP (DBP), central PP, and measured clinic and 24-hour (24-h) PP and BP. Angiotensinogen levels were determined in serum. Across different BP components, only nighttime PP decreased with increasing angiotensinogen quartiles (P-trend = 0.021). We found higher circulating angiotensinogen levels in White individuals as compared to their Black counterparts. After adjustments for multiple covariates in regression analyses, clinic SBP (β = 0.12, p < 0.001), clinic DBP (β = 0.10, p = 0.011), 24-h DBP (β = 0.11, p = 0.008), daytime DBP (β = 0.11, p = 0.009) and nighttime DBP (β = 0.11, p = 0.014) were positively associated with angiotensinogen only in the White group. Additional adjustment for heart rate (HR) modified these associations. In White individuals, clinic SBP (β = 0.12, p < 0.001) and clinic DBP (β = 0.08, p = 0.046) were positively associated with angiotensinogen, independent of HR, while other associations lost significance. No associations were observed in the Black group. The positive association of clinic BP with angiotensinogen in young, healthy White adults, independent of HR, suggests a probable direct role for angiotensinogen in BP regulation.